INTERMOLECULAR HYDROGEN BONDING BETWEEN N-SUBSTITUTED CAPROAMIDES AND TETRAHYDROFURAN (330,00 руб.)

The spectroscopic characteristics for N—HO hydrogen bonded complexes are given. <...> The B3LYP functional with 6-31G** basis set has been used to calculate the structural parameters of the studied hydrogen bonded complexes. <...> It can be assumed that both inductive and steric effects play an important role in the stability of these hydrogen bonded complexes. <...> Knowledge of N—HO interactions of N-substituted amides contributes to a better understanding of the structure of polypeptides and proteins. [ 4 ]. <...> In our laboratory, during continuous and extensive research of N-substituted amides and their interactions in solutions, N—H O, [ 5—8] hydrogen bonded complexes were investigated using IR techniques. <...> The application of the B3LYP density functional with various basis sets can provide reasonable information about the geometry and energy of different hydrogen bonded complexes [ 9, 10 ]. <...> In the present work, we investigated the N—HO interactions of newly synthesised N-alkyl caproamides in order to provide better insight into the nature of the hydrogen bonding of secondary amides. <...> EXPERIMENTAL Various N-monosubstituted caproamides (NsCA) of general formula CH3(CH2)4CONHR, wherein R is n-propyl, n-butyl, sec-butyl, iso-butyl, tert-butyl, and n-pentyl (NPrC, NBuC, NsBC, NiBC, NtBC, NPeC), were synthesised by Schotten-Baumann reaction, by acylation of the corresponding amines with alkyl chloride. <...> Tetrahydrofuran was obtained from commercial sources (Fluka, > 97 %) and was used without further purification. <...> In order to avoid self-association, amide concentrations in carbon tetrachloride solutions were below 0.003 mol dm–3. <...> Infrared spectra were obtained using a Thermo-Nicolet Nexus 670 instrument. <...> A DTGS detector was employed in IR measurements. <...> Samples were placed in 1—5 cm (IR) UVIRSIL cells and the measurements were performed at 298 K. The reported frequencies and half-widths were reproducible © Jovi B., Nikoli A., Hollу B., 2013 Hydrogen bonding has a great importance in chemistry and biology. <...> IR spectra of N-substituted caproamides in the presence of tetrahydrofuran: a) N-propyl caproamide, b) N-butyl caproamide, c) N-iso-butyl caproamide, d) N-sec-butyl caproamide, e) N-tert-butyl caproamide, f ) N-pentyl caproamide within 0.2 and 1 cm–1, respectively <...>