Theoretical study on photophysical property of C_(60)M(CO)_5 (M=Cr,Mo and W)

Configurations of three η2 models of transition-metal 60 fullerene derivatives C60M(CO)5(M=Cr,Mo and W) have been optimized at B3LYP/LanL2DZ level.On the basis of the optimized geometrical structures,their electronic spectra and the frequency dependence of third-order nonlinear optical polarizabilities γ in different optical processes of third-harmonic generation(THG),electric-field-induced sec-ond-harmonic generation(EFISHG) and degenerate four-wave mixing(DFWM) are calculated by using TDB3LYP model based on LanL2DZ level coupled with the SOS(sum-over-state) method.The obtained results show that their electronic spectra have a red shift compared with that of 60 fullerene and dif-ferent transition-metal functional groups added to C60 cage may result in different spectrum properties.For the three studied species,(η2-C60)Mo(CO)5 has the largest third-order nonlinear optical polarizability.     

Nonlinear optical properties of Eu<Subscript>2</Subscript>O<Subscript>3</Subscript> doped 5ZnO-20Nb<Subscript>2</Subscript>O<Subscript>5</Subscript>-75TeO<Subscript>2</Subscript> glasses

The third-order optical nonlinearities, including third-order nonlinear susceptibility X^(3), nonlinear refractive index (n2) and temporal response, were measured with forward DFWM using Nd:YAG mode-locked pulse laser. The results show that Eu203 doped 5ZnO-20Nb2O5-75TeO2 glasses have large n2 and ultra-fast temporal response. Raman spectra show that Eu2O3 dopant induces the changes in the local structure of glasses. The higher the dopant concentration, the larger the nonlinear refractive n2 and the faster the temporal response. The enhancement on the third-order optical nonlinearities can be attributed to the deformation of the electronic clouds in [TeO4] enhanced by Eu2O3 dopant.     

Hybridized Nano-Structure Composed of Metal and Polydiacetylene

Polydiacetylene （PDA） is one of the promising candidates for organic third-order nonlinear optical （NLO） material, due to fast optical responsibility and easy processability in comparison with semiconductors etc. The magnitude of NLO property, however, is not still sufficient for the devices applications. Neeves, et al theoretically predicted the enhancement of NLO property for core-shell type hybridized nanocrystal （NC） composed of PDA and metal. In the present study, we have prepared the two kinds of core-shell type hybridized nano-structure, and investigated their optical properties.     

Structural dependences of the <Emphasis Type="Italic">η</Emphasis><Superscript>6</Superscript> complexes of 3-amino-9-ethylcarbazole with chromium tricarbonyl fragment on third-order optical nonlinearities

Degenerate four-wave mixing measurements, using the 35 ps pulses at 532 nm, have been employed to investigate the third-order nonlinear optical parameters of two chromium tricarbonyl complexes η6-bonded to 3-amino-9-ethylcarbazole at either the NH2-substituted aryl ring （1） or the unsubstituted ring （2） and their precursor 3-amino-9-ethylcarbazole （AECz）. The second-order hyperpolarizability y of the compounds 1 and 2 were found to be 42.9×10^-31 and 35.9×10^-31 esu, respectively, approximately one order of magnitude greater than AECz. The relation between the molecular structure and second-order hyperpolarizability of the compounds I and 2 was explored in detail based on the three-level model and the density functional theory （DFT） calculation. The theoretical results indicate that the spatial distribution of electron density has the profound role in the third-order nonlinear optical properties.     

Tunable tribological properties in water-based lubrication of water-soluble fullerene derivatives via varying terminal groups

In this paper,three kinds of water-soluble fullerene derivatives were synthesized via electrophilic addition reaction and cycloaddition reaction,respectively.The chemical composition characterizations of these derivatives indicated the successful preparation of C60(OH)x,C60(C(COOH)2)x and C60(OH)x(NHCH2COOH)y fullerene derivatives.The aggregation and morphology characterizations showed that the three kinds of derivatives had an ideal spherical aggregating structures and excellent dispersibility in water,especially C60(OH)x and C60(C(COOH)2) x.The lubrication performance of the fullerene derivatives acted as lubricant additives were investigated at different concentrations in the range of 0-1 wt%.The results indicated that the addition of polyhydroxyl and carboxylic derivatives could improve the lubrication properties,which led to the reduction of wear to about 40% at most.It is attributed that the optimized substitutions of fullerene molecules may be of benefit to their distribution properties and lubricating behaviors in water based lubrication.     

