Crystal data for cupric penicillamine disulphide hydrates

Crystals of Cu(II)-penicillamine disulphide pentahydrate, Cu(C₁₀H₁₈N₂S₂O₄).3H₂O, D_m =1.542±0.005 g cm⁻³, have been grown from aqueous solution. Their morphology and diffraction aspect indicate space group A2, with a = 15.51, b = 19.94, c = 12.24 Å, all ±0.3%, β =92°18′±10′, Z = 8. A single crystal dehydrates rapidly to a pseudomorphous monotactic aggregate of trihydrate crystals, D_x = 1.61± 0.01 g cm⁻³, which all retain the original c (measured 12.32 Å); their a and b can either be equal to 14.88 and 18.62 Å, both ±0.7%, with space group P222₁ and Z = 8, or be doubled, with lattice C and an undetermined space group.