SYNTHESIS, STRUCTURES AND SUPRAMOLECULAR ASSOCIATIONS OF SOME Μ-OXO-BIS [DIALKYLTELLUROXANES (IV), DIALKYLHALIDO TELLUROXANES (IV)]

Abstract

The reactions of dialkyltellurium (IV) diiodide [R₂TeI₂ (R = C₂H₅, n-C₃H₇)] with Conc. HNO₃ afford diorganotelluroxanes viz. µ-oxo-bis[nitrato diethyl tellurium (IV)]  [(C₂H₅)₂Te(NO₃)]₂O (1), µ-oxo-bis[nitrato-n-propyl tellurium (IV)]  [n-(C₃H₇)₂Te(NO₃)]₂O (2) indicating high stability of Te-C (alkyl) in acidic medium. The diorganohalido telluroxane viz. µ-Oxo-bis[iodo-diethyl tellurium (IV)] [(C₂H₅)₂TeI]₂O (3) was synthesized by the reaction of (C₂H₅)₂TeI₂ with Na₂S₂O₅ in deionised water while µ-oxo-bis[chloro-diethyl tellurium (IV)] [(C₂H₅)₂TeCl]₂O (4) and µ-oxo-bis[bromo-diethyl tellurium (IV)] [(C₂H₅)₂TeBr]₂O (5) has been prepared by the reactions of [(C₂H₅)₂TeI]₂O (3) with HgCl₂ and Br₂ in dichloromethane respectively. The X-ray crystal structures of 1, 2, 3 & 5 reveal the immediate co-ordination geometry about the central tellurium atom to be pseudotrigonal bipyramidal (ψ TBP) with one stereochemically active electron lone pair. The supramolecular associations of these diorganotelluroxanes (IV) and diorgano halido telluroxanes (IV) are generated through Te---X (X = O, Br, I) secondary bonds.