Crystal structure of tetrakis(μ2-acetato)bis(2-aminopyrimidine)dizinc(II), Zn2(CH3COO)4(C4H3N2NH2)2

Ci6H22N60gZn2, triclinic, PI (no. 2), a = 7.701(2) A, b = 8.677(2) A, c = 8.918(2) A, a = 99.45(3)°, s = 106.11(3)°,γ= 105.66(3)°, V=532.6A 3 ,Z = 1, Rgf(F) = 0.033, wRreffF) = 0.089, T= 291 K. Source of material The title compound was prepared as follows: a solution of Zn(CH3COO)2 · 4H2O (10 mmol) in 20 ml ethanol was added to a solution of 2-aminopyrimidine (20 mmol) in 20 ml methanol. The reaction mixture was refluxed for 1 h with stirring, then the resulting pale precipitate was obtained by filtration, washed several times with ethanol and dried in vacuo (yield 60 %). Colorless crystals suitable for X-ray structure analysis were obtained by recrystallization from methanol solution. All commercially available reagents were used as supplied. Experimental details The hydrogen atoms bound to the nitrogen atom were freely refined in order to show their significance. Discussion During the past two decades, considerable attention has been paid to the chemistry of heterocyclic compounds and their complexes withmetalions[l]. The chemical and pharmacological properties of heterocyclic compounds have been investigated extensively, owing to their chelating ability with metal ions and to their potentially beneficial chemical and biological activities, such as magnetic, antitumor, antineoplastic and antibacterial [2]. The crystal structure of the title compound reveals as a dinuclear centrosymmetrical complex with two ligands (figure, top). Two Ζη(Π) centers are bridged by oxygen atoms of carboxylato groups. Each Ζη(Π) center is five-coordinated with four Ο donor atoms of acetate and an Ν donor of 2-aminopyrimidine. The Zn—Ο distances are in the range of2.037(3) A 2.059(3) A and the Zn—Ν bond is 2.068(3) A, which is similar to the corresponding bond lengths of similar compounds previously reported [3,4]. Zn 1 -01 -C5-02-Zn 1A-01A-C5A-02A and Znl-03-C7-04ZnlA-03A-C7A-04A form two eight-membered chelate rings, which are perpendicular to each other. The structure has one intraand one intermolecular hydrogen bond of the type N-H—O, whereas the former stabilizes the dimer and the latter interlinks the molecules into chains running along the c axis and resulting in an ID coordination polymer (figure, bottom). Table 1. Data collection and handling. Crystal: Wavelength: