Electronic Absorption Spectra and Third-Order Nonlinear Optical Property of Dinaphtho[2,3-b:2’,3’-d]Thiophene-5,7,12,13- Tetraone (DNTTRA) and Its Phenyldiazenyl Derivatives: DFT Calculations

Third-order nonlinear optical (NLO) materials have broad application prospects in high-density data storage, optical computer, modern laser technology, and other high-tech industries. The structures and frequencies of Dinaphtho[2,3-b:2’,3’-d]thiophene-5,7,12,13-tetraone (DNTTRA) and its 36 derivatives containing azobenzene were calculated by using density functional theory B3LYP and M06-2X methods at 6-311++g(d, p) level, respectively. Besides, the atomic charges of natural bond orbitals (NBO) were analyzed. The frontier orbitals and electron absorption spectra of A-G5 molecule were calculated by TD-DFT (TD-B3LYP/6-311++g(d, p) and TD-M06-2X/6-311++g(d, p)). The NLO properties were calculated by effective finite field FF method and self-compiled program. The results show that 36 molecules of these six series are D-π-A-π-D structures. The third-order NLO coefficients γ (second-order hyperpolarizability) of the D series molecules are the largest among the six series, reaching 107 atomic units (10-33 esu) of order of magnitude, showing good third-order NLO properties. Last, the third-order NLO properties of the azobenzene ring can be improved by introducing strong electron donor groups (e.g. -N(CH3)2 or -NHCH3) in the azobenzene ring, so that the third-order NLO materials with good performance can be obtained.

Electronic Absorption Spectra of Copper(Ⅱ) Sulphophthalocyanine and Aggregation of the Dye in Aqueous Solution

Aggregation behavior of C.I.Direct Blue 86 was discussed using analyses of its UV-Vis spectra.The experiment results show that the dye molecules are inclined to aggregate in aqueous solution.Even in a very dilute solution of 0.050μmol/L,A618/A659 =1.2398,showing that the dye monomers still coexist with its dimers.The strong aggregation trend may cause dye precipitates at a higher concentration,which is an important factor that should be considered in producing a formula of ink-jet inks containing the dye as a colorant.

Intersubband optical absorption of electrons in double parabolic quantum wells of Al_xGa_(1-x)As/Al_yGa_(1-y)As

Some realizable structures of double parabolic quantum wells（DPQWs） consisting of Al_xGa_（1-x）As/Al_yGa_（1-y）As are constructed to discuss theoretically the optical absorption due to the intersubband transition of electrons for both symmetric and asymmetric cases with three energy levels of conduction bands. The electronic states in these structures are obtained using a finite element difference method. Based on a compact density matrix approach, the optical absorption induced by intersubband transition of electrons at room temperature is discussed. The results reveal that the peak positions and heights of intersubband optical absorption coefficients（IOACs） of DPQWs are sensitive to the barrier thickness, depending on Al component. Furthermore, external electric fields result in the decrease of peak, and play an important role in the blue shifts of absorption spectra due to electrons excited from ground state to the first and second excited states. It is found that the peaks of IOACs are smaller in asymmetric DPQWs than in symmetric ones. The results also indicate that the adjustable extent of incident photon energy for DPQW is larger than for a square one of a similar size. Our results are helpful in experiments and device fabrication.

ABSORPTION SPECTRA OF 4f ELECTRON TRANSITIONS IN THE SYSTEM OF NEODYMIUMSEMIXYLENOL ORANGE-CETYLPYRIDINIUM CHLORIDE

In this paper the absorption spectra of Nd-SXO-CPC complex by 4f electron transitions have been studied by zero-order and fourth-order derivative spectrophotome-try. The molar absorptivity is 2.6×10~3 1.mol^(-1).cm^(-1) at 585 nm, the fourth-order derivative molar absorptivity is 1.4×10~4 1.mol^(-1).cm^(-1) at 584.5(-) and 587(+) nm. They are 300 times and 1600 times greater than those of the chloride, respectively.

