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  • 1. Banyai, I.
    et al.
    Glaser, Julius
    KTH, Superseded Departments, Chemistry.
    Toth, I.
    Cyanide exchange on Tl(CN)(4)(-) in aqueous solution studied by Tl-205 and C-13 NMR spectroscopy2001In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, no 7, p. 1709-1717Article in journal (Refereed)
    Abstract [en]

    Dynamics of cyanide exchange between Tl((CN)-C-13)(4)(-) and (CN-)-C-13 was studied by means Tl-205 and C-13 NMR. The rate law consists of two parts: w = k(CN)[Tl(CN)(4)(-)][CN-] + k(OH)[Tl(CN)(4)(-)][CN-][OH-] with k(CN) = 9.7(+/-0.4) x 10(6) M(-1)s(-1) and k(OH) = 5.4(+/-0.4) x 10(10) M(-2)s(-1). It was shown that the exchange between the two cyano species can be studied, not only by C-13 NMR, but also by Tl-205 NMR using the heteronuclear carbon-thallium scalar coupling as an indicator, despite the fact that only one Tl site is present in the system. The reaction mechanism is discussed in terms of an associative interchange mechanism, I-A. Penetration of the incoming cyanide ion into the coordination sphere of Tl(CN)(4)(-) Tl(CN)(4)(OH)(-) is suggested to be the rate-determining step for the two parallel reactions paths. Possible reasons for the strong labilizing effect of the cyanide ligand is discussed in the light of thermodynamic and structural data. The possibility of detection of an exceptional exchange reaction, namely cyanide exchange between two Tl(CN)(4)(-) entities by a direct encounter was theoretically settled, but found to be too slow to be detected.

  • 2. Bodor, A.
    et al.
    Banyai, I.
    Kowalewski, J.
    Glaser, Julius
    KTH, Superseded Departments, Chemistry.
    Thallium(III) coordination compounds: chemical information from Tl-205 NMR longitudinal relaxation times2002In: Magnetic Resonance in Chemistry, ISSN 0749-1581, E-ISSN 1097-458X, Vol. 40, no 11, p. 716-722Article in journal (Refereed)
    Abstract [en]

    Tl-205 longitudinal relaxation rate measurements were performed on several thallium(III) complexes with the composition Tl(OH)(n)(H2O)(6-n)((3-n)+) (n = 1,2), Tl(Cl)(n)(H2O)(m-n)((3-n)+), Tl(Br)(n)(H2O)(m-n)((3-n)+) (m = 6 for n = 1-2, m = 5 for n = 3, m = 4 for n = 4), Tl(CN)n(H2O)(m-n)((3-n)+) (m = 6 for n = 1-2, m = 4 for n = 3-4) in aqueous solution, at different magnetic fields and temperatures. C-13 and D-2 isotopic labelling and 114 decoupling experiments showed that the contribution of the dipolar relaxation path is negligible. The less symmetric lower complexes (n < 4) had faster relaxation rate dominantly via chemical shift anisotropy contribution which depended on the applied magnetic field: T, values are between 20 and 100 ms at 9.4 T and the shift anisotropy is &UDelta;σ = 1000-2000 ppm. The tetrahedral complexes, n = 4, relax slower; their T-1 is longer than 1 s and the spin-rotation mechanism is probably the dominant relaxation path as showed by a temperature dependence study. In the case of the TICl4- complex, presumably a trace amount of TICl52- causes a large CSA contribution, 300 ppm. Since the geometry and the bond length for the complexes in solution are known from EXAFS data, it was possible to establish a correlation between the CSA parameter and the symmetry of the complexes. The relaxation behaviour of the Tl-bromo complexes is not in accordance with any known relaxation mechanism.

  • 3. Chen, W. Z.
    et al.
    Liu, F. H.
    Matsumoto, K.
    Autschbach, J.
    Le Guennic, B.
    Ziegler, T.
    Maliarik, M.
    Glaser, Julius
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Inorganic Chemistry.
    Spectral and structural characterization of amidate-bridged platinum-thallium complexes with strong metal-metal bonds2006In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 45, no 11, p. 4526-4536Article in journal (Refereed)
    Abstract [en]

    The reactions of [Pt(NH3)(2)((NHCOBu)-Bu-t)(2)] and TlX3 (X = NO3-, Cl-, CF3CO2-) yielded dinuclear [{Pt(ONO2)(NH3)(2-)((NHCOBu)-Bu-t)}Tl(ONO2)(2)(MeOH)] (2) and trinuclear complexes [{PtX(RNH2)(2)((NHCOBu)-Bu-t)(2)}(2)Tl](+) [X = NO3- (3), Cl- (5), CF3CO2- (6)], which were spectroscopically and structurally characterized. Strong Pt-Tl interaction in the complexes in solutions was indicated by both Pt-195 and Tl-205 NMR spectra, which exhibit very large one-bond spin-spin coupling constants between the heteronuclei ((1)J(PtTl)), 146.8 and 88.84 kHz for 2 and 3, respectively. Both the X-ray photoelectron spectra and the Pt-195 chemical shifts reveal that the complexes have Pt centers whose oxidation states are close to that of Pt-III. Characterization of these complexes by X-ray diffraction analysis confirms that the Pt and Tl atoms are held together by very short Pt-Tl bonds and are supported by the bridging amidate ligands. The Pt-Tl bonds are shorter than 2.6 angstrom, indicating a strong metal-metal attraction between these two metals. Compound 2 was found to activate the C-H bond of acetone to yield a platinum(IV) acetonate complex. This reactivity corresponds to the property of Pt-III complexes. Density functional theory calculations were able to reproduce the large magnitude of the metal-metal spin-spin coupling constants. The couplings are sensitive to the computational model because of a delicate balance of metal 6s contributions in the frontier orbitals. The computational analysis reveals the role of the axial ligands in the magnitude of the coupling constants.

  • 4. Dolidze, T. D.
    et al.
    Khoshtariya, D. E.
    Behm, Mårten
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Lindbergh, Göran
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Glaser, Julius
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Inorganic Chemistry.
    Two-equivalent electrochemical reduction of a cyano-complex Tl-III(CN)(2) (+) and the novel di-nuclear compound (CN)(5)Pt-II-Tl-III (0)2005In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 50, no 22, p. 4444-4450Article in journal (Refereed)
    Abstract [en]

    Extending our recent insights in two-electron transfer microscopic mechanisms for a Tl-III/Tl-I redox system, the electrochemical response of glassy carbon electrode in acidified solutions of Tl-III (ClO4)(3) containing different concentrations of sodium cyanide has been extensively studied for the first time by use of cyclic voltammetry and the CVSIM curve simulation PC program. The complex [Tl-III(CN)(2)](+) has been thoroughly identified electrochemically and shown to display a single welldefined reduction wave (which has no anodic counterpart), ascribed to the two-equivalent process yielding [Tl-I(aq)](+). This behavior is similar to that of [Tl-III (aq)](3+) ion in the absence of sodium cyanide, disclosed in the previous work, and is compatible with the quasi-simultaneous yet sequential two-electron transfer pattern (with two reduction waves merged in one), implying the rate-determining first electron transfer step (resulting in the formation of a covalently interacting di-thallium complex as a metastable intermediate), and the fast second electron transfer step. Some preliminary studies of the two-equivalent reduction of directly metal-metal bonded stable compound [(CN)(5)Pt-II-Tl-III](0) has been also performed displaying two reduction waves compatible with a true sequential pattern.

