吡唑-3-甲酸Cu(Ⅱ)/Mn(Ⅱ)配合物的合成、表征及常压下对二氧化碳催化转化

合成和表征了2个吡唑-3-甲酸过渡金属配合物[Cu₂（pca）₂（H₂O）₆]·2H₂O（1）,[Mn（Hpca）₂（phen）]·3H₂O（2）（H₂pca=吡唑-3-甲酸;phen=菲咯啉）。X射线单晶衍射分析结果表明,配合物1属于单斜晶系P2₁/n空间群,它是一个畸变八面体的双核铜配合物;配合物2是一个畸变八面体的单核锰配合物。配合物1和2分别通过分子间的O-H…O,N-H…O氢键形成了三维网状结构。配合物1在二氧化碳的环加成反应中显示出了良好的催化效率（转化率高达97.4%;选择性高达98.9%）。     

以5-甲基-3-吡唑甲酸和菲咯啉为配体的锰和镉的配合物的合成、晶体结构和荧光性能

以5-甲基-3-吡唑甲酸和菲咯啉为配体, 合成了一个单核锰(Ⅱ)配合物[Mn(HMPCA)₂(phen)]·2H₂O (1)和一个具有双核结构单元的一维镉(Ⅱ)的配位聚合物[Cd₂(HMPCA)₂(phen)₂(H₂O)₂]·2H₂O (2)(H₂MPCa=5-甲基-3-吡唑甲酸, phen=菲咯啉), 并用元素分析、红外光谱、X-射线单晶衍射结构分析、热重分析等对其进行了表征。配合物1属于三斜晶系, 空间群为P1, 配合物2属于正交晶系, 空间群为Pccn。配合物1中的锰(Ⅱ)离子位于一个畸变的八面体配位环境中, 独立结构单元间通过分子间氢键作用构成一个三维的超分子结构。而在2中, 每个镉(Ⅱ)离子位于一个五角双锥体中, 来自5-甲基-3-吡唑甲酸根的氧原子桥联2个相邻的镉(Ⅱ)离子, 形成一个一维链;这些一维链和水分子通过分子间氢键进一步形成一个三维的超分子结构。考察了配合物1和2的热稳定性和荧光性能。     

以5-甲基-3-吡唑甲酸为配体的锰和钴的配合物的合成、晶体结构和磁性

以5-甲基-3-吡唑甲酸为配体,合成了1个单核锰（Ⅱ）配合物[Mn（HMPCA）₂（phen）]·2H₂O（1）和1个钴（Ⅱ）的一维配位聚合物{[Co（HMPCA）₂（pyz）]·5H₂O}_n（2）（H₂MPCA=5-甲基-3-吡唑甲酸;phen=1,10-菲咯啉;pyz=吡嗪）,并用元素分析、红外光谱、X-射线单晶衍射结构分析、热重分析等对其进行了表征。配合物1属于正交晶系,空间群为Pbca,配合物2属于单斜晶系,空间群为P2₁/c。配合物1和2中的金属离子都位于1个畸变的八面体构型中。配合物1中的独立结构单元间通过分子间氢键作用构成1个三维结构。而在2中,每个吡嗪分子桥联2个相邻的钴（Ⅱ）离子,形成1个一维链;这些一维链和水分子通过分子间氢键进一步形成一个三维的结构。变温磁化率数据（300~1.8K）表明配合物2中的钴（Ⅱ）离子间存在弱的反铁磁性作用。     

吡唑-3-甲酸Cu(Ⅱ)/Mn(Ⅱ)配合物的合成、表征及常压下对二氧化碳催化转化

合成和表征了2个吡唑-3-甲酸过渡金属配合物[Cu₂（pca）₂（H₂O）₆]·2H₂O（1）,[Mn（Hpca）₂（phen）]·3H₂O（2）（H_2pca=吡唑-3-甲酸;phen=菲咯啉）。X射线单晶衍射分析结果表明,配合物1属于单斜晶系P2¹/_n空间群,它是一个畸变八面体的双核铜配合物;配合物2是一个畸变八面体的单核锰配合物。配合物1和2分别通过分子间的O-H…O,N-H…O氢键形成了三维网状结构。配合物1在二氧化碳的环加成反应中显示出了良好的催化效率（转化率高达97.4%;选择性高达98.9%）。     

