β-环糊精与二苯胺超分子包合物

研究了β-环糊精(主体)与二苯胺(客体)的包合反应。通过元素分析、核磁共振、差热分析及X-射线粉末分析方法确定了包合物的形成，用荧光光谱法测定了包合反应的形成常数。实验结果表明：β-环糊精与二苯胺分子形成摩尔比为2∶1的包合物。二苯胺的苯环嵌入β-环糊精分子的疏水性空腔内。包合物的分子式为C₉₆H₁₅₁O₇₀N。热稳定性比相应主客体明显提高。     

氯合间取代四苯基卟啉铁与咪唑类配体轴向配位反应的研究

用紫外可见光谱测量了在丙酮溶剂中氯合间取代四苯基卟啉铁［Fe(m-X)TPPCl, X=-CH₃, -Cl］与咪唑(Im), 氯甲基咪唑(N-MeIm), 克霉唑(GMZ)轴配反应平衡常数，并利用温度系数法测定了反应体系的热力学函数Δ_rH_m和Δ_rS_m。用停流分光光度法测定了Fe(m-CH₃)T     

二维网状Cu(ntp)2(H2O)4晶体的直接合成、晶体结构和热分解机理研究

用直接法合成了配合物Cu(ntp)₂(H₂O)₄，并测定了其晶体结构。分子式为C₁₆H₁₆CuN₂O₁₆。晶体属单斜晶系，C2/c空间群，晶胞参数为a=2.266 5(7) nm, b=0.706 8(2) nm, c=1.575 5(4) nm, β=126.42(1)°。对晶体进行了DSC和TG-DTG热分析，根据结果提出了可能的热分解过程。     

氢氧化2，9，16，23-四羧基酞菁合铁(Ⅲ)与硫醇轴配反应

用分光光度法研究了酞菁合铁［Fe(Ⅲ)Pc(COOH)₄OH^-］与β-羟基乙硫醇(HOCH₂CH₂SH)的轴向配位反应热力学，求得了配位数(n)，稳定常数(β_n)及热力学参数Δ_rH⁰_m、Δ_rS⁰_m。用停流法研究了［Fe(Ⅲ)Pc(COOH)₄OH^-］与β-羟基乙硫醇及苯硫酚的轴配反应动力学，讨论了反应机理，求得了预平衡步的平衡常数(K)和速控步的速率常数(k)；研究了温度等诸因素对反应动力学的影响，得到了预平衡的Δ_rH⁰_m、Δ_rS⁰_m和速控步的活化参数Δ^≠H_m、Δ^≠S_m     

WxC-MCM-48催化剂的合成、表征及加氢脱硫催化性能

以正硅酸乙酯(TEOS)为硅源，十六烷基三甲基溴化铵(CTAB)为表面活性剂，仲钨酸铵为钨源，采用水热晶化法一步合成了不同钨含量(以Si、W物质的量比n_Si/n_W表示)的WO₃-MCM-48，然后经甲烷/氢气(V/V=1/4)混和气体程序升温还原碳化(TPC)，制备出了W_xC-MCM-48(x=1、2)催化剂，采用XRD、N₂吸附-脱附和NH₃-TPD对样品的结构进行了表征，用噻吩作为模型化合物，对W_xC-MCM-48催化剂的加氢脱硫催化活性进行了评价。结果表明，在一定钨含量的条件下，WO₃-MCM-48和W_xC-MCM-48样品仍然保持MCM-48的三维立方有序介孔结构，n_Si/n_W=30～15时，碳化钨的物相为W₂C；n_Si/n_W=7.5时，碳化钨为W₂C和WC物相，W_xC-MCM-48催化剂表现出了良好的加氢脱硫催化性能。     

两种一维链铜配合物的合成与晶体结构

本文分别用N，N′-二(2-吡啶基)-2，6-吡啶二酰胺(H₂L)和2-吡啶酸得到了2种具有一维链结构的铜配合物。通过X-射线单晶衍射，测定了晶体的结构。配合物1，{Cu₃L₂(C₄H₄O₄)·10H₂O}_n,属于三斜晶系，空间群是P1，晶胞参数如下：a=0.706(1) nm，b=1.113(8) nm，c=1.288(7) nm，α=110.810(5)°，β=90.422(6)°，γ=101.183(6)°，V=0.926 2(2) nm³，Z=1。配合物2，{Cu(pic)₂·2H₂O}_n，也属于三斜晶系，空间群是P1，晶胞参数如下：a=0.513(6) nm，b=0.765(0) nm，c=0.924(6) nm，α=74.839(4)°，β=84.386(5)°，γ=71.401(5)°，V=0.332 3(0) nm³，Z=1。通过分子中未配位的水分子的氢键作用，配合物1构成了1个三维结构；而配合物2通过弱配位键作用形成了一维的链状结构。CCDC：603470，1；608265，2。     

