Syntheses, characterisations and X-ray crystal structures of 5,5′-bis(diphenylphosphino)2,2′-bithiophene derivatives, Ph2(X)P(C4H2S)2P(X)Ph2(X = O, S and CH3+ · I−)

Abstract

Phosphine-substituted oligothiophenes are interesting third-order nonlinear materials. Both their linear and nonlinear optical properties can be altered by varying the group attached to the nonbonding pair of electrons on the phosphorus atoms, the nu