N-对甲苯磺酰-5-氨基间苯二甲酸构筑的一维配位聚合物的合成、晶体结构和荧光性质

采用普通溶液法和水热法分别合成了2个金属-有机配位聚合物：{[Cu（Ts-5-AIPA）（phen）（H₂O）]·H₂O}_n（1）和[Cd（Ts-5-AIPA）（phen）]_n（2）（Ts-5-AIPA=N-对甲苯磺酰-5-氨基间苯二甲酸根,phen=菲咯啉）,并用红外光谱、热重和X射线单晶衍射对配合物的结构进行了表征。结果表明：2个配合物均为单斜晶系,配合物1为P2₁/c空间群,配合物2为C2/c空间群;2个配合物均为一维链状结构,再通过氢键和π-π堆积作用形成三维超分子结构。另外,还研究了2个配位聚合物的荧光性质。     

以5-甲基-3-吡唑甲酸和菲咯啉为配体的锰和镉的配合物的合成、晶体结构和荧光性能

以5-甲基-3-吡唑甲酸和菲咯啉为配体, 合成了一个单核锰(Ⅱ)配合物[Mn(HMPCA)₂(phen)]·2H₂O (1)和一个具有双核结构单元的一维镉(Ⅱ)的配位聚合物[Cd₂(HMPCA)₂(phen)₂(H₂O)₂]·2H₂O (2)(H₂MPCa=5-甲基-3-吡唑甲酸, phen=菲咯啉), 并用元素分析、红外光谱、X-射线单晶衍射结构分析、热重分析等对其进行了表征。配合物1属于三斜晶系, 空间群为P1, 配合物2属于正交晶系, 空间群为Pccn。配合物1中的锰(Ⅱ)离子位于一个畸变的八面体配位环境中, 独立结构单元间通过分子间氢键作用构成一个三维的超分子结构。而在2中, 每个镉(Ⅱ)离子位于一个五角双锥体中, 来自5-甲基-3-吡唑甲酸根的氧原子桥联2个相邻的镉(Ⅱ)离子, 形成一个一维链;这些一维链和水分子通过分子间氢键进一步形成一个三维的超分子结构。考察了配合物1和2的热稳定性和荧光性能。     

以3, 5-二甲基-1-羧甲基-4-吡唑甲酸为配体的两个锌的配合物的合成、晶体结构和荧光性能

以3, 5-二甲基-1-羧甲基-4-吡唑甲酸和4, 4'-联吡啶为配体, 合成了1个单核锌(II)配合物[Zn(4,4'-bpy)(Hcmdpca)₂(H₂O)₃]·2H₂O (1)和1个锌(II)的一维配位聚合物[Zn(4, 4'-bpy)(Hcmdpca)₂(H₂O)]·3H₂O (2)(H₂cmdpca=3, 5-二甲基-1-羧甲基-4-吡唑甲酸;4, 4'-bpy=4, 4'-联吡啶), 并用元素分析、红外光谱、X-射线单晶衍射结构分析、热重分析等对其进行了表征。配合物1和2都属于单斜晶系, 空间群为P2₁/c。配合物1的锌离子都位于一个畸变的八面体构型中。配合物1中的独立结构单元间通过分子间氢键作用构成一个三维的超分子结构。而在2中, 锌离子位于一个畸变的四方锥构型中, 每个4, 4'-联吡啶分子桥联2个相邻的 锌(II)离子, 形成一个一维链;这些一维链和水分子通过分子间氢键进一步形成一个三维的结构。此外还考察了1和2的热稳定性和固体荧光性质。     