  • 5. Jalilehvand, F.
    et al.
    Eriksson, L.
    Glaser, Julius
    KTH, Superseded Departments, Chemistry.
    Maliarik, M.
    Mink, J.
    Sandstrom, M.
    Toth, I.
    Toth, J.
    Tl-Pt(CN)(5) in the solid state - A multimethod study of an unusual compound containing inorganic wires2001In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 7, no 10, p. 2167-2177Article in journal (Refereed)
    Abstract [en]

    The crystal and molecular structure of a polycrystalline powder with a metal-metal bond and the composition TlPt(CN)(5) has been determined by combining results from X-ray powder diffraction (XRD), extended X-ray absorption fine structure (EXAFS) and vibrational spectroscopic studies. The XRD data gave the tetragonal space group P4/nmm (No. 129). with a = 7.647(3), c = 8.049(3) Angstrom, Z = 2, and well-determined positions of the heavy metal atoms. The Pt-Tl bond length in the compound is 2.627(2) Angstrom. The platinum atom coordinates four equivalent equatorial cyano ligands, with a fifth axial CN ligand and a thallium atom completing a distorted octahedral coordination geometry. The Tl-Pt(CN)(5) entities are linked together in linear -NC-Pt-Tl-NC-Pt-Tl chains through the axial cyano ligand. These linear wires are the essential structural features and influence the properties of the com-pound. A three-dimensional network is formed by the four equatorial cyano ligands of the platinum atom that form bridges to the thallium atoms of neighbouring antiparallel chains. The platinum atom and the five nitrogen atoms from the bridging cyano groups form a distorted octahedron around the thallium atom. EXAFS data were recorded at the Pt and Tl L-III edges for a more complete description of the local structure around the Pt and Tl atoms. The excessive multiple scattering was evaluated by means of the FEFF program. Raman and infrared absorption spectroscopy reveal strong coupling of the vibrational modes of the TlPt(CN)(5) entities, in particular the metal - metal stretching mode, which is split into four Raman and two IR bands. Factor group theory shows that a structural unit larger than the crystallographic unit cell must be used to assign vibrational bands. Intra- and intermolecular force constants have also been calculated. The compound exhibits red luminescence at 700+/- 3 nm in glycerol and has a corresponding excitation maximum at 240 nm. X-ray photoelectron spectra (XPS) show that the metal atoms have intermediate oxidation states, Pt3.2+ and Tl1.6+, between those in the parent Pt-II and Tl-III species and the decomposition products, Pt-IV and Tl-I. The solid compound TlPt(CN)(5) is stable to 520 degreesC. However in presence of water, a two-electron transfer between the metal atoms results in the cleavage of the metal-metal bond at 80 degreesC, forming a Pt-IV pentacyanohydrate complex and a monovalent thallium ion.

  • 6. Jalilehvand, F.
    et al.
    Maliarik, M.
    Mink, J.
    Sandstrom, M.
    Ilyukhin, A.
    Glaser, Julius
    KTH, Superseded Departments, Chemistry.
    Structure studies of dimeric Pt-2(CN)(10) (4-) pentacyanoplatinum(III) and monomeric pentacyanoplatinum(IV) complexes by EXAFS, vibrational spectroscopy, and X-ray crystallography2002In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 106, no 14, p. 3501-3516Article in journal (Refereed)
    Abstract [en]

    The Structures of the dimeric bispentacyanoplatinate (III) (Pt-Pt) complex [Pt-2(CN)(10)](4-) and the pentacyanoplatinuni(IV) species [Pt(CN)(5)(OH)](2-), [Pt(CN)(5)(H2O)](-), and [Pt(CN)(5)I](2-) have been studied in aqueous solution by the EXAFS technique. A nonsupported Pt-Pt bond, 2.73(l) Angstrom, connects two Pt(CN)(5) entities in the dimer. Normal coordinate analyses have been made on the basis of the Raman spectra, and the force constants have been used for discussions of the bonding. The metal-metal stretching force constants for the [Pt-2(CN)(10)](4-) Complex, the [(NC)(5)Pt-TI(CN)(n)](n-) (n = 1, 2, and 3) complexes, and some other dimetallic complexes have been correlated with the metal-metal bond distances. In the [Pt(CN)(5)X](n-) complexes, the mean Pt-C bond distance of the pentacyanoplatinum group was found to increase, and the corresponding Pt-C force constants were found to decrease, with increasing donor ability of the ligand X in the order X = H2O, OH, I, and Pt(CN)(5). The crystal structures of the compounds Tl-2[Pt(CN)(5)(OH)] and K-2[Pt(CN)(5)I].0.6H(2)O were determined by single-crystal X-ray diffraction techniques and used for comparisons with the EXAFS models. The Pt-I bond distance of the [Pt(CN)(5)I](2)- complex is 2.676(2) Angstrom in the crystal structure and 2.66(1) Angstrom in solution by EXAFS. A method is described for estimating the force constant for the metal-metal bond stretch in dimetallic complexes with heavy metal atoms, based on the use of an effective spectroscopic mass of the metal atoms in a diatomic model. The 18-electron rule is found to be useful for rationalizing the structures of the metal-metal bonded cyano complexes and a guideline in searching for metal cyano complexes analogous to those currently described.

