Synthesis of N-acetamide C60 nitride and its performance of optical limiting

N-acetamide C60 nitride (N-acetamide-1,2-dihydro-1,2-aza-fullerene[60]) has been synthesized by the reaction of C60 and azidoacetamide and initially characterized. Its mechanism was that the objective product is formed through intermediate triazoline. The computational study shows that N-nitride structure is thermodynamically more stable by using the semi-empirical AM1 SCF-MO method. The properties of optical limiting were tested by using double frequency Nd∶YAG pulse laser system and showed that the optical limiting mechanism is reverse saturation absorption. A wavelength of 532 nm, compared with optical limiting for ns pulse, this new material has good optical limiting character for ps pulse. At wavelength of 707 nm, the capacity of optical limiting of the derivative is prior to C60.     

C60氮丙啶衍生物的表征及其光限幅效应

研究了叠氮乙酰胺与C60反应,其反应机理为经过一个三唑啉中间体结构形成最终产物;分析表征了C60氮乙酰胺,通过量化计算确定了氮丙啶闭环结构为热力学稳定结构;应用倍频Nd:YAG脉冲激光测试了它的光限幅性能,确定其光限幅机制为反饱和吸收,长波长(707 nm)激光的限幅效果要优于C60,表明C60衍生物是一种非常有希望的激光限幅材料.     

嘧啶环二炔氮桥C60衍生物的合成及非线性光学性质

合成了嘧啶环二炔氮桥C₆₀衍生物C₆₀NPD ,研究了在532nm、脉宽 8ns条件下的非线性光学特性。通过Z-扫描实验发现C₆₀NPD有很强的非线性吸收和非线性折射,并获得了三阶非线性光学系数χ⁽³⁾ 。同时也研究了光限幅特性，实验结果表明C₆₀NPD有较低的光限幅箝位值。     

富勒烯衍生物非线性光学及其光限幅研究

应用倍频Nd：YAG脉冲激光,在波长为532nm、脉冲宽度为8ns的条件下,测试了富勒烯衍生物非线性吸收与光限幅特性。测试结果表明,C60衍生物的光限幅性能优于C60的光限幅性能。     

Theoretical study on photophysical property of C60M（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 second-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 different transition-metal functional groups added to C60 cage may result in different spectrum properties. For the three studied species, （η^2-C60）Mo（CO）5 has the largest third-order nonlinear optical polarizability.     

对N,N-二羟乙基胺基偶氮苯基乙炔的光限幅性能研究

研究4-乙炔基-4′-[N,N-二羟乙基]胺基偶氮苯单体的光限幅效应,发现它对40ps脉宽,1064nm的激光呈现出较好的光限幅性能。并初步探讨了光限幅机理。     

Preparation and optical properties of solid solution semiconductor (Zn x Cd1−x S) doped silica glasses

Semiconductor(Zn_xCd_1−x S) doped silica glasses were prepared by Sol-Gel process andin situ growth technique. The structure of the materials was characterized by X-ray diffraction technique, the particle size of semiconductor crystallites from X-ray patterns was estimated less than 10 nm. From absorption spectra, it is obtained that the absorption edges shifted to short wavelength direction when Zn contents increased, and the absorption edge can be adjusted from 2.46 eV to 2.96 eV by controlling Zn contents. The third-order nonlinear optical susceptibility was studied at 532 nm with 8 ns pulse laser by degenerate four wave mixing (DFWM) technique.     

Structural stability of C<Subscript>60</Subscript> films under the bombardment of 1.95 GeV Kr ions

The structural stability of C₆₀ films under the bombardment of 1.95 GeV Kr ions is investigated. The irradiated C₆₀ films were analyzed by Fourier Transform Infrared (FTIR) spectroscopy and Raman scattering technique. The analytical results indicate that the irradiation induced a decrease of icosahedral symmetry of C₆₀ molecule and damage of C₆₀ films; different vibration modes of C₆₀ molecule have different irradiation sensitivities; the mean efficient damage radius obtained from experimental data is about 1.47 nm, which is in good agreement with thermal spike model prediction.     

Decoration of C60 nanorods with nickel and their magnetic properties

We studied the coating of C60 nanorods with nickel by electroless plating method and investigated their magnetic properties. The morphology and structure of the nickel layer coated on C60 nanorods were characterized by transmission electron microscopy （TEM）, energy-dispersive X-ray spectroscopy （EDX）, X-ray diffraction （XRD） and Raman spectroscopy. The coated nickel is in the form of nano-sized crystals and becomes a continuous layer as reaction time increases. The hysteresis loop shows a super paramagnetic characteristic similar to that of nanometer-sized nickel particle. These results suggest that the average size of nickel particles on C60 rods is below 10 nm. Our study has shown that electroless plating is an efficient and simple method for coating C60 nanorods with nickel.     

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     

Hydrothermal synthesis, characterization and nonlinear optical effect of orthorhombic phase Ca2B6O11 · H2O

Hydrothermal treatment of calcium oxide and boric acid mixtures at temperatures between 234 °C and 300 °C has produced a colorless, transparent, orthorhombic compound Ca₂B₆O₁₁ · H₂O. Of the seven known members of the series of hydrated dicalcium hexaborate containing boron-oxygen six-membered ring anionic group (B₃O₈)^-7, only the title compound has been found to have the nonlinear optical effect. The second harmanic generation (SHG) effect of its crystal is larger than that of KH₂PO₄ (KDP). The reflection spectrum has shown that this compound has no absorption in the experimental wavelength range (800–240 nm). Its crystal structure is favorable for generating the nonlinear optical effect.     

