Synthesis, crystal structure, supramolecular associations and third-order non-linear optical (NLO) properties of some organotellurium (IV) derivatives

Abstract

Reactions of acyclic and cyclic organotellurium (IV) compounds [R2TeI2 {R2=(C2H5)2, (n-C3H7)2, C5H10}] with the silver salt of carboxylic acids and sodium diethyldithiocarbamate form the organotellurium (IV) complexes (C2H5)2Te(4-NO2C6H4OCO)2 (1), (C2H5)2Te(C6H5CHCHOCO)2 (2), (n-C3H7)2Te(C6H5OCO)2 (3), (n-C3H7)2Te(4-NO2C6H4OCO)2 (4), (n-C3H7)2Te(3,5-NO2C6H3OCO)2 (5), (n-C3H7)2Te(4-OCH3C6H4OCO)2 (6), (n-C3H7)2Te(C6H5CHCHOCO)2 (7), C5H10Te(C6H5CHCHOCO)2 (8) and C5H10TeCl[SCSN-(C2H5)2] (9). The X-ray structures of some of these organotellurium (IV) derivatives indicate that they possess ψTBP geometry and dimeric and tetrameric supramolecular associations are achieved through cooperative participation of inter- and/or intramolecular Te···O secondary bonds and/or C–H···O hydrogen bonds. The intramolecular Te···O secondary bond lengths seem to be dependent on the cis- and trans-position placements of free oxygens of the carboxylate groups. It is found that the third-order non-linear optical susceptibilities (χ(3)) of these complexes are in the range 7.21–8.20×10−14esu and the second order hyperpolarizabilities (γ) are in the range 4.89–5.56×10−32esu. The presence of the telluracyclopentane (C5H10Te) cyclic organic group and cinnamate (C6H5CHCHOCO)/diethyldithiocarbamate (SCSN(C2H5)2) ligands having conjugation in the organotellurium (IV) derivatives (8 and 9), appears to be responsible for the higher χ(3) and γ values.