聚脲分子的非线性光学极化率  

Nonlinear OPtical Properties of Polyurea

作　　者：杨明理[1] 孙泽民[1] 鄢国森[1] 

机构地区：[1]四川联合大学化学系,成都610064

出　　处：《物理化学学报》1999年第8期693-697,共5页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金资助项目!(29706115)

摘　　要：用ａｂ　ｉｎｉｔｉｏ／ＣＰＨＦ方法研究了尿素及其二聚体和三聚体分子的线性极化率，一阶超极化率和二阶超极化率．聚脲分子中含有多个交替排列的供电基和吸电基．计算发现，聚二脲和聚三脲较尿素具有更大的非线性光学极化系数，且其电荷分布具有新的特点，即聚脲分子由基态到激发态电荷并不发生分子范围内的长程传递，仅在局域内转移．The polarizabilihes, first and second hyperpolarizabilities of urea, urea dimer and trimer have been studied by ab initio/couple perturbed Hartree-Fork (CPHF) method. A polyurea molecule contains two or more alternatively ordered electron-donating and electron-withdrawing groups. Compared to urea, its dimer and trimer possess much greater nonlinear optical susceptibili- ties. The calculations also show a particularly intramolecular short-range, rather than long-range, charge transfer.

关 键 词：尿素 聚脲 非线性光学 聚二脲 聚三脲 

分 类 号：O623.663[理学—有机化学]