The title compound bis（1-（4-（dimethylamino）benzylidene）-4-phenylthiosemicar-bazato）-palladium（Ⅱ）（PdL2） was obtained by reacting 1-（4-（dimethylamino）benzylidene）-4-phenyl-thiosemicarbazide with dichloro...The title compound bis（1-（4-（dimethylamino）benzylidene）-4-phenylthiosemicar-bazato）-palladium（Ⅱ）（PdL2） was obtained by reacting 1-（4-（dimethylamino）benzylidene）-4-phenyl-thiosemicarbazide with dichlorobis（benzonitrile）palladium（Ⅱ） in methanol,and its structure was characterized by single-crystal X-ray diffraction.The crystal of PdL2 was obtained in dimethyl-formamide（DMF） solvent with solvent molecules involved in the cell and crystallizes in the monoclinic system,space group C2 with a = 18.485（15）,b = 7.090（5）,c = 17.595（11） ,β = 121.21（3）o,V = 1972（2） 3,Z = 2,Mr = 847.40,Dc = 1.427 g/cm3,μ = 0.624 mm-1,F（000） = 880,R = 0.0607 and wR = 0.1358.The Pd atom adopts a distorted square planar coordination geometry with two Pd-N and two Pd-S bonds.The ligand loses a proton from its tautomeric thiol form and coordinates to the Pd atom via mercapto sulfur and the imine nitrogen atom,which binds to palladium as bidentate N,S-donors forming five-membered chelate rings.The complex formed hydrogen bonding interaction with solvent DMF molecules from the hydrogen of phenylamine to the oxygen of DMF and several intramolecular hydrogen bonds.Pd（Ⅱ） perturbed ligand π-π＊ transition and metal-to-ligand charge transfer（MLCT） transition are observed in its electronic absorption spectra.The complex exhibits intraligand 1π-π＊（IL） state and MLCT state dual fluorescent emissions in organic solvent at room temperature.展开更多
A new dual fluorescent N,N-dimethylaniline derivative, sodium 4-(N,N-dimethylamino)-benzenesulfonate (SDMAS), is reported. In SDMAS, the electron acceptor is linked to the phenyl ring via a sulfur atom at the para-pos...A new dual fluorescent N,N-dimethylaniline derivative, sodium 4-(N,N-dimethylamino)-benzenesulfonate (SDMAS), is reported. In SDMAS, the electron acceptor is linked to the phenyl ring via a sulfur atom at the para-position of the electron donor. It was found that SDMAS emits dual fluorescence only in highly polar solvent water but not in organic solvents such as formamide, methanol and acetonitrile. In organic solvents only a single-band emission atca.360 nm was observed in the short wavelength region. The dual fluorescence of SDMAS in water was found at 365 and 475 nm, respectively. Introduction of organic solvent such as ethanol, acetonitrile, and 1,4-dioxane into aqueous solution of SDMAS leads to blue-shift and quenching of the long-wavelength emission. Measurements of steady-state and picosecond time-resolved fluorescence indicate that the long wavelength fluorescence is emitted from a charge transfer (CT) state that is populated from the locally excited (LE) state, with the latter giving off the short wavelength fluorescence. The fact that a highly polar solvent is required to bring out the dual fluorescence suggests that the CT process of SDMAS has a high activation energy (E a). In supporting this assumption the timeresolved fluorescence measurements give anE a of 15.35 kJ·mol-1. It was assumed that the participation of the sulfur atom d-orbital in the conjugation of sulfonate group with phenyl ring and the strong twisting and inverting of the dimethylamino plane relative to the phenyl ring could be the reasons for the high activation energy. A molecular configuration change upon charge transfer in water was suggested for SDMAS based on the thermodynamic data. SDMAS reported here represents the example of the dual fluorescent amine substituted aromatic sulfonate.展开更多
基金supported by the National Basic Research Program of China (973 Program,2007CB815301)NSF (No. 20721001)the Science & Technology Innovation Project of Xiamen University (No. K70025)
文摘The title compound bis（1-（4-（dimethylamino）benzylidene）-4-phenylthiosemicar-bazato）-palladium（Ⅱ）（PdL2） was obtained by reacting 1-（4-（dimethylamino）benzylidene）-4-phenyl-thiosemicarbazide with dichlorobis（benzonitrile）palladium（Ⅱ） in methanol,and its structure was characterized by single-crystal X-ray diffraction.The crystal of PdL2 was obtained in dimethyl-formamide（DMF） solvent with solvent molecules involved in the cell and crystallizes in the monoclinic system,space group C2 with a = 18.485（15）,b = 7.090（5）,c = 17.595（11） ,β = 121.21（3）o,V = 1972（2） 3,Z = 2,Mr = 847.40,Dc = 1.427 g/cm3,μ = 0.624 mm-1,F（000） = 880,R = 0.0607 and wR = 0.1358.The Pd atom adopts a distorted square planar coordination geometry with two Pd-N and two Pd-S bonds.The ligand loses a proton from its tautomeric thiol form and coordinates to the Pd atom via mercapto sulfur and the imine nitrogen atom,which binds to palladium as bidentate N,S-donors forming five-membered chelate rings.The complex formed hydrogen bonding interaction with solvent DMF molecules from the hydrogen of phenylamine to the oxygen of DMF and several intramolecular hydrogen bonds.Pd（Ⅱ） perturbed ligand π-π＊ transition and metal-to-ligand charge transfer（MLCT） transition are observed in its electronic absorption spectra.The complex exhibits intraligand 1π-π＊（IL） state and MLCT state dual fluorescent emissions in organic solvent at room temperature.
文摘A new dual fluorescent N,N-dimethylaniline derivative, sodium 4-(N,N-dimethylamino)-benzenesulfonate (SDMAS), is reported. In SDMAS, the electron acceptor is linked to the phenyl ring via a sulfur atom at the para-position of the electron donor. It was found that SDMAS emits dual fluorescence only in highly polar solvent water but not in organic solvents such as formamide, methanol and acetonitrile. In organic solvents only a single-band emission atca.360 nm was observed in the short wavelength region. The dual fluorescence of SDMAS in water was found at 365 and 475 nm, respectively. Introduction of organic solvent such as ethanol, acetonitrile, and 1,4-dioxane into aqueous solution of SDMAS leads to blue-shift and quenching of the long-wavelength emission. Measurements of steady-state and picosecond time-resolved fluorescence indicate that the long wavelength fluorescence is emitted from a charge transfer (CT) state that is populated from the locally excited (LE) state, with the latter giving off the short wavelength fluorescence. The fact that a highly polar solvent is required to bring out the dual fluorescence suggests that the CT process of SDMAS has a high activation energy (E a). In supporting this assumption the timeresolved fluorescence measurements give anE a of 15.35 kJ·mol-1. It was assumed that the participation of the sulfur atom d-orbital in the conjugation of sulfonate group with phenyl ring and the strong twisting and inverting of the dimethylamino plane relative to the phenyl ring could be the reasons for the high activation energy. A molecular configuration change upon charge transfer in water was suggested for SDMAS based on the thermodynamic data. SDMAS reported here represents the example of the dual fluorescent amine substituted aromatic sulfonate.
