Enantiomorphic Helical Coordination Polymers of {[M(pyrimidine)(OH<sub>2</sub>)<sub>4</sub>][SiF<sub>6</sub>]·H<sub>2</sub>O}<sub>∞</sub> (M = Co<sup>2+</sup>, Cu<sup>2+</sup>, Zn<sup>2+</sup>)

2007-10-03T00:00:00Z (GMT) by David, B. Cordes Robin D. Rogers
Helical coordination complexes, {[M(pyrimidine)(OH<sub>2</sub>)<sub>4</sub>][SiF<sub>6</sub>]·H<sub>2</sub>O}<sub>∞</sub>; (M = Co, <b>1</b>; Cu, <b>2</b>; Zn, <b>3</b>), were inadvertently but reproducibly isolated when corresponding metal tetrafluoroborates were reacted with pyrimidine in glass vials in 1:1 molar ratios. The crystal structures of complexes <b>1</b>−<b>3</b> revealed spontaneously resolved helical coordination polymers in enantiomorphic space groups <i>P</i>4<sub>3</sub>2<sub>1</sub>2 (<b>1</b>) and <i>P</i>4<sub>1</sub>2<sub>1</sub>2 (<b>2</b> and <b>3</b>) despite the high molecular symmetry associated with the constituent building blocks. The individual helical polymer chains were linked together by hydrogen bonding involving the H<sub>2</sub>O solvent and SiF<sub>6</sub><sup>2-</sup> anions to form a topologically complex three-dimensional network.