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Synthesis and photophysical properties of Ir~Ⅲ-Ln~Ⅲ(Ln=Nd,Yb,Er) bimetallic complexes containing bipyrimidines as bridging ligands

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Science China Chemistry 2009年第11期52卷 1808-1813页

作者： CHEN FangFang,JIANG WeiLi,LOU Bin,BIAN ZuQiang & HUANG ChunHui beijing national laboratory for molecular sciences,State Key laboratory of Rare Earth Materials Chemistry and Applications,College of Chemistry and molecular Engineering,Peking University,beijing 100871,China beijing national laboratory for molecular sciences State Key Laboratory of Rare Earth Materials Chemistry and Applications College of Chemistry and Molecular Engineering Peking University Beijing China

Bipyrimidines have been chosen as(N^N)(N^N) bridging ligands for connecting metal ***Ⅲ-LnⅢ(Ln = Nd,Yb,Er) bimetallic complexes [Ir(dfppy)2(μ-bpm)Ln(TTA)3]Cl were synthesized by using Ir(dfppy)2(bpm)Cl as the ligand coordinating to lanthanide complexes Ln(TTA)3·*** stability constants between Ir(dfppy)2(bpm)Cl and lanthanide ions were measured by fluorescence *** obvious quenching of visible emission from IrⅢ complex in the IrⅢ-LnⅢ(Ln = Nd,Yb,Er) bimetallic complexes indicates that energy transfer occurred from IrⅢ center to *** emissions from NdⅢ,YbⅢ,and ErⅢ were obtained under the excitation of visible light by selective excitation of the IrⅢ-based *** was proven that Ir(dfppy)2(bpm)Cl as the ligand could effectively sensitize NIR emission from NdⅢ,YbⅢ,and ErⅢ.

关键词： bipyrimidine IrⅢ-LnⅢ bimetallic complexes stability constant NIR emission excitation of visible light

Periodic tables of diatomic and triatomic molecules

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Science China Chemistry 2012年第6期55卷 618-625页

作者： KONG FanAo & WU WeiQiang beijing national laboratory for molecular sciences, Institute of Chemistry, Chinese Academy of sciences, beijing 100190, China beijing national laboratory for molecular sciences Institute of Chemistry Chinese Academy of Sciences Beijing China

The Mendeleev periodic table of atoms is one of the most important principles in natural science. However, there is shortage of analog for molecules. Here we propose two periodic tables, one for diatomic molecules and one for triatomic molecules. The form of the molecular periodic tables is analogous to that of Mendeleev periodic table of atoms. In the table, molecules are classified and arranged by their group number G, which is the number of valence electrons, and the periodic number P, which represents the size of the molecules. The basic molecular properties, including bond length, binding energy, force constant, ionization potential, spin multiplicity, chemical reactivity, and bond angle, change periodically within the tables. The periodicities of diatomic and triatomic molecules are thus revealed. We also demonstrate that the periodicity originates from the shell-like electronic configurations of the molecules. The periodic tables not only contain free molecules, but also the "virtual" molecules present in polyatomic molecules. The periodic tables can be used to classify molecules, to predict unknown molecular properties, to understand the role of virtual molecules in polyatomic molecules, and to initiate new research fields, such as the periodicities of aromatic species, clusters, or nanoparticles. The tables should be of interest not only to scientists in a variety of disciplines, but also to undergraduates studying natural sciences.

关键词： molecular periodicity – periodic table – diatomic molecules – triatomic molecules – molecular property

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Electron structure and substituent effects in o-,m-,p-IC_6H_4OCH_3 iodoanisoles

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Science China Chemistry 2009年第11期52卷 1932-1937页

作者： TONG ShengRui,WANG WeiGang,MA ChunPing,GE MaoFa & WANG DianXun beijing national laboratory for molecular sciences(BNLMS),State Key laboratory for Structural Chemistry of Unstable and Stable Species,Institute of Chemistry,Chinese Academy of sciences,beijing 100190,China beijing national laboratory for molecular sciences (BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing China

The electronic structures and substituent effects in o-,m-,and p-iodoanisoles have been investigated by ultraviolet photoelectron spectroscopy(UPS).The observed UPS bands were analyzed by combining empirical arguments and theoretical *** to the electron-donating nature of both iodoand methoxy substituents,the first ionization potentials of the three iodoanisoles are lower than those of iodobenzene and *** presence of the two substituents in iodoanisoles leads to an electronrich structure,which might contribute to the observed high reactivity of iodoanisoles in a number of organic reactions.

