H. A. Patel

Coordination complexes of acetylenic phosphines and diphosphines : V. Acetylene bridged derivatives of dicobalt octacarbonyl

Abstract Reactions of the phosphinoacetylenes RR′PCCR″ (R  R′  Ph, R″  H, CF 3 , Ph, Me, t-Bu; R  R′  C 6 F 5 , R″  Ph, Me; R  Ph, R′  Me, R″  Me) with Co 2 (CO) 8 have been studied. Complexes of four types have been characterised: (A)(RR′PC 2 R″)CO 2 (CO) 6 (R  R′  C 6 F 5 , R″  Ph, Me; R  R′  Ph, R″  t-Bu), (B) (RR′PC 2 R″) 2 Co 4 (CO) 10 (R  R′  Ph, R″  H, CF 3 , Ph, Me; R  R′  C 6 F 5 , R″  Me; R  Ph, R′  Me, R″  Me), (C) (RR′PC 2 R″) 2 Co 2 (CO) 6 (R  R′  Ph, R″  t-Bu), (D) (RR′P(O)C 2 R″)Co 2 (CO) 6 (R  R′  Ph, R″  t-Bu; R  R′  C 6 F 5 , R  Ph). The complexes were characterised by microanalysis, IR, NMR and where possible mass spectra. Substitution reactions of the complexes with tertiary phosphites are described. In complexes of type (A) only the alkyne function is utilised whereas the tetranuclear compounds (B) have structures in which both alkyne and phosphorus moieties are coordinated. Compounds of type (C) are simple disubstituted phosphine complexes of Co 2 (CO) 8 and those of type (D) are μ-alkyne derivatives of acetylenic phosphine oxides. The mechanism of formation of complexes of type (B) is discussed in the light of IR data.

A trans-effect in gallium complexes: the crystal structure of trichloro-(2,2′,2″-terpyridyl)gallium(III)

The molecular structure of GaCl3·terpyridyl is interpreted in terms of a trans-effect in d10 complexes which influences the M–X (X = halogen) distances and is instrumental in determining the geometry of the metal–halide complexes.