Modification of binuclear Pt-Tl bonded complexes by attaching bipyridine ligands to the thallium site
2004 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 43, no 14, 4328-4340 p.Article in journal (Refereed) Published
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.
Place, publisher, year, edition, pages
2004. Vol. 43, no 14, 4328-4340 p.
metal-metal bond, 1, 10-fenantrolinom i 2, 2'-dipiridilom, closed-shell interactions, aqueous-solution, structural-characterization, photoelectron-spectra, molecular-structure, multinuclear nmr, model compounds, solid-state
IdentifiersURN: urn:nbn:se:kth:diva-23561DOI: 10.1021/ic034571eISI: 000222541700032ScopusID: 2-s2.0-3142715970OAI: oai:DiVA.org:kth-23561DiVA: diva2:342259
QC 20100525 QC 201109262010-08-102010-08-102011-09-26Bibliographically approved