Quantum chemical descriptors based QSAR modeling of neodymium carboxylate catalysts for coordination polymerization of isoprene

Based on the quantum chemical descriptors and the activities for isoprene polymerization of 12 neodymium carboxylates obtained by authors’earlier work,statistical analysis of data was made and a QSAR model correlating the quantum chemical descriptors and the activity was built with the partial least square(PLS)approach.The model is:A=51602εHOMO+6σ+12546,which indicates that the catalytic activity A is positively correlated with the HOMO energyεHOMOand the ligand polarizabilityσ,with the contribution ofσbeing larger,εHOMO smaller.The model’s coefficient of determination r^2=0.96 and that of cross validation q^2=0.94,both being close to 1,which means that its quality is well and its predictive power is strong.Analysis of the modeling process and the resulted QSAR model,together with the interpretation of the model’s mechanism,also shows that the model obtained from this study is valid and reliable.According to the QSAR model,the mechanism of catalyst activity can be interpreted as that neodymium carboxylates with higher HOMO energy and larger ligand polarizability are easier to react with the co-catalysts so as to produce more active and stable centers of catalyst,resulting in a higher activity.

COORDINATION POLYMERIZATION OF BENZOTRIAZOLE ON THE SURFACE OF METALLIC COPPER

The coordination polymerization of benzotriazole with metallic copper has been investigated by infrared and X-ray photoelectron spectroscopies. We found that benzotriazole could react with copper (0) under mild conditions to form bis (benzotriazolato) copper (Ⅱ) and benzotriazolato copper (Ⅰ)which covered the surface of copper metal in the shape of polymeric materials. Since benzotriazole is of great interest as a ligand in that its presence in many biological system with metal ions, and is considered as a corrosion inhibitor, this work will be in favour of the study of protective corrosion.

SYNTHESIS OF STYRYL-CAPPED POLYPROPYLENE via METALLOCENE-MEDIATED COORDINATION POLYMERIZATION: APPLY TO POLYPROPYLENE MACROMOLECULAR ENGINEERING

In this paper, we review our recent progress in the synthesis and application of styryl-capped polypropylene （PP-t- St）, an excellent reactive polyolefin that is both convenient and efficient in synthesis and facile and versatile in application for preparing advanced polypropylene materials via macromolecular engineering. The synthesis of PP-t-St is made possible by a unique chain transfer reaction coordinated by a bis-styrenic molecule, such as 1,4-divinylbenzene （DVB） and 1,2-bis（4- vinylphenyl）ethane （BVPE）, and hydrogen in typical C2-symmetric metallocene （e.g. rac-Me2Si（2-Me-4-Ph-Ind）2ZrC12, in association with methylaluminocene, MAO） catalyzed propylene polymerization. The regio-selective 2,1- insertion of the styrenic double bond in DVB or BVPE into the overwhelmingly 1,2-fashioned Zr-PP propagating chain enables substantial dormancy of the catalyst active site, which triggers selective hydrogen chain transfer that, with the formed Zr-H species ultimately saturated by the insertion of propylene monomer, results in an exclusive capping of the afforded PP chains by styryl group at the termination end. With a highly reactive styryl group at chain end, PP-t-St has been used as a facile building block in PP macromolecular engineering together with the employment of state-of-the-art synthetic polymer chemistry to fabricate broad types of new polypropylene architectures.

SIMULTANEOUS POLYMERIZATION AND FORMATION OF POLYPHENYLACETYLENE FILMS BY RARE-EARTH COORDINATION CATALYSIS Ⅳ.KINETICS AND MECHANISM OF POLYMERIZATION

The CO_2 quenching method has been used for the first time to determine the active complex concen- tration in Nd(naph)_3-Al(i-Bu)_3 catalyst system for polymerization of phenylacetylene into polyphenylacetylene(PPA)films.The kinetics and mechanism of this polymerization have been investigated by CO_2 quenching and IR,UV analytical methods.The kinetic equation can be expressed as Rp=k[M][Cp],and the apparent activation energy is about 13.6 kJ/mol.There is self-termination of chain propagating.Models for formation of the active complex and polymerization mechanism are proposed.

POLYMERIZATION MECHANISM OF DIENES WITH HOMOGENEOUS RARE EARTH CATALYSTS

The reaction mechanisms of diene polymerization with homogeneous rare earth catalyst are studied by means of the spectra of ~1H-NMR, one-and two-dimensions ^(13)C-NMR. Based on the data of above NMR spectra, it is proposed that the polymerization reaction proceeds according to the following mechanism: η~4-diene (cis-trans-)and η~3-allyl (syn-anti-).

Synthesis and Crystal Structure of a Two-dimensional Coordination Polymer Constructed by Thiophene-2,5-dicarboxylic Acid and 1,4-Bis(imidazol-1-yl)-butane

A metal-organic coordination polymer [Cd（tdc）（bimb）（μ2-H2O）]n （H2tdc = thiophe-ne-2,5-dicarboxylic acid, bimb = 1,4-bis（imidazol-l-yl）-butane） 1 has been hydrothermally synthe- sized and characterized by elemental analysis, IR, TG, luminescence spectrum and single-crystal X-ray diffraction. Colorless crystals crystallize in the triclinic system, space group P^-1 with a = 5.8945（3）, b = 10.3129（5）, c = 11.2226（5） A, a = 95.1430（10）,β = 97.9020（10）, γ = 90.5910（10）°, V = 672.84（6） A^3, C11H11CdN2O5S, Mr= 395.68, De = 1.953 g/cm^3, μ（MoKa） = 1.797 mm^-1, F（000） = 390, Z = 2, the final R = 0.0209 and wR = 0.0508 for 2514 observed reflections （I 〉 2σ（I））. The structure of 1 exhibits a two-dimensional layer-like structure.

Synthesis, Structure and Luminescent Property of a 2D Cd(Ⅱ) Coordination Polymer Based on Mixed-ligands of 1,3-Bis(imidazol)propane and Pyridine-3,5-dicarboxylic Acid

A new Cd（Ⅱ） coordination polymer, namely, [Cd（1,3-bip）（3,5-pdc）]n （1,3-bip = 1,3-bis（imidazol）propane and 3,5-pdc = pyridine-3,5-dicarboxylic acid） has been synthesized under hydrothermal conditions. Compound 1 was characterized by infrared spectrum, elemental analysis, powder X-ray diffraction （PXRD） and single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/c with a = 1.40178（7）, b = 1.72502（12）, c = 1.41635（6） ran, β = 92.653（4）°, V = 3.4212（3） nm3, Z = 4, C16HIsCdNsO4, Mr = 453.73, Dc = 1.762 g/cm3, F（000） = 1808,μ = 1.310 mm1, R = 0.0899 and wR = 0.1945. In compound 1, each 3,5-pdc ligand links three Cd（lI） ions and each Cd（Ⅱ） attaches to bip ligands to form a complicated 2D double-layer structure. In addition, the thermal stability and luminescent property of 1 have been studied in the solid state at room temperature.

Synthesis, Crystal Structure and Electrochemical Properties of a One-dimensional Chain Coordination Polymer [Cu(phen)(2,4,6-TMBA)_2(H_2O)]_n

A one-dimensional chain coordination polymer [Cu（phen）（2,4,6-TMBA）2（H2O）]n has been synthesized by reacting 2,4,6-trimethyl-benzoic acid, 1,10-phenanthroline and Cu（Ⅱ） perchlorate and its structure was characterized. Crystal data for this complex： tetragonal, space group I41, a = 2.0293（3）, b = 2.0293（3）, c = 1.3758（2） nm, α =β= γ = 90°, V= 5.6657（13） nm3, Dc= 1.379 g/cm3, Z = 8, μ（MoKa） = 0.815 mm-1, Mr = 588.14, F（000） = 2456, S = 1.047, R = 0.0459 and wR = 0.1053. The crystal structure shows that two neighboring Cu（Ⅱ） ions are linked together by one bridging-chelating 2,4,6-trimethyl-benzoic group, forming a one-dimensional chain structure. Each Cu（Ⅱ） ion is coordinated with two nitrogen atoms from one 1,10-phenanthroline molecule, three oxygen atoms from three 2,4,6-trimethyl-benzoic acid molecules and one oxygen atom from one water molecule, giving a six-coordinate distorted octahedral coordination geometry. The cyclic voltammetry behavior of the complex was also investigated.

