卟啉化合物电化学性质研究 Ⅰ.5,10,15,20-四-(4-乙酰氧基苯)卟吩及其Cu、Zn、Fe、Co、Ni配合物的合成及循环伏安研究

本文报道了５，１０，１５，２０－四（４－乙酰氧基苯）卟吩（Ｔ（４ＡＯＰ）Ｐ）及其Ｃｕ，Ｚｎ，Ｆｅ，Ｃｏ，Ｎｉ配合物的合成及其在ＣＨ２Ｃｌ２－０．１ｍｏｌ／ＩＴＢＡＰ体系中的循环伏安（ＣＶ）。研究结果。ＣＶ实验表明：Ｃｕ＾２＾＋，Ｚｎ＾２＾＝，Ｎｉ＾２＾＋离子以稳定的＋２价存在于Ｔ（４ＡＯＰ）Ｐ中，电子转移反应在卟啉环上进行，而Ｆｅ＾３＾＋，Ｃｏ＾２＾＋离子在氧化还原过程中发生价态变化。实验发现...     

邻苯二酚紫在光度分析测定痕量镉中的应用

研究了邻苯二酚紫在镉－ＫＩ－邻苯二酚紫－溴化十二烷基吡啶四元胶束混配物协同增效显色反应，在ｐＨ＝５－６的弱酸性条件下，Ｃｄ＾２＋－ＰＶ和ＫＩ，ＤＰＢ形成稳定的配合物。     

硝酸钠对几种显色反应作用机理的探讨

本文试验了硝酸钠对Ｍ＾２＋－５－Ｃｌ－ＰＡＤＡＢ、Ｍ＾２＋－３，５－ｄｉＢｒ－ＰＡＤＡＢ、Ｍ＾２＋－５－Ｂｒ－ＤＥ－ＰＡＰ及Ｍ＾２＋－ＰＡＲ（Ｍ＝Ｃｏ、Ｎｉ、Ｃｕ）显色体系的影响，发现硝酸钠对前两种显色体系有较大的影响，而对后两种显色体系的影响甚小。从引入ＮａＮＯ３后吸收光谱的变化，ｐＫａ３的改变，配合物的稳定常数等方面探讨了ＮａＮＯ３对显色反应的作用机理。     

邻苯二酚衍生物与稀土元素配位反应的研究（V）：3,4—二羟 …

研究了稀土元素铈（Ⅲ）离子与３，４－二羟基苯甲酸（Ｈ３Ｌ）在水溶液体系中生成羧基配位化合物的条件，表征其组成为Ｃｅ（Ｈ２Ｌ）２（ＯＨ）．３Ｈ２Ｏ。并研究了该配合物在一定条件下，铈离子由羧基配位反应变由为两个邻酚羟基配位的配合物（Ｃｅ（ＨＬ）ｎ的转型反应及氧化物铈（ＶＩ）配合物的反应。     

金属键有机化合物的研究—非对称型η^5—取代环戊二烯…

通过η＾５－Ｒ＾１Ｃ５Ｈ４（ＣＯ）３ＭＨａ与η＾５－Ｒ＾２Ｃ５Ｈ４（ＣＯ）２ＭＮａ（Ｍ＝Ｍｏ，Ｗ）以及η＾５－Ｒ＾１Ｃ５Ｈ４（ＣＯ）３ＭｏＮａ与η＾５－Ｒ＾２Ｃ５Ｈ４（ＣＯ）３ＷＮａ在Ｆｅ２（ＳＯ４）３醋酸水溶液作用下的交叉氧化偶联反应，合成了７个新的非对称型金属单键化合物η＾５－Ｒ＾１Ｃ５Ｈ４（ＣＯ）３Ｍｏ－Ｍｏ（ＣＯ）３Ｃ５Ｈ４Ｒ＾２－η＾５（Ｒ＾１，Ｒ＾２：Ｃ（Ｏ）Ｍｅ，ＣＯ２Ｅｔ），η＾５     

掺Ce提高（CoFe）3O4的矫顽力

采用添加剂湿法制备了掺入不同Ｃｅ含量的Ｃｅｘ（ＣｏＦｅ）３－ｘＯ４铁氧体。对产物的物相，形貌，磁性能研究表明，所得产物均为单一的尖晶石结构，一般情况下呈颗粒状，矫顽力随溶液中Ｃｅ＾４＋浓度的增加而增加。当溶液中含有Ｃｅ＾３＋和Ｃｅ（ＯＨ）４时，产物显示有部分棒状晶体，矫顽力有明显提高，且当「Ｃｅ＾３＋」占（「Ｃｅ＾３＋」＋Ｃｅ＾４＋「）总量的５％左右时所得产物矫顽力最大。     

