摘要:

AbstractBased on the calculation results of pair correlation energy contributions of the various electron pairs in Nazand H2NNH2systems and the application of the scaling ionic partition scheme for symmetrical A2type systems, the total correlation energies of Na2and H2NNH2have been reproduced by using this simple scheme. The two results show that the absolute deviations are within an acceptable range of mr, however, in this way, more than 90% of computational work can be. saved. The most attractive result in present paper is that, in these two molecules the coefficientsc1andc2in the estimation equation can be obtained by the proportion of correlation energy of A−to that of A+singlet system. Therefore, it is believed that the proposed ionic partition scheme for symmetrical A2molecules would be very useful to estimate the correlation energies of large symmetrical molecule

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220402

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY

摘要:

AbstractVibrational (IR and Raman) spectra for the metal‐free phthalocyanine (H2Pc) have been comparatively investigated through experimental and theoretical methods. The frequencies and intensities were calculated at density functional B3LYP level using the 6‐31G(d) basis set. The calculated vibrational frequencies were scaled by the factor 0.9613 and compared with the experimental result. In the IR spectrum, the characteristic IR band at 1008 cm−1is interpreted as C—N (pyrrole) in‐plane bending vibration, in contrast with the traditional assigned N—H in‐plane or out‐of‐plane bending vibration. The band at 874 cm−1is attributed to the isoindole deformation and aza vibration. In the Raman spectrum, the bands at 540. 566, 1310, 1340, 1425, 1448 and 1618 cm−1are also re‐interpreted. Assignments of vibrational bands in the IR and Raman spectra are given based on density functional calculations for the first time. The present work provides valuable information to the traditional empirical assignment and will be helpful for further investigation of the vibration spectra of phthalocyanine analogues an

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220403

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY

摘要:

AbstractThe first hyperpolarizabilities of four squaric acid homologues: squaric acid, 1, 2‐dithiosquaric acid, 1, 2‐diselenosquaric acid and 1,2‐ditellurosquaric acid have been calculated usingab initioand DFT methods. The effects of equilibrium geometries. basis set and electron correlation on the first hyperpolarizabilities of these molecules were investigated. The frequency dispersion effect and solvent effect, which are essential to get reliable outputs in comparison to the experimental results, have also been explored. On the basis of these investigations, it is worthy to point out that the heavy atom effect takes effect for these squaric acid homol

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220404

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY

摘要:

AbstractOligomeric titanium(IV) cation ([Ti(OH)x(H2O)y]&z−;)‐intercalated niobate was prepared through a stepwise ion‐exchange mute, in whichn‐decylamine was employed as a preswelling agent and titanium isopropoxide as titanium source. Titania‐pillared layered niobic acid was then obtained by calcining oligomeric titanium(IV) cation‐intercalated niobate at 450 °C in air. Characterization of this pillared material indicated that the material had a porous layered structure with an interlayer distance of 1.38 nm and a BET (Brunauer‐Emmett‐Teller) surface area of 34 m2·g−1. The layered structure was still retained after the pillared material

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220405

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY

摘要:

AbstractA novel 1,6‐hexamethylenediamine‐zincophosphite has been synthesized hydrothermally. Its single‐crystal structure refinement has shown the zincophosphite with the composition NH+3(CH2)6NH+3[Zn(HPO3)2]2−,Mr=343.55. It crystallizes in monoclinic, space groupC2/c(No. 15).a=2.2391 nm,b=0.8695 nm,c=0.7919 nm, β=101.062(6)°,V=1.513 nm3,Dc=1.508 kg/m3, Z=4, F(000)=712, μ=1.849 mm−1, R1=0.0416. wR2=O.1023. This phase exhibits infinite inorganic chains of vertex‐linked ZnO4and HPO3. Via the electrostatic attraction, 1.6‐hexamethylenediamine cations and inorganic chains construct a novel interesting two‐dimensional inorgan

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220406

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY

摘要:

