Publications (12)28.22 Total impact
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Article: TDDFT studies on chiral organophosphonate substituted divacant Keggin-type polyoxotungstate: diplex multistep-redox-triggered chiroptical and NLO switch.
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ABSTRACT: We theoretically investigate a novel switching phenomenon based on the divacant Keggin-type polyoxotungstate bearing chiral organophosphonate [{NH(2)CH(CH(3))PO}(2)(γ-SiW(10)O(36))](4-), that is the synchronous chiroptical and nonlinear optical (NLO) switch triggered by redox. The ECD calculations on the Boltzmann weighted conformations of the three oxidation states of this chiral polyoxometalate (POM) clearly present a chiroptical switching process. The electronic transition and the bond-length alternation studies show that the chirality transfer from chiral carbon atom to POM cage increases as the polyanion is reduced. Simultaneously, the static first hyperpolarizability of studied chiral POM quadrupled from the oxidized state to the 1e-reduced state, and is further doubled to the 2e-reduced state, which is mainly due to the increasing electronic-dipole-allowed d-d charge transfer transitions in the POM cage. This work firstly reproduces the ECD spectrum of chiral POM with high accuracy and proves the possibility for confirming the molecular conformations of flexible chiral POMs in solution by the aid of ECD calculations. Most importantly, a sensitive diplex switch based on a chiral POM is predicted in theory, which may aid the design of novel POM-based switches.Dalton Transactions 07/2012; 41(33):10097-104. · 3.84 Impact Factor -
Article: Charge transport and luminescent properties of C6F5Cu(py) and their relationships with cuprophilic interactions: a density functional theory investigation
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ABSTRACT: Weak interactions between copper atoms so called cuprophilic interactions, lead to the supramolecular stacks of C6F5Cu(py), which possess unique luminescent and charge transport properties. First-principle band-structure calculations have been used to investigate the relationship between its charge transport property and cuprophilic interactions for the first time. The valence bandwidth was found three times larger than the conduction bandwidth. Meanwhile, the effective mass of hole is 0.46 m0, which is only one-third of the electron, and much smaller than that of the pentacene. Thus, C6F5Cu(py) would become a promising candidate for hole transport material. The analysis based on density of states and band structure shows that holes transport mainly along the direction of cuprophilic interactions (c-axis) and cuprophilic interactions are in favor of hole transport. Thus, the cuprophilic interactions play an important role in determining charge transport. By the replacement of copper atoms with silver and gold atoms, the results show that there are close relationships between the metallophilic interactions and transport ability, i.e., the stronger metallophilic interactions are, the better hole transport ability is. The solid state emission of C6F5Cu(py) is attributed to the monomer rather than the dimer. This emission is assigned as the metal-to-ligand charge transfer (MLCT), and combined with some contributions from ligand-to-ligand charge transfer (LLCT). KeywordsC6F5Cu(py)-Cuprophilic interactions-Band structure-Charge transport-DFTTheoretical Chemistry Accounts 04/2012; 127(5):735-742. · 2.16 Impact Factor -
Article: TDDFT studies on the structures and ECD spectra of chiral bisarylimidos bearing different lengths of o-alkoxy chain-substituted polyoxomolybdates.
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ABSTRACT: The chiroptical properties of bisarylimidos bearing o-alkoxy chain-substituted polyoxomolybdates [Mo(6)O(17)(2,2'-NC(6)H(4)OC(n)H(2n)OC(6)H(4)N)](2-) [n=4(2), 6(3±), 8(4)] were investigated using the time-dependent density functional method. The results showed that the studied chiral polyoxometalates (POMs) manifested similar absorption sites but displayed different shapes and magnitudes in their electronic circular dichroism (ECD) spectra. The ECD spectra of the studied chiral POMs originated from charge-transfer (CT) transitions from arylimido fragments to the POM cages and from oxygen atoms to the molybdenum atoms in the POM cages. The o-alkoxy chain served as a scaffold for generating chirality rather than contributing to the ECD spectrum of the studied POMs. The induced chiralities of the POM cages were defined by the CT transitions, which were completely localized on the POM cages. Furthermore, the long-range corrected CAM-B3LYP hybrid functional and a basis set that is larger than Lanl2DZ should be used for ECD calculations of chiral POMs. Our work establishes the use of computational studies to investigate the chiroptical properties of chiral POMs and provides theoretical interpretations.Journal of molecular graphics & modelling 02/2012; 35:49-56. · 2.17 Impact Factor -
Article: Theoretical investigations on electronic spectra and the redox-switchable second-order nonlinear optical responses of rhodium(I)-9,10-phenanthrenediimine complexes.
