RESUMEN
The conformational effects in bicyclo[3.3.1]nonanes, while thoroughly studied, have not yet received the full theoretical explanation. R. F. W. Bader's quantum theory of atoms in molecules presents unique opportunities for studying the stereoelectronic interactions (SEI) and weak intramolecular bonding leading to these effects. Here, we report the study of 3,7-dithia-1,5-diazabicyclo[3.3.1]nonane by means of the topological analysis of the calculated (MP2(full)/6-311++G**) and experimental (X-ray derived) charge density to reveal the origins of the so-called "hockey sticks" effect observed in similar compounds. A new explanation of the relative stability of bicyclo[3.3.1]nonane conformers based on the analysis of the QTAIM atomic energies is given. The H···H and S···S interactions in bicyclo[3.3.1]nonane and its dithia derivatives are shown to be significant factors contributing to the differences in the relative stability of the conformers.
Asunto(s)
Compuestos de Azabiciclo/química , Teoría Cuántica , Electrones , Conformación MolecularRESUMEN
New non-nucleoside esters of phosphoric acid containing various hydrophobic groups, namely (1) N-(2-tripticencarbonyl)-4-aminobutyl; (2) 5-phenylsubstituted N-(2,4-dinitrophenyl)-4-aminobutyl; (3) N-(4-phenylbenzoyl)- and N-(4-(N-benzylamino)benzoyl)-2-aminoethyl groups, as well as (4) diphenylmethyl and fluorenyl groups were synthesized and studied as substrates of terminal deoxynucleotidyl transferase. With the exception of the two latter derivatives, all the analogues displayed substrate properties and could incorporate into the deoxyoligonucleotide 3'-end. As it was shown in biochemical experiments and by computer modeling, a linker joining the triphosphate and hydrophobic fragments of the molecule was necessary for these compounds to display substrate properties.