三原子卤代卡宾振转光谱及其微扰的理论研究

The triatomic halocarbenes are model systems for understanding the electronic state, spectroscopy, dynamics and chemistry of carbenes. The ground state and the first excited singlet state of the tri-atomic halocarbenes are degenerate at linear configuration leading to the Renner-Teller coupling between the states. The electronic degeneracy results in the classic breakdown of the Born-Oppenheimer separation of the electronic and the nuclear motion. In addition to the Renner-Teller effect, the lowest triplet state interact with the RT mixed ground state and the first excited singlet state via spin-orbit interaction .The coupling between the electronic state leading the complicated spectrum. In this proposal, the ro-vibronic spectrum of the lowest three electronic states of the halocarbenes including the Renner-Teller effect and the spin-orbit coupling will be calculated. The absorption and emission spectra from the ground state to the first excited singlet state at T=10-20K will be simulated. This project aims to obtain the ro-vibronic structure of the electronic state and the photodissociation process of the first excited singlet state, the barrier to linearity and dissociation of the first excited singlet state. The.result will help us to understand the first excited singlet state, the coupling mechanism between electronic states.The results will compared with the available experimental data to test the accuracy of the method and promote the improvement of theory and method

三原子卤代卡宾是含二价碳的高活性中间体，电子态密度高，能量间隔小，电子态之间存在各种复杂的相互作用，是研究卡宾电子态，光谱及反应动力学过程的典型体系。三原子卤代卡宾基态和第一单重激发态之间存在很强的Renner-Teller效应，破坏了Born-Oppenheimer近似，使得电子运动和核运动相互耦合；最低三重态通过旋轨耦合效应和基态与第一单重激发态形成的RT对相互作用。这些相互作用对振转能级造成微扰，导致光谱常伴有异常伴线以及跃迁禁阻的谱线。本项目拟采用从头算方法，考虑Renner-Teller效应以及旋轨耦和效应计算卤代卡宾最低三个电子态的振转光谱以及耦合机制对振转光谱的微扰。通过本项目的实施，不仅可以了解和掌握卤代卡宾的光谱结构、电子态的光解离机制，而且对于深入探究分子电子态之间的各种耦合机制，以及验证和建立多原子分子电子态的理论计算方法具有重要的意义。

三原子卤代卡宾是研究自由基电子态、光谱和反应动力学的典型模型，本项目研究了CH2，CHF，CHCl，CFCl卡宾自由基电子态的结构，简谐振动频率，跃迁能等光谱常数，电子态势能曲线，以及CHF自由基基态的势能面，解释了CFCl自由基的电子态的电离解离情况。具有高度共轭离域π电子的金属酞菁系统是最优秀的光学限制器。本项目研究了纳秒、皮秒脉冲激光与萘酞菁和酞菁化合物的动力学作用过程。萘酞菁具有更加明显的光限幅效应，中心金属元素序数越大，光限幅行为越明显。萘酞菁和酞菁具有较好的光限幅动力特性。与单脉冲作用过程不同，连接较轻金属元素的萘酞菁具有更突出的光限幅特性。分支脉冲的脉宽持续时间对作用过程的影响最明显。增加单个脉冲的脉宽，分子的光限幅行为更显著。