多二茂铁基二氮杂己烷及其过渡金属配合物的合成

乙二胺与二茂铁甲醛或双二茂铁甲基氟硼酸盐反应，合成了１，６－二（二茂铁基）－２，５－二氮杂己烷和１，１，６，６－四（二茂铁基）－２，５－二氮己烷，它们与过渡金属（Ｆｅ＾２＋，Ｃｏ＾２＋，Ｎｉ＾２＋，Ｃｕ＾２＋，Ｚｎ＾２＋）盐在乙醇或乙醇－二氯甲烷中反应，是１４种过渡金属配合物，对这些化合物进行了表征，二种配体及其铜配合物用作复合固体推进剂的燃速调节剂时，基本不迁移，而燃速催化效率均超过辛基二茂铁。     

[Fe（CN）6]^4—还原trans—[Co（en）2（ImH02]^3＋的电子转移反应 …

在不同的温度下，考察了六氰合铁配阴离子「Ｆｅ（ＣＮ）５」＾４－还原ｔｒａｎｓ－「Ｃｏ（ｅｎ）２（ＩｍＨ０２」＾３＋的反应动力学。结果表明，反应遵循Ｈ．Ｔａｕｂｅ所提出的外配位界电子传递机理。在２５℃，Ｉ＝０．５ｍｏｌ．Ｌ＾－１，ｔｒａｎｓ－「Ｃｏ（ｅｎ）２（ＩｍＨ）２」＾３＋／「Ｆｅ（ＣＮ）６」＾４－反应体系的前驱配合物离子对形成常数为Ｑ１ｐ＝９８．９ｍｏｌ＾－１．Ｌ，电子转移速率常数为Ｋｍ＝１．     

等瓣置换反应的研究——手性簇合物[η^—MeO2CC5H4）（CO）2Mo…

用Ｘ射线衍微法测定了由η＾５－ＭｅＯ２ＣＣ５Ｈ４（ＣＯ）３ＭｏＮａ和〔（η＾５－ＭｅＯ２ＣＣ５Ｈ４）（ＣＯ）２Ｗ〕Ｆｅ－（ＣＯ）３Ｃｏ（ＣＯ）３（μ３－Ｓ）的等瓣置换反应所生成的手性簇合物－〔（η＾５－ＭｅＯ２ＣＣ５Ｈ４）（ＣＯ）２Ｍｏ〕－〔（η＾５－ＭｅＯ２ＣＣ５Ｈ４）（ＣＯ）２Ｗ〕Ｆｅ（ＣＯ）３（μ３－Ｓ）的分子结构及晶体结构。晶体属Ｐ１空间群，晶胞参数ａ＝０．８７１６２（５）ｎｍ，ｂ＝０．８     

相转移催化下肟类的选择性间接电氧化研究

以Ｃｅ＾４＋／Ｃｅ＾３＋为间接电氧化还原体系，在相转移催化剂ＰｈＣＨ２Ｎ（Ｃ２Ｈ５）３Ｃｌ存在下，对肟类化合物进行选择性间接电氧化。结果表明，在室温条件下，电解２ｈ，肟类能被选择性地氧化为相应的羰基化合物，收率７５－９５．６％。     

Binding of catechols to mononuclear titanium(IV) and to 1- and 5-nm TiO2 nanoparticles

The binding of catechol derivatives (LH 2 = catechol, 4-methyl catechol, 4-t-butyl catechol, and dopamine) to 1- and 4.7-nm TiO2 nanoparticles in aqueous, pH 3.5 suspensions has been characterized by UV-vis spectroscopy. The binding constants derived from Benesi-Hildebrand plots are (2-4) x 10(3) M(-1) for the 1-nm nanoparticles and (0.4-1) x 10(4)M(-1) for the 4.7-nm particles. Ti(IV)L3 complexes were prepared from the same catechols. The L = methyl catechol, and dopamine complexes are reported for the first time. The TiL3 reduction potentials are not very sensitive to the nature of the catechol nor evidently are the binding constants to TiO2 nanoparticles. The intense (epsilon > or = 10(3) M(-1)cm(-1)), about 400-nm, ligand-to-metal charge-transfer (LMCT) absorptions of the nanoparticle complexes are compared with those of the TiL 3 complexes (epsilon approximately 10(4)M(-1) cm(-1)) which lie in the same spectral region. The nanoparticle colors are attributed (as are the colors of the Ti(IV)L3 complexes) to the tails of the about 400-nm LMCT bands.     

