A new ruthenium polypyridine complex, [Ru(phen) 2(pMIP)] 2+(phen=1,10-phenanthroline, pMIP=2-(4-methylphenyl)imidazo phenanthroline), was synthesized and characterized by elementary analysis, MS and 1H NMR. Spectrosco...A new ruthenium polypyridine complex, [Ru(phen) 2(pMIP)] 2+(phen=1,10-phenanthroline, pMIP=2-(4-methylphenyl)imidazo phenanthroline), was synthesized and characterized by elementary analysis, MS and 1H NMR. Spectroscopic methods have been carried out on the interaction mechanism of the Ru (Ⅱ) complex with yeast tRNA systematically. The experimental results indicate that the complex binds to yeast tRNA with an intercalative mode possibly, and interacts with yeast tRNA enantioselectively. The experimental results also suggest that spectroscopic method is effective on studying the interaction mechanism of Ru (Ⅱ) complexes with RNA. Information obtained from the study is potentially useful in the design of new RNA-targeting drugs.展开更多
Efficiently converting CO_(2)and H_(2)O into value-added chemicals using solar energy is a viable approach to address global warming and the energy crisis.However,achieving artificial photocatalytic CO_(2)reduction us...Efficiently converting CO_(2)and H_(2)O into value-added chemicals using solar energy is a viable approach to address global warming and the energy crisis.However,achieving artificial photocatalytic CO_(2)reduction using H_(2)O as the reductant poses challenges is due to the difficulty in efficient cooperation among multiple functional moieties.Metal-organic frameworks(MOFs)are promising candidates for overall CO_(2)photoreduction due to their large surface area,diverse active sites,and excellent tailorability.In this study,we designed a metal-organic framework photocatalyst,named PCN-224(Zn)-Bpy(Ru),by integrating photoactive Zn(Ⅱ)-porphyrin and Ru(Ⅱ)-bipyridyl moieties.In comparison,two isostructural MOFs just with either Zn(Ⅱ)-porphyrin or Ru(Ⅱ)-bipyridyl moiety,namely PCN-224-Bpy(Ru)and PCN-224(Zn)-Bpy were also synthesized.As a result,PCN-224(Zn)-Bpy(Ru)exhibited the highest photocatalytic conversion rate of CO_(2)to CO,with a production rate of 7.6μmol·g^(-1)·h^(-1)in a mixed solvent of CH_(3)CN and H_(2)O,without the need for co-catalysts,photosensitizers,or sacrificial agents.Mass spectrometer analysis detected the signals of^(13)CO(m/z=29),^(13)C^(18)O(m/z=31),^(16)O^(18)O(m/z=34),and^(18)O_(2)(m/z=36),confirming that CO_(2)and H_(2)O acted as the carbon and oxygen sources for CO and O_(2),respectively,thereby confirming the coupling of photocatalytic CO_(2)reduction with H_(2)O oxidation.In contrast,using PCN-224-Bpy(Ru)or PCN-224(Zn)-Bpy as catalysts under the same conditions resulted in significantly lower CO production rates of only 1.5 and 0μmol·g^(-1)·h^(-1),respectively.Mechanistic studies revealed that the lowest unoccupied molecular orbital(LUMO)potential of PCN-224(Zn)-Bpy(Ru)is more negative than the redox potentials of CO_(2)/CO,and the highest occupied molecular orbital(HOMO)potential is more positive than that of H_(2)O/O_(2),satisfying the thermodynamic requirements for overall photocatalytic CO_(2)reduction.In comparison,the HOMO potential of PCN-224(Zn)-Bpy without Ru(II)-bipyridyl moieties is less positive than that of H_(2)O/O_(2),indicating that the Ru(II)-bipyridyl moiety is thermodynamically necessary for CO_(2)reduction coupled with H_(2)O oxidation.Additionally,photoluminescence spectroscopy revealed that the fluorescence of PCN-224(Zn)-Bpy(Ru)was almost completely quenched,and a longer average photoluminescence lifetime compared to PCN-224(Zn)-Bpy and PCN-224-Bpy(Ru)was observed.These suggest a low recombination rate of photogenerated carriers in PCN-224(Zn)-Bpy(Ru),which also supported by the higher photocurrent observed in PCN-224(Zn)-Bpy(Ru)compared to PCN-224(Zn)-Bpy and PCN-224-Bpy(Ru).In summary,the integrated Zn(II)-porphyrin and Ru(II)-bipyridyl moieties in PCN-224(Zn)-Bpy(Ru)play important roles of a photosensitizer and CO_(2)reduction as well as H_(2)O oxidation sites,and their efficient cooperation optimizes the band structure,thereby facilitating the coupling of CO_(2)reduction with H_(2)O oxidation and resulting in highperformance artificial photocatalytic CO_(2)reduction.展开更多
文摘A new ruthenium polypyridine complex, [Ru(phen) 2(pMIP)] 2+(phen=1,10-phenanthroline, pMIP=2-(4-methylphenyl)imidazo phenanthroline), was synthesized and characterized by elementary analysis, MS and 1H NMR. Spectroscopic methods have been carried out on the interaction mechanism of the Ru (Ⅱ) complex with yeast tRNA systematically. The experimental results indicate that the complex binds to yeast tRNA with an intercalative mode possibly, and interacts with yeast tRNA enantioselectively. The experimental results also suggest that spectroscopic method is effective on studying the interaction mechanism of Ru (Ⅱ) complexes with RNA. Information obtained from the study is potentially useful in the design of new RNA-targeting drugs.
