Aromatic polyethers,polysulfones, and polyketones as laminating resins

m-Hexaphenyl ether, diphenyl ether, and 1,3-bis(p-phenoxybenzenesulfonyl)benzene were polymerized with isophthaloyl and terephthaloyl chloride in a Friedel-Crafts type polymerization. The polymers were endcapped with p-cyanobenzyl chloride or had units of 5-cyanoisophthaloyl chloride in the backbone. They were crosslinked effectively, possibly by the trimerization of the nitrile groups to triazines. Model reactions were carried out for each type of polymer.     

Aromatic polyethers,polysulfones, and polyketones as laminating resins. IV. Polymers with p-cyclophane units for crosslinking

1,3-Bis(p-phenoxybenzenesulfonyl)benzene, 4,4′-bis(p-phenoxybenzenesulfonyl)diphenyl ether, and 4,4′-diphenoxydiphenyl sulfone were polymerized with isophthaloyl or terephthaloyl chlorides in Friedel-Crafts type polymerizations. These polymers had [2,2]p-cyclophane units in the backbone, introduced by employing 3,9-bis(p-phenoxybenzoyl) [2.2]p-cyclophane as part of the polyaryl ether component. Thermolysis of the dimethylene bridge of the [2.2]p-cyclophane monomer produced diradicals which combined across polymer chains to provide crosslinks. p-Cyclophane polymers with 1,3-bis-(p-phenoxybenzenesulfonyl)benzene showed potential as high performance, thermally stable laminating resins.     

Aromatic polyethers,polysulfones, and polyketones as laminating resins. III

4,4′-Diphenoxydiphenylsulfone was polymerized with isophthaloyl chloride and terephthaloyl chloride in Friedel-Crafts polymerizations. These polymers had 5-cyanoisophthaloyl units in the backbone obtained either by using 1,3-bis(p-phenoxybenzoyl)-5-cyanobenzene or 5-cyanoisophthaloyl chloride as part of the acid chloride monomer. A terpolymer having 22 wt-% 5-cyanoisophthaloyl unit was also prepared from the Friedel-Crafts polymerization of 1,3-bis(p-phenoxybenzenesulfonyl)benzene and 5-cyanoisophthaloyl chloride. These terpolymers were crosslinked through heating to give insoluble products which proved to be thermally less stable than the uncrosslinked polymers.     

Aromatic polyethers,polysulfones, and polyketones as laminating resins. II

1,3-Bis(p-phenoxybenzenesulfonyl)benzene and 4,4′-bis(p-phenoxybenzenesulfonyl)-diphenyl ether were polymerized with isophthaloyl and terephthaloyl chloride in Friedel-Crafts type polymerizations. These polymers had 5-cyanoisophthaloyl units in the backbone, obtained by using 5-cyanoisophthaloyl chloride as part of the acid chloride monomer. A number of catalysts were screened to effect the trimerization of the pendant nitrile groups in the polymer to the triazines. Model reactions were carried out for each polymer. Physical and thermal properties of the laminates obtained from these polymers are discussed.     

Aromatic polyethers,polysulfones, and polyketones as laminating resins. V. Polymers containing acetylenic side groups

1,3-Bis(p-phenoxybenzenesulfonyl)benzene and 4,4′-diphenoxydiphenyl sulfone were polymerized with isophthaloyl and terephthaloyl chloride in Friedel-Crafts type polymerizations. These polymers had 2,4-diphenoxyacetophenone in the backbone. The acetyl group was then converted into an acetylene group. They were crosslinked effectively by cyclization of the acetylene groups with a catalyst or by cyclo-addition with bisnitrile oxides.     

Aromatic polyethers,polysulfones, and polyketones as laminating resins. VI. Polymers from 2,5-dicyanoterephthalic acid

Aromatic poly(keto ether sulfones) containing various amounts of pendant cyano groups were synthesized from 1,4-bis(p-phenoxybenzoyl)-2,5-dicyanobenzene, 1,3-bis(p-phenoxybenzenesulfonyl)benzene, and isophthaloyl chloride by a Friedel-Crafts type polymerization. These polymers softened at 160–190°C and had inherent viscosities of 0.44–0.61 in hexamethylphosphoric triamide. Crosslinkings were made by heating the polymers alone or in the presence of zinc chloride at 360–370°C to give black resinous materials that were insoluble in hexamethylphosphoric triamide in which the original polymers dissolved quite readily.     

Aromatic polyethers,polysulfones, and polyketones as laminating resins. VIII. Aryl disulfide units as crosslinking agents

Oxidation of 1,4-phenylenedimercaptan has given a cyclic trimeric disulfide. Oxidation of 1,3-phenylenedimercaptan has yielded a similar product. These monomers have been incorporated in the chains of aromatic polyether, sulfone, ketone polymers and serve as crosslinking sites on heating these polymers.     

