Control of Spin purity in excited state using distortion of coordination structure in transition metal compounds

研究了具有四面体结构的d^&lt；10&gt；金属化合物[Cu(I)(Diimine)_2]^+或[Pt(0)(BINAP)_2]的单态和三态电荷转移态(MLCT)的光物理性质。测得铜(I)化合物的‘MLCT寿命为13-16ps，铂(O)化合物的寿命为3.2ps，远长于从强自旋轨道耦合常数(880 cm^~(-1))或铂-5d(4000 cm^~(-1)~(-1)~(gt；))的预期。基于密度泛函理论的理论分析表明，MLCT态的结构扭曲导致HOMO和HOMO-1之间的能量分裂，从而阻止了由于这些轨道之间强烈的自旋-轨道相互作用而产生的非常快的ISC。虽然在较低温度下观察到的磷光是由于从^1MLCT→GS跃迁借用的强度，但HOMO和HOMO-2之间的巨大能量差异由于自旋-轨道相互作用减少了最低的^3MLCT和^1MLCT之间的混合程度，从而降低了…开发了峰值性能为90G/s的PC机群计算机系统。为了了解Ru(II)-Co(III)双核化合物的光激发后的超快光化学过程，计算了分子内坐标和溶剂坐标下的势能曲线，并计算了分子内电子相互作用能的大小。结果表明，由于钴上的d&lt；x2-y2&gt；轨道和氮上的π-轨道与钴配位的不对称振动，Ru(II)的MLCT态向Co(III)的超实能量和电子转移发生了振动耦合。发展了一种利用实验发射光谱来评估量子化学计算得到的几何构型的新方法。用UHF、UDFT、TDDFT、CIS和CASSCF等几种量子化学模型模拟得到的荧光光谱与实验结果进行了比较，证实了UDFT和TDDFT在几何构型上计算的准确性。较少

Photophysical properties of singlet and triplet metal-to-ligand charge transfer states (MLCT) of d^<10> metal compounds with tetrahedral structure, e.g., [Cu(I)(diimine)_2]^+ or [Pt(0)(binap)_2] have been studied. The lifetimes of 'MLCT were determined to be 13-16 ps for the Cu(I) compounds and 3.2 ps for the Pt(O) compound, much longer than expected from strong spin-orbit coupling constant of Cu-3d (880 cm^<-1>) or Pt-5d (4000 cm^<-1>) orbitals. Theoretical analysis based on density functional theory revealed that structural distortion in the MLCT states causes large energy splitting between HOMO and HOMO -1, which prevents a very fast ISC due to the strong spin-orbit interactions between these orbitals. Although the phosphorescence observed at lower temperatures is due to intensity borrowing from ^1MLCT→GS transition the large energy difference between HOMO and HOMO -2 reduces the extent of mixing between the lowest ^3MLCT and ^1MLCT due to spin-orbit interaction, thereby decreasing … More the radiative rate of the phosphorescence.A PC-clustering computer system with the peak' performance of 90Gflops was developed. To understand ultrafast photochemical processes following the light excitation of Ru(II)-Co(III) binuclear compounds, potential energy curves along with both intramolecular coordinates and solvent coordinates were calculated and the magnitudes of intramolecular electronic interaction energy between these potential curves were evaluated. It was revealed that ultrafact energy and electron transfer from MLCT state of the Ru(II) moiety to the Co(III) moiety occurred with vibronic coupling due to asymmetric vibrations which mixed d_<x2-y2> orbital on cobalt and π-orbitals on nitrogen coordinating to the cobalt.A new method to assess the geometries obtained from quantum chemical calculations using experimental emission spectra was developed. The fluorescence spectra simulated from geometries obtained using several quantum chemical models such as UHF, UDFT, TDDFT, CIS, and CASSCF were compared with the experimental ones, confirming the accuracy of UDFT and TDDFT calculation on geometries. Less