Palladium（ Ⅱ ） and Platinum（ Ⅱ ） Compounds Derived From Potentially Terdentate Ligands

Transition metal complexes derived from potentially terdentate ligands have attracted great interest in the late years. Among all the examples described so far, those containing palladium（ Ⅱ ） or platinum（ Ⅱ ） and ligands holding three heteroatoms with different donor abilities are particularly relevant. In compounds of this kind, the potential hemilability of one of the terminal σ（M-donor atom） bonds, plays an important role in the view of their applications in homogeneous catalysis. On the other hand, it is well-known that in dimetallic complexes the presence of two different metals in a close vicinity may influence their mutual cooperation in a wide variety of processes. Besides that, some examples of the utility of chiral palladium（ Ⅱ ） as well as platinum（ Ⅱ ） complexes as precursors for organic and/or organometallic synthesis, as chiral recognitors or discriminators, or even in Bio-Medicine have also been reported. However, chiral heterodimetallic compounds holding ferrocenyl units and potentially terdentate ligands are scarce.     

Optical nonlinearity and ultrafast dynamics of ion exchanged silver nanoparticles embedded in soda-lime silicate glass

Ag nanoparticles embedded in soda-lime silicate glass were fabricated by ion-exchange and subse-quently annealing method. Z-scan technique, femtosecond time-resolved optical Kerr effect （OKE） technique and femtosecond pump-probe experiment were used to investigate the effects of laser wavelength and laser pulse duration as well as annealing temperature on the third-order optical nonlinearity and ultrafast dynamics of the composites. It was found that the third-order susceptibility of Ag nanoparticles composite glass measured by 400 nm pulse source is larger than that measured by 800 nm pulse source due to an enhancement effect of local field near surface plasmon resonance of Ag nanoparticles in silicate glass. The third-order optical nonlinearity measured by ns laser source is about two orders of magnitude larger than that measured from fs pulse. The annealing temperature has an important effect on the third-order optical nonlinearity and ultrafast dynamics of the composites. Third-order nonlinear susceptibility up to 10^-l0 esu and fast relaxation process up to 0.2 ps have been obtained in Ag nanoparticles doped glass.     

The self-aggregation of chiral threonine-linked porphyrins and their zinc(II) complexes

The self-aggregation of chiral threonine-linked porphyrins and their zinc(Ⅱ) complexes in water-alcohol system and water-alcohol-NaCI system has been studied by circular dichroism (CD), UV-Vis absorption spectra and fluorescence spectra methods. The experiment results indicate that chiral threonine-linked porphyrins and their zinc(Ⅱ) complexes have two different kinds of aggregates in water-alcohol system and water-alcohol-NaCI system. And the porphyrins may form highly organized and orientated aggregates in water-alcohol-NaCI system. The aggregates in water-alcohol-NaCI system may have helical structures.     

Electronic structures and nonlinear optical properties of XAuPH<Subscript>3</Subscript>

The studies on model systems XAuPH3(X-H,F,Cl,Br,I,CN,CH3)have been carried out by using ab intiol HF and DFT B3LYP methods at pseudopotential and double-zeta LANL2DZ level.The results are compared with those of MP2,The properties of the models.i.e.the atomic net charge populations.the frontier molecular orbitals and nonlinear optical(NLO)properties have been investigated under an applied electric field on the basis of optimized structures.The computational results show that for these models characterized as electron acceptor-metal-electron donor(A-M-D)system,the NLO properties are due to intramolecular charge-transfer interaction between the acceptor and the donor.The more charges transfer gives,the better NLO properties.In the selected model systems,IAuPH3 has the biggest βvec and γof 1184.1942 a.u.and 17341.9214 a.u.,whereas IC6H4PH3^ ,A TYPICAL a-π-D organic conjugated system,has βvec and γof 710.7697 and 11664.1405 a.u.respectively.In comparison.IAuPH3 has significant NLO properties.     

Photo-functional materials based on copper(Ⅰ) complexes

Copper(Ⅰ) complexes are attractive photo-functional materials due to their rich photochemical and photophysical properties. It has been proved that these new materials have potential application in many fields, such as organic light-emitting diodes, optical sensor, nonlinear optics and dye sensitized solar cells. The goal of this review is to outline the progress in this field. Many aspects, including new ligands, stereochemical control and the construction of supramolecules, design of the excited states, the high-energy emission and low-energy emission, the Cu-Cu bonding interactions and applications, are discussed.     

