SPEKTROSKOPISCHE SUBSTITUENTENKONSTANTEN,VI SYNTHESE UND UV-SPEKTREN VON 4-PIPERIDINO-PHENYL-PHOSPHOR-VERBINDUNGEN

Abstract

Triarylphosphines containing 4-piperidinophenyl rings are conveniently prepared by PO-activated nucleophilic aromatic substitution of fluorine by piperidine and subsequent reduction of the phosphine oxides. The UV spectra of the 4-piperidinophenyl-phosphorus compounds closely resemble those of the analogous dimethylanilines. Spectroscopic substituent constants are obtained by application of the Doub-Vandenbelt equation.

Triarylphosphine mit 4-Piperidinophenyl-Ringen sind durch PO-aktivierte nukleophile aromatische Substitution von Fluor durch Piperidin bequem zugänglich; die Phosphine entstehen durch Reduktion der Phosphinoxide. Die UV-Spektren der 4-Piperidinophenyl-phosphor-Verbindungen sind denen der analogen Dimethylaniline sehr ähnlich. Mit Hilfe der Doub-Vandenbelt-Gleichung werden spektroskopische Substituentenkonstanten gewonnen.     

Directly estimating nonclassicality

We establish a method of directly measuring and estimating nonclassicality--operationally defined in terms of the distinguishability of a given state from one with a positive Wigner function. It allows us to certify nonclassicality, based on possibly much fewer measurement settings than necessary for obtaining complete tomographic knowledge, and is at the same time equipped with a full certificate. We find that even from measuring two conjugate variables alone, one may infer the nonclassicality of quantum mechanical modes. This method also provides a practical tool to eventually certify such features in mechanical degrees of freedom in opto-mechanics. The proof of the result is based on Bochner's theorem characterizing classical and quantum characteristic functions and on semidefinite programming. In this joint theoretical-experimental work we present data from experimental optical Fock state preparation.     

The vibrational spectra, molecular structure and conformation of organic azides Part II. 2-Azido-1,3-butadiene

A sample of 2-azido-1,3-butadiene was synthesized from 4-bromo-1,2-butadiene and tetramethylguanidinium azide. Although the sample is highly explosive, we succeeded in making a structure determination by gaseous electron diffraction. IR spectra of the vapour, of the matrix isolated species in argon at 15 K, and of an amorphous and crystalline solid at 90 K were recorded. A Raman spectrum of the liquid, including semiquantitative polarization data, was obtained at 240 K.

The title compound was found to be planar with the CNN angle 117° oriented syn to the adjacent C=C double bond, the NNN angle was ca. 177° oriented anti to the C---N bond. The following bond distances (r_a) were obtained: N---N(N), 114.3; N---N(C), 125.3; C---N, 143.4; C=C, 135.0; and C---C, 146.7 pm.

No additional conformers were observed in the vapour, liquid, amorphous or crystalline states.     

The vibrational spectra, molecular structure and conformation of organic azides Part III. 2,3-Diazido-1,3-butadiene

A sample of 2,3-diazido-1,3-butadiene has been synthesized from 1,4-dibromo-2-butyne and tetramethylguanidinium azide. The highly explosive sample has been studied by gaseous electron diffraction and by IR spectroscopy. Only incomplete Raman spectra have been recorded due to sample decomposition in the laser beam. The title compound is found to be planar with the CNN angle equal to 114.5°, oriented syn to the adjacent C=C double bond; the NNN angle is ca. 167°, oriented anti to the C---N bond. The following bond distances (r_a) are obtained: N---N(N), 114.1; N---N(C), 124.2; C---N, 143.2; C=C 134.8; and C---C, 148.5 pm. The vibrational spectra are tentatively assigned in terms of C_2h molecular symmetry, supported by force constant calculations.     

Effect of Epinephrine and Insulin on Glucose Metabolism in Isolated Fat Cells

Since epinephrine and insulin are known to counteract each other in several metabolic respects, it was found of interest to evaluate the interaction of these hormones on glucose metabolism in isolated fat cells. Results indicate that in spite of reduced lipolysis, insulin potentiates the conversion of glucose to glyceride-glycerol. This means that a certain degree of esterification of fatty acids must take place. So the low rate of lipolysis is sufficient to provide fatty acids for this esterification.     

Synthesis of a bicyclic double-headed nucleoside

An attempt of preparing a carbocyclic LNA-analogue using different RCM-methods failed. However, a compound with a hemiacetal linker between the C2′ and the C4′-positions was isolated and found to be a suitable substrate for making a conformationally restricted double-headed nucleoside. This contains two uracil nucleobases organized on a bicyclic skeleton and is locked in an N-type conformation.