过渡金属体系非线性光学性质计算的ECP基组研究

有效核势(ECP)方法是计算含有过渡金属体系的电子结构及物理性质的有效方法. 本文比较了一系列典型的ECP基组对计算含过渡金属体系非线性光学性质精度的影响. 分别在HF, MP2和DFT理论水平上对过渡金属元素使用不同的ECP基组, 计算了几个过渡金属有机化合物的静态一阶超极化率β₀. 研究结果表明: 使用有效核势计算含过渡金属体系时, 核电子的选取是提高计算精度的前提, ns和np电子应该和nd电子一同作为价电子处理; 对于重原子, 必须考虑自旋-轨道耦合相对论效应. 经过综合评估, 认为使用Stuttgart/Dresden赝势的ECP基组, MHF, 在计算含有过渡金属体系非线性光学性质方面是比较好的基组; Stuttgart RSC 1997和SBKJC VDZ相对而言是较好的基组; 基组Lanl2dz, Hay-Wadt MB (n＋1)和Hay-Wadt VDZ (n＋1)由于没有考虑自旋-轨道耦合, 计算精确度次之; 而基组CRENBL和CRENBS计算的偏差要大一些, 尤其是CRENBS基组由于价电子选择得太少而导致与实验值的偏差最大.     

Synthesis, Structure and Secondorder Nonlinear Optical Activities of a New Tungsten（0） Compound with Pyridine-2-thiolato Ligand, [Et4N][W（pyS）（CO）4] （pys = C5H4NS^-）

The reaction of W(CO)6 with pyOSNa (C5-H4NOSNa) and Et4NCl in MeCN affords a new tungsten(0) complex [Et4N][W(pyS)(CO)4] 1 (Mr.= 536.29).The crystal and molecular structures have been determined by X-ray single-crystal diffraction.Complex 1 crystallizes in the orthorhombic system,space group P212121 with a = 8.2429(5),b = 9.1045(4),c =26.8851(14) (A),β = 90.00°,V= 2017.66(18) (A)3,Z = 4,Dc.= 1.765 g/cm3,μ = 58.51 cm-1,F(000) =1048,the final R = 0.0204 and wR = 0.0400 for 4432 observed reflections with I ＞ 2σ(I).X-ray structure analysis revealed that the molecule is acentric and has large first-order hyperpolarizability (7.2 × 10-30 esu),so it could be an IR second-order nonlinear optical candidate material.     

含Pt配合物电子结构和非线性光学性质的TDDFT研究

利用含时密度泛函理论(TDDFT)对trans-(PEt3)2Pt(X)(p-Ph-NO2)的有机金属配合物进行结构优化, 并计算了电子光谱和二阶非线性光学(NLO)性质, 结果表明在1064 nm光场下, 2个分子的共振效应很强, 在远离共振的1907nm的下, 分子的一阶超极化率是尿素的40倍左右。     

Reaction of Molybdenum Hexa-carbonyl with Mercapto-pyridine （PySH） or Mercapto-pyridine Oxide （PyS→O） and Crystal Structure of [Et4N][Mo2（PyS）3（CO）5]

Introduction Mercapto-pyridine, C5H4NS-(PyS), containing two active atoms, S and N, is a bidentate ligand, which may act as a 3-electron donor or a 5-electron donor and may be a bridging ligand to link two metal atoms to form polynuclear metal clusters or a chelating agent to coor-dinate to a metal atom by S and N atoms. So the mer-capto-pyridine is a very important reagent and its reac-tion with metal compound is very useful for simulating the active center in metal enzymes and syntheses …     

Reaction of Mo(CO)_6 with Alkoxide: Synthesis and Structure of the Mo(0)-OR Complex [Et_4N]_3[Mo_2(CO)_6(μ-OC_6H_4OCH_2C_6H_5)_3]

The reaction of molybdenum hexacarbonyl with C6H5CH2OC6H4ONa and Et4NBr in CH3CN at 60 ℃ afforded the di-nuclear Mo(0) compound [Et4N]3[Mo2(CO)6(μ-OC6H4OCH2- C6H5)3] 1. 1 crystallizes in monoclinic, space group P21/c with a = 15.359(2), b = 18.378(3), c = 24.952(2), β = 102.268(4)°, V = 6882.3(16) 3, Mr = 1348.34, Z = 4, Dc = 1.301 g/cm3, F(000) = 2832 and μ = 0.424 mm-1. The final R = 0.0606 and wR = 0.1552 for 9396 observed reflections (I > 2σ(I)). 1 contains a [Mo2O3]3- core in triangular bi-pyramidal configuration and each Mo atom adopts a distorted octahedral geometry with three carbon atoms from carbonyls and three μ-O atoms from C6H5CH2OC6H4O- bridging ligands. The Mo…Mo distance is 3.30(8) , indicating no metal- metal bonding. A formation pathway via forming a di-molybdenum(0) di-bridging OR compound [Mo2(μ-OR)2(CO)8]2- has been figured out and the reaction of Mo(CO)6 with alkoxide has also been discussed.     

