3-Trifluoromethyl-pyrazoles containing strong fluorophore groups:triphenylamine(TPAPz)and carbazole(CarbPz),and their trinuclear silver(Ⅰ)complexes are found to be emissive in solution and the solid state,giving the ...3-Trifluoromethyl-pyrazoles containing strong fluorophore groups:triphenylamine(TPAPz)and carbazole(CarbPz),and their trinuclear silver(Ⅰ)complexes are found to be emissive in solution and the solid state,giving the first example of silver pyrazolate adducts emissive in solution at room temperature.The electronic coupling was observed for pyrazole with a structurally flexible triphenylamine substituent,determining the intraligand charge-transfer(ILCT)nature of the excited states.The association-dissociation of the trinuclear complex core with the heavy atom effect leads to the intense phosphorescence of the triphenylamine-containing complex.The structural rigidity of the N-ethyl carbazole substituent allows only twisting via the bond to the pyrazolate core leading to typical carbazole-centered(LC)fluorescence in solution.In the solid-state,aggregation plays the primary role in emission properties.The observed behavior is in good agreement with the theoretical calculations.展开更多
The complexation of 4,4’-halogen-substituted biphenyls(BPs)with a trinuclear silver(I)3,5-bis(trifluoromethyl)pyrazolate adduct([AgL]_(3))is observed in the solution and solid states.Infinite stacks are formed by alt...The complexation of 4,4’-halogen-substituted biphenyls(BPs)with a trinuclear silver(I)3,5-bis(trifluoromethyl)pyrazolate adduct([AgL]_(3))is observed in the solution and solid states.Infinite stacks are formed by alternating BPs and[AgL]_(3) molecules via multiple metal-πinteractions in a crystal.Encapsulation of the biphenyl derivatives between the[AgL]_(3) units allows room-temperature phosphorescence in the solid state.Furthermore,the intercalation of BPs results in the formation of planar geometry,which allows the reduction of non-radiative relaxation and enhances luminescence due to the planar geometry of the excited states.Another crucial factor in efficient light emission is the asymmetry of the intermolecular complexes.The obtained complexes exhibited both phosphorescence and fluorescence bands spanning a wide spectral range.Furthermore,fine-tuning of emissions by varying excitation energy could produce white light.展开更多
基金financially supported by the Russian Science Foundation(project no.19-73-20262).
文摘3-Trifluoromethyl-pyrazoles containing strong fluorophore groups:triphenylamine(TPAPz)and carbazole(CarbPz),and their trinuclear silver(Ⅰ)complexes are found to be emissive in solution and the solid state,giving the first example of silver pyrazolate adducts emissive in solution at room temperature.The electronic coupling was observed for pyrazole with a structurally flexible triphenylamine substituent,determining the intraligand charge-transfer(ILCT)nature of the excited states.The association-dissociation of the trinuclear complex core with the heavy atom effect leads to the intense phosphorescence of the triphenylamine-containing complex.The structural rigidity of the N-ethyl carbazole substituent allows only twisting via the bond to the pyrazolate core leading to typical carbazole-centered(LC)fluorescence in solution.In the solid-state,aggregation plays the primary role in emission properties.The observed behavior is in good agreement with the theoretical calculations.
基金supported by the Russian Science Foundation(project№19-73-20262)NMR investigations were performed with the financial support of the Ministry of Science and Higher Education of the Russian Federation employing the equipment of Center for molecular composition studies of INEOS RAS.The crystal structures of 1Ag,2Ag and 3Ag were established using the equipment of St.Petersburg University Research Park(Center of X-ray Diffraction).
文摘The complexation of 4,4’-halogen-substituted biphenyls(BPs)with a trinuclear silver(I)3,5-bis(trifluoromethyl)pyrazolate adduct([AgL]_(3))is observed in the solution and solid states.Infinite stacks are formed by alternating BPs and[AgL]_(3) molecules via multiple metal-πinteractions in a crystal.Encapsulation of the biphenyl derivatives between the[AgL]_(3) units allows room-temperature phosphorescence in the solid state.Furthermore,the intercalation of BPs results in the formation of planar geometry,which allows the reduction of non-radiative relaxation and enhances luminescence due to the planar geometry of the excited states.Another crucial factor in efficient light emission is the asymmetry of the intermolecular complexes.The obtained complexes exhibited both phosphorescence and fluorescence bands spanning a wide spectral range.Furthermore,fine-tuning of emissions by varying excitation energy could produce white light.
