Tris(propionitrile-κN)[1,4,7-tris(cyanomethyl)-1,4,7-triazacyclononane-κ3 N 1,N 4,N 7]copper(II) bis(perchlorate) dihydrate

In the title compound, [Cu(C3H5N)3(C12H18N6)](ClO4)2·2H2O, the CuII atom lies on a threefold rotation axis and is coordinated in a distorted N6 octahedral environment by three tertiary amines from the tridentate chelating azamacrocyclic ligand and three propionitrile molecules. Intermolecular non-classical C—H⋯N hydrogen bonding interlinks the [Cu(C3H5N)3(C12H18N6)]2+ cations into a two-dimensional supramolecular sheet extending along the ab plane. The crystal packing also exhibits weak C—H⋯O interactions.

In the title compound, [Cu(C 3 H 5 N) 3 (C 12 H 18 N 6 )](ClO 4 ) 2 Á-2H 2 O, the Cu II atom lies on a threefold rotation axis and is coordinated in a distorted N 6 octahedral environment by three tertiary amines from the tridentate chelating azamacrocyclic ligand and three propionitrile molecules. Intermolecular nonclassical C-HÁ Á ÁN hydrogen bonding interlinks the [Cu(C 3 H 5 N) 3 (C 12 H 18 N 6 )] 2+ cations into a two-dimensional supramolecular sheet extending along the ab plane. The crystal packing also exhibits weak C-HÁ Á ÁO interactions.

Comment
The coordination chemistry of the azamacrocycles with nitrile pendant arms has been studied extensively. Usually, these azamacrocycle derivatives only chelate the metal through tertiary amines and the pendant nitrile groups do not involve in the coordination (Aneetha et al., 1999;Freeman et al., 1984;Kang et al., 2002a;Kong et al., 2000;Tei et al., 2003).
However, the reactivity of the nitrile group in these complexes towards nucleophilic reagents, such as water, alcohols and amines, provides a convenient route to the synthesis of a variety of N-functionalized azamacrocycles (Freeman et al., 1984;Kang et al., 2002bKang et al., , 2005Kang et al., , 2008Siegfried et al., 2005;Tei et al., 2003;Zhang et al., 2006). In order to obtain further knowledge about the reactivity of the nitrile groups attached to the triazamacrocycle, a title compound of Cu II with 1,4,7-tris(cyanomethyl)-1,4,7-triazacyclononane has been prepared and structurally characterized.
As shown in Fig. 1, the distorted octahedral Cu II center in the title compound is located on a threefold rotation axis and is ligated by three N donors of the tridentate azamacrocycle backbone and other three from coordinated propionitrile molecules.
The Cu-N(macrocycle) length (2.089 (3)Å) is slightly longer than that of the Cu-N(propionitrile) (2.030 (3)Å), while the bond angles subtended by cis-pairs of donor atoms at Cu II range from 84.13 (13)° to 96.12 (11)°. In the ab-plane, each [Cu(C 12 H 18 N 6 )(C 3 H 5 N) 3 ] 2+ cation are linked with six neighbouring cations by means of C-H···N hydrogen bonding (Table 1) to form an extended two-dimensional supramolecular network, as depicted in Fig. 2. Perchlorate counter-anions are embedded in the two-dimensional supramolecular cationic layer via weak interactions.
To the propionitrile solution (20 ml) of the triazamacrocyclic ligand (49 mg

Refinement
All H atoms were placed in calculated positions and refined as riding atoms, with C-H = 0.96-0.97Å and O-H = 0.85Å, and with U iso (H) = 1.2U eq (C and O) or 1.5U eq (methyl C). OW2 lies on a threefold rotation axis, so its hydrogen supplementary materials sup-2 atoms are disordered with site occupancy factor of 0.33. OW1 and OW3 are disordered on special positions with threefold roto-inversion symmetry and each of them has 0.17 occupancy in the asymmetric unit. Fig. 1. An ORTEP plot for the title compound with the atom labelling scheme. Displacement ellipsoids are drawn at 30% probability level. H atoms of the macrocyclic ligand are omitted for clarity. The disorder in the solvent water molecules are not shown. Symmetry codes: