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1.
The dynamic first hyperpolarizabilities of a series of 1,10-phenanthroline Ru(Ⅱ) complexes were carried out using density functional theory(DFT).The results indicate that these complexes have large second-order nonlinear optical(NLO) responses.Specially,complex 6b has a maximal first hyperpolarizability βtot value.The first hyperpolarizabilities can be tuned by changing the ancillary ligand,introducing electron-acceptor group NO2 and/or increasing π-conjugation on phenanthroline.Calculations on absorption spectra demonstrate that the second-order NLO responses of complexes in series a are ascribed to the intraligand charge transfer(ILCT),while the complexes in series b exhibit metal-to-ligand charge transfer(MLCT) and ligand-to-ligand charge transfer(LLCT) transition at relatively low-energy absorptions.  相似文献   

2.
Two new mixed-ligand ruthenium(Ⅱ) complexes,Ru(dcbpy)-(LL)NCS)2[where dcbpy=4,4‘-dicarboxyl-2,2‘‘-bipyridine,LL=4,4‘-bis(N-methyl-anilinomethyl)-2,2‘‘-bipyridine(2)],were synthesized,and the tphotophysical properties of these complexes were studied.The metal-to-ligand charge transfer (MLCT) transitions of these complexes exhibited solvatochromic effect due to the existence of NCS ligands.The MLCT energies also strongly depend on the pH values of the solutions because of protonation and deprotonation of the carboxyl groups.The pKa values of the ground state,4.0 for 1 and 3.8 for 2,were obtained from the titration curves.The photoelectrochemical properties of 1 and 2 as sensitizers in sandwich-type solar cells have been studied.Complex 1 exhibited better photoelectrochemical behavior than complex 2 as expected.It was proved that the design of mixed-ligand complex by introducing electron donating group in one of the ligands should be a promising approach.  相似文献   

3.
刘昌炎  胡日恒 《化学学报》1983,41(4):289-296
In this report, a method for deconvoluting the multi-band spectra of charge-transfer complex is presented and a relation between double-bands is proposed. 49 such spectra in which double-bands appear are calculated. It has been found that the deviation between the calculated and the measured values is less than 3%. The scheme can be extended to deconvolute the CT peaks are used to evaluate the electron affinities of these acceptors. But, the scheme can be used to the π-π charge-transfer complexes.  相似文献   

4.
LIU  Sheng-Nan CAO  Duan-Lin REN  Fu-De REN  Jun 《结构化学》2010,29(10):1459-1466
The structures and energies of the side-on complexes B2(N2)2 and monocyclic Bn(N2)nm (n = 3~6,m = -1~+2) between N2 (1∑+g) and B (2P) have been investigated by the DFT-B3LYP and MP2 methods at the 6-311+G(2d) and aug-cc-pVTZ levels. The analyses of NICS (Nucleus Independent Chemical Shifts),NBO (nature bond orbital),AIM (atoms in molecules) and frontal orbitals have been used to reveal the origin of coordination bond between the π-electron donor N2 group and B atom,accompanied by the comparison with the end-on complexes. The results have indicated that the side-on coordination complexes can be formed due to the relative strong fluidity of the π-electrons,and the nature of the coordination bond has been exposed to be that the N2 group offers 1πu electron to the 2p orbital of boron. The coordinate energies of the side-on complexes are less than those of the end-on complexes. Furthermore,the aromaticity of side-on coordination complex is weaker than that of the corresponding end-on coordination complex.  相似文献   

5.
In this study the viewpoint is taken that the supported complexes react with active groups on the surface of the support to form new entities which may be called surface complexes.Various interactions between the support and the solute in solution of impregnation have been found,and these interactions may be divided into four calsses: (1) there is no noticeable chemical interaction between the dissolved coordination compound and the support,except the physical adsorption;(2) the metal ion of the complex is anchored on the surface through the surface group as a ligand forming a surface complex,or the support provides the central ion for the formation of a surface polynuciear complex through the bridging ligand of the complex;(3) the surface of the support provides the central ion for ligands dissociated from the complex or for the solvent molecules;(4) the metal hydroxide might be formed,when the acidity of the cation of the support is weaker than that of the metal ion of the complex in a aqueous solutio  相似文献   

