Synthesis of Aminotelechelic Polymers with the Redox System TiCl3/NH2OH in the Hydrochloric Aqueous Phase. I. Polymerization Possibilities and Limits

Among recent progress in the field of macromolecular chemistry, of considerable interest has been the synthesis of α, ω-ordifunctional polymers. These polymers, called “telechelic” polymers, are interesting because many reactions are possible on their functional end-groups:     

Synthesis of new ferrocene derivatives with a 4,5-dichloroisothiazole fragment

Conjugates of ferrocene and 4,5-dichloroisothiazole were synthesized, where the ferrocene and isothiazole moieties are linked through various structural fragments. The acylation of ferrocene with 4,5- dichloroisothiazole-3-carbonyl chloride gave (4,5-dichloroisothiazol-3-yl) ferrocenyl ketone; the acylation of aminomethylferrocene furnished the corresponding amide. The esterification of ferrocene-1,1′-dicarboxylic acid with 4,5-dichloroisothiazol-3-yl-methanol resulted in the formation of the corresponding ester. The condensation of 1,1′-diacetylferrocene with 4,5-dichloroisothiazole-3-carbaldehyde afforded ferrocenophane containing 4,5-dichloroisothiazole moieties.     

Metallocene monomers and polymers. Ferrocenyl and ferrocenylene derivatives

The synthesis and study of some polyenes, polýiminoimides and Schiff polybases with ferrocene obtained by either polymerization or polycondensation are reported.The following monomers were used: ethynylferrocene, 1-chloro-1′-ethynyl-ferrocene, α-chloro-β-formyl-p-ferrocenylstyrene, p-ferrocenylphenylacetylene, p-ferrocenylacetophenone, 1,1′-diacetylferrocene and 1,1′-bis[β-(2-furyl)acryloyl]ferrocene which were characterized by spectral and thermodifferential analyses and Hückel MO calculations. The polymerization was performed in the presence of benzoyl and lauroyl peroxides, triisopropylboron and complex catalysts of [P(C₆H₅)₃]₂ NiX₂ type. The ferrocene derivatives were polycondensed with biuret, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl thioether, 4,4′-diamino-2,2′-dinitrodiphenyl disulphide in the presence of metallic salts and p-toluene sulphonic acid as catalysts.Polymers with either linear or tridimensional structure showing good thermal stability and semiconducting properties have been obtained. Some polymers show catalytical activity in the polymerization of chloroformylated vinylic derivatives.     

Bridged ferrocenes : VII. Synthesis of di- and tri-bridged ferrocenes with pentamethylne chains

Double or successive bridge-enlargement reactions were used on appropriate α-ketones followed by reduction to prepare 1,1′-pentamethyleneferrocene, VIII, 1,1′,3,3′-bis(pentamethylene)ferrocene, XX, and 1,1′,2,2t?,4,4′-tris(penta-methylene)ferrocane, XXX. The bridge-enlarging reactions are discussed, and the PMR spectral behavior of the polybridged ferrocenes is briefly discussed.     

Main chain 1,1′‐ferrocene‐containing polyelectrolytes exhibiting thermotropic liquid‐crystalline and fluorescent properties

A series of 1,1′‐ferrocene‐containing polyelectrolytes ( 3, 4 ) were prepared when 1,1′‐bis(N,N‐dimethylaminomethyl)ferrocene ( 1a ) or 1, 1′‐bis{[1‐(2‐methyl)imidazol‐1‐yl]methyl}ferrocene ( 1b ) was quaternized with 1,4‐dibromobutane or α, α′‐dibromo‐p‐xylene. The counterion was bromide or bis(trifluoromethanesulfonyl)‐amide formed after metathesis with the lithium salt. Their chemical structures were determined by IR and NMR spectra. Molecular weights in the range of ～5400 ( 4a )– ～14,700 ( 4c ) for number‐average molecular weights (M_n) over narrow molecular weight distributions were determined for polymers 4 by gel permeation chromatography. Thermal properties of these materials were obtained by differential scanning calorimetry and thermogravimetric analysis that showed the polymers had thermal stabilities ranging between 172 and 330 °C. Liquid‐crystalline behavior was investigated on a hot stage polarizing optical microscope. Polymers 3a , 4b , and 4d formed either a high‐order or a low‐order smectic phase above their melting or fusion temperatures, and exhibited smectic‐to‐isotropic transitions. The ranges of the liquid‐crystalline phases for these materials were 22, 46, and >55 °C. Compounds 3b , 4a , and 4c are crystalline before melting or decomposing. All of the polymers exhibited absorption bands at ～430 nm. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 974–983, 2005     

