Experimental measurements and second-order polarization propagator approach (SOPPA) calculations of (77)Se-(1)H spin-spin coupling constants together with theoretical energy-based conformational analysis in the series of 2-substituted selenophenes have been carried out. A new basis set optimized for the calculation of (77)Se-(1)H spin-spin coupling constants has been introduced by extending the aug-cc-pVTZ-J basis for selenium. Most of the spin-spin coupling constants under study, especially vicinal (77)Se-(1)H couplings, demonstrated a remarkable stereochemical behavior with respect to the internal rotation of the substituent in the 2-position of the selenophene ring, which is of major importance in the stereochemical studies of the related organoselenium compounds.

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A complex cascade of solid-state processes initiated by variation of temperature was found for the heterospin complex [Cu(hfac)2L(Me/Et)] formed in the reaction of copper(II) hexafluoroacetylacetonate [Cu(hfac)2] with stable nitronyl nitroxide 2-(1-methyl-3-ethyl-1H-pyrazol-4-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl (L(Me/Et)). The cooling of the compound below 260 K initiated a solid-state chemical reaction, which led to a depolymerization of chains and formation of a pair heterospin complex [Cu(hfac)2L(Me/Et)2][[Cu(hfac)2]3L(Me/Et)2]. Further decrease in temperature below 144 K led to a spin transition accompanied by a drastic decrease in the effective magnetic moment from 2.52 to 2.24 μB. When the compound was heated, the order of effects was reversed: at first, the magnetic moment abruptly increased, and then the molecular fragments of the pair cluster united into polymer chains. Two hysteresis loops correspond to this cascade of temperature-induced structural transformations on the experimental dependence μeff(T): one at high (T↑ = 283 K and T↓ = 260 K) and the other at low (T↑ = 161 K, T↓ = 144 K) temperature. The spin transitions were also recorded for the [[Cu(hfac)2]3L(Bu/Et)2] and [[Cu(hfac)2]5L(Bu/Et)4] molecular complexes, which are models of the trinuclear fragment of the {[Cu(hfac)2]3L(Me/Et)2} pair cluster.

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SHORT COMMUNICATIONSAcrylamide and N-substituted acrylamides are used in both fine organic synthesis and industry as intermediate products for the preparation of carbo-and heterochain polymers and copolymers and polyfunctional acyclic and heterocyclic compounds. While performing our systematic studies on the synthetic potential of halogen-containing N-sulfonyl imines, which have become readily accessible as a result of development of methods for their synthesis from N,N-dichlorosulfonamides, polyhaloethenes, and phenylacetylene [1], we examined reactions of N-(2,2,2-trichloroethylidene)trifluoromethane-and -arenesulfonamides Ia-Ic and N-(2-phenyl-2,2-dichloroethylidene)-4-chlorobenzenesulfonamide (Id) with acrylamides.We previously showed that carboxamides, ureas, and sulfonamides add to N-sulfonyl imines derived from polychlorinated aldehydes to give the corresponding symmetric and asymmetric 1,1-bis(acylamino)polychloroalkanes [1].In the present work we found for the first time that Schiff bases Ia-Id obtained from the corresponding N,N-dichloro sulfonamides, trichloroethylene, and phenylacetylene readily take up acrylamide (within 2-3 h) to give N-(1-sulfonylamino-2-polychloroethyl)-acrylamides IIa-IId. Heating of the reaction mixture to 40-50°C accelerates the process. We observed no formation of poly(acrylamide), though acrylamide is known to readily undergo polymerization in the presence of radical initiators.The structure of acrylamide derivatives IIa-IId was proved by spectral data and elemental analyses. The IR spectra of IIa-IId contained absorption bands due to stretching vibrations of the amide NH, carbonyl, and sulfonyl groups. Amides IIa-IId showed in the 1 H NMR spectra signals corresponding to protons in the aromatic rings, NH-CH-NH fragment, and vinyl group. The latter appeared as an ABX spin system. In the 13 C NMR spectra of IIa-IId we observed signals from carbon atoms in the polyhaloethyl fragment and carbonyl group; the CF 3 signal in the spectrum of IIa was split into a quartet due to coupling with fluorine nuclei.Compounds IIa-IId are colorless crystalline substances which are insoluble in water, poorly soluble in nonpolar organic solvents, and readily soluble in acetone, DMSO, and aqueous alkali. The presence of proton-donor and proton-acceptor substituents, polyhalomethyl fragments, and a double bond in molecules IIa-IId makes these compounds potential ligands for complex formation with metals and promising intermediate products for fine organic synthesis, specifically for the preparation of nitrogen-containing acyclic and heterocyclic compounds and carbo-and heterochain polymers and copolymers having labile hydrogen atoms. Structural features of amides IIa-IId could give rise to formation of strong intra-and intermolecular hydrogen bonds; therefore, these compounds may X = Cl, R = CF 3 (a), Ph (b), 4-ClC 6 H 4 (c); X = Ph, R = 4-ClC 6 H 4 (d). RSO 2 NH CH HN CCl 2 X C HC O CH 2

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