K3Na(FeO4)2的电合成及其晶体结构

本文采用间接法电合成出较高纯度的复盐K₃Na(FeO₄)₂晶体，用粉末XRD结构分析法对其晶体结构作了详细研究。用EDX和AAS确认了其化学式。结构分析表明，K₃Na(FeO₄)₂晶体属三方晶系，具有六方晶胞，空间群为P3m1(No.164)，Z=1,晶胞中有6个O位于6(i)位，O,Fe和K各自有2个位于2(d)位，1个K和Na分别位于1(b)位和1(a)位，晶胞参数a=0.583 3(1) nm,c=0.755 9(1) nm，D=2.824 g·cm^-3。同时晶胞中各原子间化学键键长得到确定。     

［La(CH2ClCOO)2(NO3)(phen)(H2O)］n的合成和晶体结构

合成了混合阴离子配合物［La(CH₂ClCOO)₂(NO₃)(phen)(H₂O)］_n。配合物经元素分析、IR、DTA-TG和UV等表征。用X射线单晶结构分析解析了标题配合物的晶体结构，三斜，空间群P1，晶胞参数为a=10.533(2)?，b=13.136(3)?，c=7.776(1)?，α=96.59(1)°，β=95.76(1)°，γ=108.42(2)°，V=1003.3(3)?³，Z=2,Dc=1.940 g/cm³, F(000)=572, μ(Mo Kα)=24.36 cm^-1。     

含樟脑衍生物氰基桥联双金属配合物的合成、结构及磁性质

采用樟脑衍生物为配体，分别合成了氰基桥联Cu(Ⅱ)-Fe(Ⅲ)-Cu(Ⅱ)三核配合物[{Cu(D,L-La)₂}₂Fe(CN)₆](ClO₄) (1)和Mn(Ⅲ)-Fe(Ⅲ)双核配合物[Mn(D,L-Lb)(DMF)(Tp)Fe(CN)₃]·(H₂O)₆ (2)。晶体结构分析表明，化合物1中Cu(Ⅱ)离子处于五配位的配位环境，分别和1个D-La，1个L-La及[Fe(CN)₆]^3-中的1个氰基配位，2个Cu(Ⅱ)离子通过[Fe(CN)₆]^3-桥联。通过分子间氢键作用，化合物1形成二维超分子网络结构。化合物2中，[(Tp)Fe(CN)₃]^-通过其中的1个氰基与[Mn(D，L-Lb)]⁺桥联，其中Mn(Ⅲ)离子为六配位，分别和四齿配体Lb的2个氧原子和2个氮原子、DMF的1个氧原子及[(Tp)Fe(CN)₃]^-中的氰基氮原子配位。磁性研究表明，在化合物1中，Cu(Ⅱ)离子与Fe(Ⅲ)离子之间表现出铁磁相互作用，用哈密顿函数H=-2J(S₁·S₂+S₂·S₃)对其χ_MT-T曲线进行拟合，得到1的朗日因子g为2.190，交换常数J为0.55 cm^-1。     

常温常压下硼磷酸盐的直接合成与形成过程研究

在常温常压条件下直接合成了硼磷酸盐NaCd(H₂O)₂[BP₂O₈]·0.8H₂O(Hexagonal，P6₁22，a=0.971 30(14) nm，c=1.613 6(3) nm，V=1.318 36(40) nm³，Z=6)和NaZn(H₂O)_2<     

Multiple fluorescence spectra of fluorescein molecules encapsulated in the silica xerogel prepared by the sol-gel reaction

The fluorescence and fluorescence-excitation spectra of fluorescein molecules during the sol-gel-xerogel transitions of tetraethyl orthosilicate (TEOS) solutions have been observed as functions of doped concentration, in the order of 10^-2 and 10^-5 mol dm^-3, and of the sol-gel-xerogel transition time. It was shown that with a lower initial concentration only the cation was encapsulated in the pores of the silica xerogel state during the sol-gel reaction processes. On the other hand, with a high concentration four species, i.e., cation, monoanion, dianion, and dimer, were encapsulated in the silica xerogel during the sol-gel reaction processes. These results have the potential to open the way to the development of simultaneous multiple-band solid-state laser emitting materials.     

