The spectroscopy of electrochemically reduced ruthenium(II) complexes with 2,2′-biquinoline and 2,2′-binaphthyridine ligands have been investigated. These compounds are: [Ru(bn)(bpy)2][BF4]2 (where bn = 2,2′-bi-1,8-naphthyridine and bpy = 2,2′-bipyridyl); [Ru(dbn)(bpy)2][BF4]2 (where dbn = 3,3′-dimethylene-2,2′-bi-1,8-naphthyridine); [Ru(dbn)3][BF4]2; [Ru(dbq)(bpy)2][BF4]2 (where dbq = 3,3′-dimethylene-2,2′-biquinoline). Resonance Raman spectra of the parent species showed the bichromophoric nature of the visible absorptions of the heteroleptic complexes; both bpy and non-bpy ligand vibrations are enhanced depending on the excitation wavelength. Changes in the electronic absorption spectra for the complexes upon electrochemical reduction suggest the reducing electron is localised on the non-bpy ligand. For the complexes with the dimethylenebinaphthyridine ligand the second reduction also appears localised on the non-bpy ligand. Resonance Raman spectra of the reduced species confirm that the first and second reduction are based on the dbn ligand. Single crystal structures of [Ru(bn)(bpy)2][BF4]2 and [Ru(dbn)(bpy)2][BF4]2 have been determined and significant distortions of the ligands are apparent.
研究了具有 2,2′-biquinoline 和 2,2′-binaphthyridine
配体的电
化学还原
钌(II)配合物的光谱。这些化合物是[Ru(bn)(bpy)2][BF4]2(其中 bn = 2,2′-联-
1,8-萘啶,bpy = 2,2′-联
吡啶);[Ru(dbn)(bpy)2][BF4]2(其中 dbn = 3,3′-二亚甲基-2,2′-联-
1,8-萘啶);[Ru(dbn)3][BF4]2;[Ru(dbq)(bpy)2][BF4]2(其中 dbq = 3,3′-二亚甲基-2,2′-联
喹啉)。母体物种的共振拉曼光谱显示了异极配合物可见吸收的双色性;
铋和非
铋配体的振动都会随激发波长的不同而增强。电
化学还原时,配合物电子吸收光谱的变化表明还原电子位于非
铋配体上。对于含有二亚
甲基萘啶
配体的配合物,第二次还原也出现在非
铋配体上。还原物种的共振拉曼光谱证实,第一次和第二次还原是基于 dbn
配体。测定了 [Ru(bn)(bpy)2][BF4]2 和 [Ru(dbn)(bpy)2][BF4]2 的单晶结构,发现
配体发生了明显的变形。