Keggin-type phenylimido-polyoxometalates α-[PM12O39NPh]3- (M = W and Mo) have been systematically investigated on the electronic structures, redox as well as nonlinear optical (NLO) properties by density functional t...Keggin-type phenylimido-polyoxometalates α-[PM12O39NPh]3- (M = W and Mo) have been systematically investigated on the electronic structures, redox as well as nonlinear optical (NLO) properties by density functional theory (DFT). The strong M≡N bond confirmed by natural bond orbital (NBO) analysis comprises one σ bond and two π bonds, the same as Mo≡N in [Mo6O18NPh]2-. Furthermore, phenylimido segment effectively modifies the electronic properties of α-[PM12O39NPh]3-. On one hand, when enlarging the inorganic cluster from {Mo6O18} to {PMo12O39}, the energy gap between HOMO and LUMO in α-[PMo12O39NPh]3- decreased, resulting in enormously anodic shift for the reduction potential, while the excitation energy is less and the total second-order polarizability β0 is up to 438.3×10?30 esu, which is nearly 10 times larger than that of [Mo6O18NPh]2-. On the other hand, when metal W in α-[PM12O39NPh]3- is substituted by Mo, the interaction between Mo and N is enhanced and the redox ability becomes stronger. The β0 value for α-[PMo12O39NPh]3- is more than 5 times higher than that of α-[PW12O39NPh]3?. It indicates that changing appropriate metal or enlarging the inorganic cluster will improve the redox properties and second-order nonlinear response. Moreover, the electron transition for three compounds mentioned above occurred mainly from organoimido segment (as the electron donor) to polyanion cluster (as the acceptor). As a result, α-[PMo12O39NPh]3- may be a promising candidate for oxidant and nonlinear optical material.展开更多
The second-order nonlinear optical (NLO) properties of a series of benzothiazole derivatives were studied by use of the ZINDO-SOS method. These chromophores are formed by a donor-π-bridge-acceptor system, based on a ...The second-order nonlinear optical (NLO) properties of a series of benzothiazole derivatives were studied by use of the ZINDO-SOS method. These chromophores are formed by a donor-π-bridge-acceptor system, based on a nitro group connected with benzothiazole as the acceptor and a hydroxyl-functional amino group as the donor. For the purpose of comparison, we also designed molecules in which nitrobenzene is an acceptor. The calculation results indicate that benzothiazole derivatives exhibit larger second-order polarizabilities than nitrobenzene derivatives. In order to clarify the origin of the NLO response of these chromophores, their electron properties were investigated as well. The benzothiazole derivatives are good candidates for application in electro-optical device due to their high optical nonlinearities, good thermal and photonic stability.展开更多
Second-order polarizabilities of BMC and MMONS were determined by solvatocbromic method. The second-order polarizabilities of BMC and MMONS were also calculated by quantum chemical semiempirical CNDO/S-CI method and p...Second-order polarizabilities of BMC and MMONS were determined by solvatocbromic method. The second-order polarizabilities of BMC and MMONS were also calculated by quantum chemical semiempirical CNDO/S-CI method and perturbation theory and second-order nonlinear optical data respectively. Calculated values are in good agreement with experimental results. The effect of molecular and crystal structure on second-order polarizabilities has also been discussed.展开更多
The equilibrium geometries and UV visible spectra of a series of donor C 60 molecules were obtained by means of the AM1 and INDO/CI method, on the basis of accurate geometric and electronic structures. The nonl...The equilibrium geometries and UV visible spectra of a series of donor C 60 molecules were obtained by means of the AM1 and INDO/CI method, on the basis of accurate geometric and electronic structures. The nonlinear second order optical polarizabilities were calculated using the method INDO/SDCI combined with the Sum Over States (SOS) expression. The calculated β ( λ =1 34 μm) values are 28 81, 48 56, 57 33, 66 99, 70 85, 85 84, and 142 14 (×10 -30 esu) for the molecules A, B, C, D, E, F and G, respectively. The frontier orbitals were plot for the representative molecules in order to exhibit the intramolecular charge transfer. The results indicate that introduction of thienylethylene can enhancethe NLO response and the dimethyl^aniline substituted di^thienyl^ethylene C 60 (molecule G) possesses the largest NLO second order optical polarizability. The large β values can be attributed to the charge transfer between the substituents and C 60 , as well as within the three dimensional conjugated sphere of C 60 .展开更多
The second-order nonlinear optical properties of thiophene S,S -dioxides derivatives were studied by using the ZINDO-SOS method. The computed results show that the thiophene S,S -dioxide derivatives exhibit larger sec...The second-order nonlinear optical properties of thiophene S,S -dioxides derivatives were studied by using the ZINDO-SOS method. The computed results show that the thiophene S,S -dioxide derivatives exhibit larger second-order polarizabilities than their thiophene precursors. In order to clarify the origin of the different NLO responses among these chromophores, their electron properties and frontier orbital properties were investigated as well. These thiophene S,S -dioxides derivatives are good candidates for their application in electro-optical device due to their high nonlinearities, good thermal and photo stabilities.展开更多
