Dinuclear molybdenum thiolato-bridged compounds: syntheses, reactivities and electrochemical studies of site–substrate interactions

Dithiolene transfer from nickel to a dimolybdenum centre: the first dithiolene alkyne complex

“…The sulfur atoms are again asymmetrically disposed, with S(1) closer to Mo(2) and S(2) to Mo(1), but of the bridging carbon atoms, C (14) is almost symmetrically bridging. The atoms S(1), S(2), C (12) and C(14) adopt the familiar orthogonal paddle-wheel arrangement observed in [Mo 2 (l-S) 2 (l-SMe) 2 Cp 2 ] [12] and other related compounds [13]. The metallacyclic unit present in 3 has been observed previously in di-iron complexes [14]; indeed one such complex was prepared by Schrauzer through the reaction of the methylated nickel dithiolene complex [Ni(MeSCPh@CPhSMe)(SCPh@CPhS)] with iron pentacarbonyl [15].…”

“…In accord with their 13 C NMR shifts, the two dithiolene ligands are each bonded such that one sulfur atom bridges the two molybdenums whereas the other is bonded only to one metal; this coordination mode is well known in Mo chemistry [11]. Each CpMo unit therefore achieves a four-legged pianostool environment consisting of three dithiolene sulfurs and the alkyne.…”

“…Mass spectrometry and analytical data were in agreement with this assessment. The 13 C NMR spectrum provided the additional information that two peaks are observed for the dithiolene carbons at d 163.3 and 116.0.…”

“…1 H and 13 C NMR spectra were obtained in CDCl 3 solution on a Bruker AC250 machine with automated sample-changer or an AMX400 spectrometer. Chemical shifts are given on the d scale relative to SiMe 4 ¼ 0.0 ppm.…”

Mixed μ-phosphido or μ-thiolato μ-halo-dimolybdenum(III) compounds [Mo2Cp2(μ-SMe)2(μ-X)(μ-Y)] (X=PPh2, Y=Cl; X=SCH3, Y=Br, I): Electrochemical and structural comparisons – The X-ray structure of [{Mo2Cp2Br(μ-O)(μ-SMe)2}2(μ-MoO4)]

“…If the potential of dinuclear organometallic systems as catalysts for molecular activation is ever to be fully developed, it is essential to understand and predict how different ligands control the activity of these systems [1]. For example, choosing a ligand with different electronic or steric properties may induce discrimination between substrates and alter the activity and selectivity of substrate-binding sites.…”