71986-97-5Relevant academic research and scientific papers
Halogen-Metal Exchange in Coordinated Halophosphanes: Synthesis of Phosphinidene Complexes
Lang, Heinrich,Mohr, Gerhard,Scheidsteger, Olaf,Huttner, Gottfried
, p. 574 - 596 (2007/10/02)
Coordination compounds of halophosphanes such as (R)(Hal)2P-MLn (MLn = Cr(CO)5, 1; MnCp(CO)2, 2; Fe(CO)4, 4) or (R)2(Hal)P-MLn (MLn = MnCp(CO)2, 3) react with R'Li species in various different ways; Reaction of 2 with R'Li (R' = CH3, n-C4H9) yields the substitution products 5, (R)(R')2P-MnCp(CO)2. 3 reacts with t-C4H9Li/TMEDA to give -Li+, 6, by lithium-halide exchange.The salts 6 are characterized by their reactions with various electrophiles leading to compounds 7, (R)2(R')P-MnCp(CO)2 with R' = H, D, Alkyl, (CH3)3Si, (CH3)3Sn.The salts 6 are also obtained by deprotonation of 7a (R' = H) with n-C4H9Li. - Compounds (Aryl)(Hal)2P-MnCp(CO)2, 2j-m, react with t-C4H9Li/TMEDA to produce deeply coloured phosphinidene complexes R-P2, 10, in yields up to 80percent.Analogously, (Ph)(Cl)2As-MnCp(CO)2 gives the arsinidene compound Ph-As2 (11) in 90percent yield.Whereas 11 had already been known, the compounds 10 are rare examples of phosphinidene complexes containing an R-P ligand bridging the two 16-electron fragments MnCp(CO)2.The phosphanediyl ligand is stabilized by metal-d?-phosphorous-p? interactions with the phosphorous atom in a trigonally planar environment.The unconventional bonding situation in 10 is evident from the electron spectra as well as from the 31P NMR shifts, which range up to 896 ppm.