N-苯基亚氨基二乙酸桥联的双核铜配合物的合成、表征与晶体结构

由Cu(Ⅱ)、2，2′-联吡啶(邻菲咯啉)与N-苯基亚氨基二乙酸在溶液中组装得到2个双核配合物[Cu₂(L)₂(2，2′-bipy)₂]·8H₂O (1)、[Cu₂(L)₂(phen)₂]·2H₂O (2)(H₂L=N-苯基亚氨基二乙酸，2，2′-bipy=2，2′-联吡啶，phen=邻菲咯啉)。用元素分析、红外光谱、热重分析等进行了表征，并测定了其晶体结构。晶体结构表明，配合物1的晶体属三斜晶系，空间群P1;配合物2的晶体属单斜晶系，空间群P2₁/c。在这2个双核配合物中，中心铜离子的配位形式均为五配位的畸变四方锥构型，配体L中的N原子没有参与配位，而是采用1个羧基的1个氧原子与Cu²⁺离子螯合、另1个羧基上的1个氧原子以μ₂-桥联的配位模式连接2个Cu²⁺离子。     

含有未配位羧基的吡唑羧酸基镉和铜的配合物的合成、晶体结构和荧光性能

以菲咯啉和3,5-二甲基-1-羧甲基-4-吡唑甲酸为配体,合成了2个新的配合物[Cd(Hcmdpca)2(phen)(H_2O)](1)和[Cu2(Hcmdpca)2(phen)4(NO3)2]·4H_2O(2)(H2cmdpca=3,5-二甲基-1-羧甲基-4-吡唑甲酸;phen=菲咯啉),并用红外光谱、元素分析、热重分析和X射线单晶衍射结构分析等对其进行了表征。配合物1和2都属于单斜晶系,1和2的空间群分别为C2/c和P21/c。配合物1的镉离子采取七配位的方式,Hcmdpca-阴离子桥联2个镉离子形成一个双核结构;这些双核结构单元间通过分子间氢键及π-π相互作用构成一个三维的超分子结构。配合物2是一个由2个分立的单核铜配阳离子构成的独立单元,铜离子位于一个畸变的八面体构型中;这些单核铜配阳离子和硝酸根通过静电引力和分子间氢键作用,进一步形成一个三维的超分子结构,而溶剂水分子填充在该结构的空隙中。此外还考察了1和2的热稳定性和固体荧光性质。     

金属离子导向自组装的磺酰化对氨基苯甲酸配合物的合成与表征

用普通溶液法合成了4个配合物：[Cu（Ts-p-aba）₂（phen）（H₂O）]_n（1）、[Zn（Ts-p-aba）₂（phen）（H₂O）]·H₂O（2）、[Pb（Ts-p-aba）₂（phen）]2（3）和{[Pb（Ts-p-aba）（phen）（NO₃）]（DMF）}_n（4）（Ts-p-aba=N-对甲苯磺酰对氨基苯甲酸,phen=菲咯啉,DMF=N,N-二甲基甲酰胺）。X-射线单晶衍射结果表明：配合物1和2均为三斜晶系,P1空间群。配合物1的中心铜离子处于变形的八面体配位环境,并通过配体N-对甲苯磺酰对氨基苯甲酸扩展为一维直线链结构;配合物2是个单核分子,锌离子的配位多面体为四角锥体。配合物3和4均为单斜晶系,P2₁/c空间群。配合物3由配体N-对甲苯磺酰对氨基苯甲酸桥联成二聚体,铅离子处于变形的八面体配位环境;配合物4是具有一维链状结构的配位聚合物,铅离子处于变形的一面心八面体配位环境。另外,对4个配合物的热稳定性、电化学性能和荧光性质也进行了研究。     

