Foliations by complex curves and the geometry of real surfaces of finite type

We show that if the Levi form of a smooth CR manifold is de-generate in every conormal direction, then on a dense open set, the manifold is foliated by complex curves. As a consequence we show that every real analytic manifold of finite D'Angelo type can be stratified so that each stratum locally is contained in a Levi nondegenerate hypersurface. Received in final form: 11 June 2001 / Published online: 28 February 2002     

Composition of lipids of the grain of opaque-2 maize

It has been established that the change in the composition of the total lipids and the fall in the fatty acid content depend on the initial maize genotype. A decrease in the amount of unsaponifiable substances in the grain of mutants is accompanied by qualitative changes in the composition regardless of the nature of the genotype.Scientific-Research Institute of Biology Dnepropetrovsk State university. Translated from Khimiya Prirodnykh Soedinenii. No. 3. pp. 360–363. May–June, 1988.     

Controlled Generation of 9-Boratriptycene by Lewis Adduct Dissociation: Accessing a Non-Planar Triarylborane

A highly bent triarylborane, 9-boratriptycene, was generated in solution by selective protodeboronation of the corresponding tetra-aryl boron ate complex with the strong Brønsted acid HNTf₂. The iptycene core confers enhanced Lewis acidity to 9-boratriptycene, making it unique in terms of structure and reactivity. We studied the stereoelectronic properties of 9-boratriptycene by quantifying its association with small N- and O-centered Lewis bases, as well as with sterically hindered phosphines. The resultant Lewis adducts exhibited unique structural, spectroscopic, and photophysical properties. Beyond the high pyramidalization of the 9-boratriptycene scaffold and its low reorganization energy upon Lewis base coordination, quantum chemical calculations revealed that the absence of π donation from the triptycene aryl rings to the boron vacant p_z orbital is one of the main reasons for its high Lewis acidity.     

IR Microscopy as a Method for Studying the Influence of An External Electric Field on the Spin Crossover Exemplified by the Fe(II) Complex with 2,6-Bis(pyrazol-1-yl)pyridine

Russian Journal of Coordination Chemistry - The influence of the electric field on the spin state of the single crystal of [Fe(1-Bpp)2][BF4]2 demonstrating the spin crossover phenomenon is studied....     

ABnKi NMR spectra in second-order perturbation theory

General equations are derived for the AB_nK_i NMR spectra in second-order perturbation theory. The states of the system used in the derivation are characterized by the total spin and its projection for each group of equivalent nuclei.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 14–18, January, 1971.The author thanks Yu. S. Konstantinov for useful discussions.