Molecular and supramolecular structures of diethyltellurium diiodide and diethyltellurium bis(carboxylates)

Abstract

Diethyl tellurium bis(carboxylates) (C₂H₅)₂TeR¢₂ (R′ = C₆H₅OCO, 4-NO₂C₆H₄OCO, 3,5-(NO₂)₂C₆H₃OCO, C₆H₅CH=CHOCO, 4-OCH₃C₆H₄OCO) have been synthesised from the metathetical reactions of diethyl tellurium diiodide (C₂H₅)₂TeI₂ and corresponding silver salts and characterized by IR, ¹H, ¹³C and ¹²⁵Te NMR spectroscopy. The structures of (C₂H₅)₂TeI₂, (C₂H₅)₂Te(C₆H₅OCO)₂, (C₂H₅)₂Te(4-NO₂C₆H₄OCO)₂, (C₂H₅)₂Te{3,5-(NO₂)₂C₆H₃OCO}₂, (C₂H₅)₂Te(C₆H₅-CH=CHOCO)₂ and (C₂H₅)₂Te(4-OCH₃C₆H₄OCO)₂ have been established by single crystal X-ray diffraction studies. The structures of these complexes (the immediate environment about tellurium is that of distorted trigonal bipyramidal geometry with a stereochemically active electron lone pair) are described in the context of their ability to generate intermolecular Te---I and Te---O secondary bonds and C(<i style="">sp²</i>)-H---O and C(<i style="">sp³</i>)-H---O hydrogen bonds leading to the formation of zig-zag ribbons, stairs, dimeric, trimeric, tetrameric and extended supramolecular assemblies. The modification of supramolecular assembly present in the precursor (C₂H₅)₂TeI₂ by replacing the iodines with carboxylate groups is demonstrated and the cooperative participation of intermolecular C(<i style="">sp²</i>)-H---O and C(<i style="">sp³</i>)-H---O hydrogen bonds in strengthening the supramolecular assemblies is discussed.