  • 7. Jalilehvand, F.
    et al.
    Maliarik, M.
    Sandstrom, M.
    Mink, J.
    Persson, I.
    Persson, P.
    Toth, I.
    Glaser, Julius
    KTH, Superseded Departments, Chemistry.
    New class of oligonuclear platinum-thallium compounds with a direct metal-metal bond. 5. Structure determination of heterodimetallic cyano complexes in aqueous solution by EXAFS and vibrational spectroscopy2001In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 40, no 16, p. 3889-3899Article in journal (Refereed)
    Abstract [en]

    The structures of three closely related heterodimetallic cyano complexes, [(NC)(5)Pt-Tl(CN)(n)](n-) (n = 1-3), formed in reactions between [Pt-II(CN)(4)](2-) and Tl-III cyano complexes, have been studied in aqueous solution. Multinuclear NMR data ((TI)-T-205, Pt-195, and C-13) were used for identification and quantitative analysis. X-ray absorption spectra were recorded at the Pt and TlLIII edges. The EXAFS data show, after developing a model describing the extensive multiple scattering within the linearly coordinated cyano ligands, short Pt-Tl bond distances in the [(NC)(5)Pt-Tl(CN)(n)](n-) complexes: 2.60(1), 2.62(1), and 2.64(1) Angstrom for n = 1-3, respectively. Thus, the Pt-Tl bond distance increases with increasing number of cyano ligands on the thallium atom. In all three complexes the thallium atom and five cyano ligands, with a mean Pt-C distance of 2.00-2.01 Angstrom, octahedrally coordinate the platinum atom. In the hydrated [(NC)(5)Pt-Tl(CN)(H2O)(4)](-) species the thallium atom coordinates one cyano ligand, probably as a linear Pt-TI-CN entity with a Tl-C bond distance of 2.13(1) Angstrom, and possibly four loosely bound water molecules with a mean Tl-O bond distance of about 2.51 Angstrom. In the [(NC)(5)Pt-Tl(CN)(2)](2-) species, the thallium atom probably coordinates the cyano ligands trigonally with two TI-C bond distances at 2.20(2) Angstrom, and in [(NC)(5)Pt-Tl(CN)(3)]Tl3- coordinates tetrahedrally with three TI-C distances at 2.22(2) Angstrom. EXAFS data were reevaluated for previously studied mononuclear thallium(III)-cyano complexes in aqueous solution, [Tl(CN)(2)(H2O)(4)](+), [Tl(CN)(3)(H2O)], and [Tl(CN)(4)](-), and also for the solid K[TI(CN)(4)] compound. A comparison shows that the TI-C bond distances are longer in the dinuclear complexes [(NC)(5)Pt-TI(CN)(n)](n-) (it = 1-3) for the same coordination number. Relative oxidation states of the metal atoms were estimated from their Pt-195 and (TI)-T-205 chemical shifts, confirming that the I(NC)5Pt-TI(CN),]n- complexes can be considered as metastable intermediates in a two-electron-transfer redox reaction from platinum(II) to thallium(III). Vibrational spectra were recorded and force constants from normal-coordinate analyses are used for discussing the delocalized bonding in these species.

  • 8. Khoshtariya, D. E.
    et al.
    Dolidze, T. D.
    Zusman, L. D.
    Lindbergh, Göran
    KTH, Superseded Departments, Chemical Engineering and Technology.
    Glaser, Julius
    KTH, Superseded Departments, Chemistry.
    Two-electron transfer for Tl(aq)(3+)/Tl(aq)(+) revisited. Common virtual Tl-II-Tl-III (4+) intermediate for homogeneous (superexchange) and electrode (sequential) mechanisms2002In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 41, no 7, p. 1728-1738Article in journal (Refereed)
    Abstract [en]

    Homogeneous and electrochemical two-electron transfers within the TI(aq)(3+)/TI(aq)(+) couple are considered on a common conceptual basis. For the 2 equiv electrochemical reduction of TI(aq)(3) to TI(aq)(+), the intermediate state with a formal reduction potential, E-1* = 1.04 +/- 0.10 V vs the normal hydrogen electrode, was detected, different from the established value of 0.33 V for a TI3+/TI2+ couple. Examination of obtained electrochemical (cyclic voltammetry (CV) and rotating disk electrode techniques, along with the CV-curve computer simulation procedure) and literature data indicate that the detected formal potential cannot be the property of electrode-adsorbed species, but rather of the covalently interacting dithallium intermediate [TI11-TI11](4+) located at the outer Helmholtz plane. The analysis of microscopic mechanisms, based on the recent hypothesis of H. Taube and the Marcus-Hush theory extended by Zusman and Beratan, and Koper and Schmickler, revealed that the homogeneous process most probably takes place through the superexchange inner-sphere two-electron-transfer mechanism, via an essentially virtual (undetectable) dithallium intermediate. In contrast, the electrochemical process occurs through a sequential mechanism, via the rate-determining step of TI(aq)(2+) ion formation immediately followed by activationless formation of the metastable (CV-active) dithallium state. The second electrochemical electron-transfer step is fast, and shows up only in the peak height (but not in the shape) of the observed CV cathodic wave, The anodic wave for a microscopically reverse process of the oxidation of TI(aq)(+) to TI(aq)(3+) cannot be observed within the considered potential range due to the blocking of through-space electron transfer by the competitor process of ion transfer to the electrode.

  • 9. Kritikos, M.
    et al.
    Ma, G. B.
    Bodor, A.
    Glaser, Julius
    KTH, Superseded Departments, Chemistry.
    Novel bis(diethylenetriamine)thallium(III) complex. Synthesis and characterization in pyridine solution and in solid2002In: Inorganica Chimica Acta, ISSN 0020-1693, E-ISSN 1873-3255, Vol. 331, p. 224-231Article in journal (Refereed)
    Abstract [en]

    A new complex of thallium(ill) with the nitrogen donor ligand diethylenetriamine (dien) has been prepared and characterized by multinuclear NMR (H-1, C-13. Tl-205), infrared and Raman spectroscopy. and X-ray diffraction. In solution, the symmetric s-facial isomer of [Tl(dien)(2)](3+) is formed. This is a fluxional molecule even at low temperature (235 K): therefore, the different rotamers cannot be observed separately. A complete characterization of the complex is given from its non-trivial NMR spectra. The crystal structure of [Tl(dien)(2)](ClO4)(3).H2O shows u-facial geometry. where the coordination environment around thallium can be described as a distorted trigonal prism.

  • 10. Ma, G. B.
    et al.
    Fischer, Andreas
    KTH, Superseded Departments, Chemistry.
    Glaser, Julius
    KTH, Superseded Departments, Chemistry.
    The trigonal-bipyramidal triiodothallium(III) complex TlI3{(CH3)(2)SO}(2)2002In: Acta Crystallographica Section C: Crystal Structure Communications, ISSN 0108-2701, E-ISSN 1600-5759, Vol. 58, p. m177-m178Article in journal (Refereed)
    Abstract [en]

    The title compound, bis(dimethyl sulfoxide)triiodothallium(III), [TlI3 (C2H6OS)(2)], was crystallized from equimolar amounts of (TlI)-I-I and I-2 in a dimethyl sulfoxide (DMSO) solution. After the initial redox reaction, the thallium(III)- iodo complex forms and precipitates as a DMSO solvate. In the crystal structure, Tl is surrounded by three iodide ligands in the equatorial plane and two O-coordinated DMSO molecules in the axial positions, forming a slightly distorted trigonal bipyramid. The complex lies on a twofold rotation axis, making the DMSO molecules and two of the I atoms crystallographically equivalent.

