摘要
合成了烟酰胺合硝酸钕的络合物。用四园衍射仪测定了它的晶体结构,用MoKa辐射收集了4008个独立衍射点,其中2597个可观察点参加了结构修正,最终偏差因子R=0.042。结果表明晶体属P2_(1/a)空间群。晶体学数据:a=7.447(1)(?),b=30.926(5)(?),c=9.152(2)(?);β=95.27°,Z=4。钕原子的配位数为10,其中2个氧来自水分子,平均Nd-O键长2.493(?);2个氧原子来自烟酰胺,平均Nd-O键长2.418(?),其余6个氧原子分别来自3个硝酸根,平均键长2.597(?)。配位多面体为一变形的双盖四方反棱柱,对络合物的红外光谱及热谱也进行了研究。
The title complex, having molecular formula Nd(NO3)3 · 2(m-C5H4NCONH2) · 2H2O, was synthesized. Its crystal and molecular structure has been determined by single crystal X-ray diffractometer. A total of 4008 independent reflections were collected in the range of 2°<θ<25° by ω-2θ scan technique at room temperature, of which 2597 reflections with I>3σ(I) were observed and used in the refinement. The final divation factor R =0.042. The complex crystallizes in monoclinic with space group P21/a. The unit cell parameters are as follows:a=7.447(1)A β=95.27(2)°b = 30.926(5)A z =4c =9.152(2)AThe Nd atom is coordinated by ten oxygen atoms, of which six from three biden-tated nitrate groups. As expected, the nicotinic amide coordinate to Nd atom through oxygen but not nitrogen in pyridyl nor nitrogen in -NH2 group. The average bond length of Nd-0 is 2.541A. The bond length of Nd-O(1) and Nd-O(2), forming between the central atom and >C = 0 groups, are 2.403(4) and 2.432(5)A respectively, which are significentely shorter than the average bond length of Nd-O. It may be due to the 5d orbitals taking part in the conjugate system.
出处
《北京大学学报（自然科学版）》
CAS
CSCD
北大核心
1991年第2期157-162,共6页
Acta Scientiarum Naturalium Universitatis Pekinensis
基金
国家自然科学基金
关键词
烟酰胺
硝酸钕
铬合物
晶体结构
Nicotinamide
Neodymium nitrate
Complex
Structure
