Stanley L. Manatt

A compilation of the absorption cross-sections of SO2 from 106 to 403 nm

Abstract Available spectrophotometric data on absorption cross-sections of SO2 for the gas phase from 106 to 403 nm at 293 ± 10 K have been evaluated and, where necessary, converted to a digital form. Plotting and comparing various overlapping data sets has demonstrated that systematic errors in wavelength and cross-section exist in the data sets. A scheme, which uses newer data sets that were recorded over limited wavelength ranges, to correct the wavelengths and cross-sections of older data sets, is discussed. In one region photoplate data were compared with spectrophotometric data. The spectral regions where reinvestigation is warranted are discussed. A data file of the cross-sections of SO2 was assembled from 106.1 to 403.7 nm at a resolution of 0.1 nm.

An NMR Study of Indene Using a Proton‐Proton Decoupling Technique

The 60 Mc/sec high‐resolution NMR spectrum of the protons of the five‐membered ring of indene [Complex chemical formula] has been studied with the aid of the audio sideband phase detection proton—proton spin decoupling technique. The chemical shifts and the spin—spin coupling constants have been measured. The relative sign of the spin coupling constant JAX was determined to be different than that of JAK and JKX by double irradiation experiments. Certain long‐range couplings of the aromatic protons with the five‐membered ring protons were detected.

Proton NMR Spectra of Cyclopentadiene, 1,3‐Cyclohexadiene, 1,3‐Cyclooctadiene, and 1,2‐Dihydronaphthalene

The proton NMR coupling constants between vinyl protons in cyclopentadiene (I), 1,3‐cyclohexadiene (II), and 1,3‐cyclooctadiene (III) have been obtained by analyses of the spectra of the latter protons when the methylene protons were decoupled. An analysis of the full spectrum of I has also been achieved. Analysis of the spectrum of 1,2‐dihydronaphthalene (IV) was undertaken both to obtain a value of 3JHH across the olefinic double bond, and to compare certain of its coupling constants with those from our previous work on indene. The long‐range coupling constants between vinyl protons in the planar molecule I and nearly planar II are significantly different from those in the nonplanar III. The differences are discussed in terms of the conformations of these molecules, and the importance of these results for testing theories of long‐range coupling constants is pointed out.

Ferromagnetic resonance of lunar samples

Abstract Evidence is presented to support that the electron spin resonance (ESR) spectra observed for a selection of Apollo 11 lunar samples (10087-10, 11; 10046-29, 30; 10062-26, 27; 10017-35, 36) arise from the ferromagnetic centers consisting of metallic Fe. A model study to simulate the polycrystalline spectra has been carried out, from which it was possible to ascertain with some degree of certainty the size and shape of the ferromagnetic centers as well as the metallic iron content. Some variations in the metallic Fe content have been noted in these samples, for example, between rocks and fine soil.

Relative Signs of the Nuclear Spin Coupling Constants in Propylene Oxide and Indene Oxide

The 60‐Mc/sec high‐resolution NMR spectrum of propylene oxide was analyzed as an ABCD3 nuclear spin system in the conventional iterative manner utilizing in addition double resonance to decouple the D3 (methyl group) protons from the ABC protons. A fit was obtained by two sets of parameters whose main difference was that either both long‐range couplings JBD and JCD are positive with respect to the other couplings or only JCD is negative. By use of a weak perturbing rf field to irradiate a particular resonance transition it was determined that JCD has a different sign than the other couplings.The 60‐Mc/sec spectrum of the protons of the five‐membered ring of indene oxide (II) was analyzed as an ABCD system with the aid of triple‐irradiation experiments in which the long‐range couplings of the A, C, and D protons with the aromatic ring protons were destroyed by a large rf irradiation applied at the resonance position of the aromatic protons while a second weaker perturbing irradiation was applied at particu...

Electron spin resonance of manganous ions in frozen methanol solution.

An analysis of the electron spin resonance of Mn2+ in frozen methanol is presented. The broadened, asymmetric lineshape is shown to be due to inhomogeneous broadening caused by combined second - and third-order effects of randomly distributed zero-field splittings in the range of 80-150 G.

Magnetic resonance studies of lunar samples.

Electron spin resonance searches at 9.5 gigahertz on several fines samples and portions of several rocks have yielded signals whose lineshapes and temperature dependences show that the samples are principally ferromagnetic in nature. Proton magnetic resonance searches at 60 megahertz of these samples have not revealed any signals ascribable to water or any other types of hydrogen in concentrations greater than 0.0001 percent by weight contained in narrow lines (5 oersteds wide or less) and 0.01 percent by weight in wide lines (as wide as 100 oersteds).

THE RELATIVE SIGNS OF THE NMR COUPLING CONSTANTS IN STYRENE OXIDE BY DOUBLE RESONANCE

Abstract The relative signs of the nuclear magnetic resonance spin-spin coupling constants between the three protons of the oxirane ring of styrene oxide have been determined to be the same by the audio side band phase detection proton-proton decoupling technique.

Energy-level iterative NMR method for sets of magnetically nonequivalent, chemical-shift equivalent nuclei.

A technique is described which greatly facilitates the use of the Swalen and Reilly energy‐level NMR spectral analysis method for spin systems having sets of magnetically nonequivalent, chemical‐shift equivalent nuclei and systems in which it is not possible to assign sufficient transitions to link all energy levels within a particular symmetry group of energy levels. As a test of this scheme, results are described for five iterative analyses of the fluorine‐19 spectrum of hexafluoro‐1,3‐butadiene for the cases where the problem is arbitrarily broken into 27, 16, 8, and 4 groups and the actual problem which involves two groups of energy levels. For the 27‐group case it is demonstrated that an excellent set of NMR parameters could be derived based on iteration with only 37 experimental lines to determine the 64 energy levels. The problem of convergence in the cases involving many groups of energy levels is discussed.

Concerning the chloromethylation of alkylbenzenes and polystyrenes by chloromethyl methyl ether

Abstract Chloromethyl methyl ether-stannic chloride treatments of toluene, ethylbenzene, isopropylbenzene and tert -butyl benzene afforded respectively, 26.5, 16.8, 5.5 and 2.5% ortho -products. No meta -products could be detected (less than 0.5%). Similar chloroalkylation of linear polystyrenes followed by conversion of the chloromethyl groups to hydroxylmethyl, yielded products possessing 5.0 ± .3% ortho -substitution.