Kinetics and mechanism of the reaction of a quasi-aromatic copper(II) complex, [Cu(PnAO)-6H]0, with formaldehyde

The kinetics of the reaction of CH₂O with a quasi-aromatic metal complex (1,1,2,8,9,9-hexamethyl-4,6-dioxa-5-hydro-3,7,10,14-tetraazacyclotetradecane-2,7,10,12-tetraene)copper(II), [Cu(PnAO)-6H]⁰ (AH), have been studied spectrophotometrically under neutral conditions in 1/3(v/v) MeOH–H₂O. The Cu, 2N, 3C quasi-aromatic heterocyclic ring in AH is highly reactive towards CH₂O at the central-aromatic-carbon atom, C(12) and the following reaction mechanism is proposed. The compounds AH, A—CH₂OH and A—CH₂—A were isolated and identified by i.r spectroscopy and by elemental analysis. The kinetic data supported the proposed reaction sequence. All reactions were second order overall. The rate constants and corresponding activation parameters for every step were obtained and are discussed.     

2,9-二甲基-1,10-菲咯啉的α-氨甲基吡啶衍生物的合成表征及其Mn(II),Co(II),Ni(II),Cu(II),Zn(II)配合物稳定性研究

以2,9-二甲基-1,10-菲咯啉为初始原料,合成了2,9-二甲基-1,10-菲咯啉的α-氨甲基吡啶衍生物-N,N'-二(2'-吡啶基)甲基-1,10-菲咯啉-2,9-二甲胺(L).该配体经过元素分析、红外光谱、核磁共振氢谱表征.在25±0.1℃、I=0.1mol·dm-3NaNO3的条件下,用pH电位滴定法测定了该配体在水溶液中的质子化常数及其分别与Mn(II),Co(II),Ni(II),Cu(II)和Zn(II)的配合物的稳定常数,提出了配合物的可能结构.进一步讨论了相应稳定常数较大的内在原因.     

Thermodynamic study of axial coordination reaction of zinc porphyrin with metal Schiff base and imidazole complex

A thermodynamic study is reported for the coordination reaction of ZnT ( m-X)PP derivatives (X = NO2, Cl, OCH3, H or CH3) with various ligands L (L= imidazole (Im), 2-methylimidazole (MeIm), clotrimidazole (CIM), imidazole-4-carboxaldehyde (4-CHOIm), unsymmetrical tetradentate copper Schiff base, CuIm(p-Cl), CuIm(p-Br), and nickel Schiff base, NiIm(p-Cl)), in dichloromethane solvent. Conversion of the four-coordinated ZnT( m-X)PP to the five-coordinated species is followed and isosbestic behavior is exhibited in the region among 450 and 700 run. The reaction of a copper(Ⅱ) or nickel(Ⅱ) imidazolate Schiff base with ZnT(m-X)PP results in the formation of an imidazolate bridged heterobinuclear complex. The stoichiometric number is unity for all axial ligands. The equilibrium constants were determined using the β band of ZnT( m-X)-PP in the 293-308 K range by the method of Rose and Drago. It increases with decrease in temperature, and △H0 < 0, △S0 < 0. The stronger the nucleophilic ability of the axial     

Synthesis and thermodynamic properties of novel tripod ligands and their cobalt(II), nickel(II), copper(II) and zinc(II) complexes

Three novel compounds, based on the 1,3,5-benzene core with C₃-symmetry, have been prepared and characterized by elemental analysis, i.r. and ¹H-n.m.r. Thermodynamic properties of the ligands and their Co^II, Ni^II, Cu^II, and Zn^II metal complexes have been investigated and the corresponding stability constants obtained at 25.0 ± 0.1 °C and with I = 0.1 mol dm^–3 in KNO₃ by potentiometric titration. A linear free energy relationship exists between the stability constants of complexes and the protonation constants of ligands in the ternary system of the Cu^II-5-substituted phenanthroline-tripod ligand complexes.     

