Synthesis, characterization and reactivity of linear-type S-bridged trinuclear complexes containing vanadium(III) ion. Crystal structures of [V-III{M(aet)(3)}(2)](ClO4)(3) (M = Rh-III, Ir-III; aet=2-aminoethanethiolate)

Citation
Y. Miyashita et al., Synthesis, characterization and reactivity of linear-type S-bridged trinuclear complexes containing vanadium(III) ion. Crystal structures of [V-III{M(aet)(3)}(2)](ClO4)(3) (M = Rh-III, Ir-III; aet=2-aminoethanethiolate), J CHEM S DA, (14), 2001, pp. 2089-2094
Citations number
30
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Inorganic & Nuclear Chemistry
Journal title
JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS
ISSN journal
1472-7773 → ACNP
Issue
14
Year of publication
2001
Pages
2089 - 2094
Database
ISI
SICI code
1472-7773(2001):14<2089:SCAROL>2.0.ZU;2-J
Abstract
Reactions of fac(S)-[M(aet)(3)] (M=Rh-III, Ir-III; aet=2-aminoethanethiolat e) with an excess of VCl3 gave linear-type S-bridged trinuclear complexes [ V-III{M(aet)(3)}(2)](3+) (M=Rh-III 1, Ir-III 2). The Delta Lambda isomers ( 1a(ClO4)(3) and 2a(ClO4)(3)) were selectively crystallized and their struct ures were determined by X-ray diffraction. Both the complex cations consist of two terminal fac(S)-[M(aet)(3)] units and a central vanadium atom, whic h is situated in an octahedral environment with a (VS6)-S-III chromophore. The Ir complex 2a was also formed by using (VOCl2)-O-IV instead of (VCl3)-C l-III in a redox reaction, whereas the Rh complex 1a was not formed by a si milar method. The optically active isomer (Lambda Lambda -1b) of the Rh com plex was selectively obtained by using Lambda -fac(S)-[Rh(aet)(3)], and cha racterized by IR, UV-VIS absorption and CD spectra. All the obtained comple xes exhibit a unique strong absorption band at ca. 18x10(3) cm(-1). Stabili ty and reactivity relating to V-S bond cleavage for the complexes were inve stigated using UV-VIS absorption spectroscopic methods. These studies show first order decomposition or metal exchange. While 2a has weaker V-S bonds than 1a (from the X-ray analyses), the former is considerably more stable i n water than the latter. Cyclic voltammograms of 1a and 2a in water show on ly irreversible oxidation and reduction waves including V-IV/III and V-III/ II processes. The V(III) ions in the S-bridged trinuclear structures exhibi t a lower magnetic moment (2.59 mu (B) for 1a and 2.27 mu (B) for 2a) at ro om temperature than the spin-only value for a d(2) electronic configuration .