Aromatic polyether, -ketone, -sulfones as laminating resins. XI. Polymers derived from 2,2′-diiododiphenyl-4,4′-dicarboxylic acid

Aromatic polyether-keto-sulfone polymers and related model compounds have been synthesized from 2,2′-diiododiphenyl-4,4′-dicarboxylic acid and a variety of intermediates. It was hoped to convert them to 2,2′-diphenylethynyl derivatives which could be cured by rearrangement to give dibenzanthracene units in the chain. Low solubilities and high melting points of the products prevented their use in the desired manner.     

Aromatic polyethers with 1,3,5-triazine units as hole blocking/electron transport materials in leds

Various difluoro functionalized aromatic 1,3,5-triazine monomers were prepared. A series of poly-(1,3,5-triazine-ether)s was synthesized by polycondensation with 4,4′-(hexafluoroisopropylidene)diphenol. The polymers have excellent thermal stability and are amorphous with glass transition temperatures in the range of 190–250°C. In order to examine the potential to apply these polymers in organic electroluminescent devices, the redox properties were studied by cyclic voltammetry. It was found that the monomers have high electron affinity and reach LUMO values in the range of −2.7 to −3.1 eV. This opens the possibility to utilize 1,3,5-triazine containing materials as electron injecting/hole blocking layer in LEDs. First LED results are in accordance to these high electron affinities.     

Ethynyl[2.2]paracyclophanes and 4-isocyano[2.2]paracyclophane as ligands in organometallic chemistry

An alternative synthesis of (±)-4-ethynyl[2.2]paracyclophane (PCPCCH) (5) and 4,16-diethynyl[2.2]paracyclophane (6) via the Corey-Fuchs reaction has been developed. The olefinic intermediate 4-dibromovinyl[2.2]paracyclophane (3) has been isolated and structurally characterized. The racemic terminal alkyne 5 was employed as starting material for assembling of a luminescent extended π-conjugated system containing a thiophene unit and for a catalytic bis-silylation reaction yielding the olefinic dithioether Z-PhSCH₂Me₂SiC(H)C(PCP)SiMe₂CH₂SPh (9). The dimetallatetrahedran [Co₂(CO)₆(μ-η²-PCP-CCH)] (10) has been prepared and its crystal structure determined by an X-ray diffraction analysis. Alkyne 5 has also been used for the preparation of the Pt(0) complex [Pt(PPh₃)₂(PCPCCH)] (11) and the heterodinuclear dimetallacyclopentenone [(OC)₂Fe{μC(O)C(PCP)C(H)}(μ-dppm)Pt(PPh₃)] (12). The synthesis and reactivity of 4-isocyano[2.2]paracyclophane (15) towards heterobimetallic iron-platinum and palladium-platinum complexes is also presented. Opening of the dative iron → platinum bond of [(OC)₄Fe(μ-dppm)PtCl₂] (16) occurred upon addition of 15 to a CH₂Cl₂ solution of 16 leading to [(OC)₄Fe{μ-dppm}PtCl₂(CNPCP)] (17). Treatment of [ClPd(μ-dppm)₂PtCl] (18) with isocyanide 15 in a 1:1 ratio affords the A-frame compound [ClPd(μ-dppm)₂(μ-CNPCP)PtCl] (19), resulting from formal insertion of 15 into the Pd-Pt bond. Addition of 2 equiv. of 15-18 leads to the ionic A-frame compound [ClPd(μ-dppm)₂(μ-CNPCP)Pt(CNPCP)]Cl (20).     

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.     

Polymers with quinoxaline units. IV. Polymers with quinoxaline and oxazine units

Six ladder or partly ladder polymers have been prepared by the condensation of diaminodiphenols with tetrachloro- or terahydroxyquinoxaline derivatives with the use of poly (phosphoric acid), pyridine, and naphthalene as reaction media. The polymers thus obtained are highly colored powdery materials which are slightly soluble in concentrated sulfuric acid and methanesulfonic acid. These polymers show good thermal stability.     

Polymers with quinoxaline units. V. Polymers with quinoxaline and dioxin units

Ladder or partly ladder polymers have been prepared by condensation of tetraphenols with tetrachloroquinoxaline compounds in melt, or in pyridine, naphthalene, and nitrobenzene reaction media. The polymers are dark-colored, powdery materials with good thermal stability. Some of the samples are slightly soluble in sulfuric acid, while others are completely insoluble. No other solvents were found.     

Polymers with quinoxaline units. III. Polymers with quinoxaline and thiazine recurring units

Six ladder or partly ladder polymers have been prepared by the condensation reactions of combinations of two diaminodithiophenols, 4,6-diamino-1,3-dithiophenol and 3,3′-dimercaptobenzidine, with three tetrachloroquinoxaline derivatives, 2,3,7,8-tetrachloro-1,4,6,9-tetraazaanthracene, 2,2′,3,3′-tetrachloro-6,6′-bisquinoxaline, and 2,2′,3,3′-tetrachloro-6,6′-diquinoxalyl ether, with the use of dimethylacetamide, hexamethylphos phoramide, and polyphosphoric acid as reaction media. The polymers thus obtained are highly colored, powedery materials which are slightly soluble in methanesulfonic acid and concentrated sulfuric acid. These polymers (η_inh > 1) show good thermal stability.     

