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用原位变温31PNMR和分子模拟研究了手性氮磷配体与金属钌的配位过程。首先确定了配体及其与金属的配合物的化学位移信号分别在δ=-13.0ppm和δ=48.2ppm。配位过程在293～343K温度范围内,相继生成四配位和五配位中间体。四配位体在31PNMR上对应于30.8ppm和-15.0ppm的两个信号;五配位中间体对应于35.1ppm和-16.5ppm的两个信号;最后在343K,产物中只有六配位的配合物存在,其信号出现在48.2ppm。为了得到各种中间体的结构,用分子模拟方法进行了结构优化计算,并比较了它们的构象能。计算结果表明,四配位中间体有两种构象,能量相差9kcal·mol-1,它们可能同时存在于平衡状态。而五配位中间体只有一种绝对优势构象,尚有一个磷原子未参与配位。六配位的钌金属配合物的结构优化结果显示,两个氯原子分别位于PNNP原子所构成平面的两侧。其构象能为162.0kcal·mol-1,其中键角能的贡献是112.5kcal·mol-1,而非键静电作用是-41.4kcal·mol-1,这表明分子内的静电吸引力对于形成完全配位产物是十分有利的,但是收敛的配体分子却承受了较大的键角张力。
The coordination of chiral nitrogen and phosphorus ligands with ruthenium metal was investigated by in situ temperature-programmed thermophysics (31P NMR) and molecular simulation. First, the chemical shifts of ligands and their complexes with metals were determined at δ = -13.0 ppm and δ = 48.2 ppm, respectively. Coordination process in 293 ~ 343K temperature range, have been generated four coordination and five coordination intermediate. The four ligands corresponded to two signals of 30.8 ppm and -15.0 ppm at 31 NMR; the five coordinate intermediates corresponded to two signals of 35.1 ppm and -16.5 ppm; and finally, at 343K there was only a six-coordinate coordination of the product The signal is present at 48.2 ppm. In order to get the structure of various intermediates, the structural optimization calculations were carried out using molecular simulation methods, and their conformational energies were compared. The calculated results show that there are two conformations of the four-coordinate intermediate with energy difference of 9 kcal · mol-1, which may exist in equilibrium at the same time. However, the five coordination intermediate has only one absolute dominant conformation, and one phosphorus atom does not participate in the coordination. Structural optimization of hexacoordinated ruthenium metal complexes shows that two chlorine atoms are located on opposite sides of the plane of PNNP atoms. The conformational energy is 162.0 kcal · mol-1, of which the contribution of bond angle energy is 112.5 kcal · mol-1, while the non-bond electrostatic effect is -41.4 kcal · mol-1, indicating that the intramolecular electrostatic attraction is very strong Coordination products are very beneficial, but the convergent ligand molecules are subjected to a larger bond angle tension.