Segmented poly(ether urethane) films containing ferrocene units in the hard segments

Segmented poly(ether urethanes) were synthesized from polypropylene glycol (PPG) and 4,4′-methylene-bis(phenyl-isocyanate) (MDI), using 1,1′-bis(β-aminoethyl)ferrocene (BAF) and 1,1′-bis(β-hydroxyethyl)ferrocene (BHF) as chain extenders. These polymers were characterized by infrared and ¹³C-NMR spectroscopy. Mass spectrometry was also utilized to determine the linkage of BAF and BHF in these polymers.     

Supramolecular architecture of diammonium ferrocene-1,1′-diyldiphosphinates

Diammonium ferrocene-1,1′-diyldi(H-phosphinate) (1) and diammonium ferrocene-1,1′-diylbis(phenylphosphinate) (2) were obtained for the first time and structurally characterized. Compound 1 shows a supramolecular 3D structure in the crystal; the structure is stabilized by hydrogen bonds between the layers of ammonium cations and the layers of ferrocene-1,1′-diyldiphosphinate anions. The more hydrophobic and sterically crowded ferrocene-1,1′-diylbis(phenylphosphinate) anion of compound 2 together with ammonium cations and solvate water molecules forms supramolecular 2D layers in the crystal.     

Synthesis of ferrocene paracyclophanes

Paracyclophanes containing one or two ferrocene units can be efficiently synthesized directly from 1,1′-di(hydroxymethyl)ferrocene and aromatic dithiols. In the reaction with di(4,4′-dimercaptomethylphenyl)methane the mononuclear paracyclophane was formed, while with the dithiophenols di(4,4′-dimercaptophenyl)methane and di(4,4′-dimercaptophenyl)ether, cyclophanes bearing two ferrocene units were obtained. For comparison three open-chain analogues were also prepared.     

Synthesis and complexation of a new 1,1′-disubstituted ferrocene with two pendant chelating sites of an α,β-unsaturated β-keto amine subunit

Condensation of 1,1′-bis(aminomethyl) ferrocene with acetylacetone gave 1,1′ -bis(3 - methyl - 5 - oxo - 2 - aza - 3 - hexenyl)ferrocene in a 56% yield. In chloro-bridge splitting reactions of dinuclear cyclopalladated complexes of benzo[h] quinoline and NN-dimethylbenzylamine, the condensed compound served as a binucleating ligand of an α,β-unsaturated β-keto aminate subunit. These new compounds formed were characterized by means of ¹H and ¹³C NMR and IR spectroscopy. Their electrochemical properties were discussed also.     

N,N-Dialkylierte N′-Ferrocenoylthioharnstoffe und Ferrocen-1,1′-dicarbonsäure-di-N,N-dialkyl-thioureide als Liganden für Übergangsmetalle: Darstellung,pH-potentiometrische,röntgenkristallstrukturanalytische und EPR-Einkristalluntersuchungen

N,N-Dialkyl-N′-ferrocenoylthioureas and Ferrocene-1,1′ -dicarbonic-acid-di-N,N-dialkylthioureides as Ligands for Transition Metals: Synthesis, Acid-Dissociation Constants, X-Ray Structure Determination, and EPR-Single Crystal Investigation Reaction of ferrocenoylisothiocyanate or ferrocene-1,1′ -dicarbonic acid -diisothiocyanate with secondary amines gives N,N-dialkyl-N′ -ferrocenoylthioureas or the respective ferrocene-1,1′-dicarbonic acid-di-N,N-dialkyl-thioureides. The former yield neutral complexes with transition metal ions (Ni²⁺, Cu²⁺, Co³⁺, Pt²⁺, Fe³⁺). The acid dissociation constants of the ligands were determined. The EPR spectra of a bis-(N,N-diⁿbutyl-N′-ferrocenoylthioureato)copper(II) single crystal are discussed. The X-ray structure determination of ferrocene-1,1′-dicarbonic acid-di-N,N-diethyl-thioureide and its different behaviour against Ni²⁺ and Cu²⁺ is presented.     

