Phosphorus containing hydrogels

Since the discovery of poly(2‐hydroxyethyl methacrylate) by Wichterle and Lim in 1960, hydrogels have been of great interest to biomedical scientists. Hydrogels are three dimensional hydrophilic polymer networks capable of swelling in water or biological fluids and retaining a large amount of fluids in the swollen state. In the last decade, hydrogels containing organophosphorus moieties were synthesized and used for proton conducting membrane, drug carriers, and scaffold for tissue engineering, pharmaceutical formulation, cosmetics, and bioseparation. One of the most versatile and rapidly developing classes of biomedical polymers is a family of polymers with a nitrogen and phosphorus backbone—polyphosphazenes. The advantage of the phosphorus–nitrogen backbone is that it can be rendered hydrolytically unstable when combined with appropriate side groups. Because of the tremendous variety of substituents that can be introduced in their structure, phosphazene polymers exhibit a very broad and sophisticated spectrum of chemical and physical properties leading to almost unlimited possibilities in the preparation of biodegradable materials Copyright © 2009 John Wiley & Sons, Ltd.     

Ferrocene containing polymers

Polymers with pendent ferrocene units are synthesized by radical and anionic methods. It has been demonstrated that polymer-analogous reactions are an attractive alternative to prepare those polymers. Polymers with ferrocene units in the main chain are available from interfacial condensation reaction between ferrocene-1,1′-dicarbonic acid dichloride with α, ω-diamines. Addition of ferrocene-1,1′-dithiol onto norbornadiene yields a polymer with repeating units from ferrocene disulfide and norbornene and nortricyclane end-groups. End-capping reactions of α, ω-dimercapto-telechelics with vinylferrocene yield polymers with ferrocene end-groups.     

Peptides containing N-dichloroacetyl-DL-serine

Conclusions N-Dichloroacetylserylphenylalanine and N-dichloroacetylserylmethionine ethyl esters were produced.     

Polybismaleimide containing tetrakisphenoxycyclotriphosphazenes

A heat-resistant polybismaleimide was obtained by the thermal polymerization of bis(maleimidophenoxy)- tetrakis(phenoxy)cyclotriphosphazene. The thermal stabilities of the polybismaleimide were evaluated in nitrogen and in air by thermogravimetric analysis. The polybismaleimide was stable to 340°C and has char yield of 70% at 800°C in nitrogen and of 60% at 700°C in air. The monomer bismaleimide was obtained by the reaction of bis(4-aminophenoxy)tetrakis(phenoxy)cyclotriphosphazene with maleic anhydride. The diamine was synthesized by a stepwise reaction of hexachlorocyclotriphosphazene with phenol and 4-nitrophenol to give bis(4-nitrophenoxy)tetrakis(phenoxy)cyclotriphosphazene and reducing the nitro groups. The structure of the cyclotriphosphazenes were characterized using Fourier transform infrared (IR), proton nuclear magnetic resonance (¹H-NMR) spectroscopy, and elemental analysis.     

Phosphorus containing spiroaziridines

2-[Benzoylamino(dialkoxyphosphoryl)methyl]-2-chloro-4-butanolides are readily prepared by treating the corresponding half amidal of -chloro--formyl--butyrolactone with chlorophosphites. They undergo intramolecular nucleophilic substitution using sodium hydride to give previously unknown phosphorus containing aziridines.Kazan State Technological University, Kazan 420015. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1196–1198, September, 1997.     

Polymers containing phenylquinoxaline rings

The synthesis and properties of poly(phenylquinoxalines) containing hexafluoroisopropylidene or silylene units in the backbone are described. The polymers have been prepared by polycondensation of aromatic diamines containing preformed phenylquinoxaline rings with a dianhydride or diacid chlorides containing hexafluoroisopropylidene groups, or with a dianhydride or diacid chlorides containing silylene units. The solubility, thermal stability, film forming ability, and electric insulating, mechanical, and electroluminescent properties of the thin films are discussed and compared with those of related heterocyclic polymers. Potential applications of poly(phenylquinoxalines) are outlined.Based on the report presented at the International Conference Modern Trends in Organoelement and Polymer Chemistry dedicated to the 50th anniversary of the A. N. Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences (Moscow, May 30–June 4, 2004).Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1739–1748, September, 2004.     

Photoconductive copolymers containing N-vinylcarbazole

The synthesis of N-vinylcarbazole (VCbz) copolymers in which electron-accepting groups are incorporated into the polymer chain is reported. The acceptors were introduced by appropriate reactions of VCbz–vinyl acetate or VCbz–acryloyl chloride copolymers and consisted of 3,5-dinitrobenzoyl, 2,4-dinitrophenyl acrylate, β-2,4-dinitrophenoxy propionate, and trichlorobenzoquinone units. The copolymer containing the 3,5-dinitrobenzoyl units required no chloranil as a dopant to be photoconductive, and in fact showed a slightly improved photoresponse relative to conventional poly VCbz doped with external chloranil.     

Fluorine containing phosphazene polymers

In this paper we highlighted the synthesis, characterization, and practical exploitation of different types of polyphosphazenes substituted with fluorinated groups. There are several ways in which fluorine atoms can be inserted into polyphosphazenes, all of which leading to different polymers showing a wide range of characteristics. In general it is true that the insertion of fluorine atoms into phosphazene macromolecules leads to an enhancement of the thermal stability, flame resistance, low-temperature elastomericity, and chemical inertness of the phosphazenes obtained. The contribution of Italian research groups to the preparation and exploitation of organic commercial macromolecules grafted onto fluorinated polyphosphazenes is also reviewed.     

Polybenzimidazoles containing anthracene photodimer

Polybenzimidazoles that contained anthracene photodimer were prepared. The molecular weights of the polymers prepared by the photopolymerization of bis-anthrylbenzimidazoles were limited by the precipitation of the resulting polymers from the reaction organic solvents. Higher molecular weight polymers were obtained by the photopolymerization of bis-anthryl-Schiff's bases, followed by the oxidation of the resulting polymers. These polymers were soluble in acidic solvents such as formic and sulfuric acids but were insoluble in organic solvents.     

Polyimides containing oxyethylene units

Four aromatic dinitro compounds containing oxyethylene units 1,2-bis(4-nitrophenoxy)ethane, bis(2)-(4-nitrophenoxy)ethyl ether, 1,2-bis(2)-(4-nitrophenoxy)ethoxy)ethane, and bis(2-(2-(4-nitrophenoxy)ethoxy)ethyl) ether were prepared by an aromatic nucleophilic substitution reaction that involved 1-fluoro-4-nitrobenzene and the appropriate oxyethylene glycol. Each of the dinitro compounds could be reduced chemically or catalytically to produce the diamines 1,2-bis(4-aminophenoxy)ethane, bis(2-(4-amino-phenoxy)ethyl ether, 1,2-bis(2-(4-aminophenoxy)ethoxy)ethane, and bis(2-(2-(4-aminophenoxy)ethoxy)ethyl) ether. Polymerization of the diamines was carried out in m-cresol with toluene as an azeotroping agent. Polymides derived from 5,5′-[2,2,2-trifluoro-1-(trifluoromethyl)ethylidene]bis-1,3-isobenzofuradione exhibited good solubility in chlorinated solvents, glass transition temperatures as low as 140°C, as evidenced by viscous flow, and good thermal stability; a 5% weight loss generally occured at greater than 450°C. Isothermal aging studies conducted at 600°F(315°C) for 200 h indicated that weight loss is directly related to oxyalkylene chain length–10% for the shortest and 50% for the longest chain.     

Polymers containing carbohydrate residues

2,3,4,6-Tetra-O-methyl-D -glucosyl methacrylate and acrylate were prepared and subsequently polymerized by radical initiation. The optical rotatory dispersions of the polymers in tetrahydrofuran and in chloroform obeyed a first-order Drude equation.     

Novel sulfur containing polymers

Sulfur containing polymers were synthesized by the addition of thiols to alkenes and alkynes. Although the polymer formation is explained on the basis of a radical intermediate these processes show typical characteristics of step growth polymerizations. These reactions have been applied for the syntheses of telechelics.     

Chiral aminoacid containing macrocycles

Optically active macrocycles (R, R)-$\text{8}$-$\text{10}$ and diastereomeric mixtures of (±)-$\text{8}$-$\text{10}$ and meso-(R, S)-$\text{8}$-$\text{10}$ were prepared containing two (R)- or (S)-α-phenylglycine units as sources of chirality.     

Water-soluble copolymers containing N-vinylcarbazole

Water-soluble or dispersable copolymers of N-vinylcarbazole (VCbz) with sodium N-acryloylsulfanilate (SAS), or sodium styrene-sulfonate (SSS), or N,N,N-triethyl-N-[2-(methacryloxy) ethyl]-ammonium iodide (TAI), or N,N,N-trimethyl-(p-vinylbenzyl)ammonium chloride (TVBA) were prepared by using a radical initiator. VCbz and SAS were copolymerized in N,N-dimethylacetamide. Copolymers containing more than 49% SAS were water-soluble. In the case of VCbz and SSS, copolymerization was also carried out in DMAN to yield water-soluble copolymers when the SSS content was greater than 36%. VCbz–TAI and VCbz–TVBA were similarly copolymerized in DMAN to give water-soluble polymers when the TAI content was greater than 58% or the TVBA content was 60%. In addition, a copolymer of VCbz and methyl acrylate was partially hydrolyzed with NaOH in tetrahydrofuran to yield a water-dispersable polymer.     

Polymers containing 12-hydroxymethyltetrahydroabietanol

12-Hydroxymethyltetrahydroabietanol has been polymerized with hexamethylene diisocyanate and a low molecular weight polyurethane produced. Low molecular weight polyurethanes have also been prepared from 12-hydroxymethyltetrahydroabietyl chloroformate, hexamethylenediamine, and sym.-dimethylethylenediamine. 12-Hydroxymethyltetrahydroabietanol has been “end-capped” with tolylene-2,4-diisocyanate and hexamethylene diisocyanate. The resulting diisocyanates have been polymerized with polytetramethylene glycol, hexamethylenediamine and hydrazine.     

Polypeptide chains containing D-gamma-hydroxyvaline

Life has an unexplained and distinct l-homochirality. Proteins typically incorporate only l-amino acids into their sequences. In the present study, d-Val and d-gamma-hydroxyvaline (d-Hyv; V) have been found within ribosomally expressed polypeptide chains. Four conopeptides were initially isolated, gld-V/gld-V'from the venom of Conus gladiator and mus-V/mus-V' from the venom of Conus mus. Their complete sequences (gld-V/gld-V' = Ala-Hyp-Ala-Asn-Ser-d-Hyv-Trp-Ser and mus-V/mus-V' = Ser-Hyp-Ala-Asn-Ser-d-Hyv-Trp-Ser) were determined by a combination of nano/pico-NMR and MS/MS methods. The amino acid triad that contains the gamma-hydroxylated residue, Ser-d-Hyv-Trp, is a novel structural motif that is stabilized by specific interactions between the d-amino acid and its neighboring l-counterparts. These interactions inhibit lactonization, a peptide backbone scission process that would normally be initiated by gamma-hydroxylated residues. Conopeptides possessing the Ser-d-Hyv-Trp motif have been termed gamma-hydroxyconophans. We have also isolated analogous conopeptides (gld-V and mus-V) containing d-Val instead of d-Hyv; these are termed conophans. gamma-Hydroxyconophans and conophans are particularly atypical because (i) they are not constrained as most conopeptides, (ii) they are extremely short in length, (iii) they have a high content of hydroxylated residues, and (iv) their sequences have no close match with other peptides in sequence databases. Their modifications appear to be part of a novel hyperhydroxylation mechanism found within the venom of cone snails that enhances neuronal targeting. The finding of d-Val and d-Hyv within this family of peptides suggests the existence of a corresponding d-stereospecific enzyme capable of d-Val oxidation.