Three-dimensional 3d-4d Heterometallic Coordination Polymer——Synthesis,Structure,Magnetic and Luminescent Properties

A new three-dimensional 3d-4d heterometallic coordination polymer,[Cd2Mn(H2O)4(BTC)2]·2H2O(BTC=1,3,5-benzenetricarboxylate) was prepared under hydrothermal conditions and characterized by single crystal X-ray diffraction.This compound crystallized in the monoclinic space group C2/c,with cell parameters a=1.9452(4) nm,b=0.7094(2) nm,c=1.8064(4) nm,β=118.02(3)°,V=2.2004(8) nm3 and Z=4.Its structure contains trinuclear mixed metal clusters,which are further connected by BTC to form a three-dimensional framework.The compound exhibits intense photoluminescence at room temperature.Magnetic studies of the compound show a dominant antiferromagnetic exchange between the Mn(Ⅱ) ions.     

Synthesis and characterization of polymeric triphenyltin and cyclotetrameric tricyclohexyltin 2-(1H-imidazol-1-yl)acetates

The reaction of 2-(1H-imidazol-1-yl)acetic acid with (Ph₃Sn)₂O or Cy₃SnOH (Cy?=?cyclohexyl) yields triphenyltin 2-(1H-imidazol-1-yl)acetate (1) and tricyclohexyltin 2-(1H-imidazol-1-yl)acetate (2), respectively. 2-(1H-imidazol-1-yl)acetates in these two complexes show remarkably different coordination modes. Complex 1 forms a polymeric chain structure through intermolecular Sn–N interactions, while 2 displays a 28-membered macrocyclic tetranuclear structure by the assembly of Sn–N coordination bonds.     

Synthesis,crystal structure and properties of manganese(II) complexes with the tripod ligand tris(2-benzimidazylmethyl)amine and α,β-unsaturated carboxylates

Two new ternary complexes of manganese(II) with tris(2-benzimidazylmethyl)amine (ntb), and two different α,β-unsaturated carboxylates, {[Mn(ntb)(acrylate)](ClO₄)}₂?·?(H₂O)·3(CH₃OH) (1) and {[Mn(ntb)(α-methacrylate)](ClO₄)}₂·(H₂O)·2(CH₃OH) (2), have been synthesized and characterized by means of elemental analyses, thermal analyses, IR, UV and single crystal X-ray diffraction. In the two complexes, ntb functions as a tripodal tetradentate ligand, resulting in trigonal pyramidal geometry. In each complex, an additional ligand, acrylate anion, or α-methacrylate anion, is coordinated at the opened site trans to the apical nitrogen atom of the ntb ligand. The crystal structure of 1 shows two crystallographically independent but chemically identical [Mn(ntb)(acrylate)]⁺ cations. In 2, the crystal structure shows two crystallographically independent and chemically different [Mn(ntb)(a-methacrylate)]⁺ cations. Cyclic voltammograms of the manganese complexes indicate a quasireversible Mn³⁺/Mn²⁺ couple. The X-band EPR spectrum of the complexes exhibits a six-line manganese hyperfine pattern with g?=?2, A?=?97 (1) and 93?G (2). The spectrum confirms that the material is high-spin Mn(II).     

Crystallization of carboxylic acid salts in poly(ethylene oxide) oligomers at higher temperatures

Many alkali metal carboxylates when dissolved in poly(ethylene oxide) (PEO) oligomers, are phaseseparated by heating. These were revealed to be the crystals of the initially dissolved corresponding salts from the X-ray diffraction patterns. Some acetate salts achieve the lower limit of the lattice energy for phase separation of ordinary inorganic salts by heating in PEO oligomers. These carboxylate salts were therefore expected to show crystallization behavior in PEO oligomers by heating. The effects of cation size, alkyl chain length and molecular weight of PEO on the solubility are summarized. Negative temperature dependence of solubility of these acetate salts is seen in the PEO oligomers only when the salts have long alkyl chains. The salts containing larger cations needed a longer chain length of PEOs for crystallization by heating. These salts with longer alkyl chains showed positive temperautred dependence in lower molecular weight polyethers, but negative temperature dependence in solubility in PEO with molecular weights higher than 400. In PEO₄₀₀, all the carboxylates with longer alkyl chains were phase separated by heating.     

Studies on the transesterification of glycerides: I. The methanolysis of tripalmitin catalysed by diorganotin(IV) compounds

The potential of diorganotin compounds, in particular alkoxides and phenoxides, to function as neutral and non‐corrosive catalysts in the methanolysis of tripalmitin (the main triglyceride in palm oil) to methyl palmitate has been investigated. The compounds reveal a strong dependence of catalytic activity on the nature of the organic moiety on tin, the ring‐borne substituent on the phenoxyl group and the chain length of the alkoxyl fragment, as well as the ring size in cyclic alkoxides derived from bifunctional ligands such as diethanolamine. Kinetic studies, based on detailed compositional analysis of the reaction mixture by gas chromatography, were performed typically at 70.0 ± 0.1 °C in mixed methanol–tetrahydrofuran (3:2, v/v) medium and at 1.0 mol% catalyst concentration with respect to tripalmitin. The catalysts used for the kinetic studies were dibutyl bis( p‐chlorophenoxyl)tin 1, dibutyl bis(phenoxyl)tin 2, 1,1‐dibutyl‐5‐aza‐2,8‐dioxo‐1‐stannacyclo‐octane 3, 2,2‐dibutyl‐2‐stanna‐1,3‐benzdioxane 4 and dioctyltin oxide 5. The methanolysis was shown to proceed by a consecutive reaction pathway. Numerical analysis of the rate data yielded values of the three rate constants k₁, k₂ and k₃ corresponding to the respective conversions, tripalmitin → dipalmitin → monopalmitin → glycerol. Based on t values ranging from 7.2 to 22.3 h⁻¹, the following order of catalytic activity was established: 1 > 2 > 3 ≫ 5 ≫ 4; for catalyst 4 the t value was close to that of the uncatalysed reaction. A six‐fold increase in rate was observed when the catalyst concentration was raised from 1.0 to 3.0 mol% for 3. ¹¹⁹Sn NMR analysis of the chloroform extracts of the pot residue following solvent removal at the end of 24 h of the transesterification reaction revealed that the catalysts 1 and 3 essentially retained their chemical integrity. Copyright © 2000 John Wiley & Sons, Ltd.     

