Gan Xin-Min, Rapko Brian M, Fox Jesse, Binyamin Iris, Pailloux Sylvie, Duesler Eileen N, Paine Robert T
Department of Chemistry, University of New Mexico, Albuquerque, New Mexico 87131, USA.
Inorg Chem. 2006 May 1;45(9):3741-5. doi: 10.1021/ic051937+.
A multistep synthesis for 2-(2-pyridyl-N-oxide) ethylphosphonic acid 6-H2 is described along with its spectroscopic (IR, NMR) data and a single-crystal X-ray diffraction structure analysis. Combination of the ligand with Nd(OH)3 results in the formation of a complex Nd(6-H)3. Single-crystal X-ray diffraction analysis reveals a three-dimensional crystal network generated by hydrogen-bonded chains along the crystallographic c axis. The hydrogen bonds are formed between phosphonic acid anion (6-H)(-1) protons on one chain and pyridyl N-oxide oxygen atoms in neighboring chains. The asymmetric unit contains 1/3[Nd(6-H)3] and there are two unique Nd(III) atoms, each with point symmetry. As a result, each Nd(III) ion is bound to six (6-H)(-1) ligands and the symmetry about the Nd(III) ion is octahedral with each vertex occupied by a phosphonate oxygen atom. The Nd-O bond lengths are essentially identical: Nd(1)-O(3), 2.336 (1) A; Nd(2)-O(4), 2.340 (1) A. The monoanionic ligand (6-H)(-1), therefore, serves to bridge the unique Nd(III) centers.
描述了2-(2-吡啶基-N-氧化物)乙基膦酸6-H₂的多步合成方法，以及其光谱（红外、核磁共振）数据和单晶X射线衍射结构分析。该配体与Nd(OH)₃结合形成配合物Nd(6-H)₃。单晶X射线衍射分析揭示了沿晶体学c轴由氢键链生成的三维晶体网络。氢键在一条链上的膦酸根阴离子(6-H)(⁻¹)质子与相邻链上的吡啶基N-氧化物氧原子之间形成。不对称单元包含1/3[Nd(6-H)₃]，有两个独特的Nd(III)原子，每个具有点对称性。因此，每个Nd(III)离子与六个(6-H)(⁻¹)配体结合，Nd(III)离子周围的对称性为八面体，每个顶点被一个膦酸根氧原子占据。Nd-O键长基本相同：Nd(1)-O(3)，2.336(1) Å；Nd(2)-O(4)，2.340(1) Å。因此，单阴离子配体(6-H)(⁻¹)用于桥连独特的Nd(III)中心。
