纳米SnO2的制备

ＳｎＯ２在陶瓷、气敏半导体材料及催化剂等方面被广泛应用［１］．纳米级的ＳｎＯ２因具有明显的表面效应而受到关注，其制备方法也受到重视［２］．纳米ＳｎＯ２的制备方法较多，有沉淀法［２］、水热法［３，４］、溶胶－凝胶法［５］、火焰合成法［６］等．然而要制备...     

较低反应温度下Hβ沸石上积炭的性质

沸石催化剂在许多反应过程中常常因积炭而失活［１，２］．通常认为，较低温度（低于２００℃）下的积炭主要是吸附较弱、不易挥发的物质，而较高温度（高于４００℃）下的积炭主要为碳／氢比较高、易挥发的多核芳烃［１，３，４］．刘中民等［５］研究了甲醇转化过程中的...     

铱(I)苯乙胺Schiff碱络合物催化苯乙酮的不对称氢转移反应

以光学活性的苯乙胺和吡啶－２－甲醛缩合而得到的Ｓｃｈｉｆ碱（ＰＰＥＩ）（ＰＰＥＩ＝２－［［Ｎ－（１－ｐｈｅｎｙｌｅｔｈｙｌ）ｉｍｉｎｏ］ｍｅｔｈｙｌ］ｐｙｒｉｄｉｎｅ或２－［［Ｎ－（１－苯乙基）亚胺］甲基］吡啶）为配体，进而与［Ｉｒ（ＣＯＤ）Ｃｌ］２（ＣＯＤ＝１，５－环辛二烯）反应，合成了８个光学活性铱络合物，考察了它们在异丙醇存在下催化苯乙酮不对称氢转移反应的光学活性，发现［Ｉｒ（ＣＯＤ）（ＰＰＥＩ）Ｉ］具有较好的立体选择性．其光学产率最高可达３５．７％ｅ．ｅ．．     

[Ln(EO_2)_3](ClO_4)_3·3H_2O的晶体结构研究

合成了希土高氯酸盐开环冠醚二缩乙二醇（ＥＯ２）晶体，（Ｌｎ＝Ｎｄ，Ｈｏ），测定了结构，文内以Ｎｄ－Ｌ的数据为主要研究对象（方括号内是Ｈｏ－Ｌ的数据）。晶体属单斜晶系，Ｐ２１／ｎ空间群，化学式［Ｌｎ（ＥＯ２）３］（ＣｌＯ４）３·３Ｈ２Ｏ，晶胞参数为：ａ＝１４．１２４（１）［１４．０８７］，ｂ＝１３．９９０（１）［１４．０３９］，ｃ＝１５．２６５（１）［１５．０１４］；β＝９５．７８（１）［９５．６４］°；Ｖ＝３００１．１（６）［２９５５］３；Ｍｒ＝８１５．０１［８３５．７０］；Ｚ＝４；Ｄｃ＝１．８０４［１．８６５］ｇ／ｃｍ３；石墨单色器，μ（ＭｏＫα）＝２．０９［３．０７］ｍｍ－１，最终偏离因子Ｒ＝０．０５５［０．０７４］，ＲＷ＝０．０７１［０．１０９］。研究结果表明晶体具有相同的结构，配位多面体为九配位三帽三棱柱。发现ＥＯ２醚链有绕Ｃ－Ｃ键呈ＳＴＴＳ分布的规律。弱配体高氯酸根不参加配位。     

胶束溶液中同步荧光法测定苯半[a]芘的研究

在不同胶束溶液中考察了苯并［ａ］芘（Ｂ［ａ］Ｐ）的同步荧光光谱。结果表明，在十二烷基苯磺酸钠胶束溶液中，Ｂ［ａ］Ｐ的检测限可达０．００９３ｎｇ／ｍＬ，方法相对标准偏差为１．７％。用于实际水样的测定，结果满意。     

