Formation of conglomerate crystals: A closer look at helical pitches and unit cell volumes of P- and M-helical copper(II) coordination polymers

Conglomerate crystals of tubular helical coordination polymers, P- and M-[CuCl2(L)(S)]·S′ (L = dimethylbis(4-pyridyl)silane; S = Me2SO, HCONMe2; S′ = Me2SO, 1/2Et2O), have been obtained in high yields. Their helical pitches and unit cell volumes are sensitive to the molecular size of ligand, co-ligand, and solvate molecules. Both crystals evaporate solvate molecules at around 100 °C, and then calcination at 600 °C finally produces micro-sized chaotic surface materials consisting of copper(II) oxide/silicon(IV) oxide composite with evolving burned organics.