Recent Advances of Lanthanide-transition Heterometallic Coordination Polymers

With the improvement of high-tech and emergence of crossing and new fields, lanthanide-transition （Ln-M） heterometallic coordination polymers have attracted much attention of many researchers, which exhibit novel structures and unique properties with potential applications in the nonlinear optical materials, fluorescent materials, superconducting materials, magnetic materials, catalysis, bio-simulation, adsorption and separation, and so on. It is thus necessary to summarize Ln-M heterometallic coordination polymers. According to the transition metal ions, those coordination polymers are divided into six parts to explore the current applications and future developments.

A New 2D Zinc(Ⅱ) Coordination Polymer Constructed by Imidazole-4,5-dicarboxylic Acid(H_3IDC) and 1,4-Bis(imidazol-1-ylmethyl)-benzene(bix)

A new 2D Zn（Ⅱ） coordination polymer [Zn（HIDC）（bix）0.5]n（1） was obtained by the hydrothermal reaction of ZnCl2,imidazole-4,5-dicarboxylic acid（H3IDC） and 1,4-bis（imidazol-1-ylmethyl）-benzene（bix） with a 2：2：1 mole ratio.X-ray diffraction crystal structural analysis reveals it crystallizes in monoclinic,space group P21/n with a = 12.125（3）,b = 10.541（3）,c = 12.484（3） ,β = 115.834（4）°,V = 1436.0（6） 3,Mr = 338.60,Z = 4,Dc = 1.566 Mg·m-3,F（000） = 684,μ（MoKα） = 1.730 mm-1,the final R = 0.0439 and wR = 0.0888 for 2101 observed reflections with I ≥ 2σ（I）.In 1,each zinc（Ⅱ） ion is five-coordinated with a slightly distorted trigonal bipy-ramidal coordination geometry,and each μ2-HIDC2-acts as a bridge to bond two neighboring Zn（Ⅱ） ions,leading to a 1D zigzag chain architecture.The adjacent zigzag chains are further linked by μ2-bix to form an infinite 2D network structure.The fluorescence spectrum of 1 exhibits intense emission at 466 nm when excited at 397 nm in solid state at room temperature.

Synthesis and Crystal Structure of a New Two-dimensional Manganese Coordination Polymer:[Mn(L)(1,4-bdc)]

A new coordination polymer, [Mn（L）（1,4-bdc）] （L = 11-fluoro-dipyrido[3,2- a：2＂,3 ＂- c]phenazine, 1,4-bdc - benzene-1,4-dicarboxylate）, has been synthesized through the hydrothermal method and characterized by elemental analysis, IR and single-crystal X-ray diffraction. It crystallizes in triclinic, space group P1 with a = 9.7544（9）, b = 10.8254（10）, c = 11.5288（10） A, a = 114.1300（10）, β = 96.6110（10）, y = 105.0390（10）°, V= 1038.62（16）/k3, Z= 2, C26H13FMnN404, Mr = 519.34, Dc = 1.661 g/cm3, F（000） = 526, ,u（MoKa） = 0.691 mm^-, R = 0.0405 and wR = 0.0977. The 1,4-bdc dianions link the neighboring Mn（II） atoms to yield a two-dimensional layer structure. The L ligands are attached on both sides of the layer. The π-π interactions between the L ligands of neighboring layers result in a three-dimensional supramolecular architecture.