  • 11. Ma, G. B.
    et al.
    Fischer, Andreas
    KTH, Superseded Departments, Chemistry.
    Ilyukhin, A.
    Glaser, Julius
    KTH, Superseded Departments, Chemistry.
    Formation and structure of novel ternary complexes of thallium(III)cyanide-amine (ethylenediamine and triethylenetetramine) in solution and in solid2003In: Inorganica Chimica Acta, ISSN 0020-1693, E-ISSN 1873-3255, Vol. 344, p. 117-122Article in journal (Refereed)
    Abstract [en]

    A novel ternary Tl(III) complex [Tl(en)(2)(CN)](2+) has been synthesized and characterized in solution by NMR and in solid by Raman spectroscopy. This complex has been prepared in the solid state, [Tl(en)(2)(CN)](ClO4)(2) (1), and the related [Tl(tren)(CN)(2)](ClO4) (2), and their crystal structures determined by X-ray diffraction. A linear cyano-bridged supramolecular complex exists in [Tl(en)(2)(CN)](ClO4)(2). In [Tl(tren)(CN)(2)](ClO4), the thallium ion exists in a distorted octahedral geometry cis coordinated cyanides.

  • 12. Ma, G. B.
    et al.
    Glaser, Julius
    KTH, Superseded Departments, Chemistry.
    Novel monomeric phenanthroline-thallium(III) complexes multinuclear NMR characterization in organic solvents2002In: Chinese Chemical Letters, ISSN 1001-8417, E-ISSN 1878-5964, Vol. 13, no 7, p. 695-698Article in journal (Refereed)
    Abstract [en]

    A novel complex of monomeric thallium(III) with the nitrogen donor ligand phenanthroline (phen) has been prepared and characterized by multinuclear NMR (H-1, C-13, Tl-205). The three complexes exist in equilibria in DMSO and acetonitrile solution which was proved by the Tl-205 NMR spectra. The H-1 and C-13 NMR spectra of tris-phen Tl(III) complex have been measured, where the spin-spin coupling between Tl (I = 1/2) and C-13 or H-1 signals were observed with the H-1 and C-13 NMR spectroscopy in acetonitrile. The coupling constants are presented and the chemical shifts of complexes are discussed in detail.

  • 13. Ma, G. B.
    et al.
    Ilyukhin, A.
    Glaser, Julius
    KTH, Superseded Departments, Chemistry.
    2,2 '-Bipyridinium bis(perchlorate)2000In: Acta Crystallographica Section C: Crystal Structure Communications, ISSN 0108-2701, E-ISSN 1600-5759, Vol. 56, p. 1473-1475Article in journal (Refereed)
    Abstract [en]

    The title compound, [H(2)bipy](ClO4)(2) or C10H10N22+. 2ClO(4)(-), was obtained at the interface between an organic (2,2'-bipyridine in methanol) and an aqueous phase (perchloric acid in water). The compound crystallizes in space group P(1) over bar and comprises discrete diprotonated trans-bipyridinium cations, [H(2)bipy](2+), and ClO4- anions. The cations and anions are connected through N-H . . .O and C-H . . .O hydrogen bonds [distances N . . .O 2.817 (4) and 2.852 (4) Angstrom, and C . . .O 3.225 (6)-3.412 (5)Angstrom]. The C-C bond distance between the two rings is 1.452 (5) Angstrom. The bipyridinium cation has a trans conformation and the N-C-C-N torsion angle is 152.0 (3)degrees.

  • 14. Ma, G. B.
    et al.
    Ilyukhin, A.
    Glaser, Julius
    KTH, Superseded Departments, Chemistry.
    Toth, I.
    Zekany, L.
    Equilibrium and structure of thallium(III)-ethylenediamine complexes in pyridine solution and in solid2001In: Inorganica Chimica Acta, ISSN 0020-1693, E-ISSN 1873-3255, Vol. 320, no 02-jan, p. 92-100Article in journal (Refereed)
    Abstract [en]

    The formation of three [TI(en)(n)](3+) complexes (n = 1-3) in a pyridine solvent has been established by means of Tl-205 and H-1 NMR. Their stepwise stability constants based on concentrations, K-n = [Tl(en)(n)(3+)]/{[Tl(en)(n-1)(3+)](.)[en]}, at 298 K in 0.5 M NaClO4 ionic medium in pyridine, were calculated from Tl-205 NMR integrals: log K-1 = 7.6 +/- 0.7; log K-2 = 5.2 +/- 0.5 and log K-3 = 2.64 +/- 0.05. Linear correlation between both the Tl-205 NMR shifts and spin-spin coupling Tl-205-H-1 versus the stability constants has been found and discussed. A single crystal with the composition [Tl(en)(3)](ClO4)(3) was synthesized and its structure determined by X-ray diffraction. The Tl3+ ion is coordinated by three ethylenediamine ligands via six N-donor atoms in a distorted octahedral fashion.

  • 15. Ma, G. B.
    et al.
    Kritikos, M.
    Glaser, Julius
    KTH, Superseded Departments, Chemistry.
    Small platinum-thallium clusters stabilized by ethylenediamine, (NC)(5)Pt-Tl(en)(n-1) (n=1-3) - Characterization in solution and in the solid state2001In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, no 5, p. 1311-1319Article in journal (Refereed)
    Abstract [en]

    Three neutral binuclear platinum-thallium compounds containing a direct and naked (unsupported by ligands) metal-metal bond have been prepared in dimethyl sulfoxide (DMSO). The compounds have the formula [(NC)(5)Pt-Tl(en)(n-1)] (n = 1-3, for compounds 1, 2 and 3, respectively) and were found to exist in solution by means of multinuclear NMR (Pt-195, Tl-205, C-13 and H-1) and Raman spectroscopy. The compounds exhibit very large single bond Pt-195-Tl-205 spin-spin coupling constants of 48-66 kHz. In addition, the solid state analogues of 1 and 3, [(NC)(5)Pt-Tl(DMSO)(4)](DMSO) and [(NC)(5)Pt-Tl(en)(2)]-(DMSO)(2), were synthesized and their structures determined by single crystal X-ray diffraction. The metal-metal bond lengths of Pt-Tl are 2.6131(4) Angstrom and 2.6348(5) Angstrom in compounds I and 3, respectively. Crystal data for compound 1: monoclinic, space group Cc (No. 9), Z = 4, a = 17.2367(14), b = 9.5560(11), c = 17.7941(15) Angstrom, beta = 100.551(10)9 V = 2881.4(5) Angstrom (3), T = 110(1) K; and for compound 3: monoclinic, space group P2(1) (No. 4), Z = 2, a 9.3167(14), b 12.3007(13), c = 11.4586(16) Angstrom, beta = 112.318(16)degrees, V =1214.8(3) Angstrom (3), T = 110(1) K.

