Optical limiting （OL） properties and two-photon absorption （TPA） of a series of covalently linked graphene oxide-porphyrin composite materials have been investigated by numerically solving the rate equations and f...Optical limiting （OL） properties and two-photon absorption （TPA） of a series of covalently linked graphene oxide-porphyrin composite materials have been investigated by numerically solving the rate equations and field intensity equation with an iterative predictor-corrector finite-difference time-domain technique in nanosecond time domain. Our results show that graphene oxide-porphyrin composites exhibit enhanced OL behavior and possess larger TPA cross section compared with individual porphyrins. Interestingly~ unlike the previous result that porphyrin with heavier central metal shows better nonlinear abilities than that with- out metal substitute, graphene oxide-metal free porphyrin composite has stronger nonlinear absorption properties compared with graphene oxide-metal porphyrin composite. The com- putational results are in reasonable agreement with the experimental ones. Special attention has been paid to the influence of thickness of the medium and pulse width on TPA cross sections, which presents that larger TPA cross sections are obtained as the medium is thicker or the pulse duration is wider.展开更多
We have theoretically investigated two series of cyclometalated Pt（II） complexes, a series [Pt （C, N, N） Cl] and b series [Pt （C, N, Npyrazolyl） Cl]. The geometrical and electronic structures are calculated at t...We have theoretically investigated two series of cyclometalated Pt（II） complexes, a series [Pt （C, N, N） Cl] and b series [Pt （C, N, Npyrazolyl） Cl]. The geometrical and electronic structures are calculated at the ECP60MWB//6-31G＊（H, C, Cl, N, S） basis set level using DFT method; one-photon absorption （OPA） properties are calculated by using both TDDFT and ZINDO methods and two-photon absorption （TPA） properties are obtained with the ZINDO/SOS method. The resonance integrals parameters （βsp and βd） for Pt are adjusted to -1 and -28.5 eV, respectively, to make max OPA wavelength calculated by ZINDO closest to the experimental data and TDDFT results. The calculated results indicate the molecule 2b （[Pt （Cnaphthyl, N, Npyrazolyl） Cl]） has the biggest potential as outstanding TPA materials because （i） the TPA properties of b series are more outstanding in IR wavelength range, the molecules in b series have good transparencies and possess 1-pyrazolyl-NH that is also available for another metal coordination （e.g., dimerization） and chemical interactions; （ii） when C is CnaphthyI in the C, N, N ligand of cyclometalated Pt（II） complexes, the molecules have the best conjugation effect and the best TPA properties.展开更多
基金This work was supported by the 973 program （No.2011CB808100） and the Natural Science Foundation of Shandong Province （No.ZR2014AM026）.
文摘Optical limiting （OL） properties and two-photon absorption （TPA） of a series of covalently linked graphene oxide-porphyrin composite materials have been investigated by numerically solving the rate equations and field intensity equation with an iterative predictor-corrector finite-difference time-domain technique in nanosecond time domain. Our results show that graphene oxide-porphyrin composites exhibit enhanced OL behavior and possess larger TPA cross section compared with individual porphyrins. Interestingly~ unlike the previous result that porphyrin with heavier central metal shows better nonlinear abilities than that with- out metal substitute, graphene oxide-metal free porphyrin composite has stronger nonlinear absorption properties compared with graphene oxide-metal porphyrin composite. The com- putational results are in reasonable agreement with the experimental ones. Special attention has been paid to the influence of thickness of the medium and pulse width on TPA cross sections, which presents that larger TPA cross sections are obtained as the medium is thicker or the pulse duration is wider.
基金supported by the Youth Scholar Backbone Supporting Plan Project for General Universities of Heilongjiang Province (1155G22)China Postdoctoral Science Foundation (20100481018)+2 种基金Heilongjiang Postdoctoral Financial Assistance (LBH-Z09096)Youth Science Foundation of Harbin University of Science and Technology (2009YF020)National Natural Science Foundation of China (20973078)
文摘We have theoretically investigated two series of cyclometalated Pt（II） complexes, a series [Pt （C, N, N） Cl] and b series [Pt （C, N, Npyrazolyl） Cl]. The geometrical and electronic structures are calculated at the ECP60MWB//6-31G＊（H, C, Cl, N, S） basis set level using DFT method; one-photon absorption （OPA） properties are calculated by using both TDDFT and ZINDO methods and two-photon absorption （TPA） properties are obtained with the ZINDO/SOS method. The resonance integrals parameters （βsp and βd） for Pt are adjusted to -1 and -28.5 eV, respectively, to make max OPA wavelength calculated by ZINDO closest to the experimental data and TDDFT results. The calculated results indicate the molecule 2b （[Pt （Cnaphthyl, N, Npyrazolyl） Cl]） has the biggest potential as outstanding TPA materials because （i） the TPA properties of b series are more outstanding in IR wavelength range, the molecules in b series have good transparencies and possess 1-pyrazolyl-NH that is also available for another metal coordination （e.g., dimerization） and chemical interactions; （ii） when C is CnaphthyI in the C, N, N ligand of cyclometalated Pt（II） complexes, the molecules have the best conjugation effect and the best TPA properties.
