摘要
采用B3LYP/6 31G方法对噻吩加聚物(C4H4S)n(n=1～8)体系进行了全优化,在进行结构优化的同 时得到链式加聚物的总能量(ET)、零点能(ZPE)、热容(C0P)、熵(S0)和能隙(△E).通过对体系的能量分析,确定 得到的结构是体系的稳定构型;分析了ZPE、C0P、S0和△E与n的关系,并在能量的基础上得到噻吩分子以不同 方式聚合成链式加聚物时的焓变,并由此确定链式加聚物系列的聚合过程和相对稳定性以及加聚物导电性的变 化趋势.
Thiophene polymers (C 4H 4S) n(n=1～8) have been studied on B3LYP/6-31G theory level.Vibrational frequencies, total energy(E T), zero point energy(ZPE), capacity (C 0 P),entropy (S 0)and energy gap(△E) was calculated based on the optimized equilibrium structures. By means of frequency analysis, the equilibrium structures were confirmed.The relationships between E T, ZPE, C 0 P, S 0, △E and n were studied. The formation enthalpy of thiophene polymers was calculated with the total energies. The polymerized process and relative stability of the title compounds was determined according to the data of the formation enthalpy. The calculated results indicated that the thiophene molecular which has a planar structure exists in the stable chain polymers and the chain structures (C 4H 4S) n(n>1) present different stabilities when n is an even or odd number. ZPE, C 0 P, and S 0 show a linear increasing trend with n. The energy gaps △E show a direct proportion to n too, which indicated that the conduct property increases with n. The results also illustrated that the stepsize polymerized process is the primary way in the polymerized reactions.
基金
ProjectsupportedbytheNationalNaturalScienceFoundationofChina(20073042)
关键词
噻吩
噻吩加聚物
密度泛函理论
Thiophene, Thiophene polymers, Density functional theory