ABSORPTION SPECTRA OF 4f ELECTRON TRANSITIONS OF NEODYMIUM COMPLEX WITH 8-HYDROXYQUINOLINE AND OCTYLPHENOL POLY(ETHYLENEGLYCOL)ETHER

In this paper the absorption spectra of 4f electron transitions of the neodymlum complex with 8-hydroxyquinoline and octylphenol poly(ethyleneglycol)ether have been studied. The marked intensification of the band at low octylphenol poly(ethyleneglycol)ether concentration is found normally at 575 nm, and its resolution into three sharp bands centering at 572, 580 and 584 nm. The absorbances of the absorption maxima are 3.5 (at 572 nm), 7.2 (at 580 nm) and 10.2 (at 584 nm) times greater than that of the chloride.

Ab Initio Molecular Orbital Calculation on Dinuclear Gold(Ⅰ) Complexes──Metal-Metal Interaction and Electronic Structure of Binuclear Gold(Ⅰ) Complexes with Bridging Bidentate Ligands

The electronic structure and electronic absorption spectra of binuclear Au(Ⅰ) complexes with bidentate phophines and a bidentate ylid ligand have been studied using quasirelativistic pseudopotential ab initio calculations at the HF and MP2 levels by the LANL2DZ basis sets. The electronic properties of the spectral transition and Au(Ⅰ)—Au(Ⅰ) interaction were also discussed.

Synthesis, Electrochemistry, and Photophysics of a Novel Binuclear Polypyridyl Ru(Ⅱ)Complex with an 1,8-Adipoylamido- bis(1,10-phenanthroline-5-yl) Ligand

The present paper covers the syntheses of 1,8adipoylamidobis(1,10phenanthroline5yl)(bphaa) and its binuclear complex {[(bpy) 2Ru] 2(bphaa)}(PF 6) 4, where bpy is 2,2′bipyridine. The two novel compounds were confirmed by means of elemental analysis, IR, LDMS and 1H NMR , and 1H NMR spectra were completely assigned in virtue of 1H 1H COSY. The electrochemical behavior of the binuclear Ru(Ⅱ) complex was obtained using cyclic and squarewave voltammetry. Its photophysical property was investigated by electronic absorption, fluorescence excitation and emission spectra.

Synthesis, Crystal Structure,Characterization and Quantum Chemical Studies on 1N-Acetyl-3-(2,4-dichloro-5-fluoro- phenyl)-5-(p-methyl-phenyl)-2-pyrazoline

1N-Acetyl-3-（2,4-dichloro-5-fluoro-phenyl）-5-（p-methyl-phenyl）-2-pyrazoline has been synthesized and characterized by elemental analysis, IR, UV-Vis and X-ray single-crystal diffraction. Ab intio calculations have been carded out for the compound by using both B3LYP and HF methods at the 6-31G^＊ basis set. The calculated results show that the predicted geometry can well reproduce the structural parameters. The electronic absorption spectra calculated by B3LYP/6-31G^＊ method are approximate to the experiments and the Natural Bond Orbital （NBO） analyses suggest that the above electronic transitions are mainly assigned to n→π^＊ and π→π^＊ transitions. CIS-HF/6-31G^＊ method is not suitable to predict the electronic spectra for the title compound. The calculation of the second order optical nonlinearity was carded out, giving the value of molecular hyperpolarizability equal to 2.194^＋ 10^-30 esu. On the basis of vibrational analyses, the thermodynamic properties of the compound at different temperature have been calculated, revealing the correlation between C p, m^0, S m^0, H m^0 and temperature.