Hydrothermal Synthesis, Crystal Structure and Photoluminescent Property of a Zinc(II) Coordination Polymer Assembled by Phthalate and 4,4′-Bipyridine

A metal-organic coordination polymer {[Zn（Pht）（4,4＇-bipy）（H2O）2]·2H2O}n （Pht = phthalate, 4,4＇-bipy = 4,4＇-bipyridine） 1 has been hydrothermally synthesized and characterized by elemental analysis, IR, TG, fluorescence spectrum and single-crystal X-ray diffraction. Yellow crystals crystallize in the monoclinic system, space group P2/n, a = 7.6346（14）, b = 11.316（2）, c = 10.8133（19） ,A, β = 92.A.A,A.（3）°, V = 933.3（3） A^3, C18H20N2O8Zn, Mr = 457.73, Dc = 1.629 g/cm^3, F（000） = 472, Z = 2,μ（MoKa） = 1.367 mm^-1, the final R = 0.0323 and wR = 0.0821 for 1859 observed reflections （Ⅰ〉 2σ（Ⅰ））. The structure of 1 exhibits a two-dimensional bilayer framework formed by hydrogen bonding interactions. Furthermore, 1 shows yellow photoluminescent property at room temperature.

Synthesis, Crystal Structure and Luminescent Property of a Ag(Ⅰ) Coordination Polymer with a 3D Sandwich-like Framework

A new coordination polymer,{[Ag2（bpp）2（H2O）2]·bpdc·3H2O}n,derived from the ligand biphenyl-4,4＇-dicarboxylic acid（H2bpdc）,has been obtained through a hydrothermal technique（bpp = l,3-bis（4-pyridyl）propane）.Its single-crystal structure has been characterized by single-crystal X-ray diffraction,powder XRD,FT-IR,TGA and elemental analysis techniques.The single-crystal X-ray diffraction reveals that complex 1 consists of 1D infinite[Ag（bpp）（H2O）]n^（n＋）cationic chains,2D anionic layer constructed by bpdc anions and free water which provide charge compensation in the crystal structure.The 1D infinite[Ag（bpp）（H2O）]n^（n＋） cationic chains and 2D anionic layer are further stacked in-ABAB- fashion through intermolecular H-bonding to form a 3D sandwich-like framework.In addition,the luminescent property of complex 1 in the solid state at room temperature was investigated.

A New Cadmium(Ⅱ) Coordination Polymer Constructed by 2-(2-Chloro-6-fluorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline and 1,2,3-Benzenecarboxylate: Synthesis, Structure and Luminescence

A new Cd（II） coordination polymer, namely, [Cd3（1,2,3-BTC）2（L）2]·2.25H2O （1, L = 2-（2-chloro-6-fluorophenyl）-1H-imidazo[4,5-A][1,10]phenanthroline and 1,2,3-BTC = 1,2,3-ben- zenetricarboxylate）, has been synthesized under hydrothermal conditions. The compound was characterized by single-crystal X-ray diffraction. It crystallizes in triclinic, space group Pī with α = 11.650（2）, b = 12.240（2）, c = 19.760（4） A, α = 72.01（3）, β = 77.11（3）, γ = 83.48（3）°, V = 2609.4（9） A3, Z = 2, C56H31Cd3Cl2F2N8O14.25, Mr = 1489.99, Dc = 1.896 g/cm3, F（000） = 1466, μ（MoKa） = 1.401 mm^-1, R = 0.0401 and wR = 0.1104. Compound 1 shows a 1D chain structure, and the neigh- boring 1D chains of 1 are joined together by π···π interactions to result in a 2D supramolecular layer. In addition, the luminescent property of 1 has been studied in the solid state at room temperature.

