SbCI3, BiCl3 and Na+ Complexes of Maleonitrile-Dithiacrown Ethers: Synthesis, Crystal Structures and DEP-MS Experiments

Abstract

The reactions of MlC3 (M = Sb, Bi) with maleonitrile-dithia-15-crown-5 (mn-15S2O3) and maleonitrile-dithia-18-crown-6 (mn-18S2O4) in MeCN yielded the complexes [MCl3(mn-15S2O3)] {M = S b (l), Bi(2)} and [MCl3(mn-18S2O4)] {M = Sb(3), Bi(4)}, respectively. The pyramidal MCl3 units are coordinated very weakly to the three oxygen and two sulphur donor atoms of mn-15S2O3 in 1 and 2, and to the four oxygen donor atoms of mn- 18S2O4 in 3 and 4. Both mn-15S2O3 complexes, 1 and 2, crystallize isotypically in the m onoclinic space group P2(1)/n with four formula units per unit cell, while the isotypic mn-18S2O4 complexes, 3 and 4, are triclinic, space group P-1, with two formula units per unit cell. In the SbCl3 complexes, 1 and 3, the mean contact distances between the Sb centres and the macrocyclic donor atoms are longer than the corresponding distances in their isostructural BiCl3 analogues, 2 and 4, which may reflect a stereochemical activity of the Sb111 lone pair. Under the conditions of DEP-M S experiments with 1 and 3 the monocationic SbCl2 + complexes [SbCl2(L)]+ (L = mn-15S2O3, mn-18S2O4) were detected. NaSbCl6 and mn-18S2O4 in MeCN furnished the 2:1 complex [Na(mn-18S2O4)2]SbCl6 {(5)SbCl6). In the complex cation 5 the sodium atom is coordinated sandwich-like through the eight oxygen atoms of two mn-18S2O4 molecules. Compound (5)SbCl6 crystallize in the triclinic space group P -1 with two formula units per unit cell