Trivalent phosphorus derivatives of group via - Arabi, M.S.; Mathieu, R.; Poilblanc, R. (Elsevier)
The action of trifluoroacetic acid on the series M(CO)"6"-"n(PA"3)"n (M = Mo, W; A = CH"3, OCH"3; n = 2, 3, 4) has shown that protonation occurs if n 〉= 3. For n = 3 the basicity of the ligand PA"3 plays a more important role in the stability of [HM(CO)"3(PA"3)"3]^+complexes than for n = 4. Infrared and proton NMR give evidence of the stereochemical non-rigidity of the [HM(CO)"6"-"n(PA"3)"n]^+ heptacoordinated cation.
http://linkinghub.elsevier.com/retrieve/pii/S0022-328X(00)91378-0
Keywords: V