Pomestchenko Irina E, Polyansky Dmitry E, Castellano Felix N
Department of Chemistry and Center for Photochemical Sciences, Bowling Green State University, Ohio 43403, USA.
Inorg Chem. 2005 May 16;44(10):3412-21. doi: 10.1021/ic048376r.
The synthesis and photophysical properties of two new Re(I) complexes are reported: fac-Re(phenC triple-bond CH)(CO)(3)Cl (where phenC triple bond CH is 5-ethynyl-1,10-phenanthroline) and its Au(I)-acetylide analogue (fac-Re(phenC triple-bond CAuPPh(3))(CO)(3)Cl). Also reported are the photophysical measurements obtained for the benchmark fac-Re(phen)(CO)(3)Cl chromophore, as well as the phenC triple-bond CAuPPh(3) and phenC triple-bond CH ligands. The unstable nature of the precursor gold-containing ligand illustrates the advantage of using the "chemistry on the complex" approach, which facilitated preparation of the Re-Au binuclear complex. Where possible, all compounds were studied by static and transient absorption (TA), as well as steady-state and time-resolved photoluminescence (TRPL), at room temperature (RT) and 77 K, as well as nanosecond time-resolved infrared (TRIR) spectroscopy. The spectroscopic information provided by these techniques enabled a thorough evaluation of excited-state decay in most cases. In fac-Re(phenC triple bond CH)(CO)(3)Cl, the RT excited-state decay is most consistent with a metal-to-ligand charge transfer (MLCT) assignment, whereas at 77 K, the lowest excited state is dominated by the triplet intraligand ((3)IL) state, localized within the diimine ligand. The lowest excited state in fac-Re(phenC triple-bond CAuPPh(3))(CO)(3)Cl seems to result from an admixture of Re-based MLCT and (3)IL states resident on the phenC triple-bond CAuPPh(3) moiety. TA and TRIR methods indicate that these excited states are thermally equilibrated at room temperature. At 77 K, the MLCT energy of fac-Re(phenC triple-bond CAuPPh(3))(CO)(3)Cl is increased as a result of the glassy medium and the resulting excited state can be considered to be ligand-localized.
报道了两种新型铼（I）配合物的合成及其光物理性质：面式-Re（phenC≡CH）（CO）₃Cl（其中phenC≡CH为5-乙炔基-1,10-菲咯啉）及其金（I）-乙炔类似物（面式-Re（phenC≡CAuPPh₃）（CO）₃Cl）。还报道了对标物面式-Re（phen）（CO）₃Cl发色团以及phenC≡CAuPPh₃和phenC≡CH配体的光物理测量结果。含前体金配体的不稳定性质说明了采用“配合物上的化学”方法的优势，该方法有助于制备铼-金双核配合物。在可能的情况下，所有化合物均在室温（RT）和77 K下通过静态和瞬态吸收（TA）以及稳态和时间分辨光致发光（TRPL）以及纳秒时间分辨红外（TRIR）光谱进行了研究。这些技术提供的光谱信息在大多数情况下能够对激发态衰变进行全面评估。在面式-Re（phenC≡CH）（CO）₃Cl中，室温下的激发态衰变与金属到配体的电荷转移（MLCT）归属最为一致，而在77 K时，最低激发态由三重态配体内（³IL）态主导，该态定域在二亚胺配体内。面式-Re（phenC≡CAuPPh₃）（CO）₃Cl中的最低激发态似乎是基于铼的MLCT态和定域在phenC≡CAuPPh₃部分的³IL态混合的结果。TA和TRIR方法表明，这些激发态在室温下热平衡。在77 K时，由于玻璃态介质，面式-Re（phenC≡CAuPPh₃）（CO）₃Cl的MLCT能量增加，并且由此产生的激发态可被认为是配体定域的。