  • 16. Ma, G. B.
    et al.
    Molla-Abbassi, A.
    Kritikos, M.
    Ilyukhin, A.
    Jalilehvand, F.
    Kessler, V.
    Skripkin, M.
    Sandstrom, M.
    Glaser, Julius
    KTH, Superseded Departments, Chemistry.
    Naslund, J.
    Persson, I.
    Structure of the dimethyl sulfoxide solvated thallium(III) ion in solution and in the solid state2001In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 40, no 25, p. 6432-6438Article in journal (Refereed)
    Abstract [en]

    The structure and vibrational spectra of the dimethyl sulfoxide solvated thallium(III) ion have been studied in a dimethyl sulfoxide solution and in the solid state. X-ray crystallography shows a trigonal unit cell, space group R (3) over bar (No. 148), for the [TI(dmso)(6)](ClO4)(3) Compound with Z = 3, a = b = 11.9764(13) [11.8995(9)] Angstrom, c = 20.802(2) [20.467(2)] Angstrom, and V = 2584.0(5) [2509.9(4)] Angstrom (3) at 295 [150] K. The crystal structure comprises a highly symmetric hexakis(dimethyl sulfoxide)thallium(III) ion, with thallium in a 3 symmetry site and a TI-O bond distance of 2.224(3) Angstrom at 295 K. The octahedral TlO6 kernel is compressed along the threefold axis with an O-Tl-O bond angle of 96.20(11)degrees. The Tl-O-S bond angle of 120.7(2)degrees corresponds to a Tl . . .S distance of 3.292(2) Angstrom. One perchlorate ion centered on the (3) over bar axis was described by a statistically disordered model. A low-temperature EXAFS study (10 K) resulted in the TI-O and Tl . . .S distances of 2.221(4) and 3.282(6) Angstrom, respectively, consistent with a Tl-O-S bond angle of 120(1)degrees. The low Debye-Waller factors confirm a regular coordination without the disorder of the dimethyl sulfoxide ligands, which would have resulted from the alternative choice of space group R3 for the crystal structure. Raman and infrared spectra have been recorded and assigned, with the bands at 435 and 447 cm(-1) corresponding to the vibrational frequency of the symmetric and asymmetric TI-O stretching modes, respectively. EXAFS data of a 0.5 mol dm(-3) thallium(III) trifluoromethanesulfonate in a dimethyl sulfoxide solution were consistent with that of a hexasolvated ion with mean Tl-O and Tl . . .S distances of 2.22(1) and 3.33(2) Angstrom, respectively, which correspond to a mean Tl-O-S bond angle of 124(2)degrees. The anomalously large disorder parameter for the TI-O distances is consistent with a weal, pseudo-Jahn-Teller effect. The Tl-205, C-13, and H-1 NMR spectra of the complex in solution show single signals at 1886, 39.5, and 2.3 ppm, respectively.

  • 17. Ma, G.
    et al.
    Fischer, Andreas
    KTH, Superseded Departments, Chemistry.
    Glaser, Julius
    KTH, Superseded Departments, Chemistry.
    Synthesis and structure of monomeric and platinum-bonded (1,10-phenanthroline)thallium complexes2002In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, no 6, p. 1307-1314Article in journal (Refereed)
    Abstract [en]

    Oxidative addition of (1,10-phenanthroline)thallium(III) complexes [TI(phen)(n)(solv)](3+) (n = 1-2) (phen = 1,10-phenanthroline) to [Pt(CN)(4)](2-) in DMSO, in the presence of cyanide ions and in the absence of cyanide ions yielded heterodinuclear metal-metal-bonded complexes, [(NC)(5)Pt-Tl(phen)(n)(solv)] and [(NC)(4)Pt-Tl(phen)(n)(solv)](+) (n = 0, 1, and 2), respectively, The presence of a direct Pt-Tl bond in the complex is evident by a very strong one-bond Pt-195-Tl-205 spin-spin coupling detected by Tl-205 NMR: (1)J = 94.0 kHz (1a), 84.2 kHz (2a), and 77.1 kHz (3a) corresponding to n 0, 1, and 2 in [(NC)(4)Pt-Tl(phen)(n)(solv)](+), and (1)J 65.4 kHz (2b) and 62.5 kHz (3b) for n = 1 and 2, respectively, in [(NC)(5)Pt-Tl(phen)(n)(solv)]. The crystal structures of [(NC)(5)Pt-Tl(phen)(DMSO)(3)].(DMSO) (2b), [(NC)(5)Pt-Tl(phen)(2)].(DMSO)(3) (3b), and [Tl(phen)(2)Cl-2] (ClO4) (4) complexes were determined. Very short Pt-Tl bonds, 2.6296(3) and 2.6375(5) Angstrom, are present in structures 2b and 3b, respectively. The corresponding force constants in the molecules in the solid state, 1.84 and 1.74 N/cm for 2b and 3b, respectively, were calculated using Raman stretching frequencies of the Pt-Tl vibrations, and are characteristic for a single, strong metal-metal bond. Electronic absorption spectra were recorded for selected compounds and the optical transition attributed to the metal-metal bond was assigned. ((C) Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002).

  • 18.
    Ma, Gui-Bin
    et al.
    KTH, Superseded Departments, Chemistry.
    Kritikos, M.
    Maliarik, Mikhail
    KTH, Superseded Departments, Chemistry.
    Glaser, Julius
    KTH, Superseded Departments, Chemistry.
    Modification of binuclear Pt-Tl bonded complexes by attaching bipyridine ligands to the thallium site2004In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 43, no 14, p. 4328-4340Article in journal (Refereed)
    Abstract [en]

