Amouri Hani, Waern Jenny B, Caspar Regis, Barbieri Andrea, Sabatini Cristiana, Zanelli Alberto, Barigelletti Francesco
Laboratoire de Chimie Inorganique et Matériaux Moléculaires, UMR CNRS 7071, Université Pierre et Marie Curie-Paris 6, 4 place Jussieu, case 42, 75252, Paris Cedex 05, France.
Dalton Trans. 2007 Jun 7(21):2179-86. doi: 10.1039/b701089c. Epub 2007 May 4.
The first trans-ruthenium complex trans-[Ru(DIP)2(MeOH)2][OTf]2 (1b, where DIP = 4,7-diphenyl-1,10-phenanthroline) incorporating a pi-extended ligand was prepared via two methods: either photolysis of cis-[Ru(DIP)2(OTf)2] in MeOH-Et(2)O or via crystallization from MeOH-Et(2)O in direct sunlight. The X-ray molecular structure of is reported and confirmed the trans geometry of the title compound. The cis-trans isomerization process was monitored by 1H-NMR and showed that 1b reverts back to cis-[Ru(DIP)2(MeOH)2][OTf]2 (1a) in methanol-d4 after 15 h at 55 degrees C or several days at room temperature. The absorption spectra recorded in MeOH showed a bathochromic shift of the MLCT band of the trans-isomer 1b relative to that of the cis complex 1a. Interestingly at 77 K the emission spectrum of 1b is red shifted compared to the cis analog 1a. A rational explanation in terms of the energy of the excited states in the cis- and trans-isomers is proposed to explain this behavior.
通过两种方法制备了首例含有π-扩展配体的反式钌配合物反式-[Ru(DIP)₂(MeOH)₂][OTf]₂（1b，其中DIP = 4,7-二苯基-1,10-菲咯啉）：在甲醇-乙醚中光解顺式-[Ru(DIP)₂(OTf)₂]，或在直射阳光下从甲醇-乙醚中结晶。报道了其X射线分子结构并证实了标题化合物的反式几何构型。通过¹H-NMR监测顺反异构化过程，结果表明在55℃下15小时后或室温下放置数天后，1b在氘代甲醇中会变回顺式-[Ru(DIP)₂(MeOH)₂][OTf]₂（1a）。在甲醇中记录的吸收光谱显示，反式异构体1b的MLCT带相对于顺式配合物1a发生了红移。有趣的是，在77K时，1b的发射光谱相对于顺式类似物1a发生了红移。针对顺式和反式异构体中激发态能量提出了合理解释以说明此行为。