胶束溶液中同步荧光法测定苯并［a］芘的研究

在不同胶束溶液中考察了苯并［ａ］芘（Ｂ［ａ］Ｐ）的同步荧光光谱。结果表明，在十二烷基苯磺酸钠（ＳＤＢＳ）胶束溶液中，Ｂ［ａ］Ｐ的检测限可达０．００９３ｎｇ／ｍＬ，方法相对标准偏差为１．７％。用于实际水样的测定，结果满意。     

过硫酸钾引发丙烯酰胺微乳液聚合

以山梨醇酐单月桂酸醋（Ｓｐａｎ２０）和聚氧乙烯山梨醇酐单硬醋酸酯（Ｔｗｅｅｎ６０）的混合物为乳化剂制备丙烯酰胺微乳液，研究了体系中Ｔｗｅｅｎ６０浓度、水相丙烯酰胺浓度对微乳液电导行为的影响．用过硫酸钾引发微乳液聚合，发现聚合开始后，体系电导率迅速下降，在聚合进入恒速期后电导不再降低．聚合的动力学表达式为：Ｒｐ∝［ＡＭ］１．１７［Ｅ］－１．２６［Ｉ］０．５；Ｍｖ∝［ＡＭ］１．０５［Ｅ］－０．９４［Ｉ］－０．６２．它与常规乳液聚合的动力学相差较大，却类似于悬浮聚合．     

β-石竹烯醇的合成研究

石竹烯醇作为倍半萜醇在香料原料中占有一定地位，具有较强的生理活性，是一种平喘作用强而持久、毒性低的新平喘药物［１］．此外它还可抑制真菌和细菌的生长［２］，并且是棉田的某种甲虫的较强的引诱剂［３］．由于β－石竹烯醇存在于亚洲薄荷油或椒薄荷油的高沸点馏分...     

热对镍阳极膜光电流测定的影响

镍在碱溶液中阳极膜的形成和性质与化学电源和金属腐蚀等有关．在这方面已有较深入的研究报导．其研究方法也是多种多样,除一般的电化学方法［１,２］外,还有许多现场谱学方法,如：紫外＿可见光谱［３］,红外光谱［４］,光热光谱［５］,拉曼光谱［６］,椭圆法［７...     

纳米级TiO_2粉体的制备研究 Ⅲ.成胶温度、钛盐溶液浓度、老化时间的影响

超临界流体干燥法是制备大孔高比表面超细催化剂的有效方法之一［１］．我们曾考察了初始水凝胶ｐＨ值［２］及不同体系的絮凝剂［３］对纳米级ＴｉＯ２超细粉织构性质的影响．结果表明，选择一定浓度的强碱溶液作为絮凝剂，是制备大孔高比表面ＴｉＯ２超细粉的前提之一；...     

Reactivity of cyclooligophosphanes: synthesis and structural characterisation of cyclo-1,4-(BH3)2(P4Ph4CH2) and cyclo-1,2-(BH3)2(P5Ph5)

The borane complexes cyclo-1,4-(BH3)2(P4Ph4CH2) (3) and cyclo-1,2-(BH3)2(P5Ph5) (4) were prepared by reaction of cyclo-(P4Ph4CH2) and cyclo-(P5Ph5) with BH3(SMe2). Only the 2:1 complexes 3 and 4 were isolated, even when an excess of the borane source was used. In solution, 3 exists as a mixture of the two diastereomers (R(P)*,S(P)*,S(P)*,R(P)*)-(+/-)-3 and (R(P)*,R(P)*,R(P)*,R(P)*)-(+/-)-3. However, in the solid state the (R(P)*,S(P)*,S(P)*,R(P)*)-(+/-) diastereomer is the major stereoisomer. Similarly, while only one isomer of 4 is observed in its X-ray structure, NMR spectroscopic investigations reveal that it forms a complex mixture of isomers in solution. 3 may be deprotonated with tBuLi to give the lithium salt cyclo-1,4-(BH3)2(P4Ph4CHLi) (3 x Li), though this could not be isolated in pure form.     