关键词： electronic structures substituent effects ultraviolet photoelectron spectroscopy reactivity

CHEMICAL STRUCTURE DEPENDENCE OF THE INTERNAL ENERGY CONTRIBUTION IN RUBBER ELASTICITY

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Chinese Journal of Polymer Science 2001年第5期19卷 447-449页

作者： Juan Sun Xiao-zhen Yang Polymer Physics laboratory Center for molecular sciences, Institute of Chemistry Chinese Academy of sciences beijing 100080 China 中科院化学所高分子物理及化学国家重点实验室北京

Conformational elasticity theory recently developed has been used to explore the internal energy contribution to the elastic force f(e)/f as a function of strain for poly(cis-1,4-isoprene) and poly(trans-1,4-isoprene). Calculated f(e)/f values are in good agreement with those obtained experimentally. Results show that behavior of f(e)/f is mainly contributed by chemical structure, or intramolecular interaction, supporting the experimental observations, and that the internal energy contribution is strain dependent.

关键词： conformational elasticity theory internal energy contribution poly(cis-1,4-isoprene) poly(trans-1,4-isoprene)

2MASS photometry and age estimation of the globular clusters in the outer halo of M31

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Research in Astronomy and Astrophysics 2012年第2期12卷 115-126页

作者： Jun Ma 1,21 national Astronomical Observatories,Chinese Academy of sciences,beijing 100012,China 2 Key laboratory of Optical Astronomy,national Astronomical Observatories,Chinese Academy of sciences,beijing 100012,China national Astronomical Observatories Chinese Academy of Sciences Key laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences

We present the first photometric results in J, H and Ks from 2MASS （Two Micron All Sky Survey） imaging of 10 classical globular clusters （GCs） in the far outer regions of M31. Combined with the V and I photometric data from previous literature, we constructed a color-color diagram between J - Ks and V - Ⅰ. By comparing the integrated photometric measurements with evolutionary models, we estimate the ages of these clusters. The results showed that all of these clusters are older than 3 × 109 yr, and among them four are older than 10 Gyr and the other six have intermediate ages between 3 - 8 Gyr. The masses for these outer-halo GCs are from 7.0 × 104 M to 1.02 × 10^6 M. We argued that GC2 and GC3, whose ages, metallicities and distance moduli are almost the same, were accreted from the same satellite galaxy, if they did not form in situ. The statistical results show that the ages and metallicities of these 10 M31 outer-halo GCs do not vary with projected radial position, and a relationship between age and metallicity does not exist.

关键词： galaxies: halos - galaxies: individual (M31) - star clusters: general

A Dye-sensitized Nanocrystalline Solid State Photovoltaic Cell

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Chinese Chemical Letters 2000年第9期11卷 813-814页

作者： Dong She ZHANG Xu Rui XIAO laboratory of photochemistry, Center for molecular sciences, Institute of Chemistry, Chinese Academy of sciences, beijing, 100080 laboratory of Photochemistry Center for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences

A new type of dye-sensitized nanocrystalline solid state photovoltaic cell based on the wide band gap n-TiO2/p-CuI heterojunction was fabricated. Tetra-carboxyphenyl porphyrine (TPP-(COOH)(4)), squarylium cyanine derivative (SQ-(CH2),(SO3Py+)-Py-.) and ruthenium bipyridyl complex (RuL2(NCS)(2)) were used as photosensitizers. Larger photocurrents and photovoltages were shown in the cell sensitized by ruthenium bipyridyl complex and can be further increased by intercalation of a TiO2 thin underlayer.

关键词： nanocrystalline TiO2 electrode dye sensitization solid state cell

6-Membered ring intermediates in polymerization of N-carboxyanhydride-L-α-arginine in H_2O

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Science China Chemistry 2009年第8期52卷 1220-1226页

作者： XIN Liang1,REN Jie1,XIANG JunFeng2,YAN Qin1,XIE Yi1,WANG KongJiang1,LAI PingAn3 & BAI YaDuo3 1 Institute of Biophysics,Chinese Academy of sciences,beijing 100101,China 2 beijing national laboratory for molecular sciences(BNLMS),Centre for molecular sciences,Institute of Chemistry,Chinese Academy of sciences,beijing 100080,China 3 beijing Entry-Exit Inspection and Quarantine,beijing 100026,China Institute of Biophysics Chinese Academy of Sciences Beijing China beijing national laboratory for molecular sciences (BNLMS) Centre for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing China beijing Entry-Exit Inspection and Quarantine Beijing China

In polymerization of N-carboxyanhydride-L-α-arginine(L-Arg-NCA) in H2O,nucleophilic reaction of guanidine group with the carbonyl group of L-Arg-NCA leads to quick intramolecular rearrangement,yielding a 6-membered ring intermediate 1-amidino-3-amino-2-piperidone,which is either elongated by another L-Arg-NCA yielding arginyl-1-amidino-3-amino-2-piperidone or hydrolyzed to L-α-*** oligoarginines are formed mainly through hydrolysis of *** is a unique pathway in polymerization of L-Arg-NCA with regard to the usual pathway of elongations by reaction of N-carboxyanhydride-L-α-amino acid with L-α-amino acid or oligopeptides.