文摘Efficiently converting CO_(2)and H_(2)O into value-added chemicals using solar energy is a viable approach to address global warming and the energy crisis.However,achieving artificial photocatalytic CO_(2)reduction using H_(2)O as the reductant poses challenges is due to the difficulty in efficient cooperation among multiple functional moieties.Metal-organic frameworks(MOFs)are promising candidates for overall CO_(2)photoreduction due to their large surface area,diverse active sites,and excellent tailorability.In this study,we designed a metal-organic framework photocatalyst,named PCN-224(Zn)-Bpy(Ru),by integrating photoactive Zn(Ⅱ)-porphyrin and Ru(Ⅱ)-bipyridyl moieties.In comparison,two isostructural MOFs just with either Zn(Ⅱ)-porphyrin or Ru(Ⅱ)-bipyridyl moiety,namely PCN-224-Bpy(Ru)and PCN-224(Zn)-Bpy were also synthesized.As a result,PCN-224(Zn)-Bpy(Ru)exhibited the highest photocatalytic conversion rate of CO_(2)to CO,with a production rate of 7.6μmol·g^(-1)·h^(-1)in a mixed solvent of CH_(3)CN and H_(2)O,without the need for co-catalysts,photosensitizers,or sacrificial agents.Mass spectrometer analysis detected the signals of^(13)CO(m/z=29),^(13)C^(18)O(m/z=31),^(16)O^(18)O(m/z=34),and^(18)O_(2)(m/z=36),confirming that CO_(2)and H_(2)O acted as the carbon and oxygen sources for CO and O_(2),respectively,thereby confirming the coupling of photocatalytic CO_(2)reduction with H_(2)O oxidation.In contrast,using PCN-224-Bpy(Ru)or PCN-224(Zn)-Bpy as catalysts under the same conditions resulted in significantly lower CO production rates of only 1.5 and 0μmol·g^(-1)·h^(-1),respectively.Mechanistic studies revealed that the lowest unoccupied molecular orbital(LUMO)potential of PCN-224(Zn)-Bpy(Ru)is more negative than the redox potentials of CO_(2)/CO,and the highest occupied molecular orbital(HOMO)potential is more positive than that of H_(2)O/O_(2),satisfying the thermodynamic requirements for overall photocatalytic CO_(2)reduction.In comparison,the HOMO potential of PCN-224(Zn)-Bpy without Ru(II)-bipyridyl moieties is less positive than that of H_(2)O/O_(2),indicating that the Ru(II)-bipyridyl moiety is thermodynamically necessary for CO_(2)reduction coupled with H_(2)O oxidation.Additionally,photoluminescence spectroscopy revealed that the fluorescence of PCN-224(Zn)-Bpy(Ru)was almost completely quenched,and a longer average photoluminescence lifetime compared to PCN-224(Zn)-Bpy and PCN-224-Bpy(Ru)was observed.These suggest a low recombination rate of photogenerated carriers in PCN-224(Zn)-Bpy(Ru),which also supported by the higher photocurrent observed in PCN-224(Zn)-Bpy(Ru)compared to PCN-224(Zn)-Bpy and PCN-224-Bpy(Ru).In summary,the integrated Zn(II)-porphyrin and Ru(II)-bipyridyl moieties in PCN-224(Zn)-Bpy(Ru)play important roles of a photosensitizer and CO_(2)reduction as well as H_(2)O oxidation sites,and their efficient cooperation optimizes the band structure,thereby facilitating the coupling of CO_(2)reduction with H_(2)O oxidation and resulting in highperformance artificial photocatalytic CO_(2)reduction.
