Syntheses, Characterization, and X-Ray Crystal Structure of a Co-Crystal Containing One Neutral Mononuclear Copper (II) Unit and One Cationic Dinuclear Copper (II) Unit Assembled with Schiff Base and Perchlorate Copper(II) Salt

The use of 2-{[2-(2-hydroxybenzylideneamino)phenylimino]methyl}phenol (H2L) in metal transition chemistry has yielded a co-crystal which is composed by one neutral mononuclear, one cationic dinuclear and one perchlorate anion. During the formation of the complex, one of the salicylaldimine groups of one of the molecules of the H2L ligand hydrolyzed to form an asymmetrical ligand with an amino group leading to the molecule (2-((2-aminophenylimino)methyl)phenol (HL'). The complex was formulated as {[Cu(L)].[Cu2(L)(L')]}.(ClO4). The structure of the complex was solved by single crystal X-ray crystallography. In the mononuclear unit, the Cu2+ atom is coordinated by one dideprotonated molecule of the ligand acting in tetradentate fashion. In the dinuclear unit, one the Cu2+ atom is coordinated by one dideprotonated molecule of the ligand acting in tetradentate fashion and the other Cu2+ is coordinated by the monodeprotonated (2-((2-aminophenylimino)methyl)phenol (HL') acting in tridentate fashion. The two Cu2+ are bridged by the two phenoxo oxygen atoms of the dideprotonated molecule of the ligand. The complex crystallizes in the triclinic space group Pī with the following parameters: a = 13.8864 (3) Å, b = 14.2078 (4) Å, c = 14.5007 (4)) Å, α = 64.593 (3), β = 71.353 (2), γ = 71.707 (2)°, V = 2395.80 (13) Å3, Z = 2, R1 = 0.037, wR2 = 0.041. The supramolecular structures are consolidated by multiple hydrogen bonds.