Temperature-dependent Polymorphism in Co（II） Coordination Polymers from 5-Nitroisophthalate and 1,3-Bis（4-pyridyl）propane

The solvothermal reaction of 5-nitroisophthalic acid （H2nip）, 1,3-bis（4-pyridyl）pro- pane （bpp） and Co（NO3）2·6H：O at 130 and 160 ℃ gave rise to two polymorphic complexes [Co（bpp）（H20）（nip）], （1, 2）. Complex I belongs to monoclinic, space group C2/c with a = 14.489（6）, b = 18.242（8）, c = 19.414（9） A, β = 123.09（3）°, V = 4299（3） A3, Z = 8, C21H19CoN3O7, Mr = 484.32, Dc= 1.497 g/cm3, F（000） = 1992,/l = 0.847 mm-1. In complexes I and 2, bpp connects Co（II） into different 1D chains which are bridged by nip to form similar two-fold interpenetrating 3D frameworks.     

有机锡用于催化δ—酮腈异构化成吡啶酮的研究

本文首次使用有机锡催化δ-酮腈异构化反应成吡啶酮,对三种有机锡(BuSnO_(3/2),Cat.1 ;Bu_2Sno,cat.2;Bu_3SnF,cat.3)催化剂的活性进行了比较,并考察了反应温度、反应时间和催化剂用量等对产率的影响。     

二{氧桥-二[N,N-二甲基(或乙基)氨荒酸基乙酸二丁基锡(Ⅳ)]}的合成及结构

利用二丁基氧化锡与N,N-二甲基氨荒酸基乙酸以及N,N-二乙基氨荒酸基乙酸反应,合成了二聚体有机锡化合物{[n-Bu2Sn(O2CCH2CS2NMe2)]2O}2 (1)和{[n-Bu2Sn(O2CCH2CS2NEt2)]2O}2 (2).通过元素分析,红外光谱及核磁共振谱对它们进行了表征.并用X射线单晶衍射法测定了这两个化合物的晶体结构,结果表明1为单斜晶系,C2/m空间群,晶胞参数为a=1.3584(5) nm, b=1.9242(7) nm, c=1.4640(5) nm, β=102.505(5)°, Z=2, V=3.736(2) nm3, μ=1.490 g/cm3, F(000)=1704, R1=0.0492, wR2=0.1159. 2为三斜晶系,P1-空间群,晶胞参数为a=1.1960(14) nm, b=1.3612(16) nm, c=1.3684(16) nm, α=90.969(18)°, β=105.241(17)°, γ=103.954(16)°, Z=1, V=2.078(4) nm3, μ=1.429 g/cm3, F(000)=916, R1=0.0459, wR2=0.0957.它们都是以Sn2O2四元环为中心对称的二聚体结构.但锡原子的配位方式不同,在1中,内外环锡原子均为五配位的畸变三角双锥构型;而在2中,内环锡原子为五配位的畸变三角双锥构型,而外环锡原子为六配位的加帽三角双锥构型.     

Hybrid organic-inorganic 1D and 2D frameworks with epsilon-Keggin polyoxomolybdates as building blocks

Organic-inorganic hybrid materials based on polyoxometalate building blocks with capping La3+ ions and bidentate oxygenated ligands have been obtained by reaction at room temperature of the [epsilon-PMo12O36(OH)4[La(H2O)4]]5+ polyoxocation with glutarate (C5H6O(2)(2-)) and squarate (C4O(4)(2-)) organic ligands. [epsilon-PMo12O37(OH)3[La(H2O)4(C5H6O4)0.5]4].21 H2O (1) and [epsilon-PMo12O39(OH)[La(H2O)6]2-[La(H2O)5(C4O4)0.5]2].17 H2O (2) form unprecedented 1D chains built from alternating polyoxocations and organic ligands connected through LaO links. The structures of these materials are compared to the 2D hybrid organic-inorganic framework [NC4H12]2-[Mo22O52(OH)18[La(H2O)4]2[La(CH3CO2)2]4].8H2O (3) isolated from the hydrothermal reaction of elemental precursors (MoO(4)(2-), Mo, La3+) in acetate buffer. Compound 3 is built from previously undescribed polyoxometalate units with twenty-two MoV centers capped by six La3+ ions, four of which are bridged by acetate ligands.     

Synthesis and Crystal Structure of the Organotin Complex [(o-Cl-PhCH_2)_3SnOCOC_(10)H_8N]·0.5C_6H_6

1 INTRODUCTION There is increasing interest in the study of orga-notin carboxylic ester compounds due to their insec-ticidal, fungicidal and antibiotic activities[1, as well 2]as structure diversity. In recent years many organo-tin carboxylic ester compounds with good biologi-cal activity have been synthesized[3, . Previous stu- 4]dies show that the coordination geometry of centralatom Sn …