Heterocyclic compounds containing antimony 1. Synthesis, physicochemical properties, crystal and molecular structure of 2-(β-hydroxyethylthio) 1,3,2-oxathiastibolane

Abstract

The compound (HOCH 2CH 2S) Sb(SCH 2CH 2O ) ( 1) has been prepared by the reaction of antimony(III) isopropoxide and 2-mercaptoethanol in a 1:2 molar ratio. Reaction of 1 with MOCH 3 (where M  Li, Na and K) yields bimetallic products of the type, M[(OCH 2CH 2S) Sb(SCH 2CH 2O )]. All these derivatives have been characterized by elemental analysis, IR, NMR ( 1H and 13C) spectra and molar conductivity measurements. Crystals of 1 are triclinic, space group P 1 , with a = 6.449(2), b = 10.285(2), c = 13.494(1) Å, α = 78.08(1), β = 75.99(1), γ = 71.54(2)°, V = 815.48 Å 3, Z = 4, D calc = 2.239 g cm −3, (Mo Kα) λ = 0.7107 Å, μ = 3.55 mm −1, F(000) = 528, T = 295 K, final R = 0.0189 for 2344 reflections. One of the two mercaptoethanol moieties in 1 forms a five-membered chelate ring with antimony, Sb(1)O(11) = 2.023(2) Å and Sb(1)S(11) = 2.434(1) Å, while the other is bonded through the S atom only, Sb(1)S(12) = 2.434(1) Å. The angles between these primary bonds with a mean value of 90.2° suggest a basically pyramidal, or pseudo tetrahedral structure if the stereochemically active lone pair is included in the coordination sphere. Two molecules are linked by intermolecular hydrogen bridges. The presence of weak intermolecular secondary bonding, Sb(1)O(12) = 2.567(3) Å, in the complex indicates that the overall coordination polyhedron is best described in terms of a distorted trigonal bipyramidal arrangement.