Third-order NLO properties of metal complexes containing delocalized oxygen or sulphur donor ligands and mixed oxygen and sulphur donor ligands

摘要

The third-order nonlinear susceptibility, $chi$+(3)$/, for a series of complexes of 3,5- ditertbutyl-o-benzoquinone (dbsq), $LB@M(dbsq)$-2$/ where M $EQ Pd or Pt$RB@, o- mercaptophenol (mp), $LFBC$LB@TBA$RB$LB@Ni(mp)$-2$/$RB$RTBC@, or 1,3-dithiol- 2-thione-4,5-dithiol (dmit), $LFBC$LB@TBA$RB$LB@M(dmit)$-2$/$RB where M $EQ Ni or Pd$RTBC@, have been measured in CH$-2$/Cl$-2$/ solution by retroreflection DFWM technique at 1064 nm. The results indicate large $chi$+(3)$/ values of the order of 10$+$MIN@11$/ esu at concentration levels of 10$+18$/ molecules/cm$+3$/. These values are up to two orders higher than those found for other sulphur donor dithiolenes and nitrogen donor ligand systems, although the linear absorption is also higher.