Conjugated metallopolymers

Conjugated polymers incorporating transition metals have enormous potential for chemically-tuneable conducting and semiconducting polymers. Unfortunately, progress in this field has been limited by the challenge of preparing suitable metal-containing monomers, the difficulty of polymerizing them in a controlled manner, and the limited solubility of the resulting polymers. We are developing new, soluble conjugated metal-containing polymers that contain transition metals in a conjugated organic backbone.     

Preparation and reactivity of metal-containing monomers

The radical-induced copolymerization ofmeso-tetraphenylporphyrin monomers with the vinyl group in a benzene or pyrrole ring and their copper and zinc complexes with styrene and methyl methacrylate was studied. Porphyrin comonomers decrease the overall polymerization rate and the number-average molecular weight of the products formed compared to the weight of polystyrene obtained under similar conditions. The main reasons for termination of chain growth by vinylporphyrins were revealed, and some quantitative parameters of these reactions were obtained. IR and electronic absorption spectra of porphyrin-containing copolymers are discussed. According to the ESR spectra, the copper-containing centers in the copolymers are fairly remote from each other, and the metal-containing polymeric systems are magnetically dilute.For Part 45. seeIzv. Akad. Nauk, Ser. Khim., 1995, 2404 [Russ. Chem. Bull., 1995,44, 1758 (Engl. Transl. .)].Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2922–2929, December, 1996.     

Refractory Metal-Containing Polymers and Nanocomposites: Preparation and Properties

Summary: Novel polymers containing refractory metal in the main chain or side chains can be prepared. An attractive approach is polymerization of the Hf (Ta, Nb)-monomers with (meth)acrylate, fumarate or monomethylmethacrylate ethyleneglycol groups, synthesized for the first time in this study. New types of hafnium (tantalum, niobium)-containing nanocomposites are prepared by combining polymer synthesis and controlled thermolysis. The composition and structure of the synthesized metal-containing precursors and thermolysis products are determined by elemental analysis, IR and ¹H-NMR spectroscopies, X-ray diffraction and TEM analysis.     

Polymers based on divalent metal salts of p-aminobenzoic acid: a review

Divalent metal salts of p-aminobenzoic acid are useful starting materials for syntheses of ionic polymers into which metal is firmly incorporated. This paper is a review of a series of polymers that have been prepared using the metal salts. The salts can react with compounds having functional groups capable of reacting with amino groups. By polyaddition reactions of the salt–aromatic diamine with diisocyanate, and with isocynate-terminated adducts of diisocyanate and dialkylene glycol, halatotelechelic polyureas and polyurethane-ureas are obtained. By amine–epoxy reactions of systems of the salt–diamine–bisepoxide, and addition reactions of systems of the salt–dicarboxylic acid anhydride–bisepoxide, metal-containing cured resins are obtained. In this case, the metal carboxylate groups of the salts have catalytic activities for the curing reactions, and also for etherification of epoxy groups as a side reaction. Therefore, crosslinking of bisepoxide with the salts, and with adducts of the salts and the anhydride, has been investigated by taking advantage of the catalytic activity of the metal carboxylate groups for the etherification of epoxy groups. Interestingly, the metal-containing cured resins obtained by crosslinking by etherification of bisepoxide with the adducts show very high impact strength. © 1997 John Wiley & Sons, Ltd.     

Preparation and reactivity of metal-containing monomers

Polymethacryloylacetonates of some transition metals were obtained by free-radical polymerization of the corresponding metal-containing monomers and the main regularities of the process were studied. The complexation with a metal ion decreased the reactivity of the methacryloylacetone towards polymerization in the series Mn^II > Co^II > Ni^II > Cr^III, which is analogous to the electronegativity of these metals. Macrochelates thus obtained contain one equivalent of metal per monomer unit and their molecular weights are within 10000–18200. The structure of the coordination site was shown to be retained in the course of polymerization.For communication 34, see Ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2060–2064, December, 1993.     

Synthesis and properties of styrenetricarbonylchromium and its analogs

The methods of synthesis and the reactivity of styrenetricarbonylchromium and its analogs as model objects for the study of the effect of the metal atom on the reactivity of the monomer -bond and the aromatic ring are described systematically and discussed. These compounds are unique initial substrates for the synthesis of metal-containing polymers and for the preparation of optical stereoisomers and materials for nonlinear optics.     

新型含金属元素二胺的合成与表征

本文分别用液相法和固相法合成了一系列含不同金属元素的二胺,并通过红外光谱,~1HNMR、~(13)CNMR,紫外光谱,电化学分析及元素分析对其进行表征,还通过DSC和TG对其热性能进行了研究,结果发现这些二胺具有良好的耐热性,是合成一些耐热高聚物的优良原料.     