Synthesis,Characterization and Theoretical Studies on a Thiocarbamide Derivative Containing Schiff Base Group

A thiocarbamide derivative containing Schiff base groups,1,5-bis[4-（dimethylamino）benzylidene]thiocarbonohydrazide,has been synthesized and characterized by elemental analysis,IR,^1H NMR,UV and X-ray single-crystal diffraction.Density function theory（DFT） calculations at the B3LYP/6-31G＊ and PBE0/6-31G＊ levels for optimized geometries and electronic transition spectra have been performed.Comparative studies show that both B3LYP/6-31G＊ and PBE0/6-31G＊ methods can well reproduce the molecular structure,and the latter is more reliable than the former to simulate electronic spectra.NPA calculational results at the B3LYP/6-31G＊ level indicate the title compound to be a potential multidentate ligand to the metallic ions.Based on the vibrational analysis,thermodynamic properties at different temperatures have been obtained.

Isolation,Purification and Spectral Characteristics of Soluble Guanylate Cyclase from Bovine Lung

We isolated and purified high purity and high activity soluble Guanylate cyclase(sGC) from bovine lung. The electronic absorption and resonance Raman spectra of the ferrous and ferric forms of sGC were recorded. In the ferrous state of sGC, the electronic absorption spectra showed a sharp peak at 431 nm and a single broad peak in the α/β region at 559 nm. The resonance Raman spectra of sGC(ferrous) showed a stronger band at 1357 cm -1 and a single peak at 1473 cm -1 . For the ferric form of sGC, the Soret band was at 390 nm and resonance Raman peak was at 1375 cm -1 . These spectra show that the heme iron of the ferrous and ferric sGC are all 5 coordination and high spin.

Synthesis, Crystal Structure and Spectroscopy Studies on Complex cis-Os^Ⅱ(bpy)_2Cl_2 and Its Oxidation Product [cis-Os^Ⅲ(bpy)_2Cl_2](PF_6)

The treatment of（NH_4）_2 OsCl_6 with 2 equiv of bpy in ethylene glycol produced complex 1, cis-Os^Ⅱ（bpy）_2Cl_2（bpy = 2,2＇-bipyridine）. Its one-electron oxidation product 2, [cis-Os^Ⅲ-（bpy）_2Cl_2]（PF_6）, was obtained by the oxidation of 1 with（Cp）_2 FePF_6. Complex 1 crystallizes in the orthorhombic space group Pbca, and adopts distorted [MCl_2 N_4] octahedral coordination, in which four coordination sites are occupied by four nitrogen atoms from two bpy ligands and the other two sites are occupied by two chlorine atoms in a cis-position. Complex 2 crystallizes in monoclinic space group C2/c, and contains one [Os（bpy）_2Cl_2]^＋ cation, one PF_6^- anion and two uncoordinated water solvent molecules.

A 3D Supramolecular Pd(Ⅱ) Complex via Hydrogen-bonding and Weak M…M Interactions

The reaction of 2,4,6-tris（2-pyridyl）-1,3,5-triazine （tptz） and K2PdCl4 in THF/H2O （10：1） results in the hydrolysis of tptz to bis（2-pyridylcarbonyl）amide anion （bpca）, and affords complex Pd（bpca）Cl 1, which is the first example of Pd（Ⅱ）-promoted hydrolysis of ligands. Crystal data for 1： orthorhombic, space group Pbcn, a = 12.0136（17）, b = 14.180（2）, c = 6.9747（11）A, V= 1188.2（3） A3, Z = 4, Mr = 368.06, Dc = 2.058 g/cm3, F（000） = 720,μ = 1.786 mm^-1, λ（MoKα） = 0.71073 A, T= 293（2） K, 2θmax = 54.9°, GOOF = 1.085, the final R= 0.0647 and wR = 0.1051 for 1234 observed reflections with I 〉 2σ（I） （refinement on F2）. Complex 1 is connected through hydrogen bonding to give a 2D network. And weak Pd...Pd interactions are also found between adjacent molecules with the distance of 3.6074（5） A, so the complex is further extended into a 3D supramolecular structure. Thermal gravity analysis （TGA） shows that 1 exhibits high thermal stability below 310℃. X-ray powder diffraction （XRD） and UV/Vis spectrum of 1 are also discussed.

