Crystal structure of bis(2,2′-bipyridine)formatocopper(II)tetrachlorate, [Cu(C10H8N2)2(CHO2)][ClO4

Abstract

C21H17ClCuN4O6, monoclinic, P121/c1 (no. 14), a = 7.248(9) A, b = 10.61(1) A, c = 28.22(4) A, * = 96.732(2)°, V = 2154 A, Z = 4, Rgt(F) = 0.055, wRref(F ) = 0.157, T = 293 K. Source of material 2,2'-bipyridine (156 mg, 1 mmol) was dissolved in DMF (10 ml) at 323 K, to this solution was added Cu(ClO4)2 (1 mmol, 262mg) in alcohol (10 ml). After keeping the resulting solution in air to evaporate about half of the solvents, blue prism-like crystals of the title compound were formed. The crystals were isolated and washed with alcohol three times. Experimental details All the H atoms bonded to carbon atoms were located at the ideal positions with d(C—H) = 0.93 A, and the Uiso(H) = 1.2 Ueq(C). The Uii for the oxygen atoms in the perchlorate anion are large, because the anion is not coordinated to the metal atoms. Discussion Pyridine and its derivatives are widely used as constructional units in supramolecular chemistry [1]. Bipyridine is also an interestingmolecule among the shortest conjugated oligomers, aswell as constituent parts of conjugated polymeric polypyridines. Conjugated polymers formed with bipyridine units including their metal complexes have been found widespread interest/utilization as luminescent materials [2] with potential application an phatonics optoelectonics. In addition, 2,2'-bipyridine is the most commonly used chelate system for mononuclear and also for polynuclear transition metal complexes [3]. In the title crystal structure, theCu(II) atom is six-coordinated in a distorted octahedral manner by four nitrogen atoms from two bipy ligands and two oxygen atoms from the carboxyl group of the formate ligand, with N2 and O6 in the axial position and N1, N3, N4 and O5 in the equatorial plane (d(Cu—O5) = 2.139(5); d(Cu1—N4) = 1.992(4); d(Cu1—N1) = 1.994(4); d(Cu1—N3) = 2.067(4); d(Cu1—N2) = 2.139(4) A). It is noteworthy that the perchlorate anion does not coordinate the copper(II) due to its weak coordination ability. There are 1D channels along [010], and the perchlorate anions fill the channels through strong hydrogen bonds. These complexes are interconnected through-···stacking interaction between the bipyridine plane forming a 2Dnetworkwith central to central distance of 3.843(2)A. Analysis of themolecular packing in the title crystal structure reveals the existence of anion-interactions between the host and the anions. Z. Kristallogr. NCS 225 (2010) 735-736 / DOI 10.1524/ncrs.2010.0324 735 © by Oldenbourg Wissenschaftsverlag, Munchen Crystal: blue block, size 0.20 × 0.20 × 0.22 mm Wavelength: Mo K+ radiation (0.71073 A) .: 10.85 cm−1 Diffractometer, scan mode: Bruker SMART CCD, % 2,max: 50.02° N(hkl)measured, N(hkl)unique: 11351, 3789 Criterion for Iobs, N(hkl)gt: Iobs > 2 )(Iobs), 2638 N(param)refined: 299 Programs: SHELXS-97, SHELXL-97 [4] Table 1. Data collection and handling. H(1) 4e 1.3817 0.6755 0.3824 0.089 H(2) 4e 1.5178 0.7102 0.3149 0.098 H(3) 4e 1.4115 0.8709 0.2644 0.097 H(4) 4e 1.1469 0.9799 0.2784 0.082 H(7) 4e 0.8743 1.0516 0.2911 0.088 Table 2. Atomic coordinates and displacement parameters (in A). Atom Site x y z Uiso