Zheng Greg Y., Rillema D. Paul, DePriest Jeff, Woods Clifton
Departments of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, and Wichita State University, Wichita, Kansas 67260.
Inorg Chem. 1998 Jul 13;37(14):3588-3592. doi: 10.1021/ic980324c.
Direct access to the triplet emitting state from the ground state is observed for Pt(II) complexes containing heterocyclic (CwedgeC', CwedgeN, NwedgeN') and bis(diphenylphosphino)alkane (PwedgeP') ligands. Extinction coefficients for such transitions are in the range 4-25 M(-)(1) cm(-)(1). Emission quantum yields resulting from singlet-to-triplet excitation are as high as 61-77 times the emission quantum yields resulting from singlet-to-singlet excitation at 296 K. The intersystem crossing quantum yield from the singlet excited state to triplet emitting state is lower than 2% at 296 K but is greatly enhanced at 77 K. The forbidden electronic transition observed for Pt(II) complexes is attributed to result from spin-orbit coupling due to the presence of Pt(II) in the skeleton structure. The importance of excitation spectra on the computation of emission quantum yields is discussed.
对于含有杂环（C∧C'、C∧N、N∧N'）和双（二苯基膦基）烷烃（P∧P'）配体的Pt（II）配合物，观察到从基态直接跃迁到三重态发射态。这种跃迁的消光系数在4 - 25 M⁻¹ cm⁻¹范围内。在296 K时，单重态到三重态激发产生的发射量子产率比单重态到单重态激发产生的发射量子产率高61 - 77倍。在296 K时，从单重态激发态到三重态发射态的系间窜越量子产率低于2%，但在77 K时大大增强。观察到的Pt（II）配合物的禁阻电子跃迁归因于骨架结构中存在Pt（II）导致的自旋 - 轨道耦合。讨论了激发光谱在发射量子产率计算中的重要性。