Organometallic compounds : XII. stereochemical interconversion reactions between 1,1′−bis(α-hydroxyalkyl)ferrocenes and 7-oxa[3]ferrocenophanes

Meso and racemic isomers of 1,1′-bis(α-hydroxyalkyl)ferrocene derivatives, and trans and cis isomers of 7-oxa[3]ferrocenophanes have been isolated. The configurations of these isomers have been determined both by spectroscopy and from their reaction behavior. It has been found that the ring-closure and ring-opening interconversion reactions between 1,1′-bis(α-hydroxyalkyl)ferrocenes and 7-oxa[3]ferrocenophanes are stereospecific. PMR spectra of the diols and ethers have been examined at 100 MHz in CF₃COOH, and the existence of α-[1′-(α-hydroxyalkyl)ferrocenyl]carbonium ions has been demonstrated in this acid. A mechanism for the various interconversion reactions is proposed on the basis of their stereospecific reactivity and from the PMR spectra of the carbonium ions.     

Organometallic polymers. XXIX. Synthesis and characterization of ferrocene-containing siloxane polymers from bis(dimethylamino)silane–disilanol condensation

A new monomer, 1,1′-bis(dimethylaminodimethylsilyl)ferrocene, was synthesized by two routes and polymerized with three aryl disilanols: dihydroxydiphenylsilane, 1,4-bis(hydroxydimethylsilyl)benzene, and 4,4′-bis(hydroxydimethylsilyl)biphenyl, yielding three different polysiloxanes. Melt polymerizations carried out at 1 torr pressure and 100°C resulted in the highest molecular weight polymers. Intramolecular cyclization competed with intermolecular chain extension in polymerization of the bis(aminosilane) with dihydroxydiphenylsilane, resulting in isolation of a bridged derivative, 1,3,5-trisila-2,4-dioxa-1,1,5,5-tetramethyl-3,3-diphenyl[5]ferrocenophane. Cyclization did not compete significantly during the formation of polymers from this bisaminosilane and the two remaining diols, as evidenced by higher yields and greater molecular weights. These polymers could be cast as tough flexible films, and fibers could be drawn from their melts. TGA and DSC data showed the polymer formed from 1,1′-bis(dimethylaminodimethylsilyl)ferrocene and 1,4-bis(hydroxydimethylsilyl)benzene to be at least as thermally stable as an arylene siloxane polymer which differed from the ferrocenylsiloxane structure only in the replacement of the ferrocene moiety with a p-substituted phenylene linkage. The ferrocene-containing polymers were generally hydrolytically stable under conditions of refluxing THF–H₂O(10 : 1) for 1 hr. The polymer-forming reaction was found to follow second-order kinetics, and the specific rate constants for formation of two of the polymers were measured.     

Damage and Repair in Informational Poly(N-substituted urethane)s

The degradation and repair of uniform sequence-defined poly(N-substituted urethane)s was studied. Polymers containing an ω-OH end-group and only ethyl carbamate main-chain repeat units rapidly degrade in NaOH solution through an ω→α depolymerization mechanism with no apparent sign of random chain cleavage. The degradation mechanism is not notably affected by the nature of the side-chain N-substituents and took place for all studied sequences. On the other hand, depolymerization is significantly influenced by the molecular structure of the main-chain repeat units. For instance, hexyl carbamate main-chain motifs block unzipping and can therefore be used to control the degradation of specific sequence sections. Interestingly, the partially degraded polymers can also be repaired; for example by using a combination of N,N′-disuccinimidyl carbonate with a secondary amine building-block. Overall, these findings open up interesting new avenues for chain-healing and sequence editing.     

Synthesis,characterization, and fire retardancy of ferrocene containing polyphosphate esters

Polyphosphate esters containing ferrocene structures were synthesized from 1,1′-bis (p-hydroxyphenylamido) ferrocene and 1,1′-bis (p-hydroxyphenoxycarbonyl) ferrocene with aryl phosphorodichloridates by interfacial polycondensation using a phase transfer catalyst. The polymers were characterized by infrared, ¹H-, ¹³C-, and ³¹-NMR spectroscopy. The molecular weights were determined by end group analysis using ³¹P-NMR spectral data. The thermal stability and fire retardancy were respectively determined by thermogravimetry and limiting oxygen index (LOI) measurements. The polyamide-phosphate esters showed better thermal stability and higher LOI values than the polyester-phosphate esters.     

