Synthesis and X-ray crystal structures of dinuclear hydrogen-bonded cadmium and lead 2-aminoethanethiolates

Under varying conditions the reaction of cysteamine hydrochloride (SHCH2CH2NH3)Cl with stoichiometric amounts of Cd and Pb salts in water gave [Cd2.5Cl5(SCH2CH2NH3)] (1), [Cd(SCH2CH2NH2)(2)] (2), [Pb2Cl(SCH2CH2NH2)(3)] (3) and [Pb-2(SCH2CH2NH2)(3)](NO3)(0.67)(Cl)(0.33) (4). Compound I is a molecular solid, one that contains a solid state-like core, but is nevertheless soluble in common organic solvents. The geometry around the Cd atoms in I are octahedral with varying numbers of sulfur and chlorine atoms. In contrast the pentacoordinate Cd atoms in 2 possess distorted square pyramidal geometry comprised of cysteamine sulfur and nitrogen atoms. Compounds 3 and 4 are structurally similar despite the presence and involvement of the anion in 4. The Pb atoms in 3 possess both distorted square pyramidal and octahedral geometry, while in 4 the geometry around the Pb atoms is distorted square pyramidal. The NO3 and Cl anions in 4 participate in more extensive hydrogen bonding by comparison to 3, which has a Cl anion only. The hydrogen bonding in these compounds is not confined to the presence or absence of anions, as it is also observed between the amine of cysteamine with adjacent sulfur and nitrogen atoms. Full characterization of the compounds was achieved using IR, H-1 NMR, C-13 NMR, EA, Mass Spectrometry and X-ray crystallography. (C) 2005 Elsevier Ltd. All rights reserved.