Transition moment closure tests for ethylene

The completeness of a basis set for ethylene is examined relative to its ability to describe transition moments. The double zeta (Dunning contraction) plus polarization plus Rydberg Cartesian Gaussian set does much better for length than for velocity moments. An attempt is made to interpret the transition moment sums for the occupied orbitals.     

Carbon-13 NMR spectra of methylated cyclobutanes and ethyl cyclobutane-carboxylates

The ¹³C NMR spectra of cyclobutane and seven methylated homologs and of ethyl cyclobutanecarboxylate and five isomeric diethyl cyclobutanedicarboxylates are reported and substituent parameters for methyl groups in methylcyclobutanes are calculated. Of note is a sizeable and nearly configuration-independent upfield shifting γ-effect.     

Reactivity of 4-halogeno 1-vinyl naphthalenes in cationic polymerization

Improved methods for the synthesis of 4-halogeno 1-vinylnaphthalenes are proposed. Reactivity ratios are determined for the following systems: 4-fluoro-1-vinyl naphthalene-styrene, 4-chloro-1-vinyl naphthalene-styrene, and 4-bromo-1-vinyl naphthalene-styrene. The determinations are performed at various specific temperatures and the relative activation parameters are obtained. It appears that the reactivity of 1-vinyl naphthalene is drastically decreased when substituted by a halogen. In the case of 1-vinyl naphthalene the selection is enthalpically controlled.     

Symmetric six-quark model and associated neutral currents

A symmetric six-quark gauge model is proposed to account for the recent neutrino and antineutrino data on charged and neutral currents. As a bonus, exact isospin symmetry for strong interaction is obtained in a natural way. Further consequences are elaborated.     

Some Industrial Applications of Linear Programming

Three examples of the applications of linear programming are given, drawn from the manufacture of plywood, the distribution of grain, and industrial fermentation. In each of these widely different industries there is a problem which can be treated quite precisely by a linear programming model. The quantities evaluated are in the first case, the plywood product mix with the maximum return; in the second case, the routings and transit credits for shipping grain with the minimum freight costs; and in the third case, the production schedule for the fermentation process which yields the minimum labour cost. In most cases, the results obtained could be extended to evaluate other factors, and in all cases the formulation of the problem in linear programming form led to a greater understanding of the industry concerned.     

The photoelectron spectrum and molecular geometry of bicyclo[2.1.1]hexane

The He(I) photoelectron spectrum of bicyclo[2.1.1]hexane shows excellent correlation with a theoretical spectrum based on the eigenvalues obtained in an ab initio calculation at the theoretical molecular geometry. By contrast, a calculation performed at the experimental geometry exhibits an effect of enhanced ring strain in showing a first ionization energy which is considerably lower than the experimental value. This observation offers experimental support for the recent claim that the published structure for bicyclo [2.1.1]hexane based on electron-diffraction measurements is incorrect. It also accounts for inconsistencies observed in the calculated values of some spin—spin coupling constants for substituted bicyclo[2.1.1]hexanes.