Iron‐Promoted ortho‐ and/or ipso‐Hydroxylation of Benzoic Acids with H2O2

Regioselective hydroxylation of aromatic acids with hydrogen peroxide proceeds readily in the presence of iron(II) complexes with tetradentate aminopyridine ligands [Fe^II(BPMEN)(CH₃CN)₂](ClO₄)₂ ( 1 ) and [Fe^II(TPA)(CH₃CN)₂](OTf)₂ ( 2 ), where BPMEN=N,N′‐dimethyl‐N,N′‐bis(2‐pyridylmethyl)‐1,2‐ethylenediamine, TPA=tris‐(2‐pyridylmethyl)amine. Two cis‐sites, which are occupied by labile acetonitrile molecules in 1 and 2 , are available for coordination of H₂O₂ and substituted benzoic acids. The hydroxylation of the aromatic ring occurs exclusively in the vicinity of the anchoring carboxylate functional group: ortho‐hydroxylation affords salicylates, whereas ipso‐hydroxylation with concomitant decarboxylation yields phenolates. The outcome of the substituent‐directed hydroxylation depends on the electronic properties and the position of substituents in the molecules of substrates: 3‐substituted benzoic acids are preferentially ortho‐hydroxylated, whereas 2‐ and, to a lesser extent, 4‐substituted substrates tend to undergo ipso‐hydroxylation/decarboxylation. These two pathways are not mutually exclusive and likely proceed via a common intermediate. Electron‐withdrawing substituents on the aromatic ring of the carboxylic acids disfavor hydroxylation, indicating an electrophilic nature for the active oxidant. Complexes 1 and 2 exhibit similar reactivity patterns, but 1 generates a more powerful oxidant than 2 . Spectroscopic and labeling studies exclude acylperoxoiron(III) and Fe^IV?O species as potential reaction intermediates, but strongly indicate the involvement of an Fe^III? OOH intermediate that undergoes intramolecular acid‐promoted heterolytic O? O bond cleavage, producing a transient iron(V) oxidant.     

Aromatic Hydroxylation at a Non‐Heme Iron Center: Observed Intermediates and Insights into the Nature of the Active Species

Mechanism of substrate oxidations with hydrogen peroxide in the presence of a highly reactive, biomimetic, iron aminopyridine complex, [Fe^II(bpmen)(CH₃CN)₂][ClO₄]₂ ( 1 ; bpmen=N,N'‐dimethyl‐N,N'‐bis(2‐pyridylmethyl)ethane‐1,2‐diamine), is elucidated. Complex 1 has been shown to be an excellent catalyst for epoxidation and functional‐group‐directed aromatic hydroxylation using H₂O₂, although its mechanism of action remains largely unknown. 1 , 2 Efficient intermolecular hydroxylation of unfunctionalized benzene and substituted benzenes with H₂O₂ in the presence of 1 is found in the present work. Detailed mechanistic studies of the formation of iron(III)–phenolate products are reported. We have identified, generated in high yield, and experimentally characterized the key Fe^III(OOH) intermediate (λ_max=560 nm, rhombic EPR signal with g=2.21, 2.14, 1.96) formed by 1 and H₂O₂. Stopped‐flow kinetic studies showed that Fe^III(OOH) does not directly hydroxylate the aromatic rings, but undergoes rate‐limiting self‐decomposition producing transient reactive oxidant. The formation of the reactive species is facilitated by acid‐assisted cleavage of the O? O bond in the iron–hydroperoxide intermediate. Acid‐assisted benzene hydroxylation with 1 and a mechanistic probe, 2‐Methyl‐1‐phenyl‐2‐propyl hydroperoxide (MPPH), correlates with O? O bond heterolysis. Independently generated Fe^IV?O species, which may originate from O? O bond homolysis in Fe^III(OOH), proved to be inactive toward aromatic substrates. The reactive oxidant derived from 1 exchanges its oxygen atom with water and electrophilically attacks the aromatic ring (giving rise to an inverse H/D kinetic isotope effect of 0.8). These results have revealed a detailed experimental mechanistic picture of the oxidation reactions catalyzed by 1 , based on direct characterization of the intermediates and products, and kinetic analysis of the individual reaction steps. Our detailed understanding of the mechanism of this reaction revealed both similarities and differences between synthetic and enzymatic aromatic hydroxylation reactions.     

