Synthesis and characterisation of neutral tris(bidentate) vanadium(V) complexes containing N3S23– and catecholate ligands

The preparation and characterisation of complexes of the type [V(N3S2)Cl2L] (L = 2,2'-bipyridyl, 1; or 1,10-phenanthroline, 2) and [V(N3S2)L(L')] [L' = catecholate (cat) or 3,5-di-tert-butylcatecholate (dtbc)] 3-6 is described. The new complexes have been characterised by microanalyses, V-51 NMR, IR and visible spectroscopy as well as electrochemistry. All the new complexes are air stable as solids. Complexes 3 and 4 have a one-electron reversible couple and an anodic peak, whereas the dtbc complexes 5 and 6 have two one-electron reversible redox couples. The V-51 NMR spectra of 1-6 are characteristic, in particular there is a large downfield shift on replacing cat by dtbc.</p

SYNTHESIS AND X-RAY STRUCTURES OF BIS(3,5-DI-TERT-BUTYLCATECHOLATO)(PHENANTHROLINE)VANADIUM(IV) AND ITS VANADIUM(V) ANALOG [V(DTBC)2(PHEN)][SBF6]

Bis(3,5-di-tert-butylcatecholato)(phenanthroline)vanadium(iv) 1 is prepared, and oxidised with silver hexafluoroantimonate to give its vanadium(v) analogue 2; both complexes are characterised by X-ray crystallography revealing significant differences in their coordination geometry.</p

NON-OXO MOLYBDENUM COMPOUNDS - THE PREPARATION AND X-RAY STRUCTURE OF [(PH3P)2N][MO(N3S2)(DTBC)2].CH2CL2

Reaction of [Mo(N3S2)Cl3]x with sodium 3,5-di-tert-butylcatecholate gives Na[Mo(VI)(N3S2)(dtbc)2] which undergoes a metathetical reaction with [(Ph3P)2N]Cl to give the title compound.</p

New non-oxo vanadium-(IV) and -(V) complexes

Sequential addition of 1,10-phenanthroline (phen) or 2,2'-bipyridine (bipy) followed by 3,5-di-tert-butylcatechol (H2dtbc) to oxobis(pentane-2,4-dionato)vanadium(IV) yields [V(dtbc)2L] (L = phen or bipy) which can be oxidised using Ag[SbF6] to give [V(dtbc)2L][SbF6]. The new compounds have been characterised by microanalyses, IR, UV/VIS, V-51 NMR spectroscopy, magnetic susceptibility measurements and electrochemical studies. The X-ray structure of [V(dtbc)2(bipy)] is reported and compared with those of [V(dtbc)2(phen)] and [V(dtbc)2(phen)][SbF6].</p