Syntheses and reactions of ferrocene-containing polymers. III. Cyclopolymerization of 1,1′-divinylferrocene

1,1′-Divinylferrocene was polymerized with BF₃OEt₂ and AIBN initiators. Polymers were separated into benzene-soluble and benzene-insoluble fractions, the latter probably being crosslinked. The polymers obtained with BF₃OEt₂ were shown by infrared and NMR spectroscopy to contain both cyclized (70–80%) and uncyclized units, whereas the radical polymer consisted of more than 96% cyclized units. The benzene-soluble fraction of the cationically obtained polymer softened at temperatures below 150°C, but the insoluble fraction decomposed at 240°C. The radical polymers were stable up to 250–280°C (dec).     

Crosslinking polyferrocenylenes by polymethylol compounds

Polyferrocenylenes with mean molecular weights of 500–4 000 have been converted into thermosetting polymers by reaction with xylylene glycol and telomers thereof. The prepolymers have been used successfully as molding materials and laminating resins. Glass fiber-reinforced laminates have been made with flexural strengths of 63 × 10³ psi and flexural moduli of 4–5 × 10⁶ psi. Ferrocene–xylylene glycol copolymers were also prepared, and 1,1′-bis(hydroxymethyl)ferrocene was used as a polyferrocenylene crosslinking agent. Laminates were also made from the 1,1′-bis(hydroxymethyl)ferrocene-based polymers.     

Novel ferrocene modified poly(amide ether amide)s and investigation of physical and thermal properties

A new diamine containing ferrocene group with preformed ether and amide units was prepared via reaction of 1,1′-ferrocenedicarbonyl chloride with two moles of 2,6-bis(5-amino-1-naphthoxy)pyridine. Polycondensation reactions of the prepared diamine with different aromatic and aliphatic diacid chlorides in the presence of trimethylchlorosilane (TMSCl) resulted in preparation of novel ferrocene modified poly(amide ether amide)s. The monomer and polyamides were characterized and the effect of trimethylchlorosilane (TMSCl) as activating agent on the polymerization reaction was studied. The physical and thermal properties of the polyamides including inherent viscosity, solubility, thermal stability and behavior, flame-retardancy and crystallinity of the polymers were studied. The polymers showed good thermal stability and flame-retardancy, and also improved solubility in polar aprotic solvents.     

A New Ferrocene‐Containing Polyamide Prepared from an Improved Synthesis of 1,1′‐Ferrocene Dicarbonyl Chloride and Ferrocene‐Based Diamine

1,1′‐Ferrocene dicarbonyl chloride was prepared by an improved and efficient conversion method from 1,1′‐ferrocene dicarboxylic acid and reacted by esterification with p‐nitrophenol, followed by reduction, to form a ferrocene‐based diamine, 1,1′‐ferrocene bis (p‐amino phenylate). The diamine was characterized by elemental analysis, ¹H NMR, and Fourier transform infrared (FTIR) spectroscopy and subsequently condensed with 1,1′‐ferrocene dicarbonyl chloride to form a novel main chain ferrocene‐containing polyamide, poly{imino ferrocene bis (p‐amino phenylate) ferrocenyl}. Its polymeric nature was confirmed by its physical properties, elemental analysis, FTIR spectroscopy, differential scanning calorimetry, and thermogravimetric studies.     

Aromatic polyether, -ketone, -sulfones as laminating resins. XII. Derivatives of 2,2′-diphenylethynyldiphenyl which cure by an intramolecular cyclization

Polymers made from 2,2′-diiododiphenyl-4,4′-dicarbonyl dichloride, diphenyl ether, and isophthaloyl chloride have been made and converted to the 2,2′-diphenylethynyl derivatives. Introduction of units of isophthaloyl chloride reduced the melting point of these polymers to about 200°C, and they could then be cured by heating. A good glass laminate was prepared and cured from one of the polymers.     

Alumina Catalysed Knoevenagel Condensations of Ferrocene-1,1′-Dicarboxaldehyde

Several symmetrically and unsymmetrically bifunctionalised solvatochromic ferrocene derivatives have been synthesised via alumina catalysed Knoevenagel reactions of ferrrocene-1,1′-dicarboxaldehyde.