metal-organic compounds
In the first title salt, [Cu(C12H8N2)2(C5H10N2Se)](ClO4)2, the CuII centre occupies a distorted trigonal-bipyramidal environment defined by four N donors from two 1,10-phenanthroline (phen) ligands and by the Se donor of a 1,3-dimethylimidazolidine-2-selone ligand, with the equatorial plane defined by the Se and by two N donors from different phen ligands and the axial sites occupied by the two remaining N donors, one from each phen ligand. The Cu-N distances span the range 1.980 (10)-2.114 (11) Å and the Cu-Se distance is 2.491 (3) Å. Intermolecular - contacts between imidazolidine rings and the central rings of phen ligands generate chains of cations. In the second salt, [Cu(C10H8N2)2(C3H6N2S)](ClO4)2, the CuII centre occupies a similar distorted trigonal-bipyramidal environment comprising four N donors from two 2,2'-bipyridyl (bipy) ligands and an S donor from an imidazolidine-2-thione ligand. The equatorial plane is defined by the S donor and two N donors from different bipy ligands. The Cu-N distances span the range 1.984 (6)-2.069 (7) Å and the Cu-S distance is 2.366 (3) Å. Intermolecular - contacts between imidazolidine and pyridyl rings form chains of cations. A major difference between the two structures is due to the presence in the second complex of two N-HO hydrogen bonds linking the imidazolidine N-H hydrogen-bond donors to perchlorate O-atom acceptors.