Synthesis and reactivity of metal-containing monomers 64. Synthesis,structure, polymerization,and catalytic properties of the palladium and cobalt vinylporphyrin complexes

2-Vinylporphyrin and its complexes with Pd^II and Co^II were synthesized and characterized by NMR, IR, and mass spectra. The palladium vinylporphyrin complexes are efficient metal-containing monomers in radical copolymerization with styrene. Palladium(II) in an amount of up to 1 mol.% can thus be introduced into the polymers. The synthesized polymeric Pd complexes perform the photosynthesized activation of dioxygen to the lowest excited singlet state, which is an active oxidizing agent for anthracene producing the 1,4-addition products. The monomeric and macromolecular cobalt complexes are chain-transfer catalysts in radical styrene polymerization. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 152–158, January, 2007.     

Synthesis of polymers by using divalent metal salts of mono(hydroxyethyl) phthalate: Metal-containing polyurethane-ureas

A series of metal-containing polyurethane-ureas containing ionic links in the main chain was synthesized by the polyaddition reaction of hexamethylene diisocyanate with mixtures of metal salts of mono(hydroxyethyl) phthalate and bisureas containing two hydroxyl groups which were obtained from monoethanolamine and diisocyanates. The polyurethane-ureas obtained were generally yellowish powders or solids. Close agreement between observed and calculated values of metal content of the metal-containing polyurethane-ureas was obtained. The viscosities (in dimethylformamide) of polyurethane-ureas decreased markedly with increase of metal content. Moreover, the decomposition temperatures were lowered a little by introducing metals into the polyurethane-ureas. Dimethylformamide, m-cresol, and dimethyl sulfoxide were comparatively good solvents for the metal-containing polyurethane-ureas; however, the polymers were insoluble in all other solvents.     

Synthesis and reactivity of metal-containing monomers

The polymerization of diacrylates of the nontransition metals Mg, Zn, Ba, and Pb, which proceeds at low temperatures (5–10°C) with the complexes of alkylcobalts with tridentate Shiff bases (RCo) as initiators, was studied. The radical mechanism of the process was proved with the aid of free radical scavengers. The polymerization kinetics is given by the equationW _n = k [M] · [RCo]^0.75. The influence of the nature of the metal in the monomer and the alkyl ligand in the initiator on the polymerization process was discussed. Low temperatures promote the formation of polymers with high molecular weights and a predominantly syndiotactic structure. The effect of the steric hindrances arising during polymerization due to the formation of a three-dimensional cross-linked structure in the metal-containing polymer on the microstructure of polymer chain and on polymerization kinetics was considered.For part 24 seeBull. Acad. Sci., Div. Chem. Sci., 1992, 1609.For a preliminary communication see Ref.1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 500–503, March, 1993.     

配合物聚合反应研究──Ⅰ.以对氨基苯磺酸盐合成聚酰亚胺

以对氨基苯磺酸的二价金属配合物为原料合成了一系列主链上含金同元素（Ｃａ，Ｃｕ．Ｃｏ，Ｍｉ）的聚酰亚胺．以元素分析、ＩＲ和固体（１３）Ｃ－ＮＭＲ对其组成及结构进行了表征，通过ＴＧ－ＤＴＡ研究了其热性能，并讨论了含金属元素聚酰胺酸溶液的粘度与其中金属元素及其含量的关系     

Photochromic liquid-crystalline polymers. Main chain and side chain polymers containing azobenzene mesogens

Abstract

Two classes of thermotropic polymers were synthesized containing the trans-azobenzene unit as both a mesogenic and a photochromic group. In the former class (I) the azobenzene unit is incorporated into the main chain of substituted polymalonates, while in the latter class (II) it is appended as a side chain substituent to a polyacrylate backbone. The liquid-crystalline properties of the polymers were studied as a function of the chemical structure. All of the prepared polymers I have smectic phases. Polymers II are nematic and/or smectic, or cholesteric when including a chiral residue R'. Polymers I and II when radiated at 348 nm in chloroform solution undergo trans-to-cis isomerization of the azobenzene moiety. The calculated rate constants are comparable with those of low molar mass model compounds, and indicate that the macromolecular structure does not significantly affect the photoisomerization rate.     

Preparation of Novel Materials for Catalysts Utilizing Metal-Containing Silsesquioxanes

Recent progress of the preparation of novel materials for catalysts utilizing metal-containing silsesquioxanes are reviewed in the following categories: (i) activities of vanadium or titanium-containing silsesquioxanes as homogeneous catalysts for oxidative reactions, (ii) preparation of immobilized or polymeric catalysts, and (iii) preparation of porous oxide catalysts utilizing metal-containing silsesquioxanes. The present authors found that the liquid phase photo-oxidation of cyclohexane in the presence of a vanadium-containing silsesquioxane as a homogeneous catalyst selectively afforded cyclohexanol and cyclohexanone in high yields. Facile synthetic methods for group 4 metal-containing silsesquioxanes with functionalized silyl (or germyl) groups are presented. Remarkably, titanocene(IV)-containing silsesquioxanes have been synthesized for the first time. The presence of alkenylsilyl substituents shows a promotional effect on the epoxidation of cycloalkenes, which was found to be more significant for titanium-bridged silsesquioxanes. By utilizing these silsesquioxanes, polymeric, starburst-like, and dendritic silsesquioxanes were prepared as well as novel caged or macrocyclic molecules with organic–inorganic hybrid structures. The controlled calcination of these metal-containing silsesquioxanes at around 823 K produces porous oxides with high BET surface areas of 300–520 m²g⁻¹ and uniformly-controlled micropores of 0.5–0.6 nm diameter. The oxides are found to include a well-dispersed metallic oxide species. From group 13 elements-containing silsesquioxanes Br?nsted acidic oxides are produced. Among them, aluminum-containing oxides show excellent activities for the cracking of cumene even at low temperature, 523 K, in spite of their amorphous nature.     