6.
The intrapair and interpair correlation energies of F-, HF and H2F^ systems are calculated and analyzed using MP2-OPT2 method of MELD program with cc-PVSZ^* basis set. From the analysis of pair correlation energies of these isoelectronlc sysoterns, it is found that the 1sF^2 pair correlation energy is trans-ferable in these three isociectronic systems. According to the definition of pair correlation contribution of one electron pair to a system, the pair correlation contribution values of these three systems are calculated. The correlation contribution values of inner electron pairs and H—F bonding electron pair in HF molecule with those in H2F^ system are compared. The results indicate that the bonding effect of a molecule is one of the im-portant factors to influence electron correlation energy of the system. The comparison of correlation energy contributions in-cluding triple and quadruple excitations with those only includ-ing singles and doubles calculated with 6-311 G(d) basis set shows that the higher.excitation correlation energy contribution gives more than 2 % of the total correlation energy for these sys-tems.  相似文献   

7.
王维 《高分子科学》2010,28(3):395-404
<正>Three dendronized polymers from generation one to generation three have been prepared by complexing negatively charged Frechet-type dendrons with a polyanion,poly(diallydimethylammonium chloride)(PDADMAC).The grafting degree has been confirmed mainly by elemental analysis.In dilute solutions of tetrahydrofuran,static light scattering studies indicate that the first generation complex has a coil-like conformation,even more flexible than PDADMAC.The second and third generation complexes exhibit polyelectrolyte behavior.Dynamic light scattering experiments indicate that all the three complexes have almost the same hydrodynamic radius,indicating that they might own similar coil conformation.Atomic force microscopy shows the existence of disordered globules formed by one or a couple of complex coils.All these observations can be explained by the flowerlike coil conformation,which is formed by the intra-molecular association.This is totally different from the stretched chain conformation formed by covalently connected dendronized polymers.This result also explains why some ordered supramolecular structures,found in condensed state of the similar complexes,are not as perfect as those of conventional dendronized polymers.  相似文献   

8.
PVP/SDS complex was applied as a probe to study the interaction between β-cyclodextrin (β-CD) and sodium dodecyl sulfate (SDS) in aqueous solution. It has been found that a critical concentration, namely cs, exists in the relative viscosity of solution containing PVP/SDS complex versus β-CD concentration plot. As the β-CD concentration is less than cs, the relative viscosity of solution decreases sharply by adding β-CD into solution successively. On the other hand, as the β-CD concentration is greater than cs, the relative viscosity of solution increases gradually by adding β-CD into solution. The decrease of the relative viscosity of solution containing PVP/SDS in the presence of β-CD is just due to the inclusion complex of β-CD with the guest molecule SDS. And, this inclusion interaction takes down SDS from the PVP chains in solution. The ratio of the host molecule β-CD to the guest molecule SDS can be calculated from Cs. In our experiment the inclusion ratio of β-CD to SDS is 1/1. The further experimental results indicate that cs is associated with SDS but free from PVP in PVP/SDS complex. However, the inclusion ratio of β-CD to SDS has proved to be independent of either SDS or PVP in PVP/SDS complex.  相似文献   

9.
1 INTRODUCTION The chemical properties of acylhydrazones Schiff bases and their complexes with some transition metal ions have been intensively investigated in several re- search areas because of their chelating capability and pharmacological applications[1~10]. Intriguingly, the copper(II) complexes are shown to be signifycantly more potent than the metal free chelate, suggesting that the metal complex is the biologically active species. Owing to the biological interest in these types …  相似文献   

10.
Quantum chemical calculations were carried out to investigate the structures and properties for the inclusion complexes of nitrobenzene (NB) into β-cyclodextrin. Two low-energy conformations of β-cyclodextrin (A and B) in the gas phase were initially investigated by the PM3 and B3LYP/6-31+G(d,p) calculations, respectively. Three different orientations were considered in the inclusion process of A and B with NB to form 1:1 complexes. Potential energy scan by PM3 calculations indicated that the phenyl orientation Ab for conformation A and the equator orientation Bc for conformation B are more favorable in energy, respectively. We also considered the 2:1 inclusion complexes of host A or B with guest NB in the gas phase. PM3 calculation indicated that the host-guest interaction energies to form 1:1 complexes are more negative than those to form 2:1 NB/B complexes. Finally, we studied the solvent effect of NB/CD complex, and PM3 results show that the influence of water molecules on the inclusion process is very important. The driving forces for the inclusion process and the geometries of complexes were discussed in detail.  相似文献   