    Complex formation of monomeric thallium(III) species with 2,2'-bipyridine (bipy) in dimethyl sulfoxide (dmso) and acetonitrile solutions was studied by means of multinuclear (H-1, C-13, and (TI)-T-205) NMR spectroscopy. For the first time, NMR signals of the individual species [TI(bipy)(m)(SoIV)](3+) (M = 1-3) were observed despite intensive ligand and solvent exchange processes. The tris(bipy) complex was crystallized as [TI(biPY)(3)(dmso)](ClO4)(3)(dMSO)(2) (1), and its crystal structure determined. In this compound, thallium is seven-coordinated; it is bonded to six nitrogen atoms of the three bipy molecules and to an oxygen atom of dmso. Metal-metal bonded binuclear complexes [(NC)(5)Pt-TI(CN)(n)(SoIV)](n-) (n = 0-3) have been modified by attaching bipy molecules to the thallium atom. A reaction between [(NC)(5)Pt-TI(dMSO)(4)](s) and 2,2'-bipyridine in dimethyl sulfoxide solution results in the formation of a new complex, [(NC)(5)Pt-TI(bipy)(solv)]. The presence of a direct Pt-TI bond in the complex is convincingly confirmed by a very strong one-bond Pt-195-(TI)-T-205 spin-spin coupling ((1)J((195)pt-(TI)-T-205) = 64.9 kHz) detected in both Pt-195 and (TI)-T-205 NMR spectra. In solutions containing free cyanide, coordination of CN- to the thallium atom occurs, and the complex [(NC)(5)Pt-TI(bipy)(CN)(solv)](-) ((1)J(Pt-195-(TI)-T-205) = 50.1 kHz) is formed as well. Two metal-metal bonded compounds containing bipy as a ligand were crystallized and their structures determined by X-ray diffractometry: [(NC)(5)Pt-TI(bipy)(dMSO)(3)] (2) and [(NC)(5)Pt-TI(biPY)(2)] (3). The Pt-TI bonding distances in the compounds, 2.6187(7) and 2.6117(5) Angstrom, respectively, are among the shortest reported separations between these two metals. The corresponding force constants in the molecules, 1.38 and 1.68 N/cm, respectively, were calculated using Raman stretching frequencies of the Pt-TI vibrations and are characteristic for a single metal-metal bond. Electronic absorption spectra were recorded for the [(NC)(5)Pt-TI(bipy)(m)(solv)] compounds, and the optical transition was attributed to the metal-metal bond assigned.

  • 19.
    Ma, Gui-Bin
    et al.
    KTH, Superseded Departments, Chemistry.
    Maliarik, Mikhail
    KTH, Superseded Departments, Chemistry.
    Sun, Licheng
    KTH, Superseded Departments, Chemistry.
    Glaser, Julius
    KTH, Superseded Departments, Chemistry.
    Novel porphyrin-thallium-platinum complex with naked metal-metal bond: multinuclear NMR characterization of (tpp)Tl-Pt(CN)(5) (2-) and (thpp)Tl-Pt(CN)(5) (2-) in solution2004In: Inorganica Chimica Acta, ISSN 0020-1693, E-ISSN 1873-3255, Vol. 357, no 14, p. 4073-4077Article in journal (Refereed)
    Abstract [en]

    The novel porphyrin-thallium-platinum complexes with naked metal-metal bond, with the composition [(tpp)Tl-Pt(CN)(5)](2-) (1) and [(thpp)Tl-Pt(CN)(5)](2-) (2) (tpp = tetraphenylporphrin and thpp = tetrakis(4-hydroxyphenyl)-porphine), were synthesized and characterised by multinuclear NMR (Tl-205, Pt-195, C-13 and H-1) and Raman spectroscopies in solution. The presence of a direct Pt-Tl metal-metal bond in the complexes is convincingly confirmed by a very strong one-bond Pt-195-Tl-205 spin-spin coupling (47.8 and 48.3 kHz for 1 and 2, respectively) detected in both Pt and Tl NMR spectra. The corresponding force constant in molecule 1, 1.92 Ncm(-1), was calculated using Raman stretching frequency of the Pt-T1 vibration and is characteristic for a single metal-metal bond.

  • 20. Maliarik, Mikhail
    et al.
    Nagle, Jeffrey K.
    Ilyukhin, Andrey
    Murashova, Elena
    Mink, Janos
    Skripkin, Mikhail
    Glaser, Julius
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Inorganic Chemistry.
    Kovacs, Margit
    Horvath, Attila
    Metal-metal bonding in tetracyanometalates (M = Pt-II, Pd-II, Ni-II) of monovalent thallium. Crystallographic and spectroscopic characterization of the new compounds Tl2Ni(CN)(4) and Tl2Pd(CN)(4)2007In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 46, no 11, p. 4642-4653Article in journal (Refereed)
    Abstract [en]

    The new crystalline compounds Tl2Ni(CN)(4) and Tl2Pd(CN)(4) were synthesized by several procedures. The structures of the compounds were determined by single-crystal X-ray diffraction. The compounds are isostructural with the previously reported platinum analogue, Tl2Pt(CN)(4). A new synthetic route to the latter compound is also suggested. In contrast to the usual infinite columnar stacking of [M(CN)(4)](2-) ions with short intrachain M-M separations, characteristic of salts of tetracyanometalates of Ni-II, Pd-II, and Pt-II, the structure of the thallium compounds is noncolumnar with the two Tl-I ions occupying axial vertices of a distorted pseudo-octahedron of the transition metal, [MTl2C4]. The Tl-M distances in the compounds are 3.0560(6), 3.1733(7), and 3.140(1) A for Ni-II, Pd-II, and Pt-II, respectively. The short Tl-Ni distance in Tl2Ni(CN)(4) is the first example of metal-metal bonding between these two metals. The strength of the metal-metal bonds in this series of compounds was assessed by means of vibrational spectroscopy. Rigorous calculations, performed on the molecules in D-4h point group symmetry, provide force constants for the Tl-M stretching vibration constants of 146.2, 139.6, and 156.2 N/m for the Ni-II, Pd-II, and Pt-II compounds, respectively, showing the strongest metal-metal bonding in the case of the Tl-Pt compound. Amsterdam density-functional calculations for isolated Tl2M(CN)(4) molecules give Tl-M geometry-optimized distances of 2.67, 2.80, and 2.84 A for M = Ni-II, Pd-II, and Pt-II, respectively. These distances are all substantially shorter than the experimental values, most likely because of intermolecular Tl-N interactions in the solid compounds. Time-dependent density-functional theory calculations reveal a low-energy, allowed transition in all three compounds that involves excitation from an a(1g) orbital of mixed Tl 6p(z)-M nd(z)(2) character to an a(2u) orbital of dominant Tl 6p(z) character.

  • 21. Maliarik, Mikhail
    et al.
    Plyusnin, Victor F.
    Grivin, Vjacheslav P.
    Toth, Imre
    Glaser, Julius
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Inorganic Chemistry.
    Photoinduced electron transfer via nonbuttressed metal-metal bonds. The photochemical study of binuclear complexes with platinum-thallium bonds2008In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 112, no 26, p. 5786-5793Article in journal (Refereed)
    Abstract [en]

    The photochemistry of binuclear metal-metal bonded complexes [(NC)(5)Pt-Tl(solv)(x)] (solv is water or dimethylsulfoxide) has been studied in aqueous and dimethylsulfoxide solutions. Both stationary and nanosecond laser flash photolysis have been carried out on the species. The metal-metal bonded complexes have been photolyzed by irradiation into the corresponding intense MMCT absorption bands. Photoexcitation results in the cleavage of the platinum-thalliurn bond and the formation of a solvated thallous ion and a cyano complex of platinum(IV), [Pt(CN)(5)(Solv)](-), in both cases. The species have been characterized by multinuclear NMR and optical spectroscopy. The products of the photoreaction indicate a complementary two-electron transfer occurring between platinum and thallium ions in the binuclear Pt-T1 species. Quantum yield values for the photodecomposition of the species have been determined. The intermediates of the photoinduced metal-to-metal electron transfer have been detected and characterized by optical spectroscopy. The kinetics of transient formation and decomposition have been studied, and mechanisms of the photoactivated redox reaction have been suggested.

