Crystal structures of trans-di­aqua­(3-R-1,3,5,8,12-penta­aza­cyclo­tetra­deca­ne)copper(II) isophthalate hydrates (R = benzyl or pyridin-3-ylmethyl)

The asymmetric units of the title compounds, trans-diaqua(3-benzyl-1,3,5,8,12- pentaazacyclotetradecane-4 N1 ,N5 ,N8 ,N12)copper(II) isophthalate monohydrate, [Cu(C16H29N5)(H2O)2](C8H4O4)H2O, (I), and trans-diaqua[3-(pyridin3-ylmethyl)-1,3,5,8,12-pentaazacyclotetradecane-4 N1 ,N5 ,N8 ,N12]copper(II) isophthalate 0.9-hydrate, [Cu(C15H28N6)(H2O)2](C8H4O4)0.9H2O, (II) consist of one diaqua macrocyclic cation, one dicarboxylate anion and uncoordinated water molecule(s). In each compound, the metal ion is coordinated by the four secondary N atoms of the macrocyclic ligand and the mutually trans O atoms of the water molecules in a tetragonally distorted octahedral geometry. The average equatorial Cu—N bond lengths are significantly shorter than the average axial Cu—O bond lengths [2.020 (9) versus 2.495 (12) A˚ and 2.015 (4) versus 2.507 (7) A˚ for (I) and (II), respectively]. The coordinated macrocyclic ligand in the cations of both compounds adopts the most energetically favorable trans-III conformation. In the crystals, the complex cations and counter-anions are connected via hydrogen-bonding interactions between the N—H groups of the macrocycles and the O—H groups of coordinated water molecules as the proton donors and the O atoms of the carboxylate as the proton acceptors. Additionally, as a result of O—HO hydrogen bonding with the coordinated and water molecules of crystallization, the isophthalate dianions form layers lying parallel to the (101) and (100) planes in (I) and (II), respectively.