摘要
目的对五种苯并咪唑衍生物缓蚀剂的缓蚀性能进行理论评价,并对其缓蚀机理进行理论研究。方法采用量子化学计算与分子动力学模拟相结合的方法。结果苯并咪唑、2-丙基苯并咪唑、2-戊基苯并咪唑、2-己基苯并咪唑的最高占据轨道(HOMO)和最低空轨道(LUMO)均分布在苯并咪唑环上,而2-对氯苄基苯并咪唑的最高占据轨道分布在苯并咪唑环上,最低空轨道分布在取代基上。分子的苯并咪唑环平行吸附在金属表面,取代基含有的烷基链会垂直于表面并指向溶液,对分子吸附的影响较小,而取代基含有的苯环则会发生平行吸附。在五种缓蚀剂分子中,苯并咪唑的能隙差(ΔE)为5.572 e V,在金属表面上的吸附能为364.19 k J/mol,缓蚀性能最弱;2-对氯苄基苯并咪唑的能隙差为5.157 e V,吸附能为700.19 k J/mol,缓蚀性能最强。结论苯并咪唑衍生物分子的取代基官能团会对缓蚀性能造成一定影响,缓蚀剂分子通过其前线轨道与Fe原子形成的配位键和反馈键稳定吸附在金属表面,吸附形态和前线轨道分布有关。
Objective To evaluate inhibition performance of five benzimidazole inhibitors and study their inhibition mechanism in theory. Methods Quantum chemistry calculation and molecular dynamics simulation were combined. Results The highest occupied molecular orbital（HOMO） and the lowest unoccupied molecular orbital（LUMO） of four benzimidazole inhibitors, including benzimidazole, 2-propyl benzimidazole, 2-amyl benzimidazole and 2-hexyl benzimidazole, were mainly distributed on the benzimidazole ring. The HOMO of 2-benzyl chloride benzimidazole was distributed on the benzimidazole ring and the LUMO was distributed on its substituent group. When benzimidazole derivatives were adsorbed on metal surface, their rings were parallel to the metal surface, their alkyl chains were perpendicular to the surface and pointed to the solution, which had little influence on adsorption of molecules, and their benzene rings contained in the substituent adsorbed parallel to metal surface. Among the five inhibitors, the energy gap（ΔE） of benzimidazole was 5.572 e V and the adsorption energy on metal surface was 364.19 k J/mol, so its inhibition performance was the weakest. The energy gap of 2-benzyl chloride benzimidazole was 5.157 e V and its adsorption energy was 700.19 k J/mol, so its inhibition performance was the best. Conclusion The functional groups of substituents of benzimidazole inhibitors can affect inhibition properties to a certain extent and their molecules can be adsorbed on metal surface stably by coordinate bonds and back bonds formed between frontier molecular orbitals and Fe atoms, and their adsorption morphologies are related to the distribution of frontier orbitals.
作者
院金星
郑海英
刘艳霞
YUAN Jin-xing1, ZHENG Hai-ying1, LIU Yan-xia2(1. No.1 Middle School of Chahar Right Middle Banner, Ulanqab 013500, China; 2.College of Chemistry and Chemical Engineering, Jining Normal University, Ulanqab 012000, Chin)
出处
《装备环境工程》
CAS
2018年第8期44-49,共6页
Equipment Environmental Engineering
关键词
苯并咪唑
前线轨道
能隙差
吸附能
配位键
反馈键
平行吸附
benzimidazole
frontier molecular orbital
energy gap
adsorption energy
coordinate bond
back bond
parallel adsorption
