具有膦配体的异核d^(10)-d^8配合物结构:Au-Pt配合物激发态性质的理论研究  

Theoretical Studies on Heterobimetallic d^(10)-d^8 Complexes with Phosphine Ligands:Excited-state Properties of the Au-Pt Analogue

作　　者：郭元茹[1] 潘清江[2] 

机构地区：[1]东北林业大学材料科学与工程学院,哈尔滨150040 [2]黑龙江大学化学化工与材料学院物理化学实验室,哈尔滨150080

出　　处：《化学学报》2009年第1期27-32,共6页Acta Chimica Sinica

基　　金：国家自然科学基金(No.20703015);黑龙江省博士后(No.LBH-Z06143);黑龙江省自然科学基金(No.B200601);黑龙江省普通高等学校青年学术骨干支持计划(No.1153G028);黑龙江大学杰出青年基金(No.JC2006L2)资助项目

摘　　要：采用MP2和DFT方法优化一系列d10-d8配合物,[MM'(CN)2(PH2CH2PH2)2]+[M=AuI,M′=PtII(1),PdII(2),NiII(3);M'=PtII,M=AgI(4),CuI(5)]的基态结构,其中BH&H方法得到的金属间距离最接近相应的实验值.对于经典Au-Pt配合物:使用多种方法优化[AuPt(CN)2(PMe2CH2PMe2)2]+(1Me)的结构以验证取代基近似的合理性,采用单激发组态相互作用方法优化了1的两个低能三重激发态并且考查了环境效应(抗衡离子和溶剂分子)对其较低能激发态发射光谱的影响.计算结果显示1的两个低能三重激发态分别产生399和234nm发射,属于金属中心(Metal-centered,MC)跃迁和分子内电荷转移(Intramolecular Charge Transfer,ICT)的混合性质;由于电子激发到成键轨道,使得激发态金属间距离相对基态变短;环境效应使得较低能的MC/ICT激发态的发射光谱红移,如1·ClO的发射在473nm处,与实验测得[AuPt(CN)2(PCy2CH2PCy2)2]·ClO4的451nm固体发射相对应.The ground-state structures of heterobimetallic d^10-d^8 complexes,[MM′（CN）2（PH2CH2PH2）2]^＋[M=Au^Ⅰ,M′=Pt^Ⅱ（1）,Pd^Ⅱ（2）,Ni^Ⅱ（3）;M＇=Pt^Ⅱ,M=Ag^Ⅰ（4）,Cu^Ⅰ（5）], were optimized using density functional theory （DFT） and ab initio （MP2） methods. It was shown that the M-M＇ distances calculated with the BH＆H functional are closest to the corresponding experimental values. The attempts of methods and substituent effects on the Au-Pt complex confirm the present calculations reasonable. The CIS calculations reveal that 1 features two excited states with the combined characters of MC （metal-centered） transition and ICT （intramolecular charge transfer）. They give rise to the phosphorescent emissions at 399 and 234 nm, respectively, along with the promotion of electrons into bonding orbitals that results in the decrease of the Au-Pt distances in going from the ground state to the excited states. Optimizations on the lower-energy MC/ICT excited states of [Au^ⅠPt^Ⅱ（CN）2（PH2CH2PH2）2]·X（1·X）（X=C1, Br, I, Cio, HCN and MeCN） indicated that the environment effect （counterion and solvent） results in a red shift of emission wavelength. Among these, the emission of loC10 was predicted at 473 nm, agreeing with 451 nm of [AuPt（CN）2- （PCy2CH2PCy2）2]-CIO4 in the solid state in the experiment.

关 键 词：异核d^10-d^8配合物 激发态 环境效应 从头算和密度泛函方法 

分 类 号：O641.4[理学—物理化学]