Low valent phosphorus in the molecular anions [P5Se12]5- and beta-[P6Se12]4-: phase change behavior and near infrared second harmonic generation

The caesium salts of the novel molecular anions [P5Se12]5- and [P6Se12]4- are phase change materials and exhibit near infrared, non-linear optical second harmonic generation; [P5Se12]5- is a coordination complex with an octahedral P3+ center chelated by two [P2Se6]4- ligands whereas [P6Se12]4- features a [P2]4+ dimer chelated by two [P2Se6]4- ligands.     

31P solid state NMR studies of metal selenophosphates containing [P2Se6]4-, [P4Se10]4-, [PSe4]3-, [P2Se7]4-, and [P2Se9]4- ligands

31P solid-state nuclear magnetic resonance (NMR) spectra of 12 metal-containing selenophosphates have been examined to distinguish between the [P(2)Se(6)](4-), [PSe(4)](3-), [P(4)Se(10)](4-), [P(2)Se(7)](4-), and [P(2)Se(9)](4-) anions. There is a general correlation between the chemical shifts (CSs) of anions and the presence of a P[bond]P. The [P(2)Se(6)](4-) and [P(4)Se(10)](4-) anions both contain a P[bond]P and resonate between 25 and 95 ppm whereas the [PSe(4)](3-), [P(2)Se(7)](4-), and [P(2)Se(9)](4-) anions do not contain a P[bond]P and resonate between -115 and -30 ppm. The chemical shift anisotropies (CSAs) of compounds containing [PSe(4)](3-) anions are less than 80 ppm, which is significantly smaller than the CSAs of any of the other anions (range: 135-275 ppm). The smaller CSAs of the [PSe(4)](3-) anion are likely due to the unique local tetrahedral symmetry of this anion. Spin-lattice relaxation times (T(1)) have been determined for the solid compounds and vary between 20 and 3000 s. Unlike the CS, T(1) does not appear to correlate with P-P bonding. (31)P NMR is also shown to be a good method for impurity detection and identification in the solid compounds. The results of this study suggest that (31)P NMR will be a useful tool for anion identification and quantitation in high-temperature melts.     

Synthesis,Properties, Structure and Reactivity of Sodium 2,3,4,5-Tetra- tert -butylcyclopentaphosphanide

The reaction between Na, t BuPCl 2 , and PCl 3 in thf gives Na[ cyclo -( t Bu 4 P 5 )] ( 1 ). 1 reacts with PCl 3 to yield ( cyclo - t Bu 3 P 4 ) t BuPCl ( 2 ), and with a proton source, such as HCl, NH 4 Cl, or t BuCl, to give cyclo - t Bu 4 P 5 H ( 3 ). The reaction of 1 with [MCl 2 (PRR' 2 ) 2 ] (M = Ni; R = R' = Et; M = Pd, Pt, R = Ph, R' = Me) gives [Ni{ cyclo -( t Bu 3 P 5 )}(PEt 3 ) 2 ] ( 4 ), [Pd{ cyclo -( t Bu 4 P 5 )} 2 ] ( 5 ), and [PtCl{ cyclo -( t Bu 3 P 4 ) t BuP}(PPhMe 2 )] ( 6 ). 1-6 were characterized by 31 P{ 1 H} NMR spectroscopy, and 1 and 4-6 were also characterized by X-ray crystallography.     

Synthesis and characterization of triazenide and triazene complexes of ruthenium and osmium