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ABSTRACT: The redox-switchable second-order nonlinear optical (NLO) properties of a series of Rh(I) complexes have been studied based on density functional theory (DFT) calculations. The analysis of the electronic structure shows that the Rh(I) ion acts as the oxidation center in a one-electron-oxidized process, while both the Rh(I) ion and the 9,10-phenanthrenediimine (phdi) ligand act as reduction centers in a one-electron-reduced process. Different redox centers lead to different charge-transfer (CT) features, which alter the static first hyperpolarizabilities of the neutral complexes. Our DFT calculations indicated that these complexes show large second-order NLO responses and that the redox process can significantly enhance these NLO responses. For complexes 2 and 3, the β(tot) values of the one-electron-reduced species 2(-) and the one-electron-oxidized species 3(+) are ~10.0 and ~8.5 times larger, respectively, than those of the corresponding neutral complexes. Therefore, complexes 2 and 3 are promising candidates for redox-switchable NLO molecular materials. The large NLO responses of the oxidized species are mainly related to ligand-to-ligand charge-transfer (LLCT) transitions when combined with intraligand charge-transfer (ILCT) transitions, while the results for the reduced species are strongly associated with metal-to-ligand charge-transfer (MLCT) transitions.Journal of molecular graphics & modelling 11/2011; 33:19-25. · 2.17 Impact Factor -
Article: The influence of M…M attraction on nonlinear optical properties of (XMPH3)2 (X = F, Cl; and M = Au, Ag and Cu): A theoretical study
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ABSTRACT: It is well known that the aurophilic attraction has great influence on spectra properties. There are certain relationships between spectra and nonlinear optical properties (NLO). Here, XMPH3, (XMPH3)2 (X = F, Cl; M = Au, Ag, and Cu) were taken as the examples to be investigated to study the relationship between NLO and M···M interactions. The NLO properties of XMPH3, (XMPH3)2 (X = F, Cl; M = Au, Ag, and Cu) were carried out with finite field/second-order Møller–Plesset perturbation theory method. The results show that polarizability tensors of dimers (αtot,d) and second-order hyperpolarizability tensors of dimers (γtot,d) are significantly larger than αtot,m and γtot,m of corresponding monomers. It indicates that M…M interaction significantly increases αtot,d and γtot,d values. The analysis of the electronic transition shows that the charge transfer along M…M direction play the key role on increasing αtot,d and γtot,d. On the other hand, the βtot is significantly increased by changing ligands and is slightly influenced by M…M interaction. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010International Journal of Quantum Chemistry 02/2009; 110(4):865 - 873. · 1.36 Impact Factor -
Article: Theoretical study on a novel series of fullerene-containing organometallics Fe(eta5-C55X5)2 (X = CH, N, B) and their large third-order nonlinear optical properties.
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ABSTRACT: Geometry structures, electronic spectra, and third-order nonlinear optical (NLO) properties of Fe(eta (5)-C 55X 5) 2 (X = CH, N, B) have first been investigated by time-dependent density functional theory. We analyzed the intramolecular interactions between ferrocene and the C 50 moiety. The calculated electronic absorption spectrum indicates that the short wavelength transitions are ascribed to the C 50 moiety mixed charge transfer transition of ferrocene itself, while the low energy excitation transitions are ascribed to the unique charge transfer transition from ferrocene to C 50 moiety in these systems. The third-order polarizability gamma values based on sum of states (SOS) method show that this class of ferrocene/fullerene hybrid molecule possesses a remarkably large third-order NLO response, especially for Fe(eta (5)-C 55B 5) 2 with the static third-order polarizability (gamma av) computed to be -10410 x 10 (-36) esu and the intrinsic second hypepolarizability to be 0.250. Thus, these complexes have the potential to be used for excellent third-order nonlinear optical materials. Analysis of the major contributions to the gamma av value suggest that the charge transfer from ferrocene to C 50 moiety along the z-axis (through Fe atom and the centers of two hybrid fullerenes) play the key role in the NLO response. Furthermore, boron substitution is an effective way of enhancing the optical nonlinearity compared to CH and N substitution, owing to smaller energy gap and better conjugation through the whole molecule.The Journal of Physical Chemistry A 10/2008; 112(35):8086-92. · 2.95 Impact Factor -
Article: Effect of pi-conjugated length of bridging ligand on the optoelectronic properties of platinum(II) dimers.
