Covalently linked phthalocyanine complexes were incorporated in bilayer lipid membranes(BLN) and deposited on SnO_2 transparent electrodes, Their photovoltages were measured and compared. It has been found that a more...Covalently linked phthalocyanine complexes were incorporated in bilayer lipid membranes(BLN) and deposited on SnO_2 transparent electrodes, Their photovoltages were measured and compared. It has been found that a more favorable orientation and closer proximity are attained in the diad compounds between the donor (phthalocyanine)-acceptor(anthraquinone) pair than in the simple compound for efficient light-induced charge separation and transfer. The triad compound is the best among all tested compounds.展开更多
The EPR parameters of trivalent Er（3＋） ions doped in hexagonal Ga N crystal have been studied by diagonalizing the 364×364 complete energy matrices. The results indicate that the resonance ground states may be...The EPR parameters of trivalent Er（3＋） ions doped in hexagonal Ga N crystal have been studied by diagonalizing the 364×364 complete energy matrices. The results indicate that the resonance ground states may be derived from the Kramers doublet Γ6. The EPR g-factors may be ascribed to the stronger covalent bonding and nephelauxetic effects compared with other rare-earth doped complexes, as a result of the mismatch of ionic radii of the impurity Er（3＋）ion and the replaced Ga（3＋） ion apart from the intrinsic covalency of host Ga N. Furthermore, the J–J mixing effects on the EPR parameters from the high-lying manifolds have been evaluated. It is found that the dominant J–J mixing contribution is from the manifold 2K（15/2）, which accounts for about 2.5%. The next important J–J contribution arises from the crystal–field mixture between the ground state 4I（15/2） and the first excited state4I（13/2）, and is usually less than 0.2%. The contributions from the rest states may be ignored.展开更多
A unified theoretical method is established to determine the charge-compensated C3v(Ⅱ)centers of Er3+ions in CdF2 and CaF2 crystals by simulating the electron paramagnetic resonance(EPR)parameters and Stark energy le...A unified theoretical method is established to determine the charge-compensated C3v(Ⅱ)centers of Er3+ions in CdF2 and CaF2 crystals by simulating the electron paramagnetic resonance(EPR)parameters and Stark energy levels.The potential(Er^(3+)–F^(−)–O_(4)^(2−))and(Er^(3+)-F_(7)^(−)-O_(4)^(2−))structures for theC3v(Ⅱ)centers of Er3+ions in CdF2 and CaF2 crystals are checked by diagonalizing 364×364 complete energy matrices in the scheme of superposition model.Our studies indicate that the C3v(Ⅱ)centers of Er3+ions in CdF2 and CaF2 may be ascribed to the local(Er^(3+)-F^(−)-O_(4)^(2−))structure,where the upper ligand ion F−undergoes an off-center displacement by∆Z≈0.3˚A for CdF2 and∆Z≈0.29˚A for the CaF2 along the C3 axis.Meanwhile,a local compressed distortion of the(ErFO4)6−cluster is expected to be∆R≈0.07˚A for CdF2:Er3+and∆R≈0.079˚A for CaF2:Er3+.The considerable g-factor anisotropy for Er3+ions in each of both crystals is explained reasonably by the obtained local parameters.Furthermore,our studies show that a stronger covalent effect exists in the C3v(Ⅱ)center for Er3+in CaF2 or CaF2,which may be due to the stronger electrostatic interaction and closer distance between the central Er3+ion and ligand O2−with the(Er^(3+)-F^(−)-O_(4)^(2−))structure.展开更多
Induction,transfer,and modulation of intriguing supramolecular chirality were achieved in a chiral domino-type polymer system using a chiralα-end azobenzene(Azo)moiety as one chiral terminus and achiral Azo repeating...Induction,transfer,and modulation of intriguing supramolecular chirality were achieved in a chiral domino-type polymer system using a chiralα-end azobenzene(Azo)moiety as one chiral terminus and achiral Azo repeating units as building blocks.The Azo polymers prepared by atom transfer radical polymerization were imparted with well-controlled chain lengths and a chiral moiety at a well-defined position.One chiral terminus can effectively dictate the helical orientation of the achiral Azo stacks in the aggregation state.The spacer length between the chiral residue and the achiral repeating units dominates the preferred handedness of the side-chain Azo stacks.For instance,the R-configuration moiety with a short alkyl chain(with 0,2,and 3 carbons)induces right-handed supramolecular chirality,whereas those with long alkyl chains(with 4,5,and 6 carbons)induce the opposite helical orientation of the Azo units.Moreover,the chiral regulation of polymer aggregates is successfully achieved using the unique photoisomerization transition of the Azo chromophore and the heat-assisted reassembly approach.Chiral induction and chiral-to-achiral communication are further verified via theoretical simulations.展开更多
文摘Covalently linked phthalocyanine complexes were incorporated in bilayer lipid membranes(BLN) and deposited on SnO_2 transparent electrodes, Their photovoltages were measured and compared. It has been found that a more favorable orientation and closer proximity are attained in the diad compounds between the donor (phthalocyanine)-acceptor(anthraquinone) pair than in the simple compound for efficient light-induced charge separation and transfer. The triad compound is the best among all tested compounds.
