Mechanism of and Products from the Oxidation of Phenols by Hypervalent Iodine Compounds

Iodobenzene dichloride or diacetate initiates the polymerization of 2,6-dimethylphenolate anion to poly [oxy(2,5-dimethyl)-l, 4-phenylene]. Electron spin resonance spectroscopy was used to identify the polymeric radical that is the growing chain. Infrared and NMR spectroscopy identified the final polymer. The mechanism proposed is probably applicable also to other phenol oxidation processes yielding substituted poly(oxyphenylenes).

The anomalous chemistry of those compounds of xenon, iodine, and tellurium in which the number of bonding electrons exceeds that given by Lewis valence theory has been considered in general terms by Musher [1] who coined the term “hypervalent” to describe these substances. The oxidizing properties of these compounds is in a general way similar to that of peroxides and other strong oxidizing agents, but has not been characterized in any exact fashion. We have observed [2] that the iodobenzene esters have polymeric analogs of the formula, [-I(R)OOCXCOO-], and these compounds are stable oxidizing agents (R = aryl; X = alkylene or arylene). We have been interested in determining if -I(R)OXO- compounds can be formed.

The first question to consider is the stability of bonds in -OI(R)O- compounds. Only acyl derivatives are known [3]. However, the possibility     

Polymer Intermediates and Polymers Derived from 5-t-Butyl-m-Xylene

Abstract

A series of condensation polymer intermediates, which included several new compositions, was prepared from 5-t-butyl-m-xylene (I) so that the effect of the bulky t-butyl group on polymer properties could be determined. Compound (I) was oxidized with nitric acid to obtain 5-t-butyl-isophthalic acid (II), which was converted successively to the diacid chloride, the diamide, the dinitrile, and finally to 5-t-butyl-m-xylene-α,α′-diamine (VI); the overall yield was 80%. The dimethyl ester of (II) was prepared and converted to 5-t-butyl-m-xylene-α,α′-diol (VIII), a new composition, in 79.5% overall yield; the diphenyl ester was also prepared. The sodium salt of (II) was catalytically reduced to obtain 5-t-butyl-1,3-cyclohexanedicarboxylic acid (IIa) in 95% yield. (IIa) was converted successively to the diacid chloride, the diamide, the dinitrile, and finally to 5-t-butyl-1,3-cyclohexanebis(methylamine) (VIa), a new composition; the overall yield was 37%. (IIa) was also converted to the dimethyl ester and finally to 5-t-butyl-1,3-cyclohexanedimethanol (VIIIa), a new composition; the overall yield was 64%. Condensation polymers were prepared from the intermediates (II), (IIa), (VI), (VIa), (VIII), and (VIIIa). These polymers had higher glass transition temperatures (T_g) than corresponding polymers containing no t-butyl groups. This general effect of the t-butyl group to increase the T_g value of the polymer was noted in all polymers prepared, regardless of whether the intermediate carrying the t-butyl group was a diacid, a diol, or a diamine, or whether the polymer was a polyamide, a polyester, or a polyurethane.     

Synthesis and Characterization of Polymers Derived from the Copolymerization of 1,1′-Dihydroxyethyl-2,2′-Biimidazole and the Diglycidyl Ether of Bisphenol A

Abstract

1,1′-Dihydroxyethyl-2,2′-biimidazole has been used as a copolymerizing monomer with the diglycidyl ether of bisphenol A in the preparation of biimidazole-containing epoxy polymers. Polymerization reactions were studied in bulk, with and without catalyst, and in N,N-dimethylforma-mide and anisole solvents, with and without catalyst. FT-IR and NMR spectra, molecular weight, thermal and solubility characteristics were obtained. Polymers isolated as amorphous light brown solids were found to be only sparingly soluble in THF or in highly polar nitrogen-containing solvents (DMF, NMP, pyridine). These materials exhibited molecular weights up to 37 000 for SnC1₄-catalyzed polymerization carried out in DMF. A glass-transition temperature of 391°C was observed for polymers obtained under uncatalyzed solventless conditions. The glass transition temperature was 373°C for product obtained under SnC1₄-catalyzed, solventless conditions. Thermogravimetric analysis in air of polymers obtained under varying solvent and catalyst conditions showed less than 25% weight loss below 330°C and greater than 75% weight loss above 400°C.     

Induction of Room Temperature Ferromagnetism in N-Doped Yttrium Oxide: Ab Initio Calculation

JETP Letters - To explore the diluted magnetic semiconductors for spintronic applications, we have studied N doped Y2O3 employing density functional theory (DFT). It has been observed that the...     

Avoiding Self-Reversed D Lines in Laser-Induced Breakdown Spectroscopy of Trace-Level Sodium in Soil

Journal of Applied Spectroscopy - Self-reversed sodium D lines in laser-induced plasmas generated from soil samples with a sodium trace concentration of 42.3 ppm was examined using laser-induced...     

Design,synthesis, and molecular docking studies of new [1,2,4]triazolo[4,3-a]quinoxaline derivatives as potential A2B receptor antagonists

Molecular Diversity - Many shreds of evidence have recently correlated A2B receptor antagonism with anticancer activity. Hence, the search for an efficient A2B antagonist may help in the...     

Comparative biological study between quinazolinyl–triazinyl semicarbazide and thiosemicarbazide hybrid derivatives

Molecular Diversity - Practical synthesis and biological activities of quinazolinyl–triazinyl semicarbazides (10a–j) and quinazolinyl–triazinyl thiosemicarbazides (11a–j)...     

Quantification of Cannabinoids in Cultivars of Cannabis sp. by Gas Chromatography–Mass Spectrometry

Chromatographia - In the chemical characterization of medically valued Cannabis, the present work has used a gas chromatography (GC) method coupled with mass spectrometry (MS) for identification...     

Graph Theory Applied to Plasma Chemical Reaction Engineering

Plasma Chemistry and Plasma Processing - This work explores the following applications of graph theory to plasma chemical reaction engineering: assembly of a weighted directional graph with the key...     

New Mn(II), Co(II), Ni(II) and Cu(II) homoleptic complexes with 6-chloro-5-7-dimethyl-4oxo-4H-chromene-3-carbaldehydes and its heteroleptic complexes with quinoline-8 ol: synthesis,characterization and antimicrobial activity

Research on Chemical Intermediates - In the present study, the synthesis of ligand 6-chloro-5-7-dimethyl-4oxo-4H-chromene-3-carbaldehydes by three steps from the substituted phenol. The formed...