  • 22. Nagy, P.
    et al.
    Fischer, Andreas
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Inorganic Chemistry.
    Glaser, Julius
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Inorganic Chemistry.
    Ilyukhin, A.
    Maliarik, M.
    Toth, I.
    Solubility, complex formation, and redox reactions in the Tl2O3-HCN/CN--H2O system. Crystal structures of the cyano compounds Tl(CN)(3)center dot H2O, Na Tl(CN)(4) center dot 3H(2)O, K Tl(CN)41, and Tl-I Tl-III(CN)41 and of (Tl2C2O4)-C-I2005In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 44, no 7, p. 2347-2357Article in journal (Refereed)
    Abstract [en]

    Thallium(III) oxide can be dissolved in water in the presence of strongly complexing cyanide ions. TI111 is leached from its oxide both by aqueous solutions of hydrogen cyanide and by alkali-metal cyanides. The dominating cyano complex of thallium(III) obtained by dissolution of TI2O3 in HCN is [TI(CN)(3)(aq)] as shown by (TI)-T-205 NMR. The TI(CN)(3) species has been selectively extracted into diethyl ether from aqueous solution with the ratio CN-/TI111 = 3. When aqueous solutions of the MCN (M = Na+, K+) salts are used to dissolve thallium(III) oxide, the equilibrium in liquid phase is fully shifted to the [TI(CN)(4)](-) complex. The TI(CN)(3) and TI(CN)(4)(-) species have for the first time been synthesized in the solid state as TI(CN)(3)(H2O)-H-. (1), M[TI(CN)(4)] (M = TI (2) and K (3)), and Na[TI(CN)(4)](.)3H(2)O (4) salts, and their structures have been determined by single-crystal X-ray diffraction. In the crystal structure of 1, the thallium(III) ion has a trigonal bipyramidal coordination with three cyanide ions in the equatorial plane, while an oxygen atom of the water molecule and a nitrogen atom from a cyanide ligand, attached to a neighboring thallium complex, form a linear O-TI-N fragment. In the three compounds of the tetracyano-thallium(III) complex, 2-4, the [TI(CN)(4)](-) unit has a distorted tetrahedral geometry. Along with the acidic leaching (enhanced by TI111-CN- complex formation), an effective reductive dissolution of the thallium(III) oxide can also take place in the TI2O3-HCN-H2O system yielding thallium(l), while hydrogen cyanide is oxidized to cyanogen. The latter is hydrolyzed in aqueous solution giving rise to a number of products including (CONH2)(2), NCO-, and NH4+ detected by N-14 NMR. The crystalline compounds, TI1[TI111(CN)(4)], (TI2C2O4)-C-1, and (CONH2)(2), have been obtained as products of the redox reactions in the system.

  • 23. Nagy, P.
    et al.
    Joszai, R.
    Fabian, I.
    Toth, I.
    Glaser, Julius
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Inorganic Chemistry.
    The decomposition and formation of the platinum-thallium bond in the (CN)(5)Pt-Tl(edta) (4-) complex: kinetics and mechanism2005In: Journal of Molecular Liquids, ISSN 0167-7322, E-ISSN 1873-3166, Vol. 118, no 1-3, p. 195-207Article in journal (Refereed)
    Abstract [en]

    The [(CN)(5)Pt-T1(edta)](4-) complex, having direct metal-metal bond, has been prepared in solution by two different reactions: (a) dissolution of [(CN)(5)Pt-T1]((s)) in aqueous solution of edta ligand, (b) from Pt(CN)(4)(2-) and T1(edta)(CN)(2-) reactants. The decomposition reaction is greatly accelerated by cyanide and significantly inhibited by edta. It proceeds through the [(CN)(5)Pt-T1(CN)(3)](3-) intermediate. This complex decomposes to Pt(CN)(4)(2-) and T1(CN)(4)(-). To complete the reaction, T1CN)(4)(-) and edta(4-) react in relatively fast equilibrium step(s) giving T1(edta)(CN)(2-). The formation of [(CN)(5)Pt-T1(edta)](4-) complex can proceed via two different pathways depending on the ratio of the cyanide and the edta ligand. The 'direct path' at excess of edta means the formation of a [(CN)(4)Pt...T1(CN)(edta)](4-) intermediate followed by the release of the cyanide from the T1-center than the coordination of a cyanide from the bulk to the Pt-center of the intermediate. The 'indirect path' dominates in the absence of extra edta and the formation of the Pt-T1 bond happens between Pt(CN)(4)(2-) and T1(CN)(4)(-) as studied earlier in our laboratories.

  • 24. Nagy, P.
    et al.
    Toth, I.
    Fabian, I.
    Maliarik, M.
    Glaser, Julius
    KTH, Superseded Departments, Chemistry.
    Kinetics and mechanism of formation of the platinum-thallium bond: The (CN)(5)Pt-Tl(CN)(3) (3-) complex2003In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 42, no 21, p. 6907-6914Article in journal (Refereed)
    Abstract [en]

    Formation kinetics of the metal-metal bonded [(CN)(5)PtTl(CN)(3)](3-) complex from Pt(CN)(4)(2-) and Tl(CN)(4)(-) has been studied in the pH range-of 5-10, using standard mix-and-measure spectrophotometric technique at pH 5-8 and stopped-flow method at pH > 8. The overall order of the reaction, Pt(CN)(4)(2-) + Tl(CN)(4)(-) reversible arrow [(CN)(5)PtTl(CN)(3)](3-), is 2 in the slightly acidic region and 3 in the alkaline region, which means first order for the two reactants in both cases and also for CN- at high pH. The two-term rate law corresponds to two different pathways via the Tl(CN)(3) and Tl(CN)(4)(-) complexes in acidic and alkaline solution, respectively. The two complexes are in fast equilibrium, and their actual concentration ratio is controlled by the concentration of free cyanide ion. The following expression was derived for the pseudo-first-order rate constant of the overall reaction: k(obs) = (k(1)(a)[Tl(CN)(4)(-)] + (k(1)(a)/K-f))(1/(1 + K-p[H+]))[CN-](free) + k(1)(b) [Tl(CN)(4)(-)] + (k(1)(b)/K-f), where k(1)(a) and k(1)(b) are the forward rate constants for the alkaline and slightly acidic paths, K-f is the stability constant of [(CN)(5)PtTI(CN)(3)](3-), and K-p is the protonation constant of cyanide ion. k(1)(a) = 143 +/- 13 M-2 s(-1), k(1)(b) = 0.056 +/- 0.004 M-1 s(-1), K-f = 250 +/- 54 M-1, and log K-p = 9.15 +/- 0.05 (l = 1 M NaClO4, T = 298 K). Two possible mechanisms were postulated for the overall reaction in both pH regions, which include a metal-metal bond formation step and the coordination of the axial cyanide ion to the platinum center. The alternative mechanisms are different in the sequence of these steps.