基金Supported by National Natural Science Foundation of China (Grant No. 20573016)Training Fund of NENU’S Scientific Innovation Project (Grant No. NENU- STC07017)+1 种基金Science Foundation for Young Teachers of Northeast Normal University (Grant No. 20070304)Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT)
文摘Keggin-type phenylimido-polyoxometalates α-[PM12O39NPh]3- (M = W and Mo) have been systematically investigated on the electronic structures, redox as well as nonlinear optical (NLO) properties by density functional theory (DFT). The strong M≡N bond confirmed by natural bond orbital (NBO) analysis comprises one σ bond and two π bonds, the same as Mo≡N in [Mo6O18NPh]2-. Furthermore, phenylimido segment effectively modifies the electronic properties of α-[PM12O39NPh]3-. On one hand, when enlarging the inorganic cluster from {Mo6O18} to {PMo12O39}, the energy gap between HOMO and LUMO in α-[PMo12O39NPh]3- decreased, resulting in enormously anodic shift for the reduction potential, while the excitation energy is less and the total second-order polarizability β0 is up to 438.3×10?30 esu, which is nearly 10 times larger than that of [Mo6O18NPh]2-. On the other hand, when metal W in α-[PM12O39NPh]3- is substituted by Mo, the interaction between Mo and N is enhanced and the redox ability becomes stronger. The β0 value for α-[PMo12O39NPh]3- is more than 5 times higher than that of α-[PW12O39NPh]3?. It indicates that changing appropriate metal or enlarging the inorganic cluster will improve the redox properties and second-order nonlinear response. Moreover, the electron transition for three compounds mentioned above occurred mainly from organoimido segment (as the electron donor) to polyanion cluster (as the acceptor). As a result, α-[PMo12O39NPh]3- may be a promising candidate for oxidant and nonlinear optical material.
基金ProjectsupportedbytheNationalNaturalScienceFoundationofChina (No .2 99730 10 )andtheKeyLabofSupramolecularStructureandMate rialofJilinUniversity .
文摘The second-order nonlinear optical (NLO) properties of a series of benzothiazole derivatives were studied by use of the ZINDO-SOS method. These chromophores are formed by a donor-π-bridge-acceptor system, based on a nitro group connected with benzothiazole as the acceptor and a hydroxyl-functional amino group as the donor. For the purpose of comparison, we also designed molecules in which nitrobenzene is an acceptor. The calculation results indicate that benzothiazole derivatives exhibit larger second-order polarizabilities than nitrobenzene derivatives. In order to clarify the origin of the NLO response of these chromophores, their electron properties were investigated as well. The benzothiazole derivatives are good candidates for application in electro-optical device due to their high optical nonlinearities, good thermal and photonic stability.
文摘Second-order polarizabilities of BMC and MMONS were determined by solvatocbromic method. The second-order polarizabilities of BMC and MMONS were also calculated by quantum chemical semiempirical CNDO/S-CI method and perturbation theory and second-order nonlinear optical data respectively. Calculated values are in good agreement with experimental results. The effect of molecular and crystal structure on second-order polarizabilities has also been discussed.
文摘The equilibrium geometries and UV visible spectra of a series of donor C 60 molecules were obtained by means of the AM1 and INDO/CI method, on the basis of accurate geometric and electronic structures. The nonlinear second order optical polarizabilities were calculated using the method INDO/SDCI combined with the Sum Over States (SOS) expression. The calculated β ( λ =1 34 μm) values are 28 81, 48 56, 57 33, 66 99, 70 85, 85 84, and 142 14 (×10 -30 esu) for the molecules A, B, C, D, E, F and G, respectively. The frontier orbitals were plot for the representative molecules in order to exhibit the intramolecular charge transfer. The results indicate that introduction of thienylethylene can enhancethe NLO response and the dimethyl^aniline substituted di^thienyl^ethylene C 60 (molecule G) possesses the largest NLO second order optical polarizability. The large β values can be attributed to the charge transfer between the substituents and C 60 , as well as within the three dimensional conjugated sphere of C 60 .
基金Supported by the National Natural Science Foundation of China(No. 2 98730 2 5 )
文摘The second-order nonlinear optical properties of thiophene S,S -dioxides derivatives were studied by using the ZINDO-SOS method. The computed results show that the thiophene S,S -dioxide derivatives exhibit larger second-order polarizabilities than their thiophene precursors. In order to clarify the origin of the different NLO responses among these chromophores, their electron properties and frontier orbital properties were investigated as well. These thiophene S,S -dioxides derivatives are good candidates for their application in electro-optical device due to their high nonlinearities, good thermal and photo stabilities.