Structural, magnetic, and spectroscopic studies of YAgSn, TmAgSn, and LuAgSn

The rare earth-silver-stannides YAgSn, TmAgSn, and LuAgSn were synthesized from the elements by arc-melting and subsequent annealing. The three stannides were investigated by X-ray powder and single-crystal diffraction: NdPtSb type, P6₃mc, Z=2, a=468.3(1), pm, wR₂=0.0343, 353 F² values, 12 variables for YAgSn, and ZrNiAl type, P6¯2 m, a=726.4(2), , wR₂=0.0399, 659 F² values, 15 variables for TmAgSn, and a=723.8(2), , wR₂=0.0674, 364 F² values, 15 variables for LuAgSn. Besides conventional laboratory X-ray data with monochromatized Mo radiation, the structures were also refined on the basis of synchrotron data with , in order to clarify the silver-tin ordering more precisely. YAgSn has puckered, two-dimensional [AgSn] networks with Ag-Sn distances of 278 pm, while the [AgSn] networks of TmAgSn and LuAgSn are three-dimensional with Ag-Sn distances of 279 and 284 pm for LuAgSn. Susceptibility measurements indicate Pauli paramagnetism for YAgSn and LuAgSn. TmAgSn is a Curie-Weiss paramagnet with an experimental magnetic moment of 7.2 μ_B/Tm. No magnetic ordering is evident down to 2 K. The local environments of the tin sites in these compounds were characterized by ¹¹⁹Sn Mössbauer spectroscopy and solid-state NMR (in YAgSn and LuAgSn), confirming the tin site multiplicities proposed from the structure solutions and the absence of Sn/Ag site disordering. Mössbauer quadrupolar splittings were found in good agreement with calculated electric field gradients predicted quantum chemically by the WIEN2k code. Furthermore, an excellent correlation was found between experimental ¹¹⁹Sn nuclear magnetic shielding anisotropies (determined via MAS-NMR) and calculated electric field gradients. Electronic structure calculations predict metallic properties with strong Ag-Sn bonds and also significant Ag-Ag bonding in LuAgSn.     

Theoretical Study of Molecular Structure,Reactivity, Lipophilicity,and Solubility of N-Hydroxyurea,N-Hydroxythiourea,and N-Hydroxysilaurea

Ab initio molecular orbital methods at the CBS-QB3 level of theory have been used to study the structure and gas-phase stability of various tautomers and rotamers of N-hydroxyurea, N-hydroxythiourea, and N-hydroxysilaurea, their anions and protonated forms. The geometries of N-hydroxyurea, N-hydroxythiourea, and N-hydroxysilaurea, their anions and cations were optimized at the Becke3LYP/CBSB7 level of theory. For all compounds studied, the amidic form is computed to be substantially more stable than the iminolic tautomer. N-Hydroxyurea and its thio and sila derivatives are computed to behave as Nacids in the gas phase. These compounds are in gas-phase weak acids with a calculated acidity of about 1425 to 1355 kJ-mol^–1. Basicities increase in the order: N-hydroxyurea < N-hydroxythiourea < N-hydroxysilaurea. The most stable protonated structures are represented by several isomers with almost equal stability. Thus, in the N-hydroxyurea, N-hydroxythiourea, and N-hydroxysilaurea, both protonation at the double bonded (C=O, C=S and Si=O) oxygen and sulfur atoms, as well as the protonation at the N(H)OH nitrogen basic center is equally probable. The experimental pK _a value (10.6) of N-hydroxyurea and the computed value (9.7) for its monohydrated complex with the specifically hydrogen-bonded water molecule to the ionizable OH group are in a good agreement. The experimental partition coefficient of N-hydroxyurea is best reproduced by the Alog P_s method. The formation of nitroxide radical in the reaction of N-hydroxyurea and its sulfur and silicon substituted derivatives with the phenol radical is an exothermic process. Thus, the \bondN(H)OH moiety of these compounds may quench the structurally related tyrosyl radicals in the active site of ribonucleotide reductase.     

Structure and properties of HOO,HOS, HSO,HSS, FSO,FOS and FSS

High quality SCF-MO calculations are reported for the title molecules, including geometry optimization. One-electron properties are presented and discussed, and relative stabilities of (HOS, HSO) and (FOS, FSO) compared. Little experimental geometric data are available at present, but the calculated and experimental geometries of HO₂ agree well.     

Transition-metal-free O-, S-, and N-arylation of alcohols, thiols, amides, amines, and related heterocycles

A new protocol for the Ullmann-type arylation process of different aromatic heterocycles without any transition-metal catalyst, implying the use of a combination of an excess of potassium hydroxide and dimethyl sulfoxide, is described. The reaction can be performed between a broad range of starting nucleophiles including phenol, alcohols, amines, nitrogen-containing five-membered systems such as pyrazoles, imidazoles, and indoles, and amides with haloarenes, iodide and bromide derivatives giving the best results, the possible pathway involving the in situ generation of the corresponding benzyne intermediate. When the reaction was performed with 2-iodoaniline and either carboxamides or isothiocyanato derivatives, the corresponding benzoazole derivatives were obtained.     

