H. Ishino et al., Synthesis, structure, and reactivities of the five-coordinate molybdenum(0) mono(acetylene) complex [Mo(HC=CH)(dppe)(2)], ORGANOMETAL, 20(1), 2001, pp. 13-15
The reaction of trans-[Mo(N-2)(2)(dppe)(2)] (1; dppe = Ph2PCH2CH2PPh2) with
excess amounts of HC drop CLi(.)en (en = H2NCH2CH2NH2) afforded the five-c
oordinate Mo(0) mono(acetylene) complex [Mo(HC drop CH)(dppe)(2)] (2). Trea
tment of 2 with 2 mol of [Cp2Fe][BF4] (Cp = eta (5)-C5H5) in THF gave the M
o(II) acetylene complex trans-[MoF(HC drop CH)(dppe)(2)][BF4] while that in
THF-MeCN followed by anion metathesis with NaOTf (OTf = OSO2CF3) led to th
e formation of the metallacyclopropene complex [Mo(eta (3)-CHCHPPh2CH2CH2PP
h2-C,C',P)(MeCN)(2)(dppe)][OTf](2).