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ABSTRACT: We report a quantum-chemical study of the electronic and optical properties of several platinum(II) dimers, [Pt(pip2NCN)]2(L)(2+) (pip2NCNH = 1,3-bis(piperidylmethyl)benzene, L represents the bridging ligands pyrazine, 4,4'-bipyridine, or trans-1,2-bis(4-pyridyl)ethylene). The theoretical calculations reveal that as the pi-conjugated length of bridging ligand increases, the energies of HOMOs and LUMOs, bonding energy of Pt-N bridge, and the largest absorption strength increase whereas the ionization potentials decrease. According to the inner reorganization energy and density of states, we presume the hole-transporting properties of these dimers is better than the electron-transporting, and their inner reorganization energies for hole transport are lower than that of 4,4'-bis(phenyl-m-tolylamino)biphenyl (TPD), a well-known hole-transporting material. These platinum(II) dimers, especially [Pt(pip2NCN)]2(bpe)(2+), hold promise for use as a new kind of third-order nonlinear optical material, owing to their large third-order polarizabilty value and high transparency. Moreover, the optoelectronic properties of these complexes are easy to tailor by modifying the peripheral and central ligands. These theoretical results are beneficial to the design of new functional materials with excellent optoelectronic properties.Inorganic Chemistry 05/2008; 47(7):2347-55. · 4.60 Impact Factor -
Article: Computational Study on Second-Order Nonlinear Response of a Series of Two-Dimensional Carbazole-Cored Chromophores
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ABSTRACT: The static second-order nonlinear optical (NLO) properties on a series of two-dimensional A−π−D−π−A carbazole-cored chromophores were investigated by density functional theory (DFT). The carbazole heterocycles can be viewed as auxiliary donors in these compounds. It is found that the first hyperpolarizabilities of these two-dimensional NLO molecules are sensitive to the changing of heterocycles on the donor. Moreover, the orientation of the thiophene ring in the chromophore significantly affects the second-order NLO properties. According to the time-dependent DFT calculations, the low transition energy and strong charge transfer are the key factors to determine the first hyperpolarizability, and an auxiliary donor provides an intrinsic enhancement of the NLO response in set III.04/2008; -
Article: Theoretical Study on One‐ and Two‐Photon Absorption Properties of PPV Derivative with Electron‐Donor Phenylanthracene as Pendent Group
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ABSTRACT: Based on the equilibrium structures from quantum mechanics AM1 method, employing INDO/CI method and the sum-over-state (SOS) formula, the one-photon absorption (OPA) and two-photon absorption (TPA) properties as well as the second hyperpolarizabilities were discussed in detail for a kind of PPV derivative poly 2-(9-phenylan- thracen-10-yl)-1,4-phenylenevinylene (P1). The results indicate that the two-photon cross section (δ) increases with the increasing of the number of repeating segment (n), however only a slight increase corresponds to the increasing of molecular weight when the repeating unit number arrives at a certain number. From this point of view, the TPA cross section values of P1 were extrapolated through the linear fit of δ value vs. 1/n. The δ value of P1 is as high as 181 GM (1 GM10−50 cm4·s·photon−1). Concerning the influence of pendent group and extension of π-conjuga- tion on δ values, another four oligomers P2, PPV, P1-1, and P2-1 were investigated for comparison. The calculation results reveal that the position and property of pendent group have great influence on the OPA and TPA properties. A most crucial role for relatively larger δ value was played by the extension of π-conjugation.Chinese Journal of Chemistry 03/2007; 25(4):465 - 471. · 0.75 Impact Factor -
Article: Theoretical study on the optoelectronic properties of electron-withdrawing substituted diethynylfluorenyl gold(I) complexes.
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ABSTRACT: We report on a quantum-chemical study of the electronic and optical properties of gold(I) complex AuTFT (1) and its electron-withdrawing substitutents, AuTFOT (2) and AuTFCNT (3) [where TFT = diethynylfluorenyl, TFOT = diethynylfluorenone and TFCNT = diethynyl-(9-(dicyanomethylene)fluorene)]. Our theoretical calculations indicate that for all systems the reorganization energies of electron and hole are in the same order of magnitude and similar to those of the well-known electrontransport material Alq3. The substitution of -CO and -C(CN)2 for -CH in AuTFT significantly decreases the bond length alternation and increases the electron affinity, which would effectively lower the energy barrier for electron injection from cathode and thus qualify AuTFOT (2) and AuTFCNT (3) as candidates for the electron transport layer (ETL) in light-emitting diodes (LEDs). The lowest lying excited-states of gold(I) diethynylfluorenyl derivatives have been studied by the singles configuration interaction (CIS) method and time-dependent density functional method (TDDFT). It is found that the electron-withdrawing substitutions evidently decrease the energy gap, leading to a remarkable red shift in transition energy and transformation in the direction of charge transfer. Our research is important in the development of new functional materials for the design of LEDs with enhanced performance.The Journal of Physical Chemistry A 01/2007; 110(48):13036-44. · 2.95 Impact Factor -
Article: How Do the Different Defect Structures and Element Substitutions Affect the Nonlinear Optical Properties of Lacunary Keggin Polyoxometalates? A DFT Study
Berichte der deutschen chemischen Gesellschaft 08/2006; 2006(20):4179 - 4183. · 2.94 Impact Factor -
Article: DFT Studies on second-order nonlinear optical properties of mono (salicylaldiminato) Nickel(II) polyenyl Schiff base metal complexes
Chemical Physics Letters 443:163-168. · 2.34 Impact Factor
Top co-authors
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Institutions
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2006–2012
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Northeast Normal University
Changchun, Jilin Sheng, China
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