11.
A new series of mono-cyclometalated square planar platinum(Ⅱ) complexes have been synthesized and the single-crystal X-ray structures of complex 1 and 2 have been determined.The complexes have the general formula ppyPt(O^O),where ppy is 2-phenylpyridyl,and O^O is β-diketonate ancillary ligands with the acyl substituent group in position 3 of(D)-(+)-camphor.Although,like the many Pt(Ⅱ) complexes with square-planar geometry,these complexes have plane stacking modes in crystal structure,the sterically bulky ca...  相似文献   

12.
The title complexes crystallize in space groups C(?)-P(?) and C_(2h)~5-P2_1/c, and with unit cell parameters a=8.488. b=10.100, c=11.974. α=72.73°, β=78.56°, γ=73.55°, and a=11.496, b=9.883. c=16.360, β=100.18°, respectively. All the V coordinates are obtained from Patterson and direct methods, respectively, and then Fourier and difference Fourier methods are employed to deduce other non-hydrogen atoms. Structural parameters are refined with least-squares technic, yielding final discrepancy factors R=0.081 and 0.067, respectively. Structural analyses demonstrate that the dimer of VO_2~+ complex is formed through the sixth-position bonding of a bridge oxygen atom of one VO_2~+ group with another VO_2~+, and the formation of VO(O_2)(C_(15)H_(10)N_3O)(C_5H_5N) shows that VO~(2+) complex with strong chelating tridentate PAN-seems less difficult to transform into the pentagonal bipyramid VO~(3+) complex. Since no peroxo species has been used in the synthesis, the fact that a peroxo group forms in the  相似文献   

13.
Polymer bound palladium (Pd) complex catalysts with grafting acrylonitrile on inorganic compound(MgO,Y-molecular sieve and SiO2) by pre-radiation method were studies.The palladium-grafting polymers have been investigated by X-ray photoelectron spectrscopy(XPS).It is indicated that peak width of C1s and O1s spectra of MgO-g-PAN-Pd(radiation-induced graft) is wider than that of MgO-PAN-Pd(chemical method) and Peak numbers of former are one more than later.According to the report in reference,this peak is attributed to -O-C group.Thus,the graft acrylonitrile on MgO may complete through oxygen atoms im MgO and β-carbon atoms in acrylonitrile.The polymer catalyst obtained by radiation grafting is a higher active hydrogenation catalyst for olefines and better antioxic than that of one obtained by chemical method,and it has selectivity for hydrogenation catalyst.  相似文献   

14.
Several polymer-supported palladium complex catalysts containing two different coordinatinggroups were prepared and the cooperative effect of the coordinating groups on the catalytic behaviorsof polymer catalysts was studied. It was found that poly(acrylic acid-co-acrylonitrile)-Pd complex(PAA-AN-Pd) is a more active and stable catalyst for hydrogenation than both poly(acrylic acid)-Pd and poly(acrylonitrile)-Pd complexes. A marked change of catalytic behaviors of poly(N-substituted maleamic acid-co-styrene)-Pd complexes was observed in comparison with poly(maleicacid-co-styrene)-Pd complex. Acetophenone was reduced to 1-phenyl ethanol by poly(N-phenylmaleamic acid-Co-styrene)-Pd complex (N-1-Pd), but ethylbenzene was obtained using poly(maleicacid-co-styrene)-Pd complex as a catalyst. The influence of solvents, additives and N/Pd gramatomic ratio on the catalytic behaviors of the polymer complexes was investigated.  相似文献   

