Organometallic Complexes For Nonlinear Optics. 17. Synthesis, Third-order Optical Nonlinearities And Two-photon Absorption Cross Section Of An Alkynylruthenium Dendrimer

Abstract

A soluble, oxidatively and thermally very stable alkynylruthenium dendrimer 1,3,5-C6H3(4-CCC6H4CC-trans-[Ru(dppe)2]CC-3,5-C6H3-{4-CCC6H4CC-trans-[Ru(CCPh)(dppe)2]}2)3, containing a large two-dimensional -delocalized system, has been prepared using an experimentally straightforward convergent synthetic approach. The first third-order nonlinear optical (NLO) measurements of an organometallic dendrimer have been obtained using the Z-scan technique at a wavelength of 800 nm. Progression from 1,3,5-C6H3(4-CCC6H4CC-trans-[Ru(dppe)2]CCPh)3 to the dendrimer results in (i) no loss of optical transparency, (ii) an increase in the second hyperpolarizability, , which is proportionately greater than either the increase in the number of phenylethynyl groups or the extinction coefficient for the important MLCT band, and (iii) a dramatic enhancement of two-photon absorption.