Kinetics and reaction mechanism of phenol hydroxylation catalyzed by La-Cu<Subscript>4</Subscript>FeAlCO<Subscript>3</Subscript>

The present work synthesizes La-Cu₄FeAICO₃ catalyst under microwave irradiation and characterizes its structure using XRD and IR techniques. The results show that the obtained La-Cu₄FeAICO₃ has a hydrotalcite structure. In the phenol hydroxylation with H₂O₂ catalyzed by La-Cu₄FeAICO₃, the effects of reaction time and phenol/H₂O₂ molar ratio on the phenol hydroxylation, and relationships between the initial hydroxylation rate with concentration of the catalyst, phenol, H₂O₂ and reaction temperature are also investigated in details. It is shown the phenol conversion can reach 50.09% (mol percent) in the phenol hydroxylation catalyzed by La-Cu₄FeAICO₃, under the reaction conditions of the molar ratio of phenol/H₂O₂1/2, the amount ratio of phenol/catalyst 20, reaction temperature 343 K, reaction time 120 min, 10 ml_ distilled water as solvent. Moreover, a kinetic equation of v = k[La-Cu₄FeAlCO₃][C₆H₅OH][H₂O₂]. and the activation energy of E _a=58.37 kJ/mol are obtained according to the kinetic studies. Due to the fact that the HO-Cu⁺-OH species are detected in La-Cu₄FeAICO₃/H₂O₂ system by XPS, the new mechanism about the generation of hydroxyl free radicals in the phenol hydroxylation is proposed, which is supposed that HO-Cu⁺-OH species are transition state in this reaction.     

LiNi0.05Mn1.95O4的合成及对Li+的离子交换动力学

用溶胶-凝胶法合成出尖晶石结构的LiNi0.05Mn1.95O4,用0.5 mol·L-1过硫酸铵对其进行改型,制得锂离子筛LiNiMn-H.LiNiMn-H对Li+的饱和交换容量达5.2 mmol·g-1.用缩核模型(Shrinking-Core Model)处理该离子交换的反应动力学数据得到LiNiMn-H吸附Li+时离子交换反应的控制步骤是颗粒扩散控制(PDC),同时得到了该实验条件下锂离子筛LiNiMn-H吸附Li+的动力学方程和颗粒扩散系数De.     

Label-Free Electrochemical Sensor Based on Manganese Doped Titanium Dioxide Nanoparticles for Myoglobin Detection: Biomarker for Acute Myocardial Infarction

A label free electrochemical sensor based on pure titanium oxide and manganese (Mn)-doped titanium oxide (TiO₂) nanoparticles are fabricated and characterized for the sensitive detection of myoglobin (Mb) levels to analyze the cardiovascular infarction. Pristine and Mn-doped TiO₂ nanoparticles were synthesized via the sol-gel method and characterized in order to understand their structure, morphologies, composition and optical properties. The structural properties revealed that the pure- and doped-TiO₂ nanoparticles possess different TiO₂ planes. FTIR studies confirm the formation of metal oxide nanoparticles by exhibiting a well-defined peak in the range of 600–650 cm⁻¹. The values of the optical band gap, estimated from UV-Vis spectroscopy, are decreased for the Mn-doped TiO₂ nanoparticles. UV-Vis spectra in the presence of myoglobin (Mb) indicated interaction between the TiO₂ nanoparticles and myoglobin. The SPE electrodes were then fabricated by printing powder film over the working electrode and tested for label-free electrochemical detection of myoglobin (Mb) in the concentration range of 0–15 nM Mb. The fabricated electrochemical sensor exhibited a high sensitivity of 100.40 μA-cm^−2/nM with a lowest detection limit of 0.013 nM (0.22 ng/mL) and a response time of ≤10 ms for sample S3. An interference study with cyt-c and Human Serum Albumin (HSA) of the sensors show the selective response towards Mb in 1:1 mixture.     

