聚并苯同系分子稳定性及电子极化率规律的研究  

Studies on Changing Regulations of the Electronic Polarizability and the Stability of Polyacence Homologue

作　　者：霍玉秋[1] 苏忠民[1] 黄宗浩[1] 王秀军[1] 王荣顺[1] 

机构地区：[1]东北师范大学化学系,长春130024

出　　处：《高等学校化学学报》1997年第5期767-771,共5页Chemical Journal of Chinese Universities

摘　　要：引入外电场微扰的量子化学CNDO／2方法，计算了聚并苯同系分子（C4n＋2H2n＋4）的能量和电子极化率．结果表明：全价电子极化率和л电子极化率均随并苯数目的增加而增大，但增率逐渐降低，当n值足够大时，增率趋于一常数；极化率沿分子链增长方向的增率远远大于其它方向；л电子极化率的增率高于全价电子．聚并苯同系分子的稳定性规律为：顺反型相当，二者强于均键长型；分子链每增加一个单元（C4H2），体系能量降低，其降低值随分子链的增长略有减小．The quantum chemistry CNDO/2 method introduced with external electric field perturbation is used to calculate the energies and the electronic polarizability of polyacene homologue (C4n+,H2n+4). The results indicate that the polarizabilities of total and л electrons in crease with the increasing of the ring numbers, but the increasing rate reduces gradually. When n is large enough, the increasing rate tends to be a constant. The increasing rate of polarizability along the direction of molecular chain is much larger than that along other directions. The increasing rate of л electronic polarizability is generally higher than that of the total one. The stability laws of polyacene homologue are: the stability of the trans-type is about the same as that of the cis-type. Both of them are more stable that the average-bond type. The energies of all systems. decrease when the length of molecular chains are gradually increased. The decreasing values reduce a little with the increasing of the length of molecular chains.

关 键 词：聚并苯 电子极化率 外电场微扰 同系分子 稳定性 

分 类 号：O632.7[理学—高分子化学]