Triazenide [M(eta2-1,3-ArNNNAr)P4]BPh4 [M = Ru, Os; Ar = Ph, p-tolyl; P = P(OMe)3, P(OEt)3, PPh(OEt)2] complexes were prepared by allowing triflate [M(kappa2-OTf)P4]OTf species to react first with 1,3-ArN=NN(H)Ar triazene and then with an excess of triethylamine. Alternatively, ruthenium triazenide [Ru(eta2-1,3-ArNNNAr)P4]BPh4 derivatives were obtained by reacting hydride [RuH(eta2-H2)P4]+ and RuH(kappa1-OTf)P4 compounds with 1,3-diaryltriazene. The complexes were characterized by spectroscopy and X-ray crystallography of the [Ru(eta2-1,3-PhNNNPh){P(OEt)3}4]BPh4 derivative. Hydride triazene [OsH(eta1-1,3-ArN=NN(H)Ar)P4]BPh4 [P = P(OEt)3, PPh(OEt)2; Ar = Ph, p-tolyl] and [RuH{eta1-1,3-p-tolyl-N=NN(H)-p-tolyl}{PPh(OEt)2}4]BPh4 derivatives were prepared by allowing kappa1-triflate MH(kappa1-OTf)P4 to react with 1,3-diaryltriazene. The [Os(kappa1-OTf){eta1-1,3-PhN=NN(H)Ph}{P(OEt)3}4]BPh4 intermediate was also obtained. Variable-temperature NMR studies were carried out using 15N-labeled triazene complexes prepared from the 1,3-Ph15N=N15N(H)Ph ligand. Osmium dihydrogen [OsH(eta2-H2)P4]BPh4 complexes [P = P(OEt)3, PPh(OEt)2] react with 1,3-ArN=NN(H)Ar triazene to give the hydride-diazene [OsH(ArN=NH)P4]BPh4 derivatives. The X-ray crystal structure determination of the [OsH(PhN=NH){PPh(OEt)2}4]BPh4 complex is reported. A reaction path to explain the formation of the diazene complexes is also reported.     

纳米晶TiO2电极上半菁衍生物光敏染料

合成了具有不同共轭链长度的吡啶盐类及喹啉盐类半菁染料(E)-N-(4-磺酸丁基)-4-[2-(4-N, N-二甲基氨基苯基)乙烯基]吡啶鎓盐(P1)、(E)-N-(4-磺酸丁基)-4-[2-(4-N, N-二甲基氨基苯基)丁二烯基]吡啶鎓盐(P2)、(E)-N-(4-磺酸丁基)-4-[2-(4-N, N-二甲基氨基苯基)乙烯基]喹啉鎓盐(Q1)以及(E)-N-(4-磺酸丁基)-4-[2-(4-N, N-二甲基氨基苯基)丁二烯基]喹啉鎓盐(Q2).研究了它们的光物理性质，并将它们用作TiO2纳米晶电极的光敏化剂引入光电化学电池.与含有乙烯基共轭桥的染料P1和Q1相比，含有丁二烯基共轭桥的染料P2和Q2在甲醇和氯仿中的最大吸收均发生一定程度的红移，而且吸收光谱变宽.这两类染料都能很好地吸附于TiO2电极上.在比较了四个染料的吸收光谱、摩尔消光系数以及在TiO2电极表面的吸附量后，发现Q1具有最好的光电转化性质.     

GaxPy(x+y=8)及其阴离子团簇的结构与性质的DFT研究

用密度泛函理论方法对半导体二元微团簇GaxPy和GaxPy−(x+y=8)的几何结构、电子态、能量等进行了计算, 在B3LYP/6-311+G(2df)水平下完成结构优化和频率分析. 讨论了电荷诱导结构发生变化情况, 与中性团簇相比, 在阴离子团簇中, Ga—P键较P—P键有利于形成. 预测了未知Ga1P7−、Ga2P6−、Ga3P5−、Ga6P2−和Ga7P1−化合物的最稳定结构存在的可能性, 得出在GaxPy和GaxPy−(x+y=8)中, Ga4P4和Ga4P4−比较稳定. 给出了两种能差即绝热电子亲合势(ΔEAEA)和垂直电离能(ΔEVDE), 并与相关文献作比较. Ga4P4和Ga5P3的绝热电子亲合势与实验值相当吻合. 布居分析表明, 磷化镓团簇的成键属于混合键型.     

Triphenylphosphane-functionalised amphiphilic copolymers: tailor-made support materials for the efficient and selective aqueous two-phase hydroformylation of 1-octene

Amphiphilic copolymers (random P1 and block P2) based on 2-oxazolines were synthesised with triphenylphosphane ligands covalently linked to the polymers by means of a metal-free synthesis route. The resulting macroligands were used in the aqueous two-phase hydroformylation of 1-octene. The influence of the polymer architecture (random and block copolymers) on activity and selectivity of the hydroformylation reaction was investigated and compared with that of nonfunctionalised copolymers (random P3 and block P4) and Rh(I)/triphenylphosphane trisulfonate as a water-soluble catalyst. The highest activities were observed for the random copolymer P1 (p=50 bar, T=100 degrees C, c=8 x 10(-4) mol L(-1)) with a turnover frequency (TOF) of 3700 h(-1), whereas the corresponding block copolymer P2 reached TOF numbers of 1630 h(-1). Additionally, both macroligands indicated efficient suppression of isomerisation and led to almost constant n/iso selectivities of about 3 after complete substrate conversion. Copolymers P3 and P4 showed, under identical reaction conditions, strong isomerisation after 40-60 % conversion (n/iso approximately 0.7) and maximum activities of 1560 h(-1) (P3) and 1330 h(-1) (P4) at a concentration of 5 x 10(-3) mol L(-1).     

Paraquat substituent effect on complexation with a dibenzo-24-crown-8-based cryptand

Dibenzo-24-crown-8-based cryptand 4 forms 1:1 inclusion complexes with three paraquat derivatives, P1, P2, and P3, as demonstrated by proton NMR spectroscopy and X-ray analysis. However, it was found that methyl-substituted paraquat derivatives, P2 and P3, can bind cryptand 4 more strongly than non-methyl-substituted paraquat derivative P1. The association constants (Ka) were determined in acetone by using a UV-vis titration method to be 5.0 x 10(3) M(-1) for 4.P1, 1.0 x 10(5) M(-1) for 4.P2, and 1.2 x 10(5) M(-1) for 4.P3, respectively. In the solid state, 4.P2 and 4.P3 have similar T-type inclusion complexation conformations, which are very different from the pseudorotaxane-type complexation conformation of 4.P1. Theoretical calculations were done to explain these experimental results.     

When arsine makes the difference: chelating phosphino and bridging arsinoarylthiolato gallium complexes

The (organo)gallium compounds GaCl{(SC6H4-2-PPh2)-kappa2S,P}2 (1), Ga{(SC6H4-2-PPh2)-kappa2S,P}{(SC6H4-2-PPh2)-kappaS}2 (2), GaMe2{(SC6H4-2-PPh2)-kappa2S,P} (3), GatBu2{(SC6H4-2-PPh2)-kappa2S,P} (4), GatBu{(SC6H4-2-PPh2)-kappa2S,P}{(SC6H4-2-PPh2)-kappaS} (5), [GaMe2{(mu2-SC6H4-2-AsPh2)-kappaS}]2 (6), and GatBu{(SC6H4-2-AsPh2)-kappa2S,As}{(SC6H4-2-AsPh2)-kappaS} (7) were obtained from the reaction of 2-EPh2C6H4SH (E = P (PSH), As (AsSH)) with GaCl3 (1, 2) or GaR3 (R = Me, tBu; 3-7) in different molar ratios and under different reaction conditions. Compound 2 was also obtained from Li(PS) and GaCl3 (3.5:1). While a monomeric structure with a chelating phosphinoarylthiolato ligand is observed in GaMe2{(SC6H4-2-PPh2)-kappa2S,P} (3), a dimeric arsinoarylthiolato-bridged complex [GaMe2{(mu2-SC6H4-2-AsPh2)-kappaS}]2 (6) is obtained with the corresponding AsS- ligand. B3LYP/6-31G(d) calculations show that although the dimer is thermodynamically favored for both ligands, the formation of 3 is due to the combination of higher stability of the chelate compared with the monodentate phosphorus ligand and a higher barrier for the ring opening of the PS- than of the AsS- chelate.