Applications of Cd N.M.R. to Polycadmium Complexes. IV. Reactions of [Cd10(SCH2CH2OH)16]4+ With Chloride Ion, and the Crystal and Molecular Structure of Hexadeca(2-Hydroxyethanethiolato)-Tetrachloro-Decacadmium [Cd10(SCH2CH2OH)16Cl4

Abstract

Reaction of [Cd10(SCH2CH2OH)16]4+ (ClO4-)(1) with chloride ion in dimethylformamide produces Cd10(SCH2CH2OH)16Cl4 (4). Crystalline (4) [P bcn, a 14.802(3), b 24.950(5), c 20.891(4) Ǻ, 2032 observed data (Mo Kα ), R 0.047] contains molecular aggregates (symmetry exactly 2, approximately 4) in which the Cd10S16 core is similar to that of (1), but which differ in that eight instead of sixteen of the ligand hydroxy functions are coordinated in (4). Six inner Cdi atoms occur in pseudo- octahedral array, four with Cdi (SR)4(OH) coordination involving chelation of μ3-SCH2CH2OH [as in (1)], while the other two are six- coordinate Cdi (SR)4(OH)2 in an unusual stereochemistry which arises by partial transverse addition of a pair of hydroxy functions across an edge of the tetrahedral Cdi (SR)4 site of (1). The four CdO atoms of (4) each possess tetrahedral (SR)3CdOCl coordination. 113Cd n.m.r . spectra of mixtures of (1) and Cl - in dimethylformamide reveal ( i ) the progress of the change (1)→(4) and correlation of chemical shifts with the five different cadmium sites; (ii) the rapid interchanges of Cdi sites in (4) and between (4) and (1), interchanges which are slowed to <104 s-1 at <c. 230 K; (iii) modifications of the dynamics of Cdi site interchange caused by relatively small proportions of Cl -; and (iv) interconversion of CdO sites between (4) and (1).