Lind Per, Boström Dan, Carlsson Marcus, Eriksson Anders, Glimsdal Eirik, Lindgren Mikael, Eliasson Bertil
Department of Chemistry, Organic Chemistry, Umeå University, SE-901 87 Umeå, Sweden.
J Phys Chem A. 2007 Mar 8;111(9):1598-609. doi: 10.1021/jp066569p. Epub 2007 Feb 10.
Optical power limiting and luminescence properties of two Pt(II) complexes with thiophenyl and phenyl groups in the ligands, trans-Pt(P(n-Bu)3)2(C[triple bond]C-Ar)2, where Ar = -C4H2S-C[triple bond]C-p-C6H4-n-C5H11 (1) and -p-C6H4-C[triple bond]C-C4H3S (2), have been investigated. The fluorescence lifetimes were found to be on the sub-nanosecond time scale, and the quantum yields were low, in accord with fast intersystem crossing from the excited singlet to triplet manifold. The phosphorescence lifetimes of 1 and 2 were shorter than that of a Pt(II) complex having two phenyl groups in the ligands. In order to elucidate the C-Pt bonding nature in the ground state, the 13C NMR chemical shift of the carbon directly bonded to Pt, the coupling constants 1JPtC, 2JPtC, and 1JPtP, and IR nuC[triple bond]C wavenumbers were obtained for 1, 2, and three other trans-diarylalkynyl Pt(II) complexes. X-ray diffraction data of 1 and 2 and density functional theory calculated geometries of models of 1, 2, and trans-Pt(P(n-Bu)3)2(C[triple bond]C-p-C6H4-C[triple bond]C-C6H5)2 (3) show that 1 preferably exists in a different conformation from that of 2 and 3. The variations in photophysical, NMR, and IR data can be rationalized by differences in geometry and pi-backbonding from Pt to the alkynyl ligand.
对两种配体中含有噻吩基和苯基的Pt(II)配合物反式 - Pt(P(n - Bu)3)2(C≡C - Ar)2的光限幅和发光性质进行了研究，其中Ar = -C4H2S - C≡C - p - C6H4 - n - C5H11 (1) 和 -p - C6H4 - C≡C - C4H3S (2)。发现荧光寿命在亚纳秒时间尺度，量子产率较低，这与从激发单重态到三重态的快速系间窜越一致。1和2的磷光寿命比配体中有两个苯基的Pt(II)配合物的磷光寿命短。为了阐明基态下的C - Pt键性质，获得了与Pt直接键合的碳的13C NMR化学位移、耦合常数1JPtC、2JPtC和1JPtP以及1、2和其他三种反式二芳基炔基Pt(II)配合物的IR νC≡C波数。1和2的X射线衍射数据以及1、2和反式 - Pt(P(n - Bu)3)2(C≡C - p - C6H4 - C≡C - C6H5)2 (3)模型的密度泛函理论计算几何结构表明，1与2和3的构象不同。光物理、NMR和IR数据的变化可以通过几何结构以及从Pt到炔基配体的π反馈键合的差异来合理解释。
