聚磷氮烯及其衍生物电子结构的理论研究  

Theoretical Studies on Polyphosphazenes and Their Derivatives

作　　者：黄俭根[1] 施踏青[1] 罗秋艳[1] 

机构地区：[1]井冈山师范学院化学系,吉安343009

出　　处：《化学学报》2004年第3期236-240,共5页Acta Chimica Sinica

摘　　要：用分子轨道和晶体轨道方法 ,对聚磷氮烯及其衍生物的电子结构进行了研究 ,以期更深入地了解聚磷氮烯的结构和性能 .研究发现 ,链状聚磷氮烯和环状三聚磷氮烯为平面结构 ,其它的环状聚磷氮烯则为巢式结构 ,吸电子基团取代有使环状聚磷氮烯主链环取平面结构的倾向 .研究还发现 ,无论是链状还是环状聚磷氮烯 ,都表现为半导体 .取代基效应表明 ,吸电子基团—F和—CN的取代 ,使聚合物的电子亲和势 (EA)和电离能 (IP)均增大 ,能隙减小 ,给电子基团—CH3 和—OCH3 的取代 ,使聚合物的IP减少 ;吸电子基团取代有利于n 型掺杂 ,给电子基团取代有利于p 型掺杂 。The electronic structures of polyphosphazenes and their derivatives have been studied by crystal orbital and molecular orbital methods. The substituent effects are discussed also. The calculated results show that the linear polyphosphazenes and cyclic tri-polyphosphazene are planar, the other cyclic polyphosphazenes are nestlike, and the substitute of the electron-withdrawing group may give birth to the planar structure of cyclic quad-polyphosphazenes. The results also show that these polymers are semiconductors. Although the band gap decreases for most of the substituted derivatives of polyphosphazenes, these polymers can not be conductors in intrinsic state by the substitution. Electron affinity and ionization potential of the substituted polyphosphazene chains are raised due to the substitution of electron-withdrawing substituents, while ionization potential is decreased for the electron-donating substituents. Therefore, the substitution of electron-donating group is favorable to p-type doping, while the substitution of electron-withdrawing group to n-type doping.

关 键 词：聚磷氮烯 衍生物 电子结构 半导体 取代基效应 密度泛函 能带结构 

分 类 号：O631[理学—高分子化学]