Biodistribution of fullerene derivative C60(OH)x(O)y

The biological behavior of fullerene derivatives shows their considerable potential application in medicine field. To understand the biodistribution of C₆₀ derivatives as drugs or drug carriers, a simple water-soluble derivative C₆₀(OH)_x(O)_y was labeled with^99mTc. A γ-counter and a single photo emission computed tomography (SPECT) were used to assess the biodistribution and metabolism of the labeled compound in mice and rabbits, respectively. The results showed that the compound could be absorbed rapidly by tissues, especially by coronal bone, breastbone, backbone, extremity honeycomb, liver and spleen. The clearance was slow from all tissues except for brain. The compound might be excreted through urine and enteron. The biodistribution shows some difference from that of Yamago et al. In this note, we discuss the possible reason leading to the difference. Further study is needed to find out to what extent the C₆₀ itself determines the biodistribution of derivatives.     

Manganese(III) acetate-mediated radical reaction of [60]fullerene with bromoacetic acid, 3-chloropropionic acid or 1-naphthylacetic acid

The manganese(III) acetate-mediated radical reaction of [60]fullerene (C₆₀) with three carboxylic acids, that is, bromoacetic acid, 3-chloropropionic acid, and 1-naphthylacetic acid, was investigated. The reaction of C₆₀ with bromoacetic acid in the presence of 4-(dimethylamino)pyridine afforded the anticipated C₆₀-fused lactone, while the reaction with 3-chloropropionic acid unexpectedly led to the formation of a novel C₆₀-fused lactone with the loss of one molecule of HCl. Interestingly, the reaction with 1-naphthylacetic acid under similar conditions gave both C₆₀-fused lactone and 1,4-adduct, yet each of them could be selectively obtained by controlling reaction conditions. It was also observed that the C₆₀-fused lactone bearing a bulky naphthyl group existed as two isomers.     

Spontaneous transformation of C60Br24 to C60 in solvents

It was found that C₆₀Br₂₄ transforms to C₆₀ spontaneously in some solvents. The intermediate, C₆₀Br₈, can be separated in some cases. When the bromine trap, phenol, was added,p-bromophenol and other brominated product were obtained and identified. The influences of time, the kind of solvent, etc were investigated. Possible mechanism was suggested. Supported by the National Natural Science Foundation of China Liu Ying: born in 1969, Ph. D     

Self-assembly of N-3-γ-pyridyl Aza[60]fulleroid on Au(111)

Self-assembled monolayers of novel C₆₀ derivative, N-3-γ-pyridyl Aza[60]fulleroid (C₆₀Py), on Au(111) were studied by a scanning tunneling microscope under ultrahigh vacuum (UHV). C₆₀Py molecules were assembled on Au (111) via pyridyl nitrogen-Au interaction. The sole assembly of C₆₀Py molecules on Au (111) only exhibited randoml aggregation of C₆₀Py even the films were annealed at 50 and 105°C. By co-assembling with benzyl mercaptan (BM), the C₆₀PyBM films showed highly dense aggregation, but C₆₀Py assemblies still had disordered structure. After the co-assembled C₆₀Py-BM films were annealed at 50°C, BM molecules were partially desorbed, but the assembly of C₆₀Py remained without obvious change. After the co-assembled C₆₀Py-BM films were further annealed at 105°C, the C₆₀Py monolayers with ordered structure were obtained, while the BM molecules were nearly thoroughly desorbed from the surface. Here, the BM molecules play a key role as a surfactant in the formation of the ordered C₆₀Py monolayer.     

Vegetation evolution on the central Chinese Loess Plateau since late Quaternary evidenced by elemental carbon isotopic composition

There are many controversial issues in loess studies such as natural vegetation types on the Chinese Loess Plateau during the historical periods and the spatial and temporal evolution of C3/C4 plants. Elemental carbon isotopic composition （δ^13Cec） in the loess section may offer new evidence for these problems. Elemental carbon （EC） is produced by incomplete combustion of vegetation, and its carbon isotopic composition has a very small difference from that of the formal vegetation, then δ^13Cec can be used as a record to recover the changes of vegetation. Elemental carbon was extracted by applying the oxidation method from the Ioess-paleosol sequence in the central Chinese Loess Plateau, and its car- bon isotope composition was analyzed by the isotope mass spectrometer. The results showed that the vegetation in this region was a mixed type of C3 and C4 plants, dominated with C3 plants in most of the time. Since late Quaternary, C3/C4 plants may not follow a simple glacial-interglacial cycle mode on the Chinese Loess Plateau, but showing fluctuations. C3 plants increased gradually in L4 period, and more C3 plants occurred during $3 period, and C4 plants increased again during L3-- L2 periods, after that, Cs plants dominated again during S1 --S0 periods. During periods of paleosol development, C3 plants were abundant in S3 and S1, and there were more Ca plants in S2 and SO. During periods of loess sedimen- tation, there were more C3 plants in L4 and L1, and there were more C4 plants in L3 and L2. On the orbital timescale, the vegetation variations revealed by δ^13Cec record are consistent with the results of pollen data and also similar to the results obtained by organic carbon isotopic composition since the last glacial period.     