关键词： N-carboxyanhydride L-Arg-NCA intermediates L-α-arginine polymerization

MB_8^(2-) (M=Be,Mg,Ca,Sr,and Ba):Planar octacoordinate alkaline earth metal atoms enclosed by boron rings

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Science China Chemistry 2010年第8期53卷 1737-1745,1829-1832页

作者： PU ZhiFeng1,GE MaoFa1 & LI QianShu2 1State Key laboratory for Structural Chemistry of Unstable and Stable Species beijing national laboratory for molecular sciences (BNLMS) Institute of Chemistry,Chinese Academy of sciences,beijing 100190,China 2Center for Computational Quantum Chemistry,South China Normal University,Guangzhou 510631,China State Key laboratory for Structural Chemistry of Unstable and Stable Species beijing national laboratory for molecular sciences (BNLMS) Institute of Chemistry Chinese Academy of Sciences Beijing China Center for Computational Quantum Chemistry South China Normal University Guangzhou China

Complexes involving planar octacoordinate alkaline earth metal atoms in the centers of eight-membered boron rings have been investigated by two density functional theory (DFT) ***82-with D8h symmetry is predicted to be stable,both geometrically and electronically,since a good match is achieved between the size of the central beryllium atom and the eight-membered boron *** contrast,the other alkaline earth metal atoms cannot be stabilized in the center of a planar eight-membered boron ring because of their large *** following the out-of-plane imaginary vibrational frequency,pyramidal C8v MgB82-,CaB82-,SrB82-,and BaB82-structures are *** presence of delocalized π and σ valence molecular orbitals in D8h BeB82-gives rise to aromaticity,which is reflected by the value of the nucleus-independent chemical *** D8h BeB82-structure is confirmed to be the global minimum on the potential energy surface.

关键词： density functional theory octacoordinate alkaline earth metal aromatic molecular orbital

Thermal analysis of the baffle structure of the Solar Space Telescope

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Science China(Physics,Mechanics & Astronomy) 2010年第9期53卷 1755-1764页

作者： LI Rong1,2,3 & WANG Sen1,3 1 national Astronomical Observatories,Chinese Academy of sciences,beijing 100012,China 2 Graduate University of Chinese Academy of sciences,beijing 100049,China 3 Key laboratory of Solar Activity,national Astronomical Observatories of Chinese Academy of sciences,beijing 100012,China Chinese Academy of sciences National Astronomical Observatories Beijing China (GRID:grid.9227.e) (ISNI:***) Graduate University of Chinese Academy of sciences Beijing China (GRID:grid.458514.9) national Astronomical Observatories of Chinese Academy of sciences Key Laboratory of Solar Activity Beijing China (GRID:grid.450302.0) (ISNI:***) Chinese Academy of sciences National Astronomical Observatories Beijing China (GRID:grid.9227.e) (ISNI:***) national Astronomical Observatories of Chinese Academy of sciences Key Laboratory of Solar Activity Beijing China (GRID:grid.450302.0) (ISNI:***)

The SST(Space Solar Telescope) is an astronomical telescope with a primary mirror of 1 m in *** observes the sun with a small view field to ensure that its high spatial resolution imaging has 0.1″-0.15″ and high SNR(signal to noise ratio).Surrounding the small view field is still the sun,which is an intense source of both heat and stray *** baffles(the main baffle,the aperture,and the outer baffle),which are used to eliminate the stray light,will change the thermal flux in the SST and will weaken the effect of the thermal control *** this study,the compatibility analysis of the thermal effect of baffle structures in SST is *** GCF(Geometry Composing Function) and BRDF(Bidirectional Reflectance Distribution Function),which are two inherent related parameters in the compatibility analysis,are *** objective and method of the compatibility analysis are *** the thermal analysis software,the temperature fields are calculated for different lengths of the main baffle,different radii of apertures,different lengths of the outer baffle with a 3' tilt angle and 16' tilt angle,and different tilt angles of the outer baffle with a 200 mm length.A series of configurations and sizes of the baffles are studied with the goals of both thermal control and elimination of stray *** design of the baffle structure of SST is achieved:the main baffle of length 4100 mm,the internal shield of radius 494 mm,the outer baffle of length 200 mm,and the outer baffle of tilt angle 3' are successfully *** paper presents the relationship between the thermal control design and stray light elimination plan in the *** aims of the optimal design of the baffle structure of SST are *** thoughts and methods of the optimal analysis are also useful for similar optical telescopes designed for solar observation.

关键词： baffle the main baffle the outer baffle GCF BRDF