Photoluminescence of fullerene[60] in ultrathin ordered multilayers: The dissociation of molecular aggregation

The aggregation behavior of a substituted fullerene compound, 1-benzyl-2-hydro[60]fullerene (C₆₀-Be), in Z-type ultrathin ordered (e.g. LB) multilayers has been studied by UV-vis absorption, steady state and time-resolved fluorescence spectroscopies. The LB multilayers of pure C₆₀-Be showed J-aggregate formation, characterized by a large red-shift of two absorption peaks (ΔE∼2 098 cm¹ from 260→275 nm and ΔE∼1 076 cm^-1 from 328→340 nm, respectively). The main fluorescence emission bands were found at 710, 646, 603, 600 and 595 nm for pure (C₆₀-Be, mixed C₆₀-Be (molar percentage 50%, 25% and 20%. respectively) multilayers and monomeric C₆₀-Be in solution, respectively. The aggregates were dissociated by mixing with some inert materials. The fluorescence decay profiles of C₆₀-Be, mixed C₆₀-Be (molar percentage 50%, 25% and 20%, respectively) in LB films could be best-fitted by using a bi-exponential decay model.     

Investigation of tribological properties of composite C60-LB films

C60, as the third allotrope of carbon element, has al- ways received much attention from material scientists since it was found by Kroto in 1985. It is endowed with many special characteristics[1-4] due to its symmetrical structure such as photo-induced e…     

二维Ti3C2Tx MXene材料的制备与工艺优化

二维（2D）过渡金属碳/氮化物（MXene）材料是当前最受关注的二维材料之一,其中二维碳化钛（Ti₃C₂T_x MXene）材料的研究最为广泛。该材料目前主要通过刻蚀三元碳化物或氮化物（MAX相）后进一步插层得到,因此MAX相材料的纯度和制备工艺条件直接决定了Ti₃C₂T_x MXene材料的物化性质。主要完成了不同Ti₃AlC₂ MAX相材料的筛选,选择氢氟酸（HF）刻蚀,并优化了不同的插层方法,制备了一系列Ti₃C₂T_x MXene材料。通过X射线衍射（XRD）、场发射扫描电镜（FESEM）、透射电子显微镜（TEM）、原子力显微镜（AFM）和X射线光电子能谱（XPS）等表征,确定使用原位锂离子（Li⁺）插层法可有效获得单层Ti₃C₂T_x MXene材料。制备的单层Ti₃C₂T_x MXene材料的表面平整,片径约为150 nm,厚度约为2 nm。同时,创新性地采用涡旋震荡辅助材料分层,极大地缩短了超声时间,提高了单层Ti₃C₂T_x MXene材料的产率（可达70%）,并且可以避免材料氧化,为Ti₃C₂T_x MXene材料未来应用提供了新方法。     

富勒烯C_(60)接枝马来酸聚合物铅盐的制备与表征

以富勒烯C60和马来酸为原料合成得到一种新型富勒烯C60接枝马来酸聚合物,C60接枝马来酸聚合物再与硝酸铅反应得到C60接枝马来酸聚合物铅盐。通过单因素方法探讨了pH、反应物物料比、反应温度以及反应时间对C60接枝马来酸聚合物铅盐中铅含量的影响,获得其最佳合成工艺条件为:pH=6.92,C60接枝马来酸聚合物和硝酸铅的摩尔比为1∶7,反应时间2 h,反应温度30℃,该条件所得C60接枝马来酸聚合物铅盐中铅质量分数为56.09%。同时采用FT-IR、UV、GPC、AAS、XRD及XPS等测试手段对产物结构进行了表征。采用差热和热重分析法对C60接枝马来酸聚合物铅盐的热稳定性进行了研究,结果表明,在空气气氛下,DTA分解峰值温度为275、370、462℃,失重率为43.6%,表明产物热稳定性良好。     

Resistless photochemical etching of a silicon wafer by UV laser with an H<Superscript>2</Superscript>O<Superscript>2</Superscript> and HF aqueous solution

A new resistless etching method has been developed for Silicon wafers. This new method uses an aqueous solution consisting of hydrogen peroxide (H₂O₂) and hydrogen fluoride (HF) as the activating etchants. A 193 nm ArF excimer laser and a 266 nm fourth harmonic generation Nd: YAG laser were used as the photon sources. Results showed that pattern etching has been achieved without any photoresist film. In the case of the 193 nm laser, the optimal etching appeared at a 1.3 H₂O₂÷HF ratio, where an etch depth of 210 nm was achieved with a fluence of 29 mJ/cm² and shot number of 10000. At the same conditions, the etch depth with H₂O₂ and HF solution was three times of that by using H₂O and HF mixture. In the case of the 266 nm Nd: YAG laser, the optimal etching appeared at twice ratio of H₂O₂/HF, where the etch depth of 420 nm was achieved with a fluence of 12 mJ/cm² and shot number of 30000. Results showed that the etch effect of the 266 nm Nd: YAG laser was more desirable than that of the 193 nm ArF excimer laser.     

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.     

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.     

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.     

C60CH2和C60HR(R＝C6H5CO--)的光限幅特性

应用倍频Ｎｄ：ＹＡＧ激光研究了２种新合成的Ｃ６０衍生物Ｃ６０ＣＨ２和Ｃ６０ＨＲ（Ｒ＝Ｃ６Ｈ５ＣＯ－）甲苯溶液的光限幅性质。Ｃ６０ＨＲ的光限幅效应与Ｃ６０相比稍则Ｃ６０ＣＨ２的光限幅效应与Ｃ６０相近,并具有更低的限幅幅值。