原位红外光谱法研究Gd3+掺杂TiO2光催化降解乙烯性能

随着环境污染的日益严重,寻求环境友好、节能、高效的污染治理技术已成为各国科学研究者致力的目标。以TiO2半导体为主的多相光催化氧化技术因与传统污染处理技术相比具有许多优点而倍受青睐,但是,目前以TiO2为基础的光催化技术还存在量子效率低、太阳能利用率低等技术难题[1,2     

Solvent‐Free One‐Step Photochemical Hydroxylation of Benzene Derivatives by the Singlet Excited State of 2,3‐Dichloro‐5,6‐dicyano‐p‐benzoquinone Acting as a Super Oxidant

Photoinduced hydroxylation of neat deaerated benzene to phenol occurred under visible‐light irradiation of 2,3‐dichloro‐5,6‐dicyano‐p‐benzoquinone (DDQ), which acts as a super photooxidant in the presence of water. Photocatalytic solvent‐free hydroxylation of benzene derivatives with electron‐withdrawing substituents such as benzonitrile, nitrobenzene, and trifluoromethylbenzene used as neat solvents has been achieved for the first time by using DDQ as a super photooxidant to yield the corresponding phenol derivatives and 2,3‐dichloro‐5,6‐dicyanohydroquinone (DDQH₂) in the presence of water under deaerated conditions. In the presence of dioxygen and tert‐butyl nitrite, the photocatalytic hydroxylation of neat benzene occurred with DDQ as a photocatalyst to produce phenol. The photocatalytic reactions are initiated by oxidation of benzene derivatives with the singlet and triplet excited states of DDQ to form the corresponding radical cations, which associate with benzene derivatives to produce the dimer radical cations, which were detected by the femto‐ and nanosecond laser flash photolysis measurements to clarify the photocatalytic reaction mechanisms. Radical cations of benzene derivatives react with water to yield the OH‐adduct radicals. On the other hand, DDQ ^{. ?} produced by the photoinduced electron transfer from benzene derivatives reacts with the OH‐adduct radicals to yield the corresponding phenol derivatives and DDQH₂. DDQ is recovered by the reaction of DDQH₂ with tert‐butyl nitrite when DDQ acts as a photocatalyst for the hydroxylation of benzene derivatives by dioxygen.     

A study on the hydroxylation of 20-membered hexaaza macrocyclic bicopper complexes

A study was made on the hydroxylation of six macrocyclic bicopper complexes with bridge of SCN^?, Cl^?, Br^?, I^?, N₃^? or OH^? respectively in aqueous solution. Electronic spectra and data of titration by ion selective electrode show that the basic structure of the complexes remained unchanged during hydroxylation and hydroxyl group bound to copper atom only at the axial direction of the complexes. pH titration was made by auto-titration and data acquisition system controlled by microcomputer. Data of pH titration was pq-analysed by program LEMIT which show that 1-4 hydroxyl groups bind to copper atom stepwisely. Twenty four stepwise hydroxylation constants of the complexes were calculated and concentration distribution of various species during pH changing and hydroxylation were obtained. The six complexes except that with bridge N₃^? formed dihydroxo-complexes mainly at about pH 9 and formed monohydroxo-complexes mainly at about pH 7.5.     

Low temperature preparation and fuel cell properties of rare earth doped barium cerate solid electrolytes

The solid electrolytes, BaCe_(0.8) Ln_(0.2)O_(2.9) (Ln: Gd, Sm, Eu), were prepared by the sol-gel method. XRD indicated that a pure orthorhombic phase was formed at 900℃. The synthesis temperature by the sol-gel method was about 600℃ lower than the high temperature solid phase reaction method, The electrical conductivity and impedance spectra were measured and the conduction mechanism was studied. The grain-boundary resistance of the solid electrolyte could be reduced or eliminated by the sol-gel method. The conductivity of BaCe_(0.8)Gd_(0.2)O_(2.9) is 7.87×10~(-2) S·cm~(-1) at 800℃. The open-circuit voltage of hydrogen-oxygen fuel cell using BaCe_(0.8) Gd_(0.2)O_(2.9) as electrolyte was near to 1 V and its maximum power density was 30 mW·cm~(-2).