三芳基吡唑啉噁二唑类衍生物的合成及其荧光光谱研究

提出了一种新的合成1,3,4-噁二唑化合物的方法,并通过Wittig反应将其与1,3,5-三芳基-2-吡唑啉相连合成了6种新的三芳基吡唑啉噁二唑类化合物.用红外光谱、质谱、核磁共振谱和元素分析对合成化合物进行了结构表征.用荧光光谱仪对它们的荧光性能进行了测试,测试结果表明目标产物具有良好的荧光性,其荧光发射波长均在437～511nm范围内,荧光量子产率最大可达0.36.     

Solution-phase electronegativity scale: insight into the chemical behaviors of metal ions in solution

By incorporating the solvent effect into the Born effective radius, we have proposed an electronegativity scale of metal ions in aqueous solution with the most common oxidation states and hydration coordination numbers in terms of the effective ionic electrostatic potential. It is found that the metal ions in aqueous solution are poorer electron acceptors compared to those in the gas phase. This solution-phase electronegativity scale shows its efficiency in predicting some important properties of metal ions in aqueous solution such as the aqueous acidities of the metal ions, the stability constants of metal complexes, and the solubility product constants of the metal hydroxides. We have elaborated that the standard reduction potential and the solution-phase electronegativity are two different quantities for describing the processes of metal ions in aqueous solution to soak up electrons with different final states. This work provides a new insight into the chemical behaviors of the metal ions in aqueous solution, indicating a potential application of this electronegativity scale to the design of solution reactions.     

Fabrication of copper hydroxyphosphate with complex architectures

Copper hydroxyphosphate [Cu(2)(OH)PO(4)] with complex architectures has been synthesized through a simple and mild hydrothermal route in the absence of any external inorganic additives or organic structure-directing templates. Powder X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectrometry are used to characterize various properties of the obtained samples. Single-crystals, twinned-crystals, and various novel architectures of copper hydroxyphosphate can be constructed through a careful control of synthetic parameters, such as the molar ratio of initial reagents, reagent concentration, reaction time, and temperature. On the basis of structure and chemical bond analysis, copper hydroxyphosphate crystals tend to grow along the c-axis and have a rotation twinned-crystal growth habit, which is essential for the formation of various complex architectures. The current approach provides a facile strategy to synthesize copper hydroxyphosphate crystals with unique morphologies and complex architectures, which may be applicable to the synthesis of other inorganic materials.     

Spontaneously resolved homochiral 3D lanthanide-silver heterometallic coordination framework with extended helical Ln-O-Ag subunits

Two novel homochiral lanthanide-silver heterometallic coordination polymers LnAg(OAc)(IN)3 [Ln = Nd (1), Eu (2), HIN = isonicotinic acid, HOAc = acetic acid] have been prepared under hydrothermal conditions, which were characterized by elemental analysis, infrared, thermogravimetric analysis, and single-crystal X-ray diffraction. Both complexes are isostructural and crystallize in a hexagonal system, chiral space group P6(1)22. Both polymers are constructed from infinite right-handed homochiral helical chains with Ln-O-Ag connectivity, representing the first examples of homochiral lanthanide-transition metal heterometallic coordination polymers with a 3D coordination framework based on spontaneous resolution. Furthermore, the luminescent properties of 2 were studied.     

Early metal di- and tricyanometalates: Useful building blocks for constructing magnetic clusters

Treatment of mer-VCl3(THF)3 with KTp [Tp = hydridotris(3,5-dimethylpyrazol-1-yl)borate], followed by [NEt4]CN in acetonitrile, affords [NEt4][(Tp)V(III)(CN)3].H2O (1.H2O); aerobic oxidation affords [NEt4][(Tp)V(IV)(O)(CN)2] (2). Subsequent treatment of 2 with Mn(II)(OTf)2 (OTf = trifluoromethanesulfonate) and 2,2'-bipyridine affords {[(Tp)V(O)(CN)2]2[Mn(II)(bipy)2]2[OTf]2}.2MeCN (3). Magnetic measurements indicate that 1-3 exhibit S = 1, (1/2), and 4 spin ground states, respectively.     

Ancillary ligand functionalization of cyanide-bridged S = 6 Fe(III)4Ni(II)4 complexes for molecule-based electronics

Treatment of 1-chloro-6-iodohexane or 1-chloro-10-iododecane with lithium tris(pyrazolyl)methanide, followed by potassium thioacetate, affords bifunctional 1-S(acetyl)-tris(pyrazolyl)alkanes (L) (pz)3C(CH2)nSAc (n = 6, 1; 10, 2). Magnetic studies of {[(pzTp)Fe(III)(CN)3]4[Ni(II)L]4[OTf]4}.solvent (4, L = 1; 5, L = 2) boxes suggest that -(CH2)6 chains (4) limit intermolecular interactions while -(CH2)10 chains in 5 introduce crystallographic disorder and a distribution of relaxation times; 4 and 5 exhibit slow relaxation of the magnetization.     

Effect of tonal native language on voice fundamental frequency responses to pitch feedback perturbations during sustained vocalizations

The purpose of this cross-language study was to examine whether the online control of voice fundamental frequency (F(0)) during vowel phonation is influenced by language experience. Native speakers of Cantonese and Mandarin, both tonal languages spoken in China, participated in the experiments. Subjects were asked to vocalize a vowel sound /u/at their comfortable habitual F(0), during which their voice pitch was unexpectedly shifted (± 50, ± 100, ± 200, or ± 500 cents, 200 ms duration) and fed back instantaneously to them over headphones. The results showed that Cantonese speakers produced significantly smaller responses than Mandarin speakers when the stimulus magnitude varied from 200 to 500 cents. Further, response magnitudes decreased along with the increase in stimulus magnitude in Cantonese speakers, which was not observed in Mandarin speakers. These findings suggest that online control of voice F(0) during vocalization is sensitive to language experience. Further, systematic modulations of vocal responses across stimulus magnitude were observed in Cantonese speakers but not in Mandarin speakers, which indicates that this highly automatic feedback mechanism is sensitive to the specific tonal system of each language.     

CH3+NO的反应机理和动力学研究

在G2(B3LYP/MP2/CC)理论水平上研究了CH3自由基与一氧化氮分子(NO)的反应.计算了反应体系最低势能面上各驻点的构型参数、振动频率和能量,全面研究了此反应的反应机理及各个可能的反应通道;利用多通道TST RRKM理论计算了300～2500K的总包反应速率常数的温度效应、压力效应和各反应通道的分支比.详细讨论了活化分子碰撞失活对反应速率的贡献,计算结果和实验数据符合得较好.     

混合导电型陶瓷透氧膜材料的化学稳定性

考察了Sr-Co -Fe -O系列和Bi-Sr-Fe -O系列混合导电型无机透氧膜材料在氧分压小于 1.0 13Pa的气氛中 ,在 850℃和 950℃高温下加热 2 4～ 10 0h前后结构的变化。发现Bi -Sr -Fe-O系列透氧膜材料具有良好的化学稳定型 ,可以用于还原气氛下的催化反应。     

宽带扩展腔产生15飞秒光脉冲实验研究

用３ｍｍ长的钛宝石短棒和改进的非对称Ｚ型折叠腔结构进行自锁模实验，以石英棱镜对作为腔内色散补偿元件，在５Ｗ氩离子激光泵浦下，实现低阈值泵浦自锁模运转。在腔内不加任何调制元件的情况下实现软光阑锁模，获得最短脉冲宽度为１５ｆｓ，光谱宽度为８０ｎｍ，输出平均功率４００ｍＷ。