Di-μ-hydroxido-bis­{[bis­(6-methyl-2-pyridylmeth­yl)(2-phenyl­ethyl)amine-κ³N′,N′′,N′′′]copper(II)} bis(perchlorate)

The title compund, [Cu₂(OH)₂(C₂₂H₂₅N₃)₂](ClO₄)₂, is a copper(II) dimer, with two [CuL]²⁺ units [L is bis­(6-methyl-2-pyridylmethyl)­(2-phenyl­ethyl)amine] bridged by hydroxide groups to define the {[CuL](μ-OH)₂[CuL]}²⁺ cation. Charge balance is provided by perchlorate counter-anions. The cation has a crystallographic inversion centre halfway between the Cu^II ions, which are separated by 3.0161 (8) Å. The central core of the cation is an almost regular Cu₂O₂ parallelogram of sides 1.931 (2) and 1.935 (2) Å, with a Cu—O—Cu angle of 102.55 (11)°. The coordination geometry around each Cu^II centre can be best described as a square-based pyramid, with three N atoms from L ligands and two hydr­oxide O atoms completing the coordination environment. Each cationic unit is hydrogen bonded to two perchlorate anions by means of hydroxide–perchlorate O—H...O inter­actions.

4-(2-Hydroxy­phen­yl)-2-phenyl-2,3-dihydro-1H-1,5-benzodiazepine and the 2-(2,3-dimethoxy­phen­yl)-, 2-(3,4-dimethoxy­phen­yl)- and 2-(2,5-dimeth­oxy­phen­yl)-substituted derivatives

The 1,5-benzodiazepine ring system exhibits a puckered boat-like conformation for all four title compounds [4-(2-hydroxy­phen­yl)-2-phenyl-2,3-dihydro-1H-1,5-benzodiazepine, C₂₁H₁₈N₂O, (I), 2-(2,3-dimethoxy­phen­yl)-4-(2-hydroxy­phen­yl)-2,3-dihydro-1H-1,5-benzodiazepine, C₂₃H₂₂N₂O₃, (II), 2-(3,4-dimeth­oxy­phen­yl)-4-(2-hydroxy­phen­yl)-2,3-dihydro-1H-1,5-benzodiazepine, C₂₃H₂₂N₂O₃, (III), and 2-(2,5-dimethoxy­phen­yl)-4-(2-hydroxy­phen­yl)-2,3-dihydro-1H-1,5-benzo­diaze­pine, C₂₃H₂₂N₂O₃, (IV)]. The stereochemical correlation of the two C₆ aromatic groups with respect to the benzodiazepine ring system is pseudo-equatorial–equatorial for compounds (I) (the phenyl group), (II) (the 2,3-dimeth­oxy­phenyl group) and (III) (the 3,4-dimethoxy­phenyl group), while for (IV) (the 2,5-dimethoxy­phenyl group) the system is pseudo-axial–equatorial. An intra­molecular hydrogen bond between the hydroxyl OH group and a benzodiazepine N atom is present for all four compounds and defines a six-membered ring, whose geometry is constant across the series. Although the mol­ecular structures are similar, the supra­molecular packing is different; compounds (I) and (IV) form chains, while (II) forms dimeric units and (III) displays a layered structure. The packing seems to depend on at least two factors: (i) the nature of the atoms defining the hydrogen bond and (ii) the number of inter­molecular inter­actions of the types O—H...O, N—H...O, N—H...π(arene) or C—H...π(arene).