Benjamin P. Dailey

Bio: Benjamin P. Dailey is an academic researcher from Columbia University. The author has contributed to research in topics: Liquid crystal & Anisotropy. The author has an hindex of 18, co-authored 48 publications receiving 2186 citations.

Molecular Magnetic Susceptibility Tensor in Sulfur Dioxide

Abstract: The diagonal elements in the magnetic susceptibility tensor in the principal molecule‐fixed inertial axis system in SO2 have been determined by observing the molecular rotational Zeeman effect with a high‐resolution microwave spectrometer. The signs of gaa, gbb, gcc have been found to be negative from theroetical considerations. The principal values of the magnetic susceptibility tensor, paramagnetic susceptibility tensor, and diamagnetic susceptibility tensor are, respectively: χaa = − 14.4 ± 1.2, χbb = − 19.6 ± 0.5, χcc = − 20.6 ± 0.6; χaap = 38.9 ± 0.3, χbbp = 129.3 ± 1.4, χccp = 139.5 ± 1.2; χaad = − 53.3 ± 1.2, χbbd = − 148.9 ± 1.5, χccd = − 160.1 ± 1.3 (all in units of 10−6 erg/G2·mole). The ground‐state averages of the sum of the squares of the electronic coordinates, and approximate values of the diagonal components of the quadrupole moment tensor have also been determined.

Determination of the deuterium quadrupole coupling constant in phosphine‐d3 from studies in a nematic solvent

Abstract: The phosphorus and deuterium Fourier transform NMR spectra of PD3 in a nematic solvent are reported. The experimentally determined value of the deuterium quadrupole coupling constant is 7.8±0.6 kHz in good agreement with the recent theoretical predictions of Rothenberg, Young, and Schaefer. The ordering parameter is unambiguously determined from the P–D splittings, thus enhancing the accuracy of the present results over previous measurements of this kind.

1,3-Dipolar Cycloadditions. Past and Future†

Abstract: In contrast to the very large number of special methods applicable to syntheses in the heterocyclic series, relatively few general methods are available. The 1,3-dipolar addition offers a remarkably wide range of utility in the synthesis of five-membered heterocycles. Here the “1,3-dipole”, which can only be represented by zwitterionic octet resonance structures, combines in a cycloaddition with a multiple bond system – the “dipolarophile” – to form an uncharged five-membered ring. Although numerous individual examples of this reaction were known, some even back in the nineteenth century, fruitful development of this synthetic principle has been achieved only in recent years.

Deuterium magnetic resonance: theory and application to lipid membranes.

Abstract: Proton and carbon-13 nmr spectra of unsonicated lipid bilayers and biological membranes are generally dominated by strong proton–proton and proton–carbon dipolar interactions. As a result the spectra contain a large number of overlapping resonances and are rather difficult to analyse. Nevertheless, important information on the structure and dynamic behaviour of lipid systems has been provided by these techniques (Wennerstrom & Lindblom, 1977).

1.3‐Dipolare Cycloadditionen Rückschau und Ausblick

Abstract: Einer sehr grosen Zahl spezieller Synthesewege in die heterocyclische in die Reihe steht ein nur bescheidener Satz an Aufbaumethoden von allgemeiner Verwendbarkeit gegenuber. Eine erstaunliche Anwendungsbreite bei der Synthese funfgliedriger Heterocyclen kommt der 1.3-Dipolaren Addition zu. Dabei vereinigt sich der nur mit zwitterionischen Oktett-Grenzformeln wiederzugebende „1.3-Dipol” mit einem Mehrfachbindungssystem, dem „Dipolarophil”, in einer Cycloaddition zum ladungsfreien funfgliedrigen Ring. Wenngleich die Kenntnis zahlreicher Einzelbeispiele bis ins vorige Jahrhundert zuruckreicht, gelangte das Syntheseprinzip erst in den letzten Jahren zu fruchtbarer Entfaltung.

A new criterion for the determination of molecular structures from ground state rotational constants

Abstract: Kraitchman has shown that a single isotopic substitution on an atom is sufficient to determine directly the coordinates of that atom with respect to the principal axes of the original molecule. Kraitchman's formulas represent exact solutions of the equations for the equilibrium moments of inertia. However, the effects of the zero‐point vibrations are such that the coordinates obtained by substitution from the ground state moments of inertia I0 are systematically less than r0. These coordinates have here been called r (substitution) or rs, and it is found that rs≃(r0+re)/2, and Is= ∑ imirsi2≃(I0+Ie)/2.In the usual method of solution, the coordinate of one atom is determined from the equation for I0, and therefore the difference I0—Is must be made up by this one coordinate. This introduces a large error in the structures normally determined from ground state constants, and results in variations of 0.01 A in structures determined from different sets of isotopic species. If instead, we obtain the structure on...