A new ligand 1,4-bis(2-hydroxymethylphenyl)-1,4-dioxabutane was synthesized by reducing 1,4-bis(2-formylphenyl)-1,4-dioxabutane with NaBH4 in absolute methanol solution. The crystal structure of the title compound C16...A new ligand 1,4-bis(2-hydroxymethylphenyl)-1,4-dioxabutane was synthesized by reducing 1,4-bis(2-formylphenyl)-1,4-dioxabutane with NaBH4 in absolute methanol solution. The crystal structure of the title compound C16H18O4 has been determined by single-crystal X-ray diffraction. The ligand crystallizes in the orthorhombic system, space group Pbcn with a = 13.777(1), b = 11.731(1), c = 9.076(8) ? V = 1466.8(2) ?, Mr = 274.30, Z = 4, F(000) = 548, Dc = 1.24 g/cm3, T = 293 K, m = 8.9 cm-1 and l = 0.71073 ? The structure was refined to R = 0.0324 and wR = 0.1025 for 1112 observed reflections with I > 2s(I). The two benzene rings are not on the same plane, and the dihedral angle between them is 60.6? The ligand has C2 symmetry axis which passes through the center of C(8)C(8a). The molecules are linked to each other by hydrogen bonding network to form supramolecular chain. The ligands connect to each other through the hydrogen bonds to form one-dimensional chains which further connect through the hydrogen bonds to form two- and three-dimensional structures.展开更多
Excited-state double proton transfer(ESDPT)is a controversial issue which has long been plagued with theoretical and experimental communities.Herein,we took 1,8-dihydroxy-2-naphthaldehyde(DHNA)as a prototype and used ...Excited-state double proton transfer(ESDPT)is a controversial issue which has long been plagued with theoretical and experimental communities.Herein,we took 1,8-dihydroxy-2-naphthaldehyde(DHNA)as a prototype and used combined complete active space selfconsistent field(CASSCF)and multi-state complete active-space second-order perturbation(MS-CASPT2)methods to investigate ESDPT and excited-state deactivation pathways of DHNA.Three different tautomer minima of S1-ENOL,S1-KETO-1,and S1-KETO-2 and two crucial conical intersections of S1 S0-KETO-1 and S1 S0-KETO-2 in and between the S0 and S1 states were obtained.S1-KETO-1 and S1-KETO-2 should take responsibility for experimentally observing dual-emission bands.In addition,two-dimensional potential energy surfaces(2 D-PESs)and linear interpolated internal coordinate paths connecting relevant structures were calculated at the MS-CASPT2//CASSCF level and confirmed a stepwise ESDPT mechanism.Specifically,the first proton transfer from S1-ENOL to S1-KETO-1 is barrierless,whereas the second one from S1-KETO-1 to S1-KETO-2 demands a barrier of ca.6.0 kcal/mol.The linear interpolated internal coordinate path connecting S1-KETO-1(S1-KETO-2)and S_(1) S0-KETO-1(S1 S0-KETO-2)is uphill with a barrier of ca.12.0 kcal/mol,which will trap DHNA in the S_(1) state while therefore enabling dual-emission bands.On the other hand,the S1/S0 conical intersections would also prompt the S_(1) system to decay to the S_(0) state,which could be to certain extent suppressed by locking the rotation of the C5-C8-C9-O10 dihedral angle.These mechanistic insights are not only helpful for understanding ESDPT but also useful for designing novel molecular materials with excellent photoluminescent performances.展开更多
By introducing 2-hydroxy-4-methoxy-benzophenone(UVA) and 1,10-phenanthroline(Phen) as the ligands, the ternary rare earth complex of Eu(UVA)3Phen is synthesized, and it is characterized by elemental analysis, mass spe...By introducing 2-hydroxy-4-methoxy-benzophenone(UVA) and 1,10-phenanthroline(Phen) as the ligands, the ternary rare earth complex of Eu(UVA)3Phen is synthesized, and it is characterized by elemental analysis, mass spectra(MS) and infrared(IR) and ultraviolet(UV) spectroscopy. Results show that the Eu(III) in complex emits strong red luminescence when it is excited by UV light, and it has higher sensitized luminescent efficiency and longer lifetime. The organic-inorganic thin film of complex Eu(UVA)3Phen doped with nano-Ti O2 is prepared, and the nano-Ti O2 is used in the luminescence layer to change the luminescence property of Eu(UVA)3Phen. It is found that there is an efficient energy transfer process between ligands and metal ions. Moreover, in an indium tin oxide(ITO)/poly(N-vinylcar-bazole)(PVK)/Eu(UVA)3Phen/Al device, Eu3+ can be excited by intramolecular ligand-to-metal energy transfer process. The main peak of emission at 613 nm is attributed to 5D0→7F2 transition of the Eu3+, and this process results in the enhanced red emission.展开更多
基金The project was supported by the state key laboratory of Suzhou University and the foundation of Science Committee of Jiangsu Province
文摘A new ligand 1,4-bis(2-hydroxymethylphenyl)-1,4-dioxabutane was synthesized by reducing 1,4-bis(2-formylphenyl)-1,4-dioxabutane with NaBH4 in absolute methanol solution. The crystal structure of the title compound C16H18O4 has been determined by single-crystal X-ray diffraction. The ligand crystallizes in the orthorhombic system, space group Pbcn with a = 13.777(1), b = 11.731(1), c = 9.076(8) ? V = 1466.8(2) ?, Mr = 274.30, Z = 4, F(000) = 548, Dc = 1.24 g/cm3, T = 293 K, m = 8.9 cm-1 and l = 0.71073 ? The structure was refined to R = 0.0324 and wR = 0.1025 for 1112 observed reflections with I > 2s(I). The two benzene rings are not on the same plane, and the dihedral angle between them is 60.6? The ligand has C2 symmetry axis which passes through the center of C(8)C(8a). The molecules are linked to each other by hydrogen bonding network to form supramolecular chain. The ligands connect to each other through the hydrogen bonds to form one-dimensional chains which further connect through the hydrogen bonds to form two- and three-dimensional structures.
