Self-assembled trinuclear arsenic and antimony macrobicycles. Issue 4 (18th February 2015) - Collins, Mary S.
Abstract : Six new macrobicyclic Pn3 L2 Cl3 complexes (Pn = As, Sb) were synthesized by self-assembly of a three-fold symmetric trithiol and PnCl3 . Abstract : The synthesis of six trinuclear Pn3 L2 macrobicycles (Pn = As, Sb) was achieved by self-assembly of a pnictogen trichloride and a 2, 4, 6-trisubstituted-1, 3, 5-benzenetrimethanethiol ligand. 1 H-NMR spectroscopy reveals self-assembly in 1, 1, 2, 2-tetrachloroethane is dynamic in solution producing two structural isomers. The symmetric and the asymmetric isomers (in which a single chloride ligand is cast in an opposing direction from other chlorides) of the As3 L2 complexes exist in a ca. 2 : 1 distribution, whereas only the symmetric isomer is observed in solution for Sb3 L2 . Solvent effects appear to influence conformational isomerism and conversion to the final products. Macrobicycles were confirmed by 1 H-NMR spectroscopy and X-ray crystallography and further studied by MP2/LANL2DZ optimizations.