Reaction of olefins using cerium(IV) sulfate tetrahydrate in carbonyl compounds–H2O

The reaction of olefins with cerium(IV) sulfate tetrahydrate [Ce(SO₄)₂·4H₂O, CS] in acetone–H₂O under reflux for 5 h gave 2‐oxo‐ and 2‐oxo‐5‐hydroxy derivatives. In this reaction, the yields of 2‐oxo‐5‐hydroxy derivatives were dependent on the quantity of H₂O. Moreover, the reaction of α, β‐unsaturated ketones with CS in acetone–H₂O yielded 2,7‐dioxo‐3‐hydroxy or 3,8‐dioxo‐4‐hydroxy derivatives. The reaction mechanism is also discussed. Copyright © 2005 John Wiley & Sons, Ltd.     

The Complexes of Rare Earth Elements with 2,5-Dihydroxybenzoic Acid Preparation, properties and thermal decomposition

The conditions of the formation of rare earth(III) 2,5-dihydroxybenzoates have been studied; their compositions and solubilities in water at 293 K have been determined. The IR spectra of the anhydrous complexes with the general formula Ln(C7H5O4)3 have been recorded and their thermal decompositions in static air determined. During heating the anhydrous complexes of Y, Pr-Lu decompose to the oxides Ln2O3, Pr6O11 and Tb4O7 with formation of the intermediate Ln2(C7H4O4)3. The lanthanum complex decomposes to the oxide in three steps forming La2(C7H4O4)3 and La2O2CO3 as intermediates and the Ce(III) complex decomposes directly to CeO2. The properties of rare earth 2,5- and 2,4-dihydroxybenzoates have been compared. This revised version was published online in July 2006 with corrections to the Cover Date.     

Unexpected reaction pathways in the reaction of alkoxyalkynylchromium(0) carbenes with aromatic dinucleophiles

Thermal- or SiO(2)-induced reactions of the Michael adducts of 1,2-aromatic dinucleophiles and alkynylchromium(0) carbene complexes, compounds 7-10, form different products in good yields depending on the nature of the aromatic dinucleophile used. Thus, 1,2-diaminobenzene derivatives 7 and 8 rearrange to pentacarbonylchromium(0) isocyanide complexes 11, 12, 14, and 15 in a process that occurs through bicyclic intermediates 24. Adducts 9 derived from o-aminophenol give 2,3-dihydro-1,5-benzoxazepine derivatives 17 by intramolecular 1,2-addition, followed by protonation at the chromium center and reductive elimination. In contrast, base-promoted addition of the phenolic hydroxy group in compound 9 a affords 3-ethoxy-5-phenyl-5,6-dihydro-2H-1,6-benzoxazocin-2-one (18), together with the expected adduct 17 a. Compound 18 is formed by a nucleophilic addition to a CO ligand in a preformed carbene complex. This is a new example of the rare attack of a nucleophile on a CO ligand in a Fischer carbene complex. Adducts 10 form seven-membered-ring carbene complexes 19 and 20 by intramolecular aminolysis. In contrast, reaction of alkynyl carbene complexes with 1,8-diaminonaphthalene under very mild conditions leads to 2-substituted perimidines 33 together with the corresponding ethoxymethylmetal carbene complex 32 through an unprecedented fragmentation process in a formal retro-Aumann reaction.     

Kinetics and mechanism of the cerium (IV) oxidation of α-Hydroxycycloalkanecarboxylic acids and cyclic alcohols in acidic perchlorate media

The Ce(IV) oxidation of the five-, six-, and seven-membered ring α-hydroxycycloalkanecarboxylic (C5, C6, and C7) acids to the corresponding cyclic ketones has been studied in acidic perchlorate media. The data may be interpreted in terms of a mechanism which involves fast preequilibrium complexation steps between Ce(IV) and the hydroxy acids, yielding two complexes which differ only by a proton. Complexation is followed by rate-determining decarboxylation to an intermediate (free radical?), which reacts quickly with another Ce(IV) to give products. Of the two proposed complexes, the protonated one is virtually unreactive. The C7 ring acid is oxidized more rapidly than the C6 acid, which, in turn, is oxidized faster than the C5 acid. For comparison, the oxidation of the five-, six-, and seven-membered ring cyclic alcohols to the corresponding cyclic ketones by Ce(IV) in acidic perchlorate was also studied. The order of reactivity is cyclopentanol > cycloheptanol > cyclohexanol. The differences in observed reactivities between the hydroxy acids and the cyclic alcohols are explained in terms of differences in transition state structure. The stepwise hydrolysis constants of Ce(IV) leading to Ce(OH)^3Plus; and Ce(OH)₂²⁺ were determined. In the case of the hydroxy acids, evidence is in favor of Ce(OH)³⁺ as the reactive ceric species in aqueous acidic perchlorate media.     

