Molecular structure, supramolecular association and anion sensing by chlorodiorganotin(IV) methylferrocenyldithiocarbamates

Three new chlorodiorganotin(IV) methylferrocenyl dithiocarbamate complexes viz. [(FcCH₂)(CH₂CH₂OH)NCS₂SnMe₂(Cl)] (1), [(FcCH₂)(CH₂CH₂OH)NCS₂SnⁿBu₂(Cl)] (2) and [(FcCH₂)(CH₂CH₂OH)NCS₂SnPh₂(Cl)] (3) have been synthesized and characterized by elemental analysis, IR, UV-Vis, ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopy and X-ray crystallography. The crystal structure of 1 indicates that the coordination geometries around the tin(IV) center is intermediate between ideal trigonal-bipyramidal and square pyramidal coordination polyhedra bonded through two sulfur atoms of the dithiocarbamate ligand in an isobidentate mode, two CH₃ groups and one chlorine atom. Since, in 2 and 3 only alkyl and aryl fragments have been changed we infer that both 2 and 3 would also have the same behaviors in the solution state as observed in 1. Ionic interactions abilities of 1–3 are examined in acetonitrile through UV-vis absorption spectroscopy which offers reasonably good selectivity and sensitivity towards the detection of the acetate ion. Compounds 1–3 exhibit a bathochromic shift with the acetate ion with a moderate association constant.