Z.M. Su

Syntheses, characterization and conductivity of polyaniline doped with H5SiM11VO40(M=Mo,W)

Abstract Polyaniline (PANI) doped with vanadium-containing silicotungstic/molybdic acid have been prepared in a one-step chemical reaction. The polymers were characterised by elemental analysis, IR, XRD, The thermal stability and the conductive property of doped PANI were determined,

Nonlinear optical properties for pyridines and stilbazoles adducted by borane

Nonlinear optical (NLO) properties of Me 2 N-4-C 5 H 4 N, MeO-4-C 6 H 4 -CH=CH-C 5 H 4 N, Me 2 N-4-C 6 H 4 -C≡C-C 5 H 4 N and their Lewis acidic borane adductions were studied by using quantum chemical AM1/Finite Field (FF) method. Calculational results indicated that NLO properties of this kind of compounds were improved substantially due to adduction by Lewis acidic borane.

Calculated UV-Visible spectra and third-order nonlinear optical properties of heteroaromatic derivatives of stilbene inserted with 1,3-squaraine

Based on the geometry optimized by semi-empirical PM3 method, UV-visible spectra and second-order hyperpolarizability γ of the heteroaromatic derivatives of stilbene inserted with 1,3-squaraine were calculated by ZINDO/CI-SOS method. The relation between y and molecular structures was discussed. It is shown that the heteroaromatic derivatives of stilbene inserted with 1.3-squaraine will be promising candidates for nonlinear optical materials. which have both larger γ values and high transparency.

TD-DFT study on electronic spectrum property for Bepp2 and its related complexes

Electronic spectrum properties of Bepp 2 and BeQ 2 were studied by TD-DFT and CIS methods. Same methods were applied to the free 8-hydroxyquinoline and 2-(2-hydroxyphenyl) pyridine ligand. Remarkable agreement was observed between complexes and free ligands in their excited-state properties, which indicates the first excited states π-π* electronic transition in complexes is localized on the ligand part. As a result, new luminescent materials with different emitting colors can be predicted through ligand substitution.

Ab initio research on third-order nonlinear optical properties of linear complexes [M(I)(PH3)2]+(M=Cu, Ag, Au)

Geometry of linear complexes [M(I)(PH 3 ) 2 ] + (M=Cu, Ag, Au) were optimized at different basis set levels adopting ab initio HF and DFT methods of quantum chemistry. The third-order NLO coefficients γ were calculated with FF/HF method. The values y of [M(I)(PH 3 ) 2 ] + (M=Cu, Ag, Au) are 10596.6538, 14649.9410 and 1190.8090a.u. respectively with the basis set of 6-31+G(d) for P and H and the basis set of LANL2DZ for Au by ab initio HF method. The results show the rule of γ[Ag(I)(PH 3 ) 2 ] > γ[Au(I)(PH 3 ) 2 ] + > γ[Cu(I)(PH 3 ) 2 ] + at the different basis set levels.

H4PM11VO40-doped (M=W, Mo) polyaniline-synthesis, characterization and catalytic conversion of isopropanol

New type polymer as catalysts for isopropanol conversion were prepared from polyaniline and vanadium-containing phosphotungstic/molybdic acid. The polymers were characterized by elemental analysis, IR, XPS, TG, and the conductivity were determined. The catalysis activity of doped polyaniline were studied.

Theoretical study on C60-doped polyacenic semiconductor(PAS) interacting with lithium

The characteristics of Li n n+C 60 endohedral and exohedral complexes (n=1,2,3,4) in C 60 -doped polyacenic semiconductor (PAS) have been investigated by semiempirical MO AMI calculations with the confirmation made using density functional theory. According to the binding energy, lithium ions are inclined to stay outside of the carbon cage. It is most possible for only single lithium ion to enter C 60 . Moreover, the structure of C 60 is little changed by lithium ions. Basing on these theory results, we explain the reason why the charge/discharge capacity is decreased while the cycle times are increased when C 60 -doped PAS is used as the cathode material for Li-ion battery.

Theoretical chemical study on NLO properties of polypyridinopyridine and its derivatives

With quantum chemical PM3/FF method, effects of strucure and substituents -NO 2 and -NH 2 on nonlinear optical properties of polypyridinopyridine(PPY) were discussed. The results showed that the β and y values were -5.54 x 10 -29 esu and -1.544 x 10 -32 esu, respectively. In three stable structures of equal-bond length structure (a), cis-structure (b) and trans-structure (c), the β and y values of (a) and (c) is larger than (b). More specially, β and y values of (c) increased promptly as the number of repeat unit increased. When the number of unit was over four, (c) gave the biggest β and y. In structures of PPY substituted by NO 2 and NH 2 , the effects of pull-push electron and π-electron delocalization became stronger, β increased effectively to about 1.6 x 10 -27 esu. PPY is a promising candidate of nonlinear optical (NLO) materials.

Quantum chemical studies on intercalation of lithium into polyacene

The structure and properties of Li-doped polyacenic semiconductor (PAS) material have been investigated, Quantum Chemical methods ab initio STO-3G were used to calculate electronic properties of PAS doped with lithium. The semiempirical MO method AM1 was used to optimize the geometric parameters of PAS. The theoretical results showed that the doped lithium was neither in metallic nor ionic state in deeply doped PAS (C 2 Li). The intercalated lithium formed polycenter bonds with carbon atoms, and made the interlayer distance of two parallel polyacenic rings decrease. On the other hand, the total energy of Li-doped PAS system decreased, and made the doped state stable. The theoretical results are in good agreements with the experiment.

Conductive metal adatoms adsorbed on graphene nanoribbons: a first-principles study of electronic structures, magnetization and transport properties

Using density functional theory (DFT) in combination with non-equilibrium Greens functions, we have investigated the electronic structures, magnetization, and quantum transport properties of zigzag graphene nanoribbons (ZGNRs) functionalized with conventional conductive metal adatoms (Al, Cu, Ag and Au). On the basis of the adsorption energies, our simulation demonstrates that Al and Cu adatoms are chemically bonded with ZGNRs, while the adsorptions for Ag and Au are between weak chemisorption and strong physisorption. The properties of charge transfer and magnetic moment are in reasonable agreement with the previous calculations. The adsorption of metal adatoms induce a net magnetic moment of −1 μB in 6ZGNR–metal systems. On the other hand, the transport studies of metal adatoms adsorbed ZGNRs suggest that the metal adatoms play an important role in the transport properties of devices and exhibit different effects on the transport properties of 6ZGNR-based and 7ZGNR-based devices. The 7ZGNR-based devices show the opposite conductive order in 6ZGNR-based devices. For 6ZGNR-based devices, the transport current in 6ZGNRs can be enhanced effectively by the adsorption of metal adatoms. However, the currents in 7ZGNR functionalized with conductive metal atoms are obviously smaller than that in pristine 7ZGNR, implying that metal adsorptions reduce the electrical conductivity of 7ZGNR-based devices. In contrast to the properties of the bulk materials, the conductivity of 6ZGNR–Al is highest among 6ZGNR–metal systems, which is in agreement with that of single atomic wires of Ag, Al, Au, and Cu.