基金supported by the National Key Research and Development Program of China for BinBin Xie(No.2019YFA0709400)the National Natural Science Foundation of China for Bin-Bin Xie(No.21903068)+1 种基金Xiang-Yang Liu(No.22003043)Natural Science Foundation of Zhejiang Province for Bin-Bin Xie(No.LQ19B030007)。
文摘Excited-state double proton transfer(ESDPT)is a controversial issue which has long been plagued with theoretical and experimental communities.Herein,we took 1,8-dihydroxy-2-naphthaldehyde(DHNA)as a prototype and used combined complete active space selfconsistent field(CASSCF)and multi-state complete active-space second-order perturbation(MS-CASPT2)methods to investigate ESDPT and excited-state deactivation pathways of DHNA.Three different tautomer minima of S1-ENOL,S1-KETO-1,and S1-KETO-2 and two crucial conical intersections of S1 S0-KETO-1 and S1 S0-KETO-2 in and between the S0 and S1 states were obtained.S1-KETO-1 and S1-KETO-2 should take responsibility for experimentally observing dual-emission bands.In addition,two-dimensional potential energy surfaces(2 D-PESs)and linear interpolated internal coordinate paths connecting relevant structures were calculated at the MS-CASPT2//CASSCF level and confirmed a stepwise ESDPT mechanism.Specifically,the first proton transfer from S1-ENOL to S1-KETO-1 is barrierless,whereas the second one from S1-KETO-1 to S1-KETO-2 demands a barrier of ca.6.0 kcal/mol.The linear interpolated internal coordinate path connecting S1-KETO-1(S1-KETO-2)and S_(1) S0-KETO-1(S1 S0-KETO-2)is uphill with a barrier of ca.12.0 kcal/mol,which will trap DHNA in the S_(1) state while therefore enabling dual-emission bands.On the other hand,the S1/S0 conical intersections would also prompt the S_(1) system to decay to the S_(0) state,which could be to certain extent suppressed by locking the rotation of the C5-C8-C9-O10 dihedral angle.These mechanistic insights are not only helpful for understanding ESDPT but also useful for designing novel molecular materials with excellent photoluminescent performances.
基金supported by the National Natural Science Foundation of China(No.21346006)the Department of Scientific Research Project in Heilongjiang Province(Nos.B201111 and B201015)+4 种基金the Scientific Research Project of Heilongjiang Province Education Department(Nos.12541783,12541830,12541821 and 12531693)the National College Students'Innovation and Entrepreneurship Training Major Project(No.201310222013)the Interdisciplinary Research Project of Jiamusi University(No.JC2014-005)the Graduate Scientific and Technological Innovation Major Project of Jiamusi University(No.LZR2014_034)the Jiamusi University Students'Science and Technology Innovation Project(No.XSYD 2004-020)
文摘By introducing 2-hydroxy-4-methoxy-benzophenone(UVA) and 1,10-phenanthroline(Phen) as the ligands, the ternary rare earth complex of Eu(UVA)3Phen is synthesized, and it is characterized by elemental analysis, mass spectra(MS) and infrared(IR) and ultraviolet(UV) spectroscopy. Results show that the Eu(III) in complex emits strong red luminescence when it is excited by UV light, and it has higher sensitized luminescent efficiency and longer lifetime. The organic-inorganic thin film of complex Eu(UVA)3Phen doped with nano-Ti O2 is prepared, and the nano-Ti O2 is used in the luminescence layer to change the luminescence property of Eu(UVA)3Phen. It is found that there is an efficient energy transfer process between ligands and metal ions. Moreover, in an indium tin oxide(ITO)/poly(N-vinylcar-bazole)(PVK)/Eu(UVA)3Phen/Al device, Eu3+ can be excited by intramolecular ligand-to-metal energy transfer process. The main peak of emission at 613 nm is attributed to 5D0→7F2 transition of the Eu3+, and this process results in the enhanced red emission.