Syntheses, Crystal Structures and Magnetic Properties of Ni(Ⅱ) and Mn(Ⅱ) Coordination Polymers Constructed from 5-(2'-Carboxylphenyl) Nicotate and 2,2'-Biimidazole

Two coordination polymers, namely {[Ni（cpna）（H2biim）（H2O）]·H2O}n （1） and {[Mn（cpna）（H2biim）]·H2O}n （2） （H2cpna = 5-（2＇-carboxylphenyl） nicotic acid, H2biim = 2,2＇- biimidazole）,have been hydrothermally synthesized and characterized by elemental analysis, IR, TG, magnetic properties, and single-crystal X-ray diffraction. Compound 1 exhibits a one- dimensional （1D） step-like chain structure, which further builds a three-dimensional （3D） supramolecular architecture via O–HAAAO and N–HAAAO hydrogen-bonding and π-π stacking interactions. Compound 2 possesses a one-dimensional （1D） double chain structure, which is further assembled into a 3D supramolecular framework by N–HAAAO hydrogen bonding and π-π stacking interactions. Magnetic susceptibility measurement indicates that compound 1 shows a weak antiferromagnetic coupling between the nearest Ni（II） centers, with g = 2.11 and J = –1.87 cm^-1.

Hydrothermal Synthesis and Crystal Structure of a Cobalt(II) Coordination Polymer: [Co(C_2O_4)(bix)]_n (bix = 1,4-Bis(imidazol-1-ylmethyl)-benzene)

A new two-dimensional cobalt coordination polymer has been prepared and fully characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. The compound [Co（C2O4）（bix）]n 1 crystallizes in the monoclinic system, space group C2/c, with a = 11.549（3）, b = 15.700（3）, c = 9.260（2） A, β = 102.984（3）°, V = 1636.0（6） A^3, C16HIaCON4O4, Mr= 383.23, Dc = 1.556 g/cm^3, μ（MoKa） = 1.078 mm^-1, F（000） = 780, Z = 4, the final R = 0.0455 and wR = 0.1286 for 1483 observed reflections （I 〉 2σ（I））. Of the compound, the Co center is octahedrally coordinated with oxalate acting as a tetra-dentate ligand coordinated to the cobalt atom and each bix serving as a bridging ligand by employing two N-donors to coordinate with the Co center. An infinite {Co2（C2O4）2}∞ chain is formed along the α axis. Furthermore, the 1D chains are held together via bix ligands to generate a two-dimensional network structure with 1D coronal-like channels （ca. 5.691A × 15.700A）.

Synthesis, Structure and Characterization of a New Iron Coordination Polymer:[Fe(L)(trans-1,4-chdc)]_n

A novel Fe（II） coordination polymer [Fe（L）（trans-1,4-chdc）];~ has been hydrother- mally synthesized by using 1,4-cyclohexanedicarboxylic acid （1,4-H2chdc） and 2-（2-fluoro- phenyl）-lH-imidazo[4,5-f][1,10]phenanthroline （L）. Crystallographic data： monoclinic, space group C2/c with a = 14.571（5）, b = 32.389（6）, c = 10.948（5）A, 18 = 115.186（5）°, V= 4676（3）A3, Z = 8, C27H21FFeN404, Mr = 540.33, De --- 1.535 g/cm3, F（000） = 2224, μ（MoKa） = 0.697 mmI, R = 0.0462 and wR = 0.1110. The two kinds of trans-l,4-chdc ligands link neighboring Fe（II） atoms to yield a two-dimensional layer structure. The π-π interactions between the L ligands of neighboring layers result in a three-dimensional supramolecular architecture. The IR and UV-vis spectra of the compound have been investigated in detail.

Mixed-solvothermal Synthesis, Crystal Structure and Luminescence of a New Dinuclear Yttrium(Ⅲ) Coordination Polymer with 1-D Wave-like Infinite Chains

