Synthesis and Cleavage Reactions of Metal−Metal-Bonded [Mo<sub>2</sub>(S<sub>2</sub>CNR<sub>2</sub>)<sub>6</sub>](OTf)<sub>2</sub>, a Source of the Tris(dithiocarbamato)molybdenum(IV) Fragment
收藏资源简介：
Halide abstraction from the chlorotris(dialkyldithiocarbamato)molybdenum(IV) complexes MoCl(S2CNR2)3 (R = Et, Me) with silver triflate produces the diamagnetic dimeric complexes [Mo2(S2CNR2)6](OTf)2 in good yield. The crystallographically determined structure of the diethyldithiocarbamato complex indicates that the dimer consists of two pentagonal bipyramids sharing an axial edge, with a Mo−Mo separation (2.8462(8) Å) indicative of a metal−metal bond. A qualitative analysis of the bonding indicates that this bond is of order 2 and consists of one normal σ bond and one relatively weak “skewed π” interaction. The dimers [Mo2(S2CNR2)6](OTf)2 react with a variety of reagents to give monomeric seven-coordinate complexes, including the new cationic molybdenum(IV) complex [Mo(PMe2Ph)(S2CNEt2)3](OTf), which has been structurally characterized. Kinetic studies of the reaction of [Mo2(S2CNEt2)6](OTf)2 with halides indicate the presence of competing dissociative and associative substitution pathways, although neutral donors may react by different mechanisms.