Theoretical study of the biologically important dioxo diiron diamond core structures

Density functional theory calculations were used to investigate synthetic complexes with diiron dioxo diamond cores and models for intermediates in the catalytic cycle of methane monooxygenase (MMO). The synthetic complexes share an antiferromagnetically coupled diiron dioxo/hydroxo diamond core structure with the oxidized and reduced intermediates (H_ox and H_red, respectively) of MMO. The DFT (B3P86) calculations on model complexes of the synthetic models, with ferromagnetic coupling, reproduce the crystal structure data to within 0.05 Å and 5° for the diamond core parameters. The crystal structures of H_ox extracted from two different bacteria (Bath and OB3b) indicate that H_ox has either two bridging hydroxy ligands or one hydroxy and one water bridge. The B3P86 calculations strongly suggest that both bridging ligands in H_ox are hydroxy groups. The carboxylate shift established in the crystal structures of H_red was calculated to be a minimum at the BP86 level of theory.     

镧系四元混合配体配合物[Ce(CH2ClCOO)2(NO3)(phen)(H2O)]2的晶体结构、芳环堆积效应和2D氢键网络

The quaternary complex, ［Ce(CH2ClCOO)2(NO3)(phen)(H2O)］2, was synthesized. Interestedly, the title compound is a dimer comparing with the 1D polymer ［La(CH2ClCOO)2(NO3)(phen)*(H2O)］n and powder compound ［Nd(CH2ClCOO)2(NO3)(phen)］. In the title compound there is a monodentate NO-3, which is a first example in the all synthesized quaternary mixed anion complexes, and the NO-3 extended the complex into a 2D network with water from other molecules by inter-molecular hydrogen bonds. The intermolecular hydrogen bonds lead to the weaker Ce—O(COO), Ce—O(NO3) and Ce—N bonds comparing with other quaternary mixed anion complexes of cerium. Also the stacking effect, which makes the compound more stable in the situation of weaker Ce—O and Ce—N bonds, was first found in the series compounds.     

Nickel tetrazolato complexes synthesized by microwave irradiation: Catecholase like activity and interaction with biomolecules

1,3-Dipolar cycloaddition between nickel-ligated azide in [NiL(N₃)] [HL = 3-(2-diethylamino-ethylimino)-1-phenyl-butan-1-one] and two different organonitriles furnished two new square-planar complexes viz. [NiL(5-phenyltetrazolato)] and [NiL{5-(4-pyridyl)-tetrazolato}]. Both the complexes have been characterized by spectroscopic tools and single-crystal X-ray crystallography. Interaction with different biomolecules revealed that both complexes bind strongly to serum albumin proteins and show moderate catecholase-like activity by catalyzing the oxidation of 3,5-ditertbutylcatechol (3,5-DTBC). Identification of intermediates formed in catechol oxidation has been explored by ESI-MS spectrometry.     

Substrate binding in catechol oxidase activity: biomimetic approach

A series of dicopper(II) complexes have been investigated as model systems for the catechol oxidase active site enzyme, regarding the binding of catechol substrate in the first step of the catalytic cycle. The [Cu(2)(L(R))(mu-OH)](ClO(4))(2) and [Cu(2)(L(R))(H(2)O)(2)](ClO(4))(3) complexes are based on the L(R) ligands (2,6-bis[(bis(2-pyridylmethyl)amino)methyl]-4-R-substituted phenol) with -R = -OCH(3), -CH(3), or -F. Binding studies of diphenol substrates were investigated using UV-vis and EPR spectroscopy, electrochemistry, and (19)F NMR (fluorinated derivatives). All the complexes are able to bind two ortho-diphenol substrates (tetrachlorocatechol and 3,5-di-tert-butylcatechol). Two successive fixation steps, respectively fast and slower, were evidenced for the mu-OH complexes (the bis(aqua) complexes are inactive in catalysis) by stopped-flow measurement and (19)F NMR. From the mu-OH species, the 1:1 complex/substrate adduct is the catalytically active form. In relation with the substrate specificity observed in the enzyme, different substrate/inhibitor combinations were also examined. These studies enabled us to propose that ortho-diphenol binds monodentately one copper(II) center with the concomitant cleavage of the OH bridge. This hydroxo ligand appears to be a key factor to achieve the complete deprotonation of the catechol, leading to a bridging catecholate.     

邻苯二酚衍生物与希土元素的配位反应Ⅱ．铈(Ⅳ)配合物显现颜色机理的探讨

用实验与量化计算对邻苯二酚类衍生物与铈（Ⅵ）生成的配合笺显现颜色的机理进行了探讨，认为是由配体上大π键电子向中心金属离子跃迁所 产生的Ｌ→Ｍ荷移所致。