有机膦酸化合物阻垢缓蚀性能的量子化学研究方健.pdf

30 4 　　　　　 Vol.30 No.4 2002 4 JOURNAL OF ONGJI UN IVERSI Y 　Apr.2002 方　健, 李　杰 ( , 　200092) :, -1, 1-(1, 1-EDPA)、-1, 2-(1, 2-EDPA) (HEDP). , , , .1, 1-EDPA HEDP , , , 1, 2-EDPA . , 1, 2-EDPA;HEDP;1, 1-EDPA. 、2p , , . :;;;- :O 621.13　　　　　:A　　　　　:0253-374X(2002)04-0522-07 Quantum Chemistry Study on Microscopic Mechanism of Scale and Corrosion Inhibition for Organic Phosphonic Acid F AN G J ian, LI J ie (Department of Physics, ongji University, Shanghai 200092, China) Abstract:Quantum chemistry calculations have been performed for three organic phosphonic acids, ethane-1, 1-diphosphonic acid (1, 1-EDPA)、ethane-1, 2 -diphosphonic acid (1, 2 -EDPA )and 1-hydrox- yethylidene-1, 1-diphosphonic acid(HEDP),which have very similar structures.Molecular structures、elec- tronic state density、HOMO energy levels and orbital coefficients have been calculated by using CNDO/2 method.Quantum chemistry calculations indicate that only phosphonate oxygens in these three molecules ex- hibit negatively charged, which demonstrates that strong electrostatic interaction between these functional groups and calcium cations on the calcite surface may occur, if the distance between two phosphonate oxygens and neighbour calcium cations are exactly matched.he coulombic interaction results in the excellent scale in- hibition efficiency of 1, 1-EDPA and HEDP compared to 1, 2-EDPA .In concern with their corrosion inhibi- tion effectiveness, the calculated HOMO energy levels decrease in order of 1, 2-EDPA, HEDP and 1, 1-ED- PA, which satisfactorily compared with their measured corrosion inhibition efficiency.he formation of the chelate bonds between organic molecules and metal surface