Structure and NMR spectra of some [2.2]paracyclophanes. The dilemma of [2.2]paracyclophane symmetry

Density functional theory (DFT) quantum chemical calculations of the structure and NMR parameters for highly strained hydrocarbon [2.2]paracyclophane 1 and its three derivatives are presented. The calculated NMR parameters are compared with the experimental ones. By least-squares fitting of the (1)H spectra, almost all J(HH) coupling constants could be obtained with high accuracy. Theoretical vicinal J(HH) couplings in the aliphatic bridges, calculated using different basis sets (6-311G(d,p), and Huz-IV) reproduce the experimental values with essentially the same root-mean-square (rms) error of about 1.3 Hz, regardless of the basis set used. These discrepancies could be in part due to a considerable impact of rovibrational effects on the observed J(HH) couplings, since the latter show a measurable dependence on temperature. Because of the lasting literature controversies concerning the symmetry of parent compound 1, D(2h) versus D(2), a critical analysis of the relevant literature data is carried out. The symmetry issue is prone to confusion because, according to some literature claims, the two hypothetical enantiomeric D(2) structures of 1 could be separated by a very low energy barrier that would explain the occurrence of rovibrational effects on the observed vicinal J(HH) couplings. However, the D(2h) symmetry of 1 with a flat energy minimum could also account for these effects.     

Poly(arylene sulfides) with pendant cyano groups as high-temperature laminating resins. II

Poly(phenylene sulfides) containing various amounts of pendant cyano groups were synthesized from m-benzenedithiol and the corresponding amounts of p-dibromobenzene and 3,5-dichlorobenzonitrile. The polymers prepared by the use of 10, 15, 20, and 25% of the nitrile-containing dichloro compound were slightly off-white with melting ranges below 100°C and had inherent viscosities of about 0.15 dl/g in hexamethylphosphoric triamide at 30°C. The polymers prepared from m-benzenedithiol and the stoichiometric amounts of 2,4-dichlorobenzonitrile or 3,5-dichlorobenzonitrile looked similar to those described above, yet they possessed much higher melting ranges. The poly(phenylene sulfide) prepared by the use of 2,4-dichlorobenzonitrile had an inherent viscosity of 0.06 dl/g while the polymer prepared from the 3,5-dichloro isomer had an inherent viscosity of 0.38 dl/g. All the polymers listed above were crosslinked by heating alone or in the presence of anthracene-9,10-bisnitrile oxide to give black resinous polymers that were insoluble in hexamethylphosphoric triamide in which the original polymers dissolved quite readily.     

Arylidene Polymers. XVII. Cyclization of Aromatic Poly[dibenzylidenecyclopentanone-Hydrazide] as a Route to Polyheterocyclic 1,3,4-Oxadiazole and 1,2,4-Triazole

A new interesting class of thermal stable arylidene polymers containing 1,3,4-oxadiazole and 1,2,4-triazole moieties in the main chain have been synthesized from aromatic polyhydrazide I. Cyclization of I at 250°C in the absence of solvent was found to be the best pathway for the inclusion of the 1,3,4-oxadiazole moiety in the main chain. Heating of I with aniline, cyclohexyl amine, or 3-amino pyridine at 180°C for 30 h gave the corresponding 1,2,4-triazole polymers III. The introducing effect of different aromatic, cycloalkyl, and heterocyclic amines in III_a-c and IV_a-c on thermal stability behavior was studied by TGA analysis. Moreover, all the polymers were characterized by elemental and spectral analyses, solubility, and viscometry measurements. X-ray diffractograms of the synthesized polymers showed they had less crystallinity than the polyhydrazide precursors.     

Mass spectral study of bicyclic peroxides. 1. Dioxabicyclo[n.2.2]alkanes and the corresponding dioxabicyclo[n.2.2]alkenes

A series of dioxabicyclo[n.2.2]alkanes (n = 1,2,3 and 4) and dioxabicyclo[n.2.2]alkenes were studied under electron impact ionization. The fragmentation pathways were elucidated with the aid of accurate mass measurements, metastable scan techniojei and deuterium labelling. The preferential fragmentation of molecular ions in dioxabicyclo[n.2.2]alkanes corresponds to the loss of hydroperoxyl radical ·OOH. Hydrogens that are participating in this elimination come primarily from the syn position on the two-membered carbon bridge. The dioxabicyclo[n.2.2]alkenes undergo the retro-Diels–Alder process, which produces dioxygen and 1,3-cycloalkadiene. In both saturated and unsatutated peroxides subsequent fragmentation of the hydrocarbon ring depends upon the value of n.