Structural Studies on Complexes Containing the Peroxodisulfate Anion. I The Crystal and Molecular Structure of Cd(pds)(phen)2(H2O)·H2O and Cd(pds)(dmph)2 [pds = Peroxodisulfate (S2O8 2–); phen = 1,10-Phenanthroline; dmph = 2,9-Dimethyl-1,10-phenanthroline]

Abstract

The crystal structures of two unreported Cd^II complexes with different dinitrogenated bases and the unusual peroxodisulfate anion (pds, S₂O₈ ^2–) are presented: Cd(pds)(phen)₂(H₂O)·H₂O and Cd(pds)(dmph)₂ (phen = 1,10- phenanthroline; dmph = 2,9-dimethyl-1,10-phenanthroline). Both compounds are monomeric. In the first, the anion acts as a monodentate ligand, as in all previously reported structures where it binds to a cation, while in the second it displays novel chelate behaviour. Both structures are stabilized by hydrogen-bonding networks, with mediumstrength interactions mediated by aqua and hydration water molecules in the first case and much weaker ones provided by C–H…O contacts in the second. Compound (1) is triclinic, P1^–, a 8.745(3), b 9.260(5), c 17.564(3) Å, α 96.80(2), β 101.581(3), γ 105.97(3)˚, V 1316.6(9) ų, Z 2, R 0.044, N_o 4384. Compound (2) is monoclinic, Cc, a 22.233(12), b 9.566(5), c16.017(8) Å, β 123.78(3)˚, V2831(3) ų, Z 4, R 0.024, N_o 2363.