887773-97-9Relevant academic research and scientific papers
Synthesis of the sterically crowded cycloheptatrienyl complexes [M(CO)(PPh3)2(η-C7H7)] + (M = Mo or W): X-ray crystal structures of [W(CO)(PPh 3)2(η-C7H7)][BF4] and [W(CO)2(PPh3)(η-C7H7)][BF 4]
Fitzgerald, Emma C.,Grime, Richard W.,Knight, Heather C.,Helliwell, Madeleine,Raftery, James,Whiteley, Mark W.
, p. 1879 - 1886 (2006)
The first examples of complexes of the sterically crowded, bis(triphenylphosphine) auxiliary M(PPh3)2(η-C 7H7) (M = Mo or W) have been synthesised. [Mo(CO)(PPh 3)2(η-C7H7)][PF6] (1) was obtained by low-temperature reaction of [MoMe(CO)(PPh3)(η- C7H7)] with [Ph3C][PF6] in the presence of PPh3. The tungsten analogue [W(CO)(PPh3) 2(η-C7H7)][BF4] (3) was formed by reaction of [WI(CO)(PPh3)(η-C7H7)] with Ag[BF4] in acetone followed by addition of PPh3. An X-ray crystallographic structural comparison of complex 3 with its mono-phosphine counterpart, [W(CO)2(PPh3)(η-C7H 7)][BF4] ? CH2Cl2 (4) reveals that the principal structural differences between 3 and 4 resulting from replacement of a carbonyl ligand by PPh3 are: (i) an increase in the sum of the angles between the tripodal ligands and (ii) an elongation of the W-PPh3 bond length (from 2.4950(12) A? in 4 to 2.5360(6) and 2.5496(6) A? in the bis(phosphine) complex 3).