Abstract(Z)‐1‐[2‐(Tri‐o‐tolylstannyl)vinyl]‐l‐indanol(1) and (Z)‐1‐[2‐(tri‐p‐tolylstannyl)vinyl]‐l‐indanol (2) were synthesized by the addition reaction of l‐ethynylindanol with tri‐o‐tolyltin and m‐p‐tolyltin hydride. The aryl groups in compound 1 and 2 were substituted by Br2or I2to yield monohalide derivatives (3–6). The compounds 1–6 were characterized by elemental analysis,1H NMR and FT‐IR spectroscopy. The crystal structures of 1, 2 and 4 have been determined by single crystal X‐ray diffraction analysis. The Sn atom in 1 and 2 exhibits a tetrahedral geometry distorted towards trigonal bipyramid due to a weak intramolecular interaction between Sn and the hydroxyl O atoms [02839(4) nm and 0.2744(5) nm], while the Sn atom in 4 adopts a trigonal bipyramidal geometry with a s

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220407

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY

摘要:

AbstractA novel pyridinium salt, 2,4‐bis[p‐(N,N‐dimethylamino)styryl]‐N‐methyl pyridinium iodide (BMSPI) was synthesized and characterized by TG,1H NMR spectroscopy and elemental analysis. and the reaction process was studied by Using ES‐MS. When BMSPI was pumped by a pulsed 1064 nm, 50 ps laser him. it manifests highly efficient TPA (Two‐Photon Absorption) and up‐conversion superradiance. The up‐conversion efficiency was 6.0% at the pump energy of 4–6 mJ and the Lifetime of two‐photon fluorescence

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220408

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY

摘要:

AbstractA new type of hydrogen peroxide amperometric biosensor was fabricated based on electrochemically deposited sub‐micrometer Au particles (sm‐Au) on a glassy carbon electrode (GCE). Electrochemical deposition condition was optimized for obtaining uniformly distributed sub‐micrometer sized Au array on the electrode surface. The hydrogen peroxide sensor was fabricated by adsorbing phenothiazine methylene blue (MB) molecules on the surface of sm‐Au and covering a cross‐linked horseradish peroxidase (HRP) layer, labeled as HRP/MB/sm‐Au/GCE. The characteristics of this biosensor were evaluated with respect to applied potential and pH. The amperometric response of the sensor was linear to the H2O2concentration over a wide range of 9.9×10−6—1.11×10−2mol/L. A detection limit (s/n=3) of 3.0×10−6mol/L H2O2was estimated for a sampled chronoamperometric detection at 1.5 min after potential step of 200 to −400 mV vs. SCE. The immobilized MB molecules shuttled electrons at α=0.77 and an apparent electron transfer rate constant ofk05=0.053 s−1. Interference of ascorbic acid, dopamine and uric acid was investigated. This sensor has very good stability and reprod

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220409

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY

摘要:

AbstractA synthesis of (2R,3aR,8aR)‐6‐chloro‐3a‐hydroxy‐1,2,3a8,8a‐hexahydropyrrolo[2,3‐b]indole‐2‐carboxylic acid methyl ester (1) was achieved. An aldol reaction with Garner aldehyde, a hydroxyl introduction by Davis reagent, and a reductive intramolecular ring‐closure reaction were served as the key steps. This piece of work provides a new way to synthesize the analogues of hexahydropyrrolo[2,3‐b]indole, starting from readily available chemical substrates and

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220410

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY

摘要:

AbstractThe study on the factors influencing sulfinatodehalogenation of perfluorohexyl chloride plus octene‐1 by using Na2S2O4/NaHCO3discovered that among the various solvents tested (e.g. Me2SO, NMP, DMAc, CH3CN, CH3CN/H2O) at different temperatures, Me2SO was found to be the most suitable solvent and the conversion of the chloride was very dependent on the reaction temperature. When Me2SO was used in the reaction of perfluoroalkyl iodides. the reaction temperature could be decreased by 20 °C as compared with that carried out in CH3CN/H2O to reach the comparable yiel

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220411

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY