高分辨NMR研究金属盐对水溶性铑膦配合物分子结构的影响

用高分辨NMR研究了NaCl、NiSO₄、CuSO₄、Fe₂(SO₄)₃和Cr₂(SO₄)₃对水溶性铑膦配合物HRh(CO)(TPPTS)₃[TPPTS;P(m-C₆H₄SO₃Na)₃]分子结构的影响.³¹P(¹H)和¹HNMR谱显示,于室温下在HRh(CO)(TPPTS)₃中加入的NaCl或NiSO₄对配合物的特征³¹P(¹H)和¹HNMR谱峰无明显影响;当加入CuSO₄后,配合物的Rh-H质子峰强度弱化明显,进而消失,且原配合物的特征磷谱峰强度减弱,新生成的磷物种谱峰逐渐成为磷谱的主要物种.当加入Fe₂(SO₄)₃或Cr₂(SO₄)₃后,三价金属离子的强顺磁性使NMR灵敏度下降,谱峰宽化,该2种盐均易与水溶性铑膦配合物产生强烈的相互作用,易使配合物特征谱峰消失.实验结果表明,上述金属盐对配合物结构破坏性大小的顺序为;Fe₂(SO₄)₃>Cr₂(SO₄)₃>CuSO₄》NiSO₄～NaCl.     

阴离子磺酸盐型Gemini表面活性剂与PEO-PPO-PEO嵌段共聚物相互作用的研究

用差示扫描微量热、等温滴定微量量热、动态光散射和核磁共振(NOESY,弛豫时间)技术,研究了在pH＝9时阴离子磺酸盐型Gemini表面活性剂12-3-12(SO₃)₂与PEO-PPO-PEO嵌段共聚物F127 (EO₉₇PO₆₉EO₉₇)和P123 (EO₂₀PO₇₀EO₂₀)之间的相互作用. 研究发现,随着12-3-12(SO₃)₂浓度的增大,聚合物的临界胶束温度(CMT)降低. 与传统的单链离子表面活性剂相比,12-3-12(SO₃)₂具有更强的降低共聚物CMT的能力. 此外,在低于聚合物的CMT时,12-3-12(SO₃)₂与聚合物单体可以形成聚合物/表面活性剂胶束聚集体;在高于聚合物的CMT时,12-3-12(SO₃)₂的加入首先与聚合物单体和胶束的混合物或聚合物胶束形成聚合物/12-3-12(SO₃)₂混合胶束,然后随着12-3-12(SO₃)₂浓度的增大,混合胶束逐步解离为小的聚集体,但是,即使在很高的12-3-12(SO₃)₂浓度时,混合胶束也未完全解离.     

沉淀法制备Bi2O3的晶相转变过程及其光催化性能

以硝酸铋为原料,氨水为沉淀剂,通过液相沉淀法制得前驱体Bi(OH)₃,并将Bi(OH)₃分别在不同温度和时间下焙烧。利用X射线衍射(XRD)、拉曼光谱、热重(TG)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)及紫外-可见漫反射光谱(UV-Vis DRS)详细研究了Bi(OH)₃转变为Bi₂O₃的过程及相变过程中粒子形貌、大小、光吸收性质等。结果表明,前驱体Bi(OH)₃经过焙烧之后,发生了如下的转变过程:Bi(OH)₃→Bi₅O₇NO₃→β-Bi₂O₃/Bi₅O₇NO₃→β-Bi₂O₃/Bi₅O₇NO₃/α-Bi₂O₃→α-Bi₂O₃,而且转变过程伴随着粒子长大。在上述转变过程中,与Bi₅O₇NO₃向β-Bi₂O₃转变的过程相比,从β-Bi₂O₃到α-Bi₂O₃相变过程更为迅速。此外,以光催化降解罗丹明B(RhB)为模型反应,考察了不同晶相的Bi₂O₃光催化活性,结果表明Bi₅O₇NO₃和β-Bi₂O₃材料具有优异的光催化性能,而α-Bi₂O₃具有较低的光催化活性。     

稀土氨基酸络合物的研究(Ⅰ)——一氯化三甘氨酸二水合谱的晶体结构

在水溶液中培养了甘氨酸镨、钕的针状晶体,元素分析结果表明可用Ln(Gly)₃Cl₃·3H₂O表示(Ln为Pr,Nd;Gly为甘氨酸)。用X射线衍射方法测定了Pr(Gly)₃Cl₃·3H₂O的单晶结构,其结构式为{[Pr(Gly)₃·(H₂O)₂]·Cl₃·H₂O}_n,属正交晶系,空间群P2₁2₁2₁,每一晶胞中有4个络合单元,形成一维链式聚合物·晶胞参数如下:α=4.779(1)Å,b=12.052(3)Å,c=30.953(11)Å。络合单元中镨为九配位,其配位多面体为畸变的三冠三角棱柱体。     

1,2-双(四甲基环戊二烯基)四甲基二硅烷与六碳基钼的反应

1,2-双(四甲基环戊二烯基)四甲基二硅烷与正丁基锂作用生成(四甲基二硅撑)双(四甲基环戊二烯基负离子盐),后者随即与六碳基钼反应形成1,1'-(四甲基二硅撑)双(四甲基环戊二烯基铝负离子盐)-(Me₂SiSiMe₂)[Me₄CpMo(CO)₃-Li⁺]₂(I),I与冰醋酸作用,随即分别与CCl₄,NBS及I₂反应,生成相应的铝卤化合物(Me₂SiSiMe₂)[Me₄CpMo(CO)₃X]₂[X=Cl(1),Br(2),I(3)].I与CH₃I反应,在钼原子上发生烃基化,得到产物(Me₂SiSiMe₂)[Me₄CpMo(CO)₃Me]₂(4);I与单质I₂直接反应,生成脱硅桥产物Me₄Cp(CO)>₃I(5).经元素分析、IR及¹HNMR表征了化合物1-5的结构。     

电化学合成系列锡配合物及纳米SnO2的制备

采用锡金属为"牺牲"阳极,首次在无隔膜电解槽中,电化学一步法制备了纳米SnO₂前驱体锡配合物Sn(OEt)₄, Sn(OBu)₄, Sn(OCH₂CH₂OCH₃)₄, Sn(OEt)₂(acac)₂, Sn(OBu)₂(acac)₂, Sn(OCH₂CH₂OCH₃)₂(acac)₂[acac为乙酰丙酮基],产物通过红外光谱(FT-IR)、拉曼光谱和核磁共振进行表征.同时采用含Sn(OR)₂(acac)₂>的电解液直接水解制备纳米SnO₂粉体,纳米SnO₂通过X射线粉末衍射(XRD)和透射电子显微镜(TEM)进行表征.实验表明,电解时防止阳极钝化,控制温度在40～60℃之间,采用有机胺溴化物为导电盐,可以提高电合成效率;电解合成Sn(OCH2CH₂OCH₃)₄, Sn(OEt)₂(acac)₂, Sn(OBu)₂(acac)₂, Sn(OCH₂CH₂OCH₃)₂(acac)₂的电流效率比Sn(OEt)₄, Sn(OBu)₄高,适宜作为溶胶-凝胶(Sol-gel)法制备纳米SnO₂的原料,制备得到的纳米SnO₂经600℃煅烧后呈球形单分散结构,晶型为四方锡石型,平均粒径在(10±0.4) nm左右.     

吡啶二羧酸修饰的稀土嵌入碲钨酸盐的合成及电化学生物识别性质

在乙酸钠水溶液中, 采用微波加热一步自组装策略合成了一系列罕见的2,6-吡啶二羧酸修饰的稀土嵌入Keggin型碲钨酸盐(PTEA)₇H₃K[RE₂(B-α-TeW₉O₃₃)₃W₃O₅(H₂O)₃(HDPA)]·22H₂O[RE=Ce³⁺(1), Pr³⁺(2), Nd³⁺(3), Sm³⁺(4); H₂DPA=2,6-吡啶二羧酸; PTEA=质子化的三乙醇胺]. 化合物1~4的聚阴离子由3个三缺位Keggin型 [B-α-TeW₉O₃₃]^8-构筑块通过1个{RE₂W₃O₅(H₂O)₃(HDPA)}¹³⁺异金属簇连接而成. 该异金属簇中, 2,6-吡啶二羧酸作为四齿配体与2个稀土离子(RE1和RE2)配位形成平面三杂环结构, 且RE1和RE2所在平面与W2, W2A, W16形成的平面互相垂直. 此外, 化合物1可与羧基化多壁碳纳米管(CMWCNT)复合形成1-CMWCNT复合材料. 该复合材料可以作为电极材料构建电化学生物传感器, 用于检测特定的DNA序列.     

新型双四面体过渡金属簇合物的合成与表征

利用Co₂(CO)₈与[Cl₃CC(O)OCH₂]₂的反应合成了以C(O)OCH₂CH₂OC(O)桥联两个Co₃C四面体骨架为特征的新型双四面体簇合物[(CO)₉Co₃(μ₃-C)C(O)OCH₂]₂(1);1与不同物质的量比的Na[M(CO)₃C₅H₄R](M=Mo,W;R=H,C(O)Me)反应,得到一步交换的产物(CO)₉Co₃(μ₃-C)C(O)OCH₂CH₂OC(O)(μ₃-C)Co₂M(CO)₈(C₅H₄R)[M=Mo,R=H(2);M=Mo,R=C(O)Me(3);M=W,R=H(4);M=W,R=C(O)Me(5)]或两步交换的产物[(C₅H₄R)(CO)₈Co₂M(μ₃-C)C(O)OCH₂]₂[M=Mo,R=H(6);M=Mo,R=C(O)Me(7);M=W,R=H(8);M=W,R=C(O)Me(9)].5或9分别与Na[Mo(CO)₃C₅H₅]以12的物质的量比反应得到含一个手性四面体骨架(CoMoWC)的(C₅H₅)(CO)₈Co₂Mo(μ₃-C)C(O)OCH₂CH₂O·C(O)(μ₃-C)CoMoW(CO)₇(C₅H₄C(O)Me)(C₅H₅)(10)或含两个手性四面体骨架(CoMoWC)的[(C₅H₅)(C₅H₄C(O)Me)(CO)₇CoMoW(μ₃-C)C(O)OCH₂]₂(11);对化合物1_11进行了CH元素分析、IR和¹HNMR等表征.结果表明,在金属交换反应中处于不同簇环境下的Co(CO)₃基团反应活性不同.对化合物1进行了晶体X射线衍射分析.化合物1的晶体属单斜晶系,P2₁/n(#14)空间群,晶胞参数a=0.933 0(2)nm,b=1.519 7(4)nm,c=1.178 3(4)nm,=91.16(2)°,Z=2,F(000)=972.分子结构呈中心对称.     

液滴在不互溶液体表面上的相对界面自由能曲面及Neumann三角形的导出

根据系统的界面Helmholtz自由能自发地趋于最低的热力学原理,以浮在不互溶液体(2)表面上透镜状液滴(3)在气(1)、液₂、液₃三相交界处,气-液₃、液₂-液₃界面各自和气-液₂界面通过液滴内部的夹角θ₁、θ₂为变量(0°≤θ₁≤180°,0°≤θ₂≤180°),证明出3个界面张力γ₁₂、γ₁₃、γ₂₃各种可能组合情况下液体₃稳定时的θ₁、θ₂值与它们之间的关系,导出Neumann三角形;并按照计算数据绘出几种类型相对于气相中圆球形液滴的界面自由能曲面图。     

高氯酸二甘氨酸十二水合二铒的晶体结构

在水溶液中合成了甘氨酸铒配合物[Er₂(Gly)₂(H₂O)₁₂](ClO₄)₆·4H₂O单晶,并测定了其晶体结构。该晶体属单斜晶系,P2₁/n空间群。晶胞参数:a=1.0571(2)nm,b=1.0837(2)nm,c=1.7728(4)nm,β=90.09(3)°,V=2.0309(7)nm²,Z=2,D_c=2.239g/cm³.最终偏差因子R=0.055,R_w=0.061.每2个Er³⁺离子由2个甘氨酸羧基桥联成双核结构。Er³⁺离子还与6个水分子的氢原子配位,形成畸变的四方棱柱型配位多面体。     

Reactions of tetrakis(trifluoromethyl) diphosphine and bis(trifluoromethyl) phosphine with ruthenium carbonyl clusters; X-ray structure of tetraruthenium carbonyl cluster derivatives

Reaction of [Ru₃(CO)₁₂ with (CF₃)₂P---P(CF₃)₂ in p-xylene at 140°C yielded the compounds [Ru₄(CO)₁₃{μ-P(CF₃)₂}₂] (1), [Ru₄(CO)₁₄{μ-P(CF₃)₂}₂] (2) and [Ru₄(CO)₁₁{μ-P(CF₃)₂}₄] (3). Reaction with [(μ-H)₄Ru₄(CO)₁₂] under similar conditions yielded [(μ-H)₃Ru₄(CO)₁₂{μ-P(CF₃)₂}] (4). All four compounds have been characterised by X-ray crystallography. The fluxional behaviour of the hydrides in 4 has also been studied by variable-temperature NMR spectroscopy. Compounds 1, 2 and 4 were also obtained from the reactions of Ru₃(CO)₁₂ with (CF₃)₂PH in dichloromethane at 80°C.     

Electron transfer in organometallic clusters : XI. Redox chemistry of M3(CO)12(M = Ru, Os) and PPh3 derivatives; mechanism of catalysed nucleophilic substitution

The generality of a two-electron reduction process involving an mechanism has been established for M₃(CO)₁₂ and M₃(CO)₁₂−n(PPh₃)_n (M = Ru, Os) clusters in all solvents. Detailed coulometric and spectral studies in CH₂Cl₂ provide strong evidence for the formation of an ‘opened’ M₃(CO)₁₂²⁻ species the triangulo radical anions M₃(CO)₁₂^−· having a half-life of < 10⁻⁶ s in CH₂Cl₂. However, the electrochemical response is sensitive to the presence of water and is concentration dependent. An electrochemical response for “opened” M₃(CO)₁₂²⁻ is only detected at low concentrations < 5 × 10⁻⁴ mol dm⁻³ and under drybox conditions. The electroactive species ground at higher concentrations and in the presence of water M₃(CO)₁₁²⁻ and M₆(CO)₁₈²⁻ were confirmed by a study of the electrochemistry of these anions in CH₂Cl₂; HM₃(CO)₁₁⁻ is not a product. The couple [M₆(CO)₁₈]^−/2− is chemically reversible under certain conditions but oxidation of HM₃(CO)₁₁⁻ is chemically irreversible. Different electrochemical behaviour for Ru₃(CO)₁₂ is found when [PPN][X] (X = OAc⁻, Cl⁻) salts are supporting electrolytes. In these solutions formation of the ultimate electroactive species [μ-C(O)XRu₃(CO)₁₀]⁻ at the electrode is stopped under CO or at low temperatures but Ru₃(CO)₁₂^−· is still trapped by reversible attack by X presumably as [η¹-C(O)XRu₃(CO)₁₁]⁻. It is shown that electrode-initiated electron catalysed substitution of M₃(CO)₁₂ only takes place on the electrochemical timescale when M = Ru, but it is slow, inefficient and non-selective, whereas BPK-initiated nucleophilic substitution of Ru₃(CO)₁₂ is only specific and fast in ether solvents particulary THF. Metal---metal bond cleavage is the most important influence on the rate and specificity of catalytic substitution by electron or [PPN]-initiation. The redox chemistry of M₃(CO)₁₂ clusters (M = Fe, Ru, Os) is a consequence of the relative rates of metal---metal bond dissociation, metal-metal bond strength and ligand dissociation and in many aspects resembles their photochemistry.     

The application of BTEM to UV-vis and UV-vis CD spectroscopies: the reaction of Rh4(CO)12 with chiral and achiral ligands

Two different organometallic ligand substitution reactions were investigated: (1) an achiral reactive system consisting of Rh₄(CO)₁₂ + PPh₃  Rh₄(CO)₁₁PPh₃ + CO in n-hexane under argon; and (2) a chiral reactive system consisting of Rh₄(CO)₁₂ + (S)-BINAP  Rh₄(CO)₁₀BINAP + 2CO in cyclohexane under argon. These two reactions were run at ultra high dilution. In both multi-component reactive systems the concentrations of all the solutes were less than 40 ppm and many solute concentrations were just 1–10 ppm. In situ spectroscopic measurements were carried out using UV–vis (Ultraviolet–visible) spectroscopy and UV–vis CD spectroscopy on the reactive organometallic systems (1) and (2), respectively. The BTEM algorithm was applied to these spectroscopic data sets. The reconstructed UV–vis pure component spectra of Rh₄(CO)₁₂, Rh₄(CO)₁₁PPh₃ and Rh₄(CO)₁₀BINAP as well as the reconstructed UV–vis CD pure component spectra of Rh₄(CO)₁₀BINAP were successfully obtained from BTEM analyses. All these reconstructed pure component spectra are in good agreement with the experimental reference spectra. The concentration profiles of the present species were obtained by performing a least square fit with mass balance constraints for the reactions (1) and (2). The present results indicate that UV–vis and UV–vis-CD spectroscopies can be successfully combined with an appropriate chemometric technique in order to monitor reactive organometallic systems having UV and Vis chromophores.     

Synthesis and X-ray crystal structures of [Ru4H4(CO) 11(PPh3)] and [Ru4−x IrxH2−x(CO) 12(PPh3) ] (x = 0 or 1)

Three tetranuclear clusters [Ru₄H₄(CO)₁₁(PPh₃)] (1), [Ru₄H₂(CO)₁₂(PPh₃)] (2) and [Ru₃IrH(CO)₁₂(PPh₃)] (3) were formed in the reaction of [Ir(CO)Cl(PPh₃)₂] and Na[Ru₃H(CO)₁₁] in tetrahydrofuran. Complexes 1–3 were characterized by IR and ¹H and ³¹P NMR, and the structure of the clusters was confirmed by single crystal X-ray analysis. In 2 and 3 one of the carbonyls bridges between two ruthenium atoms; otherwise the compounds contain only terminal carbonyls.     

Surfactants having polyfluoroalkyl chains. II. Syntheses of anionic surfactants having two polyfluoroalkyl chains including a trifluoromethyl group at each tail and their flocculation-redispersion ability for dispersed magnetite particles in water

Anionic surfactants having two polyfluoroalkyl chains per molecule, i.e. the sodium salt of bis(1H, 1H, 2H,2H-heptadeca-fluorodecyl)-2-sulfosuccinate, CF₃(CF₂)₇(CH₂)₂OCOCH₂CH(SO₃Na)COO(CH₂)₂(CF₂)₇CF₃, the sodium salt of bis(1H, 1H, 2H, 2H-tridecafluoro-octyl)-2-sulfosuccinate, CF₃(CF₂)₅(CH₂)₂OCOCH₂CH(SO₃Na)COO(CH₂)₂(CF₂)₅CF₃, and the sodium salt of bis(1H, 1H, 2H, 2H-nonafluorohexyl)-2-sulfosuccinate, CF₃(CF₂)₃(CH₂)₂OCOCH₂CH(SO₃Na)COO(CH₂)₂(CF₂)₃CF₃, have been prepared from maleic anhydride, the corresponding alcohols possessing a polyfluoroalkyl chain and sodium hydrogen sulfite. The flocculation and redispersion abilities of these surfactants for dispersed magnetic particles in water have been examined to investigate the effect of the chain length. It was found that this ability was enhanced by an increase in the chain length. The contact angles for water for pelleted surface-modified magnetite have been measured. In order to compare this ability and the contact angles, data for other fluorinated surfactant have been obtained. The Kraff point, the surface tension and the pNa of the aqueous surfactant solutions have also been measured.     

Phosphinegold(I) derivatives of the metal-rich metallaborane, HFe4(CO)12BH2: a novel phosphine exchange involving cation and cluster-bound phosphine ligands

The preparation and characterisation of three new gold(I) phosphine derivatives of the ferraborane, HFe₄(CO)₁₂BH₂ are reported. In HFe₄(CO)₁₂(AuPPh₃)BH (2), the AuPPh₃ fragment formally replaces an Fe---H---B bridging hydrogen atom in the parent compound HFe₄(CO)₁₂BH₂. A comparison between 2 and the structurally characterised di-gold derivative, Fe₄(CO)₁₂(AuPPh₃)₂BH (1) is made to gain insight into the relative site preference for the heavy metal fragments in 1. Preparation of the bis(triethylphosphine)gold(I) derivative of HFe₄(CO)₁₂BH₂ from the PPN⁺ salt of its conjugate base illustrates a novel exchange reaction between the PPh₃ groups in the PPN⁺ cation and the initially, gold-associated PEt₃ groups. This leads to a distribution of products Fe₄(CO)₁₂(AuPR₃(AuPR′₃BH where R = R′ = Ph (1) or R = R′ = Et (3) or R = Ph and R′ = et (4).     

Solvothermal Synthesis,Crystal Structure and Photoluminescent Property of a Novel 3D [Ca2（HCOO）2（nds）（H2O）2]n

A novel calcium（Ⅱ） metal-organic framework [Ca2（HCOO）2（nds）（H2O）2]n（1） with mixed 1,5-naphthalenedisulfonate sodium salt（1,5-nds） and formate as organic ligands has been obtained under solvothermal conditions.It was found that theμ3-η2∶η2 bridging mode of HCOO-in compound 1 is uncommon.Moreover,the formate,which was in situ formed from N,N＇-dimethylformamide,played an important role in the formation of 3D structure.HCOO-ligands bridged Ca（Ⅱ） ions into grid-like layers that were further pillared by the 1,5-nds ligand to form a 3D Ca-based framework.Compound 1 also exhibits a strong blue luminescence at room temperature.     

La掺杂钛酸钙光催化剂在可见光下分解水制氢的影响因素

以柠檬酸为络合剂, 采用溶胶-凝胶法制备了钙钛矿型光催化剂Ca_0.99La_0.01TiO₃, 利用X射线衍射仪(XRD)、 扫描电子显微镜(SEM)、 紫外-可见漫反射光谱仪(UV-Vis DRS)等对光催化剂材料进行了表征, 并考察了N掺杂对光催化剂催化效果的影响, 探究了可见光条件下, Ca_0.99La_0.01TiO_3-xN_x在不同Pt负载量及不同种类牺牲剂中光催化分解水的产氢量, 并进行相关荧光猝灭分析. 结果表明, 在可见光条件下, Pt负载量为1%且掺杂N的钙钛矿光催化剂在Na₂SO₃/Na₂S作为牺牲剂时, 光催化分解水的产氢量最高.     

呫吨染料－双(二苯基碘鎓盐)在高分子膜中的光谱和光化学特性

近年来,在迅速发展的新材料中,许多品种是与激光技术和光化学反应密切相关的。而目前使用最多的光源为氩离子激光,He-Ne激光和半导体激光,因此开发可见光和近红外区有灵敏响应的光敏体系已成为十分迫切的问题。由于染料品种多,易得到,具有广泛的可选择性,因而染料光敏化反应体系再度引起人们的重视。     

exo-closo-Rhodacarboranes: synthesis and characterisation of [{exo-(R3P)2Rh}(closo-CB11H12)] [R3P=P(OMe)3, PCy3, 1/2dppe]

Addition of H₂ to CH₂Cl₂ solutions of [(diene)Rh(L)₂][closo-CB₁₁H₁₂] (diene=norbornadiene, cyclooctadiene, L=PCy₃, P(OMe)₃, 1/2dppe) results in the formation of the exo-closo complexes [(PR₃)₂Rh(closo-CB₁₁H₁₂)]. These have been characterised in solution by ¹H- and ¹¹B-NMR spectroscopy, and for L=PCy₃ by a single crystal X-ray diffraction study. This suggests that the metal fragment is bound with the cage through the 7,8- and not the 7,12-{BH} vertices. DFT calculations on a model system where L=PMe₃ show that there is only a negligible energy difference between these two isomers (1 kcal mol⁻¹), suggesting that both represent stable structures. The salient spectroscopic markers that indicate an interaction of [closo-CB₁₁H₁₂]⁻ with a metal fragment are discussed and compared across a range of metal complexes. Large upfield shifts in the ¹¹B-NMR spectrum and a small downfield shift of the CH vertex in the ¹H-NMR spectrum are shown to the most reliable indicators of borane interaction in solution.