15.
Platinum-based antitumour drug ZD0473 was designed to reduce the cisplatin resistance to the tumor cells. In this paper, the mixed method of molecular mechanics and quantum chemistry, HF/lanl2dz// MM/uff and B3LYP/lanl2dz//6-31G*, are used to investigate the differences between four types of GG, 3′AG5′, 3′GA5′, and AA complexes, which are formed from four discrete DNA fragments recognized by ZD0473 and cisplatin. The results show that the binding interaction of both ZD0473 and cisplatin drugs with the GG base pair is much stronger than with other base pairs, namely the recognition capability of such drugs to the GG base pair is more considerable. Moreover, the interaction of four complexes of ZD0473 with DNA fragments is stronger than that of cisplatin with corresponding DNA fragments, which indicates the stronger binding capability of ZD0473 with DNA fragments and high antitumour activity of ZD0473. The main reason for easier forming of 3′GA5′ complex than the 3′AG5′ one is that the drug molecule prefers to bind with a single G base to form a monoligand compound firstly; then the con- figuration transformation from such monoligand compound to the bi-ligand one is limited.  相似文献   

16.
The Ullmann coupling reaction is one of the most useful methods for the synthesis of symmetrical biaryls. It is usually carried out with copper as a reagent.1 However, it generally requires more than a stoichiomet-ric amount of copper and high reaction temperature. In recent years, various reagents, especially combination of the transition metal with reducing reagents,2-6 were proposed to overcome these problems. For example, Li and co-workers2a,2b have reported the Pd/C and zinc-mediated Ul…  相似文献   

17.
The crystal structure of gessypol acetic acid (C_(30)H_(30)O_8-CH_3COOH) has been determinedby X-ray diffraction method. The crystals are triclinic with space group P1, unit cell dimen-sions: a=14.278(7)A, b=6.924(5)A, c=14.706(6)A, α=91.90(5)°, β=92.34(3)°, γ=98.71(5)°, Z=2. The structure has been solved by direct methods and refined by full-matrixleast-squares to a final conventional R=0.063 for observed reflexions. The crystal structureshows that the gossypol acetic acid is a complex which consists of one gossypol molecule andone acetic acid molecule through hydrogen bonding. However, there are no additional hydro-gen bonds between these complexes. The crystal structure is stabilized by Van der Waalsinteractions only.  相似文献   

18.
Two monomeric cobalt(Ⅱ)complexes,[CoL(N3)] ClO4(1)and CoL(N3)2(2),where L is tris((3,5-dimethylpyrazol-1-yl)methyl)amine,were synthesized and their crystal structures were determined by X-ray diffraction technique.Complex 1 is five coordinated with one azide nitrogen atom and four nitrogen atoms of the tris((3,5-dimethylpyrazol-l-yl)-methyl)amine ligand,and the metal center is in distorted trigonal bipyramidal environment.Complex 2 is six coordinated distorted octahedron with the two azide nitrogen atoms and four nitrogen donors of the tris((3,5-dimethylpyrazol-1-yl)-methyl)amine ligand.The solution behaviors of the title complexes have been further investigated by UV-Vis,and 1H NMR analysis.It is found that the formation of 1 and 2 depends on the molar ratio of the azide ion to metal salt and ligand Complex 1 attached with one azide group is more stable and easy to generate than complex 2 incorporated with two azide groups,and the reasons were well discussed.  相似文献   

19.
The complex [Nd(L)(CH_3CN)(CF_3SO_3)_3] has been synthesized, where L=1-methyl-1,4,7,10-tetraazacyclododecane. The crystal structure of the complex has been determined by a fourcircle X-ray diffractometer to a final R value of 0.0370 and Rw value of 0.0385 respectively. The crystal is triclinic system, space group P1 with a=8.738(2), b=12.870(3), c=12.900(3), α=85.63(2), β=87.25(2), γ=78.30(2)°, V=1415.71(60)~3, Z=2, Dc=1.92g/cm~3. The neodymiumion is eight-coordinated, forming a distorted square antiprism.  相似文献   

20.
1 INTRODUCTION Sm(II) chemistry has been extensively studied due to the strong reduction potential of this 4f6 ion[1]. The transformation of unsaturated substrates by Sm (II) complexes into products with unusual structures is one of the most interesting research areas. For the successful examples reported, Sm(II) starting mate- rials were restricted primarily to cyclopentadienyl complexes[2]. The reactivity of Sm(II) complex with phenolate ligands has seldom been explored. Recen- tl…  相似文献   

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