A new dinuclear Y（3＋） coordination polymer{[Y2（H2O）2（C（14）H8O4）3（C（12）H8N2）2]·3 H2O}n （1, C（14）H8 O4 = 2,2＇-biphenyldicarboxylate, phen = 1,10-phenanthroline）, has been obtained by means of a mixed-solvothermal method using ethylene glycol and water as solvent. The compound was characterized by elemental analysis, energy-dispersive X-ray spectroscopy（EDS）, IR spectrum and single-crystal X-ray diffraction. The results reveal that 1 belongs to monoclinic system, space group C2/c with a = 24.249（3）, b = 12.069（48）, c = 22.7304（08） A, β = 113.480（7）°, Z = 4, V = 6102（2） A3, Dc = 1.462 g·cm^-3, F（000） = 2728, μ = 1.968 mm（-1）, the final R = 0.0673, w R = 0.1508 and S = 1.085. Its structure can be regarded as a 1-D coordination polymer constructed by Y^3＋ cations, 2,2A-biphenyldicarboxylate, 1,10-phenanthroline and water molecules. The compound not only contains two kinds of organic ligands, but also exhibits interesting wave-like infinite chains and 18-MR windows with the diameter of 4.070（7）A × 5.326（9）A. The structure is further stabilized by means of O–H…O hydrogen bonds and π-π stacking interactions. Furthermore, the luminescent properties（including emission spectrum, CIE chromaticity coordinate and decay curve） of 1 were also investigated in the solid-state at room temperature.

1D Lanthanide Coordination Polymers Based on 3-(Pyridin-4-yl)benzoic Acid: Syntheses, Structures and Luminescent Properties

ABSTRACT Four novel 1D lanthanide coordination polymers with formula [Ln（3,4-pybz）3（HzO）2. H2O]n （Ln = 1 Sm; 2 Eu; 3 Tb; 4 Dy, 3,4-Hpybz = 3-（pyridin-4-yl）benzoic acid） have been synthesized by hydrothermal reactions of lanthanide oxide and 3-（pyridine-4-yl） benzoic acid. Single-crystal X-ray diffraction shows that the four compounds are isostructural. They all crystallize in a monoelinic system, space group P1^-. They have a doubly carboxylate-bridged infinite-chain structure with alternating Ln-（carboxylate）2-Ln linkages and one chelating carboxylate group on each metal center. The Ln ion also combines to two water molecules to form an eight-coordinate square antiprismatic geometry. The pyridine nitrogen atoms of the ligand do not coordinate to the metal centers but direct the formation of a 3D network through hydrogen bonding with coordinated water molecules. The photoluminescent properties of 2 and 3 have been also studied.

Metal-directed Assembly of Two Distinct Coordination Polymers with 2,5-Furandicarboxylic Acid and 4,4'-Bipyridine

By using solvothermal method, two new metal coordination polymers based on 2,5-furandicarboxylic acid（H2FDA） ligand and 4,4＇-bipyridine（bipy）, [Cu（FDA）（4,4＇-bipy）（DMF）]n·solvent（1） and {[Zn（4,4＇-bipy）（FDA）（DMF）]·DMF}n（2）, were produced and characterized by single-crystal X-ray diffraction analyses, elemental analyses, IR and powder X-ray diffraction. Compound 1 crystallizes in monoclinic space group P21/c with a = 11.104（2）, b = 10.396（2）, c = 18.772（4） , β = 96.20（3）o, V = 2154.2（7） 3, Dc = 1.378 g/cm^3, C19H17 Cu N3O6, Mr = 446.90, F（000） = 916, μ（Mo Kα） = 1.05 mm^-1, Z = 4, R = 0.0691 and wR = 0.1341 for 3537 observed reflections（I 2σ（I））, and R = 0.1062 and w R = 0.1482 for all data. Compound 2 crystallizes in monoclinic space group C2/c with a = 29.779（6）, b = 9.6417（19）, c = 17.292（3）, β = 105.69（3）°, V = 4779.9（16） 3, Dc = 1.445 g/cm^3, C22H22N4O7 Zn, Mr = 519.81, F（000） = 2144, μ（Mo Kα）= 1.08 mm^-1, Z = 8, R = 0.0641 and w R = 0.1007 for 2985 observed reflections（I 2σ（I））, and R = 0.1028 and w R = 0.1112 for all data. Different coordination geometry of metal ions, square pyramid of Cu2＋ and trigonal bipyramid of Zn2＋, bring about different orientations of FDA2- ligands as well as 4,4＇-bipyridine ligands, and furthermore distinct assembly structures for 1 and 2. The thermal stabilities of 1 and 2 are also investigated.