Roger E. Rondeau

Nuclear magnetic resonance analysis of 1- and 2-methylbenzotriazole

Abstract The NMR parameters of 1-methyl- and 2-methylbenzotriazole have been obtained from their high resolution spectra. LAOCOON III was used to iteratively refine the reported chemical shifts and coupling constants. Huckel molecular orbital calculations were performed in the hope of facilitating the choice of input parameters for the computer analysis of the complex ABCD spectrum of the 1-methylbenzotriazole. No useful correlation was found between the π-electron densities and chemical shifts of the aromatic protons. A deuteration experiment was performed to unambiguously assign the chemical shifts of the four protons. The NMR and MO data are tabulated and compared.

Electron Spin Resonance Spectra of Gamma Radiolysis Products of Solid Acetonitrile

The electron spin resonance spectra of radicals formed in solid acetonitrile at 77 K under the action of Co 60γ-radiation were observed to guide in the interpretation of the γ-radiolysis of this material. The hyperfine pattern is centered at a g -value of 2.0025 ± 0.0004, and exhibits eleven lines symmetrically situated about this value. Analysis of this hyperfine structure indicates the probable presence of at least two different species. The radical present in the largest concentration is formed from acetonitrile by removal of a hydrogen atom and is responsible for about four-fifths of the observed signal. The remaining intensity is thought to be due to radicals resulting from the addition of a single hydrogen atom to the parent substance. The decay of these radicals has been measured, at various temperatures and the resulting material analyzed by mass spectrometry and gas chromatography. The 100-eV yields for these radicals were estimated using a diphenyl picryl hydrazyl solution standard.

Liquid Crystals: Transition Point Studies of 4(4′)-Alkoxyformyloxy-4′(4)-alkylazoxybenzenes

Abstract A series of 4(4′)-alkoxyformyloxy-4′(4)-alkylazoxybenzenes has been prepared. The transition temperatures have been determined and the applicability of the spectral shift reagent Eu(fod)3 to determine the mole percent of six isomeric mixtures was demonstrated.