Crystal structures of two enantiomorphous 2-ethylpiperazinediium hexaaquacopper sulfates [(R or S)-C5H14N2][Cu(H2O)6](SO4)2

Two new non-centrosymmetric copper sulfates are synthesized under slow evaporation conditions through the use of enantiomorphically pure sources of either (R)-2-methylpiperazine or (S)-2-methylpiperazine. Both crystallize in the non-centrosymmetric P 2 1 space group, crystal data for [(R)-C 5 H 14 N 2 ][Cu(H 2 O) 6 ](SO 4 ) 2 ( I ), a = 6.5276(2) Å, b = 11.1955(3) Å, c = 12.4559(4) Å, β = 101.196(2)°, Z = 2, V = 892.95(5) Å 3 and [(S)-C 5 H 14 N 2 ][Cu(H 2 O) 6 ](SO 4 ) 2 ( II ), a = 6.5188(2) Å, b = 11.1786(2) Å, c = 12.4365(3) Å, β = 101.205(1)°, Z = 2, V = 888.99(4) Å 3 . The three-dimensional structure networks for these compounds consist of isolated [Cu(H 2 O) 6 ] 2+ and [(R)-C 5 H 14 N 2 ] 2+ or [(S)-C 5 H 14 N 2 ] 2+ cations and SO 4 2− anions linked only by hydrogen bonds. The Cu atom is in a slightly distorted octahedral coordination environment. The crystal packings are influenced by cation-to-anion N-H…O and OW-H…O hydrogen bonds leading to an open framework structures.