基金Project supported by the Foundation of Education Department of Shaanxi Province,China(Grant No.16JK1402)
文摘The EPR parameters of trivalent Er（3＋） ions doped in hexagonal Ga N crystal have been studied by diagonalizing the 364×364 complete energy matrices. The results indicate that the resonance ground states may be derived from the Kramers doublet Γ6. The EPR g-factors may be ascribed to the stronger covalent bonding and nephelauxetic effects compared with other rare-earth doped complexes, as a result of the mismatch of ionic radii of the impurity Er（3＋）ion and the replaced Ga（3＋） ion apart from the intrinsic covalency of host Ga N. Furthermore, the J–J mixing effects on the EPR parameters from the high-lying manifolds have been evaluated. It is found that the dominant J–J mixing contribution is from the manifold 2K（15/2）, which accounts for about 2.5%. The next important J–J contribution arises from the crystal–field mixture between the ground state 4I（15/2） and the first excited state4I（13/2）, and is usually less than 0.2%. The contributions from the rest states may be ignored.
基金Project supported by the National Natural Science Foundation of China(Grant No.1170513)the Natural Science Foundation of Shaanxi Province,China(Grant No.Z20200051)+1 种基金the Foundation of the Education Department of Shaanxi Provincial Government,China(Grant No.16JK1461)the Scientific Research Foundation of Xi’an University of Architecture and Technology,China(Grant No.QN1729).
文摘A unified theoretical method is established to determine the charge-compensated C3v(Ⅱ)centers of Er3+ions in CdF2 and CaF2 crystals by simulating the electron paramagnetic resonance(EPR)parameters and Stark energy levels.The potential(Er^(3+)–F^(−)–O_(4)^(2−))and(Er^(3+)-F_(7)^(−)-O_(4)^(2−))structures for theC3v(Ⅱ)centers of Er3+ions in CdF2 and CaF2 crystals are checked by diagonalizing 364×364 complete energy matrices in the scheme of superposition model.Our studies indicate that the C3v(Ⅱ)centers of Er3+ions in CdF2 and CaF2 may be ascribed to the local(Er^(3+)-F^(−)-O_(4)^(2−))structure,where the upper ligand ion F−undergoes an off-center displacement by∆Z≈0.3˚A for CdF2 and∆Z≈0.29˚A for the CaF2 along the C3 axis.Meanwhile,a local compressed distortion of the(ErFO4)6−cluster is expected to be∆R≈0.07˚A for CdF2:Er3+and∆R≈0.079˚A for CaF2:Er3+.The considerable g-factor anisotropy for Er3+ions in each of both crystals is explained reasonably by the obtained local parameters.Furthermore,our studies show that a stronger covalent effect exists in the C3v(Ⅱ)center for Er3+in CaF2 or CaF2,which may be due to the stronger electrostatic interaction and closer distance between the central Er3+ion and ligand O2−with the(Er^(3+)-F^(−)-O_(4)^(2−))structure.
基金supported by the National Natural Science Foundation of China(92056111,21971180)the Nature Science Key Basic Research of Jiangsu Province for Higher Education(19KJA360006)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Program of Innovative Research Team of Soochow University。
文摘Induction,transfer,and modulation of intriguing supramolecular chirality were achieved in a chiral domino-type polymer system using a chiralα-end azobenzene(Azo)moiety as one chiral terminus and achiral Azo repeating units as building blocks.The Azo polymers prepared by atom transfer radical polymerization were imparted with well-controlled chain lengths and a chiral moiety at a well-defined position.One chiral terminus can effectively dictate the helical orientation of the achiral Azo stacks in the aggregation state.The spacer length between the chiral residue and the achiral repeating units dominates the preferred handedness of the side-chain Azo stacks.For instance,the R-configuration moiety with a short alkyl chain(with 0,2,and 3 carbons)induces right-handed supramolecular chirality,whereas those with long alkyl chains(with 4,5,and 6 carbons)induce the opposite helical orientation of the Azo units.Moreover,the chiral regulation of polymer aggregates is successfully achieved using the unique photoisomerization transition of the Azo chromophore and the heat-assisted reassembly approach.Chiral induction and chiral-to-achiral communication are further verified via theoretical simulations.