Optical absorption via intersubband transition of electrons in GaAs/Al_xGa_(1-x)As multi-quantum wells in an electric field

Based on the effective mass approximation, the Schrodinger equation and Poisson equation in GaAs/AlGaAs multi-quantum wells(MQWs) are self-consistently solved to obtain the wave functions and energy levels of electrons in the conduction band for the ground first excited state by considering a lateral electric field(LEF). Then, the effects of size, ternary mixed crystal, doping concentration, and temperature on linear and nonlinear intersubband optical absorption coefficients(IOACs), and refractive index changes(RICs) due to the transition between ground states and the first excited states of electrons are discussed based on Fermi’s golden rule. The results show that, under a fixed LEF, with increase of A1 composition and doping concentration, the IOACs produce a red shift. With increases of both widths of the wells and barriers IOACs appear as blue shifts and their amplitudes increase, but the barrier width change is much more important to affect nonlinear IOACs, whereas increasing the temperature results in a blue shift first and then a red shift of IOACs. When the other parameters are fixed but there is an increase in the LEF, IOACs occur with a blue shift, and the RICs have similar properties.

Structural, Spectral (IR and UV/Visible) and Thermodynamic Properties of Some 3d Transition Metal(II) Chloride Complexes of Glyoxime and Its Derivatives: A DFT and TD-DFT Study

Metal complexes bearing vic-dioxime ligands have been extensively used as analytical and biochemical reagents, and are well-known antimicrobial agents. Herein is reported a DFT study on the molecular structures, thermodynamic properties, chemical reactivity and spectral properties of some 3d metal(II) chloride complexes of glyoxime. The functionals B3LYP and CAM-B3LYP have each been used in conjunction with LANL2DZ for the metal(II) ions (Fe2+, Co2+, Ni2+ and Cu2+) and the Poplestyle basis set 6-31G+(d,p) for the rest of the elements, to perform theoretical calculations. The metal complexation abilities of the glyoxime ligands studied in this work have been evaluated on the basis of metal-ligand binding energies. These ligands were found to have high affinities towards Ni(II) and Fe(II) ions, and all complexation reactions were found to be thermodynamically feasible. Ligand-to-metal electron donations in the complexes studied have been revealed by natural population analysis. The fully optimized geometries of the complexes have adopted square planar structures around the central metal ions. On the basis of orbital composition analysis, the UV-Vis electronic absorption bands of these molecules have been attributed mainly to MLCT, LMCT and d-d electronic transitions involving metal-based orbitals.

Integrated electroabsorption-modulated DFB laser by using an improved butt-joint method

An improved butt coupling method is used to fabricate an electroabsorption modulator (EAM) monolithically integrated with a distributed feedback (DFB) laser.The obtained electroabsorption-modulated laser (EML) chip with the traditional shallow ridge exhibits very low threshold current of 12 mA, output power of more than 8 mW,and static extinction ratio of-7 dB at the applied bias voltage from 0.5 to -2.0 V.

A Density Functional Theory Study on Electronic Structure and Second-order Nonlinear Optical Properties of Some Push-Pull Molecules

Time dependent density functional theory (TDDFT) has been applied to calculate the electronic structure and second order nonlinear optical (NLO) properties of some organic molecules. The two dimensional (2 D) charge transfer characteristics of calculated molecules were studied and compared with corresponding experimental results. All the theoretical results agree well with the measurement. For 2 D molecule with two fold symmetry, the dominant charge transfer is off diagonal, while for three fold symmetry 2 D molecule, the dominant charge transfer is not only between branches and central group but also among branches.

