ORGANOMETALLIC COMPLEXES FOR NONLINEAR OPTICS .7. CUBIC OPTICAL NONLINEARITIES OF OCTAHEDRAL TRANS-BIS(BIS(DIPHENYLPHOSPHINO)METHANE)RUTHENIUM ACETYLIDE COMPLEXES - X-RAY CRYSTAL-STRUCTURE OF TRANS-[RU(C-CPH)(4-C-CC6H4NO2)(DPPM)(2)]

Cubic molecular optical non-linearities of a systematically varied ser ies of octahedral bis(bis(diphenylphosphino)methane)ruthenium sigma-ac etylide complexes have been determined by the Z-scan technique: the in fluence on the non-linear response of sequential replacement of chloro by acetylide ligand in trans-[RuCl2(dppm)(2)] and acetylide chain len gth in proceeding from 4-nitrophenyl- to 4-nitrobiphenyl- and 4-nitro- (E)-stilbenylacetylide has been studied. The first X-ray structural st udy of an unsymmetrical bis(acetylide) complex of this type, trans-[Ru (C=CPh)(4-C=CC6H4NO2)(dppm)(2)], is reported and confirms the trans-di sposed stereochemistry of the alkynyl ligands.