一种有机膦--己二胺四甲叉膦酸的Multiwfn研究

Multiwfn Study of an Organic Phosphine-Hexamethylene Diamine Tetramethylene Phosphonic Acid

己二胺四甲叉膦酸(HDTMPA)是一种有机膦,富含膦酸基团和亚氨基,膦酸基团中氧原子上的孤对电子较多且空间位阻小,常被用于和黏土矿物一起制备复合材料吸附重金属离子。采用Gaussian程序对HDTMPA分子进行结构优化,再使用Multiwfn程序对HDTMPA的原子电荷、静电势、平均离子局域化能、电子定位函数等进行分析,研究其吸附机理以及有机膦的活性位点。分析发现,HDTMPA分子中膦酸基团上的氧原子是活性位点,且P=O上的氧原子比P-OH上的氧原子活性更强。

Hexanediamine tetramethylene phosphonic acid(HDTMPA)is an organic phosphine,which is rich in phosphonic acid groups and imino groups.The oxygen atoms on phosphonic acid groups have more lone pair and less steric hindrance,so it is often used to prepare composite materials with clay minerals to adsorb heavy metal ions.The molecular structure of HDTMPA was optimized by Gaussian program,and then the atomic charge,electrostatic potential,average ion localization energy and electron localization function of HDTMPA were analyzed by Multiwfn program to study its adsorption mechanism and active sites of organophosphines.It is found that the oxygen atom on phosphonic acid group in HDTMPA molecule is the active site,and the oxygen atom on P=O is more active than that on P—OH.