No description available.

Kinetics of the iodination of a number of substituted benzenes and thiophenes by iodine and nitric acid in acetic acid solution have been studied. The reaction is catalysed by dinitrogen tetroxide and hydrogen ions and evidence is presented to show that the iodinating species is protonated nitryl iodide, which reacts in a slow step with the substrate. Acidity function data for nitric acid in 10% aqueous acetic acid are presented and the charge-transfer complex formation between iodine and m-xylene in acetic acid has been studied. The conversion of 4-iodoanisole into 2-iodo-4-nitroanisole by nitric acid, has been shown to occur by rapid nitrodeiodination and iodination to give 2,4-di-iodoanisole and 4-nitroanisole; gradual nitrodeiodination of the former compound at the 4-position with the production of free iodine, and then very slow iodination of the latter compound at the 2-position, Nitrous acid and hydrogen ions act as catalysts and the preliminary step is thought to be nitrosodeiodination. The ortho:para ratio for the methoxy-group in nitrosodeiodination is very low. The ipso factors of Perrin and Skinner are discussed in the light of this and other work. Transient intermediates observed in the nitrodeiodination reaction have been investigated using stopped-flow techniques and a water soluble substrate. These species are tentatively suggested to be o-complexes. The anomalously high rate of nitration of iodobenzene has been investigated and it has been found that this phenomenon is not due to a nitrodeiodination reaction, as had been suggested previously. Work on the nitration of ioclomesitylone has been investigated and it has been found that nitrosodeiodination is significant in this reaction, which is contrary to the findings of the previous workers. A computer programme has been written to assist calculations on data obtained from radio-isotopic dilution experiments where two products are formed simultaneously from a single substrate. Another computer programme has been written to assist in the calculation of rate constants for reactions of the first and half order.

[No abstract available] / Science, Faculty of / Chemistry, Department of / Graduate

No description available.

<p> The behaviour of iodic acid, of mixtures of iodic acid and iodine, and of various other iodine compounds as solutes in sulphuric and fluorosulphuric acids has been studied, using mainly cryoscopic and conductimetric techniques. Evidence has been obtained for the existence of polymeric species containing iodine (V), of the oxy-cation IO+, of the iodine cation, I+, in small concentrations in equilibrium with its disproportionation products, and of the cations I3+, I5+ and I2Cl+. The reaction of iodosyl sulphate with disulphuric acid has been studied. Conductimetric studies have been made of solutions of water, potassium nitrate and potassium perchlorate in fluorosulphuric acid. The results of some spectrophotometric and nuclear magnetic resonance experiments are also reported.</p> / Thesis / Doctor of Philosophy (PhD)

A pulsed-beam fourier transform microwave spectrometer was used to measure the rotational spectra of iodine heptafluoride, iodine pentafluoride, and the weakly bound complex, HCl...NNO. For IF7, only five rotational transitions were observed, and no resolvable hyperfine structure was detected. Based on this data, the A, B, and C rotational constants were determined to be 1746(3) MHz, 1732.0(8) MHz, and 1553.0(2) MHz, respectively. The existence of a pure rotational spectrum confirms that this molecule undergoes polar distortions. Twenty-two hyperfine components of the IF5 spectrum were recorded. The B rotational constant for this molecule was determined to be 2727.421(3) MHz, and the quadrupole coupling constant was found to be 1069.35(13) MHz. Though the work is still in progress on HCl...NNO, nine transitions have been recorded. In addition, five transitions have been recorded for an apparent trimer species composed of HCl, NNO, and an as yet unidentified third species.

Thesis (Ph. D.)--McMaster University (Canada), 1990. / Source: Dissertation Abstracts International, Volume: 62-13, Section: A, page: 0000.

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Dynamic isomerization of diethylstilbestrol (DES) makes it difficult to ascertain the active estrogen between its E and Z isomers. An indirect approach has been used in this project to identify the active estrogen. Methoxylated E- and Z-DES (13 and 14) and 9,10-diethylphenanthrene-3,6-diol (15), a closed ring analog of Z-DES, were synthesized and tested for their estrogenicity. The estrogenicity of 13 is higher than that of 14 and 15, which indicates that E-DES is more estrogenic than Z-DES. Dimethylstilbestrol (16), another analog of DES, was also synthesized and tested. Its estrogenicity is lower than that of DES. Non-estrogenic analogs of bisphenol-A were designed based on the observation that (15) is far less estrogenic than DES. Closed ring analogs of bisphenol-A, 3,6-dihydroxy-9,9-dimethylfluorene (34), 2,6-dihydroxy-9,9-dimethylfluorene (35), and 2,7-dhydroxy-9,9-dimethylfluorene (36) were synthesized and they were found to have little or no estrogenicity. An open ring analog of bisphenol-A, 2-(3-hydroxyphenyl)-2-(4-hydroxyphenyl)propane (33) was also synthesized and its estrogenicity is much lower than that of bisphenol-A. Polycarbonate of 36 was also synthesized and its glass transition temperature was measured using differential scanning calorimetry (DSC). Glass transition temperature of polycarbonate of 36 was found to be 199.92 oC, which is about 50o higher than that of bisphenol-A polycarbonate (150 oC). This indicates that polycarbonate of 36 forms a harder plastic than bisphenol-A polycarbonate. Compounds 2,8-dihydroxy-5,5-dioxo-dibenzothiophene (69) and 2,8-dihydroxydibenzothiophene (70) were also synthesized and were tested as non-estrogenic alternatives for bisphenol-S and bisphenol sulfide, respectively. Compound 69 and 70 were found to be less estrogenic than bisphenol-S and bisphenol sulfide respectively agreeing with our hypothesis. Iodane/quaternary ammonium halide in nitromethane was utilized to explore aromatic bromination, N-nitrosation-dealkylation, and benzoate ester formation from benzylamines. Koser's reagent was found to be a suitable iodane for aromatic bromination reaction, whereas for N-nitrosation-dealkylation, IBX gave the best yields. Further, for N-nitrosation-dealkylation reaction, the halides of quaternary ammonium salts play a crucial role. The effectiveness of halides follows F- > Cl- > Br- ~ I-. The lack of N-nitrosation-dealkylation and ester formation in the absence of nitromethane indicates that nitromethane is playing an essential role as well. Yields of benzoate ester from benzyl amines were low (~22%). Optimization experiments will be performed in the future. Plausible reaction mechanisms for these reactions were proposed. Aromatic bromination was thought to be induced either by iodane/halide adduct or by BrOH that was formed from iodane/halide adduct. Ester formation and N-nitrosation-dealkylation were believed to be induced either by alkyl nitrite or by nitrous acid, generated from the reaction of iodane/halide adduct with nitromethane.