(Co)polymerization of metal-containing monomers as a way of MMC synthesis

The principal advances and problems of the synthesis, of poly-, co- and graft- polymerization of metal-containing monomers (MCM) are analysed. The MCMs are classified on the type of the metal bond with the organic part of the molecule, viz. MCM with σ-, nv-, and π-bonds. The effect of a transition metal on both the polymerization and on the properties of the products formed is of special interest. The basic fields of application of metal-containing polymers have been summed up.     

配合物聚合反应研究──Ⅱ．以二氨基磺磷酸盐配合物合成聚脲

以二氨基磺酸盐配合物合成了一系列主链上合金属元素（Ｃａ，Ｎｉ，Ｃｏ，Ｃｕ）的聚脲聚合物．用ＩＲ和１ＨＮＭＲ对其结构进行了表征，以ＴＧ－ＤＴＡ研究了其热性能，并讨论了金属元素种类及其含量对聚脲聚合物溶液粘度的影响．     

Metal-containing nanoparticles with core-polymer shell structure

Metal-polymer nanocomposites, which comprise nanoparticles of metals and/or their oxides and carbides uniformly distributed in stabilizing polymer matrices, are prepared through solid-phase polymerization of metal-containing monomers followed by controlled thermolysis of synthesized metal-containing polymers. Using X-ray diffraction, electron microscopy, ferromagnetic resonance, and IR spectroscopy, it is shown that nanoparticles present in these systems have a characteristic core-shell structure that comprises a metal-containing core and a surface layer, i.e., a polymer shell. Parameters of the components are estimated.     

Synthesis and properties of two new series of isomeric liquid crystalline polyesters with conjugated double bonds

Two homologous series of flexible main chain liquid crystalline polyesters with isomeric mesogenic groups containing conjugated double bonds, were synthesized and studied by differential scanning calorimetry and optical microscopy. One series (S1) has the p-phenylene-diacryloyloxydibenzoyl moiety as a mesogenic unit. The other (S2) has the terephtaloyl dioxydicinnamoyl moiety as a mesogenic unit. The reactivity of the conjugated double bonds of the p-phenylenediacryloxy unit, at the temperature of mesophase formation, impedes the stability of liquid crystalline mesophases of polymers of series (S1). Two low molecular weight analogues of polymers were also prepared and their properties compared with those of polymers of similar structure. The two model compounds form stable smectic mesophases over a wide range of temperatures, which shows the high mesomorphogenic ability of both mesogenic units.     

配合物聚合反应研究──Ⅱ.以二氨基磺磷酸盐配合物合成聚脲

以二氨基磺酸盐配合物合成了一系列主链上合金属元素(Ca,Ni,Co,Cu)的聚脲聚合物。用IR和1HNMR对其结构进行了表征,以TG-DTA研究了其热性能,并讨论了金属元素种类及其含量对聚脲聚合物溶液粘度的影响。     

ADVANCES IN THE SYNTHESIS AND POLYMERIZATION OF METAL-CONTAINING MONOMERS

Abstract

Polymerization and copolymerization of metal-containing monomers (MCM) is a unique method of synthesizing metal-containing polymers wherein practically all functional groups are bound to the metal.     

Preparation and emission properties of various poly(dimethylsilylenearylenevinylene)s: Effects of geometric structures and π units on their emission properties

trans‐Poly(dimethylsilylenearylenevinylene)s (trans‐rich) and cis‐poly(dimethylsilylenearylenevinylene)s (cis‐rich) containing phenylene, biphenylene, and phenylenesilylenephenylene units were prepared by hydrosilylation catalyzed with the RhI(PPh₃)₃ complex. The addition of a phenylene π unit to poly(silylenephenylenevinylene) expanded the conjugation in the main chain, whereas the insertion of a dimethylsilylene σ unit in the biphenylene moiety reduced the conjugation. UV spectra of the trans‐type polymers showed redshifts and hyperchromic effects with respect to those of the cis‐type polymers, indicating wider conjugation, and the quantum yields of emission of the former polymers were much higher than those of the latter polymers. The quantum yield of the trans‐rich polymer with the biphenylene moiety reached 0.15, which was about 10² times as large as those of trans‐type polymers with phenylene (3.4 × 10^?3) and phenylenesilylenephenylene (1.9 × 10^?3) moieties. The effects of the geometric structure and π unit on the absorption and emission properties of these polymers were examined with molecular orbital methods. © 2002 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 535–543, 2002; DOI 10.1002/pola.10139