摘要
此文探讨了在铁垢的化学清洗过程中,HEDP、HPAA、PBTCA、ATMP、EDTMP、BHMTPMPA这几种常见的有机膦酸,只有HEDP和HPAA能够溶解铁垢,并且HEDP的溶解能力比HPAA更强,这一现象尚无理论解释。本研究工作运用Gaussian09程序,采用了密度泛函的B3LYP方法,对Fe原子采用赝势基组LANL2DZ,对其它原子采用6-31+g(d)基组。通过分子结构理论计算和分析,HEDP、HPAA具有与其它有机膦酸不同的特殊结构,HEDP的中心C原子上相连的2个膦酸基团和羟基共同参与配位,2个HEDP分子和Fe^(3+)形成六配位八面体结构的螯合物,这是其能溶解铁垢的原因。HPAA与Fe^(3+)形成的螯合物结构类似于HEDP。另外从螯合物的分子结构、NBO电荷分布和前线分子轨道等角度分析了HEDP比HPAA溶解铁垢能力更强的原因,为进一步的化学清洗分子设计奠定了基础。
This paper discussed several common organophosphonic acids including HEDP, HPAA, PBTCA, ATMP, EDTMP and BHMTPMPA. Only HEDP and HPAA can dissolve ferric scale, and the dissolution ability of HEDP is stronger than HPAA. This phenomenon has no theoretical explanation. The theoretical calculation was conducted by Gaussian09 using density functional theory（DFT） at B3LYP/LANL2DZ level for iron atom and B3LYP/6-31＋g（d） level for other atoms. HEDP and HPAA have special structures different from other organophosphonic acids. Two phosphonic group and hydroxyl which connect with HEDP＇s central C atom coordinate with Fe3＋. Two HEDP and Fe3＋ form a six-coordinated complex in octahedral geometry. The complex structure of HPAA and Fe3＋ is similar to that of HEDP. This conclusion is the mechanism of HEDP and HPAA can dissolve ferric scale. The reason why the dissolution ability of HEDP is stronger than HPAA was explained from the molecular structure, the NBO charge distribution and the frontier molecular orbital. This study laid a foundation for molecular design of chemical cleaning.
出处
《计算机与应用化学》
CAS
CSCD
北大核心
2014年第7期821-824,共4页
Computers and Applied Chemistry
基金
国家自然科学基金(J1210060)
全国大学生创新创业训练计划项目(201310459005)
关键词
有机膦酸
铁垢
化学清洗
理论计算
organophosphonic acids
ferric scale
chemical cleaning
theoretical calculation
