Synthesis, spectral and structural characterization of three zinc(II) azide complexes with aminopyrazine

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• 作者：Mohamed A.S. Goher ; Franz A. Mautner ; Beate Sodin ; Brigitte Bitschnau
• 关键词：Azide ; Zinc(II) complexes ; Aminopyrazine complexes ; Synthesis ; Spectra ; Crystal structures
• 刊名：Journal of Molecular Structure
• 出版年：2008
• 出版时间：15 May 2008
• 年：2008
• 卷：879
• 期：1-3
• 页码：96-101
• 全文大小：836 K

文摘

The reaction between zinc(II) azide, Zn(N<sub>3sub>)<sub>2sub> and aminopyrazine (ampyz) afforded the complexes: [Zn(N<sub>3sub>)<sub>2sub>(ampyz)<sub>2sub>] (<strong>1strong>), [Zn(N<sub>3sub>)<sub>2sub>(ampyz)]<sub>nsub> (<strong>2strong>) and [Zn<sub>3sub>(N<sub>3sub>)<sub>6sub>(ampyz)<sub>2sub>]<sub>nsub> (<strong>3strong>). These complexes are characterized by spectroscopic and crystallographic methods. The IR spectra of these compounds are measured and discussed. The structure of <strong>1strong> consists of isolated tetrahedral zinc atom surrounded by two mono-dentate N-ampyz and two terminal azido ligands. Complex <strong>2strong> features a zigzag chain of zinc centers in which each zinc is surrounded by alternate di-EO (end-on) and di-EE (end-to-end) azide bridges, the chain thus contains alternate four-membered Zn<sub>2sub>N<sub>2sub> and eight-membered Zn<sub>2sub>(NNN)<sub>2sub> rings. The two ampyz ligands are located in cis-arrangement and each of them further binds another zinc atom giving rise to a 3D network. Complex <strong>3strong> contains two structurally different zinc atoms; the six-coordinate Zn(1) center links two di-EO azido bridges and two trans ampyz, thus having ZnN<sub>6sub> chromophore. The five-coordinate Zn(2) center binds two di-EO bridging azido groups and the fifth position is occupied by an N atom from a bridging ampyz molecule. Both zinc centers, therefore participate in the formation of a 1D chain of cyclic Zn<sub>2sub>N<sub>2sub> units. Each ampyz ligand binds another zinc atom via the second pyrazinic N atom giving another cross-chain and thus the structure consists of 2D sheets. In these three complexes the azido ligands of all types are asymmetric and linear within the experimental error.