Crystal structure and DNA binding studies of a cobalt(Ⅱ) complex containing mixed-ligands of 1,10-phenathroline and glycollic acid

A cobalt（11） complex containing mixed-ligands of 1,10-phenathroline（phen） and glycollic acid（GA）.｜Co（GA）_2（phen）｜ was synthesized and its structure was characterized by X-ray diffraction.The interaction of the complex with DNA was investigated by electronic absorption spectra and electrochemical methods.Electronic absorption spectrum experiments showed that after interaction with DNA.the characteristic absorption peaks of ｜Co（GA）_2（phen）｜ underwent hypochromic effect as well as redshift. Also,the binding strength of 3.8×10~4L/mol was estimated by titration method.Electrochemical assays revealed that the redox peak currents of the complex decreased obviously accompanied by a positive shift of the formal potential after association with DNA.All these results revealed that the synthesized cobalt complex bound with DNA via an intercalation mode.

Synthesis and Characterization of a Terpyridine Ligand and Its Interactions with Selected Metal Ions

In this work,a terpyridine ligand L,(4΄-phenyl-2,2΄:6΄,2΄΄-terpyridine),was synthesized and fully characterized.Interactions of the ligand with selected metal ions like Cu(Ⅱ),Fe(Ⅲ),Pb(Ⅱ),Fe(Ⅱ),Cr(Ⅲ),Cd(Ⅱ),Co(Ⅱ),Zn(Ⅱ),Ni(Ⅱ)and Mn(Ⅱ)were investigated.Compared to ligand L,only Fe(Ⅱ)and Pb(Ⅱ)ions show new band in electronic absorption spectroscopy.Fluorescent spectroscopy indicates that Zn(Ⅱ)and Cd(Ⅱ)ions enhance the emission intensity of ligand L,and other selected ions quench emission intensity.To explore how Fe(Ⅱ)ion interacts with ligand L,Fe(L)-based complex 1 was synthesized,spectroscopic studies and single-crystal X-ray diffraction analysis.This implies ligand L has an excellent selectivity for Zn(Ⅱ)and Cd(Ⅱ)ions.

Synthesis and Characterization of the cis-Dicyanoiron(Ⅱ) Building Block and Its Interactions with Selected Metal Ions

In this work,a cis-dicyanoiron(Ⅱ)building block,cis-FeⅡ(bpy)2(CN)2(1,bpy=2,2?-bipyridine),has been prepared and fully characterized by IR,electronic absorption spectra,elemental analysis,cyclic voltammetry and single-crystal X-ray diffraction analysis.The interactions of complex 1 with selected metal ions,such as Cu(Ⅱ),Fe(Ⅲ),Pb(Ⅱ),Fe(Ⅱ),Cr(Ⅲ),Cd(Ⅱ),Co(Ⅱ),Zn(Ⅱ),Ni(Ⅱ)and Mn(Ⅱ),were investigated employing electronic absorption spectroscopy.The electronic absorption spectroscopy indicates Cu(Ⅱ),Fe(Ⅲ),Cr(Ⅲ),Cd(Ⅱ),Co(Ⅱ),Zn(Ⅱ)and Ni(Ⅱ)ions steadily coordinate with 1 via cyanide,respectively.Fluorescent emission intensity of 1 increased upon the addition of Zn(Ⅱ)ion,quenched by adding ions Cu(Ⅱ),Fe(Ⅲ)and Pb(Ⅱ),and it was almost unchanged when adding the Fe(Ⅱ),Cr(Ⅲ),Cd(Ⅱ),Co(Ⅱ),Ni(Ⅱ)and Mn(Ⅱ)ions.

Microwave synthesis and spectroscopic characterization of manganese oxalate nanocrystals

The microwave synthesis of MnC204.2H2O nanoparticles was performed through the thermal double decomposition of oxalic acid dihydrate （C2H204.2H20） and Mn（OAc）2.4H2O solutions using a CATA-2R microwave reactor. Structural characterization was performed using X-ray diffraction （XRD）, particle size and shape were analyzed using transmission electron microscopy （TEM）. The chemical in the structures was investigated using electron paramagnetic resonance （EPR） as well as optical absorption spectra and near-infrared （NIR） spectroscopies. The nanocrystals produced with this method were pure and had a distorted rhombic octahedral structure.Manganese oxalate