一水甲酸锂晶体三阶非线性光学性质理论研究

用含时藕合微扰Hartrre一Fork（CPHF）方法，有限场MP2理方法以及有向气 体方法，首次分别在分子和晶体水平上计算了一水甲酸锂晶体三次谐波极化率，表 明超分子γ(一3ω；ω,ω,ω)数值与超分子链长有线性关系；晶体x（一3ω;ω, ω,ω）计算值主要受到电子相关影响，其次受到基组和局域场影响，在非共振 条件下，频率色散的影响甚小'最后，估算了一水甲酸锂的三次谐波系数．     

尿素分子团簇线性和一阶非线性光学极化率的理论计算

检验分子晶体非线性光学极化率的可加性,对于确认有向气体模型(Oriented-Gas Model) 具有重要的科学意义,对探索新型实用的分子非线性光学材料也有实际的意义。本文对尿素晶体中分子簇非线性光学极化率的可加性做了详尽的理论研究。首次做到了尿素分子最近邻排布团簇的非线性光学极化率的从头算,从而扩展了前人的工作。研究结果有效地确认了有向气体模型。同时,我们还提出了壳层结构模型 (Shell-Structure Model),用以解决有向气体模型中的缺陷,可实现更为有效可靠地计算晶体宏观非线性光学系数。     

Synthesis and Structure of a New Dinuclear Molybdenum(Ⅰ) Compound with Cyclohexanthiolate Ligand, [Mo2(SC6H11)2(CO)6(CH3CN)2]

The reaction of [Et4N]2[Mo2(SC6H11)2(CO)8] and I2 in MeCN affords a new dinu- clear molybdenum(Ⅰ) complex [Mo2(SC6H11)2(CO)6(CH3CN)2] 1 (Mr = 672.46). The crystal and molecular structures have been determined by X-ray single-crystal diffraction. 1 crystallizes in monoclinic, space group P21/c with a = 9.302(1), b = 15.514(2), c = 9.307(1)(°A), β = 92.979(2)o, V = 1341.4(3)(°A)3, Z = 2, Dc = 1.665 g/cm3, μ = 11.28 cm-1, F(000) = 676, R = 0.0461 and wR = 0.1274 for 1702 observed reflections with I > 2σ(I). 1 possesses a rhombic bimetallic core MoS2Mo with the Mo-Mo bond length of 2.9712(4)(°A) and Mo-S of 2.4821(5)(°A).     

过渡金属偶氮苯衍生物二阶非线性光学性质的密度泛函理论研究

采用含时密度泛函理论方法(TDDFT)计算了IB族过渡金属及第5周期的金属杂化偶氮苯生色团的二阶非线性光学极化率。研究了金属杂化偶氮苯生色团的电子激发跃迁。结果表明, 与金属离子络合后的杂化偶氮苯生色团, 二阶非线性光学极化率明显改变, 是金属的推拉电子效应的结果。IB族金属的在原有机偶氮苯共轭体系的电荷转移方向的强拉电子效应, 增大了电荷转移范围, 使二阶非线性光学极化率增大。与Nb络合的杂化生色团, 沿原电荷转移相反的方向拉动电荷, 电荷转移跃迁局限于金属离子附近, 未能产生大的激发跃迁偶极矩, 体系的二阶非线性光学响应因而降低。激发跃迁能量是另一个主要影响因素, 同一类跃迁中, 金属杂化生色团的跃迁能量越低, 其二阶非线性光学响应就越大。络合Rh的生色团与Nb杂化生色团类似, 电荷转移跃迁范围都比较小, 同时由于Rh与羧基结合时几乎垂直羧基平面, 电荷同时沿X, Y方向转移跃迁, 属于二维电荷转移类型。     

非线性光学极化率密度泛函理论计算的基组效应

由于分子的非线性光学性质与分子外层电子行为及激发性质密切相关，扩散函数对分子的非线性光学极化率计算非常重要．在ADF程序中的DZP基组基础上缀加扩散函数，构造出我们称之为DZP df的新基组．通过对5个模型分子的含频二阶非线性光学极化率的密度泛函理论计算，表明新基组可以得出较DZP基组更为准确可靠的结果，同时比较ADF程序内置带有扩散函数的大基组，计算量大为减少．