In situ observation of C60（C（COOH）2）2 interacting with living cells using fluorescence microscopy

1 Introduction In recent years, studies on biological effects of thenanoscale materials have become the cornerstone of rapidly developed nanomedical and nanobiological technologies. Moreover, studies on the bio-effects when the different kinds of nanoscal…     

A Novel Degradation Pathway of Zn（dmid） （ phen）2 in Pyridine

The light-oxidation degradation processes of Zn(dmid)(phen)2(dmid = 4, 5-dimercapto-1,3-dithiole-2 one, phen = 1,10-phenanthroaline) in pyridine solvent has been monitored, h has been found under the light, dmid^2- of Zn(dmid)(phen)2 in pyridine solution could generate NCS^- and NCS^-replaces dmid^2- to form Zn(NCS)2 (phen)2 simultaneously. The crystal structure of Zn(NCS)2 (phen)2 has been determined. In the crystal of Zn(NCS)2 (phen)2. two NCS^- ligands are arranged in syn-configuration, and there is strong π-π interaction between the two adjacent parallel phen.     

Investigation of the cross-reaction mechanism of C<Subscript>6</Subscript>H<Subscript>5</Subscript>F-HNO<Subscript>2</Subscript> aqueous solution irradiated at 355 nm by transient absorbance spectrum technique

The transient absorption spectrum technique was employed to investigate the cross-reaction mechanism of C6H5F-HNO2 aqueous solution irradiated at 355 nm. The characteristic and the kinetic parameters of transient species were also detected. Hydroxyl radical derived from the photolysis of HNO2 was added to monofluorobenzene with a second-order rate constant of （5.83±0.17）×10^9 L·mol^-1·s^-1 to form an adduct, C6H5F…OH, which was able to react with HNO2 as the main reaction pathway with a rate constant of （8.3±0.1）×10^7 L·mol^-1·s^-1. The C6F6…OH adduct can also be decayed by elimination of H2O to yield monofluorophenyl radical C6H4F-. By GC-MS technique, the final products were identified to be monofluorophenol, nitro-monofluorobenzene, nitro-monofluorophenol and para-fluorobiphenyl.     

Theoretical study on the lithium bond interaction of furan homologues C4H4Y （Y=O,S） with LiCH3 via DFT and MP2

The optimizations geometries and interaction energy corrected by BSSE of the complexes between C4H4Y （Y=O, S） and CHiLi have been calculated at the B3LYP/6-311＋＋G^＊＊ and MP2/6-311＋＋G^＊＊ levels. Three complexes were obtained. Abnormally, the calculations showed that all the C10--Li14 bond lengths increased obviously but the blue-shift of C10-Li14 stretching frequency occurred after formed complexes. The calculated binding energy with basis set super-position error （BSSE） and zero-point vibrational energy corrections of complexes I-III is -45.757, -35.700 and -39.107 kJ·mol^-1, respectively. The analyses on the combining interaction with the atom-in-molecules theory （AIM） also showed that a relatively strong lithium bond interaction presented in furan homologues C4H4Y-LiCH3 systems. Natural bond orbital theory （NBO） analysis has been performed, and the results revealed that the complex I is formed with n-σ type lithium bond interaction between C4H40 and LiCH3, complex II is formed with TT-s type lithium bond interaction between C4H4O and LiCH3, and complex III is formed with TT-s and n-s type lithium bond interactions between C4H4S and LiCH3, respectively.     

Electronic structures and infrared spectra of C120O2, C120OS and C120S2

Electronic structures and infrared spectra of C₁₂₀XY molecules (X, Y=O, S) and some of the corresponding ions are investigated using PM3 semi-empirical molecular orbital calculations with full optimization of geometrical structures. It is found that the energy penalty is about 30–42 kJ/mol due to introducing a double bond in the fivemembered ring except for C₁₂₀O₂ ⁻ and triplet C₁₂₀O₂ ²⁻. It is also found that the structures of neutral molecules and the corresponding ions are almost the same; for instance, the change of bond length is less than 0.001 nm. The change of frontier orbits from oxide to sulfide is little as well. The triplet states of C₁₂₀O₂ ²⁻ and C₁₂₀OS²⁻ are more stable than their singlet states, which means that C₁₂₀O₂ ²⁻ and C₁₂₀OS²⁻ follow the Hund’s rule. The vibration analysis showed that the infrared spectra of neutral C₁₂₀O₂ and C₁₂₀OS molecules are in good agreement with the experimental results. Compared with the neutral molecule, vibration frequencies of triplet C₁₂₀O₂ ²⁻ change little, but the vibration intensities are enhanced obviously.