Third-order molecular optical nonlinearities of a systematically varie
d series of (cyclopentadienyl) bis(phosphine)ruthenium arylacetylide c
omplexes have been determined by Z-scan and degenerate four-wave mixin
g techniques: the influence on the nonlinear response of replacing the
acetylide by a chloro ligand, varying the phosphine, extending the ac
etylide chain length, or modifying the substituent at the 4-position o
f the arylacetylide has been studied.