An unusual trigonal D3 assembly composed of molybdate anions and multiply bonded dimolybdenum units

Abstract

Oxidation of the molybdate-linked pair having two quadruply bonded Mo(2)(4+) units, [Mo(2)(DAniF)(3)](2)(micro(2)-MoO(4)), (DAniF = N,N'-di-(p-anisyl)formamidinate) leads to the formation of a species consisting of three oxidized Mo(2)(5+) units connected by two micro(3)-MoO(4)(2-) dianions, {[Mo(2)(DAniF)(3)](3)(micro(3)-MoO(4))(2)}(2+). This cation displays overall D(3) point group symmetry due to a slight twisting of the three Mo(2)(5+) units about the threefold symmetry axis. This distortion removes all mirror symmetry but preserves all C(2) axes orthogonal to the unique C(3) axis. Cyclic voltammetry of {[Mo(2)(DAniF)(3)](3)(micro(3)-MoO(4))(2)}(2+) in CH(2)Cl(2) reveals three reversible one-electron redox processes, corresponding to successive reduction of each of the three Mo(2)(5+) units, with DeltaE(1/2) separations of 0.36 V and 0.41 V.

Chromium, molybdenum and tungsten

“…23 Oxidation of the molybdate-linked pair having two quadruply bonded Mo 2 4+ units, [Mo 2 (DAniF) 3 ] 2 (m 2 -MoO 4 ), is reported to have led to the formation of a species consisting of three oxidized Mo 2 5+ units connected by two m 3 -MoO 4 2À dianions, ([Mo 2 (DAniF) 3 ] 3 (m 3 -MoO 4 ) 2 ) 2+ . 24 Metal-metal quadruply bonded compounds [( t BuCO 2 ) 3 M 2 ] 2 (m-TT) (where M = Mo or W) and [( t BuCO 2 ) 3 M 2 ] 2 (m-DTT) (where M = Mo or W) were synthesised and characterised by various techniques. 25 Their photophysical properties were also studied by steady-state absorption as well as transient absorption and emission spectroscopy.…”