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.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
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)
关键词
尿素
聚脲
非线性光学
聚二脲
聚三脲
Ab initio, Urea, Polyurea, Nonlinear Optical property, Dipole moment