  • 25. Nagy, P.
    et al.
    Toth, I.
    Fabian, I.
    Maliarik, M.
    Glaser, Julius
    KTH, Superseded Departments, Chemistry.
    Kinetics and mechanism of platinum-thallium bond formation: The binuclear (CN)(5)Pt-Tl(CN) (-) and the trinuclear (CN)(5)Pt-Tl-Pt(CN)(5) (3-) complex2004In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 43, no 17, p. 5216-5221Article in journal (Refereed)
    Abstract [en]

    Formation kinetics of the metal-metal bonded binuclear [(CN)(5)Pt-TI(CN)](-) (1) and the trinuclear [(CN)(5)Pt-TI-Pt(CN)(5)](3-) (2) complexes is studied, using the standard mix-and-measure spectrophotometric method. The overall reactions are Pt(CN)(4)(2-) + TI(CN)(2)(+) z = 1 and Pt(CN)(4)(2-) + [(CN)(5)Pt-TI(CN)](-) = 2. The corresponding expressions for the pseudo-first-order rate constants are k(obs) = (k(1)[TI(CN)(2)(+)] + k(-1))[TI(CN)(2)(+)] (at TI(CN)(2)(+) excess) and k(obs) = (k(2b)[Pt(CN)(4)(2-)] + k(-2b))[HCN] (at Pt(CN)(4)(2-) excess), and the computed parameters are k(1) 1.04 +/-0.02 M-2 s(-1), k(-1) = k(1)/K-1 = 7 x 10(-5) M-1 s(-1) and k(2b) = 0.45 +/- 0.04 M-2 s(-1), K-2b = 26 +/- 6 M-1, k(-2b) = k(2b)/K-2b = 0.017 M-1 s(-1), respectively. Detailed kinetic models are proposed to rationalize the rate laws. Two important steps need to occur during the complex formation in both cases: (i) metal-metal bond formation and (ii) the coordination of the fifth cyanide to the platinum site in a nucleophilic addition. The main difference in the formation kinetics of the complexes is the nature of the cyanide donor in step ii. In the formation of [(CN)5Pt-TI(CN)]-, TI(CN)2+ is the source of the cyanide ligand, while HCN is the cyanide donating agent in the formation of the trinuclear species. The combination of the results with previous data predict the following reactivity order for the nucleophilic agents: CN- > TI(CN)(2)(+) > HCN.

  • 26. Purgel, Mihaly
    et al.
    Maliarik, Mikhail
    Glaser, Julius
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Inorganic Chemistry.
    Platas-Iglesias, Carlos
    Persson, Ingmar
    Toth, Imre
    Binuclear Pt-TI Bonded Complex with Square Pyramidal Coordination around Pt: A Combined Multinuclear NMR, EXAFS, UV-Vis, and DFT/TDDFT Study in Dimethylsulfoxide Solution2011In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 50, no 13, p. 6163-6173Article in journal (Refereed)
    Abstract [en]

    The structure and bonding of a new Pt-Tl bonded complex formed in dimethylsulfoxide (dmso), (CN)(4)Pt-Tl(dmso)(5)(+), have been studied by multinuclear NMR and UV vis spectroscopies, and EXAFS measurements in combination with density functional theory (DFT) and time dependent density functional theory (TDDFT) calculations. This complex is formed following the equilibrium reaction Pt(CN)(4)(2-) + Tl(dmso)(6)(3+) reversible arrow (CN)(4)Pt-Tl(dmso)(5)(+) + dmso. The stability constant of the Pt-Tl bonded species, as determined using C-13 NMR spectroscopy, amounts to log K = 2.9 +/- 0.2. The (NC)(4)Pt-TI(dmso)(5)(+) species constitutes the first example of a Pt-Tl bonded cyanide complex in which the sixth coordination position around Pt (in trans with respect to the Tl atom) is not occupied. The spectral parameters confirm the formation of the metal metal bond, but differ substantially from those measured earlier in aqueous solution for complexes (CN)(5)Pt-Tl(CN)(n)(H2O)(x)(n-)(n = 0-3). The Tl-205 NMR chemical shift, delta = 75 ppm, is at extraordinary high field, while spin spin coupling constant, J(Pt-Tl) = 93 kHz, is the largest measured to date for a Pt-Tl bond in the absence of supporting bridging ligands. The absorption spectrum is dominated by two strong absorption bands in the UV region that are assigned to MMCT (Pt -> Tl) and LMCT (dmso -> Tl) bands, respectively, on the basis of MO and TDDFT calculations. The solution of the complex has a bright yellow color a's a result of a shoulder present on the low energy side of the band at 355 nm. The geometry of the (CN)(4)Pt-Tl core can be elucidated from NMR data, but the particular stoichiometry and structure involving the dmso ligands are established by using Tl and Pt L-III-edge EXAFS measurements. The Pt-Tl bond distance is 2.67(1) angstrom, the Tl-O bond distance is 2.282(6) angstrom, and the Pt-C-N entity is linear with Pt C and Pt center dot center dot center dot N distances amounting to 1.969(6) and 3.096(6) angstrom, respectively. Geometry optimizations on the (CN)(4)Pt-Tl(dmso)(5)(+) system by using DFT calculations (B3LYP model) provide bond distances in excellent agreement with the EXAFS data. The four cyanide ligands are located in a square around the Pt atom, while the Tl atom is coordinated in a distorted octahedral fashion with the metal being located 0.40 angstrom above the equatorial plane described by four oxygen atoms of dmso ligands. The four equatorial Tl-O bonds and the four cyano ligands around the Pt atom are arranged in an alternate geometry. The coordination environment around Pt may be considered as being square pyramidal, where the apical position is occupied by the Tl atom. The optimized geometry of (CN)(4)Pt-Tl(dmso)(5)(+) is asymmetrical (C-1 point group). This low symmetry might be responsible for the unusually large NMR linewidths observed due to intramolecular chemical exchange processes. The nature of the Pt-Tl bond has been studied by MO analysis. The metal metal bond formation in (CN)(4)Pt-Tl(dmso)(5)(+) can be simply interpreted as the result of a Pt(5d(z2))(2)-> Tl(6s)(0) donation. This bonding scheme may rationalize the smaller thermodynamic stability of this adduct compared to the related complexes with (CN)(5)Pt-Tl entity, wher the linear C-Pt-Tl unit constitutes a very stable bonding system.

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