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卤代对苝醌类光敏剂光敏活性影响的量子化学研究
申亮,陈德展*
作者单位E-mail
申亮 山东师范大学化学化工与材料科学学院,济南,250014  
陈德展* 山东师范大学化学化工与材料科学学院,济南,250014 dchen@sdnu.edu.cn 
摘要:
以一种新型的苝醌类光敏剂-菌生素(HMB)为模型化合物,利用量子化学从头算HF/6-31G和含时密度泛函TD-B3LYP/6-31G方法计算研究了卤代作用对苝醌类光敏剂分子性质和光敏活性的影响.结果发现,卤代作用降低了HMB母体的HOMO和LUMO能级(EHOMO和ELUMO)及其差值△E,随卤族元素从上到下, EHOMO和ELUMO呈增大趋势,而△E呈减小趋势,使得分子激发光谱有不同程度的红移,在增加PQP三重态量子产率的同时降低了分子最低三重激发态的能量,两种作用相互抵消,使得卤代物的 1O2量子产率与母体相似;增加了分子的绝热电子亲合势,使分子产生O2-的能力下降;卤原子的引入,降低了HMB母体分子内氢键的强度,同时使顺式构型的分子内质子传递势垒增大,而使反式构型势垒减小.
关键词:  苝醌类光敏剂  卤族元素  分子性质  光敏活性  量化计算
DOI:10.1088/1674-0068/17/6/689-696
分类号:
基金项目:
Quantum Chemical Study on the Effect of Halogen Substitution on Photosensitization of Perylenequinonoid Photosensitizer
Shen Liang,Chen Dezhan*
Abstract:
Taking hypomycin B(HMB)as the model compound,HF / 6-31G and TD-B3LYP / 6-31G methods have been employed to explore the effect of chlorine,bromine and iodine substitutions on molecular properties and photosensitization of perylenequinonoid photosensitizer(PQP). It was found firstly that,the halogen substitutions lowered the EHOMO and ELUMO,and the ΔE. From chlorine,bromine to iodine substitutes,the EHOMO and ELUMO increased,while the corresponding ΔE decreased. Secondly,the halogen substitutions increased the molecular triplet-generating quantum yields and lowered the molecular lowest lying triplet energies,which resulted in the substitutes’similar 1O2 yields with their parent compounds. After halogen substitutions,the molecular adiabatic electron affinities increased,which made the substitutes possess lower O2· - -generating abilities than their parent compounds. Finally,the halogen substitutions lowered the intramolecular hydrogen bond energies,while enhancing the intramolecular proton transfer(IPT)barriers of cis isomers and lowering those of trans isomers on the ground state.
Key words:  Perylenequinonoid photosensitizer(PQP),Halogen,Molecular properties,Photosensitization,Quantum chemical calculation