Synthesis and characterization of metal-centered, six-membered, mixed-valent, heterometallic wheels of iron, manganese, and indium

Heptanuclear metal-centered, six-membered, mixed-valent, heterometallic wheels 1-3 of iron, manganese, and indium were prepared in a one-pot reaction from N-benzyldiethanolamine (H2L(1)), cesium carbonate, [PPh4]2[MnCl4], and FeCl3 or InCl3. All three complexes were characterized by the combination of elemental analysis, FAB mass spectroscopy, X-ray diffraction and cyclic voltammetry and in the case of 1 additionally by M?ssbauer spectroscopy. In 1, four Mn(II) ions in the periphery are arranged in pairs alternating with one Fe(III) ion each, with an Fe(III) ion located in the center. In 2, three Mn(II) ions alternate with three In(III) ions, whereas in 3, four In(III) ions are arranged in pairs and alternate with one Mn(II) ion each. In 2 and 3 an Mn(II) ion is encapsulated in the center.     

Synthesis of yttrium,lanthanum, neodymium,praseodymium, and lutetium alkoxides and acetylacetonates

A convenient and practical method is proposed for the synthesis of lanthanide and yttrium alkoxides. The method involves dissolving the metals or their hydrides in a solution of dry HCl in the corresponding alcohol, with subsequent dehalogenation of the LnCl₃ solution by an equivalent amount of alkali metal (Na, Li), The rareearth alkoxides are easily converted into acetylacetonates Ln(acac)₃ by the action of acetylacetone.A. N. Nesmeyanov Institute of Elementoorganic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2490–2493, November, 1992.     

Synthesis,thermal stability,heats of formation,and explosive properties of cyano-substituted di-, tri-, and tetraazidopyridines

A method of synthesis of 2,6-diazido-3,5-dicyanopyridine, 2,4,6-triazido-3,5-dicyanopyridine, and 2,3,4,5-tetraazido-6-cyanopyridine was developed. The heats of formation and explosive properties of compounds obtained were determined; kinetics and the composition of the gaseous thermolysis products were studied. The replacement of endocyclic nitrogen atoms by C-CN fragments in the aromatic ring of polyazides strongly reduces the explosive risk of these compounds with retention of the energetic properties of the molecules.     

Spectroscopy, electrochemistry, and molecular orbital calculations of metal-free tetraazaporphyrin, -chlorin, -bacteriochlorin, and -isobacteriochlorin

Metal-free tetraazachlorin (TAC), -bacteriochlorin (TAB), and -isobacteriochlorin (TAiB) were characterized by electronic absorption, magnetic circular dichroism (MCD), fluorescence, and time-resolved ESR (TR-ESR) spectroscopy, and by cyclic voltammetry. The results are compared with those of metal-free tetraazaporphyrin (TAP). The potential difference DeltaE between the first oxidation and reduction couples decreases in the order TAP>TAiB>TAC>TAB. The splitting of both the Q and Soret bands decreases in the order TAB>TAC>TAP>TAiB. Corresponding to the split absorption bands, MCD spectra show a minus-to-plus pattern with increasing energy in both the Q and Soret regions, which suggests that the energy difference between the HOMO and second HOMO is larger than that between the LUMO and second LUMO. These spectroscopic properties and redox potentials were reproduced by molecular orbital calculations using the ZINDO/S Hamiltonian. The fluorescence quantum yields of the reduced species are much smaller than that of TAP. The zero-field splitting (ZFS) parameters D and E of the excited triplet states (T1) of these species decrease and increase, respectively, on going from TAP to TAC and further to TAB. The D and E values of TAiB are larger than those of the other species. The results are supported by the absence of interaction between the spin over reduced pyrrole moieties of the HOMO and over the LUMO, and by calculations of ZFS under a half-point-charge approximation.     

Formation,structure, composition,and catalytic properties of Ni-, Cu-, Mn-, Fe-, and co-containing films on aluminum

Layers containing oxygen compounds of copper and nickel and(or) of one of transition metals (manganese, cobalt, iron) were formed on an aluminum alloy by the plasma-electrolytic oxidation method. The layers were characterized by means of X-ray phase analysis, X-ray fluorescence microanalysis, and scanning electron microscopy and tested in the reaction of CO oxidation to CO₂.