Novel 3-D Network: From the Reaction of Polyamine with Pyromellitic Dianhydride

Abstract

Under mild condition the reaction of pyromellitic dianhydride with polyamine in methanol solution results in ammonium carboxylate salts rather than amide polymer. X-ray analysis indicates a manifestation of 3-D network linked by N─H⁺…O^? H─N⁺ hydrogen bonding for the three ammonium salts, in which the porous spaces are filled with water molecules.     

Synthesis and Crystal Structure of Cd（tla）（NO_3）_2［TLA＝tris（6－methyl－2－pyridylmethyl） amine］

ＳｙｎｔｈｅｓｉｓａｎｄＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅｏｆＣｄ（ｔｌａ）（ＮＯ_３）_２［ＴＬＡ＝ｔｒｉｓ（６－ｍｅｔｈｙｌ－２－ｐｙｒｉｄｙｌｍｅｔｈｙｌ）ａｍｉｎｅ］ＢＵＸｉａｎ－Ｈｅ；ＺＨＡＮＧＺｈｉ－Ｈｕｉ；ＺＨＵＺｈｉ－Ａｎｇ；ＣＨＥＮＹｕ...     

影响间位取代四苯基卟啉锌轴向配合物稳定因素的研究

用光度滴定法研究了间位取代四苯基卟啉锌[ZnT(m-X)PP,X=NO₂,Cl,OCH₃,H,CH₃]与3种新型空间不对称金属席夫碱和4种取代咪唑的轴向配位反应动力学.采用Rose-Drago数据处理方法确定了各反应体系的平衡常数,探讨了温度、轴向配体、卟啉环上的取代基对轴向配合物稳定性的影响,发现在5种间位取代四苯基卟啉锌与7种轴向配体的配位反应中均存在线性自由能关系和等平衡关系,对所研究体系采用不同的方法求取等平衡温度β及温度T→∞时的反应对电子效应的敏感系数ρ_∞,得到吻合的结果.     

ⅡB族金属离子-5-取代邻菲罗啉-二酮肟配体三元体系的 稳定性研究

在(35±0.1)℃,I=0.1mol·dm^-^3KNO~3条件下,用pH法测定了二酮肟配体PnAO,5-取代邻菲罗啉(5-Rphen,R=CH~3,H,Cl,NO~2)的质子化常数,Zn(Ⅱ),Cd(Ⅱ),Hg(Ⅱ)分别与PnAO和5-Rphen二元体系的稳定常数,以及Zn(Ⅱ),Cd(Ⅱ),Hg(Ⅱ)-PnAO-5-Rphen三元体系的稳定常数。实验结果表明,在上述二元、三元体系中均存在良好的直线自由能关系,并从三元配合物构型上讨论了存在线性关系的内在原因。同时,讨论了金属离子、取代基对配合物稳定性的影响。     

四苯基卟啉锌[ZnTPP(H_2O)]的晶体结构及性质研究

用X射线衍射法确定了四苯基卟啉锌（Ⅱ）水合物ZnC44H28N4（H2O）的晶体结构。晶体属于单斜晶系，C2空间群，a=18903（4），b=9．672（2），c=13．379（3）A，β=134．92（3）°，V=1732（1）A3，Z=2，Dx=1．335g／cm3，Mr=696．13，μ（MoKa）＝0．764mm－1,F（000）=720。最终偏离因子R=0．055，Rw=0．050（1076、个I≥3σ（I）衍射点）。配合物分子中Zn（Ⅱ）离子落入卟啉空腔内与4个吡咯氮原子共平面，在垂直该平面上与H对H2O分子呈轴向配位，其分子结构呈四方锥型。用电子吸收光谱和1HNMR波港以及循环伏安法对其性质进行表征，并对其轴向配位反应的热力学性质进行研究。     

6-(5'-(8'-羟基喹啉)亚甲基)-1,4,8,11-四氮杂十一烷-5,7-二酮·5-取代邻菲罗啉合铜(Ⅱ)-铜(Ⅱ)或钴(Ⅱ)双核混配体系的稳定性研究

本文合成了8-羟基喹啉取代的二氧四胺开链配体L并进行了红外、元素分析、核磁和质谱表征。在(25±0.1)℃,I=0.1mol·dm