Synthesis, Crystal Structure and Spectroscopy of catena-poly-bis(azido-N1,N1)(2-Aminopyrimidine)Copper(II)
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- 作者：Gerard A. van Albada ; Maarten G. van der Horst ; Ilpo Mutikainen ; Urho Turpeinen and Jan Reedijk
- 关键词：Copper ; 2 ; Aminopyrimidine ; Azide ; Infrared ; Hydrogen bonding
- 刊名：Journal of Chemical Crystallography
- 出版年：2008
- 出版时间：June, 2008
- 年：2008
- 卷：38
- 期：6
- 页码：413-417
- 全文大小：282.4 KB
文摘
Abstract The compound [Cu(ampym)(μ1,1-N3)2]n (ampym = 2-aminopyrimidine) has been synthesized and characterized by X-ray crystallography and infrared spectroscopy. In addition, Ligand Field and powder EPR measurements have been performed. The structure is solved in space group P21/c with a = 7.303(2), b = 19.716(4), c = 5.949(1) ?, β = 98.17(3), V = 847.9(3) ?3, Z = 2 with final R = 0.0382. The coordination geometry around the Cu(II) ion is distorted square pyramidal, with four nitrogen atoms of four bridging azido anions in the basal plane with Cu–N distances that range from 1.998(3) to 2.069(3) ?. The apical position is occupied by a nitrogen atom of the ampym molecule at a Cu–N distance of 2.169(3) ?. The trans-basal angles are 165.7(1) and 143.9(1)¡ã. Weak hydrogen bonding is observed between the two amine hydrogen atoms and nitrogen of an azide anion and the pyrimidine-ring nitrogen atom of a neighbouring molecule (N¡¤¡¤¡¤N distances 3.174(5), 3.106(4) ?). These last hydrogen bonds (N7¡¤¡¤¡¤N3) are forming so-called “Watson-Crick type” hydrogen bonds. In the infrared the vibrations of the coordinated azide anion are observed at 2,062, 1,273 and 655 cm−1, while the Cu–N vibrations are observed at 370 and 224 cm−1. Ligand-field and EPR spectra are uneventful and give spectral parameters expected in the range for such Cu(II) compounds. Magnetic susceptibility measurements reveal a weak antiferromagnetic interaction between the Cu(II) ions.