开发了一条制备一系列通式为反式-[Ru(NH(3))(4)L(NO)](BF(4))(3)的反式亚硝酰基配合物的新路线,其中L =咪唑,L -组氨酸,吡啶或烟酰胺。通过元素分析,摩尔电导测量,紫外线可见,红外,质子核磁共振和电子顺磁共振光谱学和电化学技术对络合物进行了表征。该化合物具有相对较高的nu(NO)拉伸频率,表明在配位的亚硝酰基基团上存在高水平的正电荷。亚硝酰基配合物根据公式trans- [Ru(NH(3))(4)L(NO)](3+)+ 2OH(-)与OH(-)反应,右箭头在左箭头trans- [Ru( NH(3))(4)L(NO(2))](+)+ H(2)O,K(eq)(在25.0摄氏度,在1.0 mol / L NaCl中)为2.2 x 10(5 ),5.9 x 10(7),9.7 x 10(10)和4。py,nic,imN和L-hist络合物分别为6 x 10(13)L(2)
On the Photochemical Behavior of the [Ru(NH<sub>3</sub>)<sub>4</sub>(NO)nicotinamide]<sup>3+</sup> Cation and the Relative Stability of Light-Induced Metastable Isonitrosyl Isomers of Ru Complexes
作者:Christopher Kim、Irina Novozhilova、M. Scott Goodman、Kimberly A. Bagley、Philip Coppens
DOI:10.1021/ic000583d
日期:2000.12.1
Low-temperature IR experiments on crystalline samples of trans-[Ru(NH3)(4)(NO) nicotinamide](3+) salts show a light-induced absorption band typical for MS 1 NO linkage isomers upon exposure to 300-500 nm light from a Xe source. The formation of a metastable species is confirmed by DSC measurement on a sample irradiated at low temperature with 457 nm light from an Ar+ laser. The light-induced species decays between 250 and 260 K according to both IR and DSC results. This decay temperature (Td) is somewhat below that observed for other high-Td linkage isomers, even though the NO-stretching frequency of the of [Ru(NH3)4(NO) nicotinamide](3+) ion is above that of the other isomers, demonstrating a lack of precise correlation between the two physical properties. The 90 K crystal structure of trans-[Ru(NH3)(4)(NO)nicotinamide](SiF6)(NO3).H2O is reported. The geometry from theoretical DFT calculations of the ground-state structure agrees well with the experimental results, except for the orientation of the CONH2 substituent in the pyridine ring, which is rotated by 180 degrees in the crystal due to packing effects. The MS1 and MS2 linkage isomers are found to correspond to local minima on the ground-state potential energy surface, and their geometries and energies are reported.