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摘要
New 1,3-bis(phenylselanylmethyl)benzene (1, 2 and 4) and butyl phenylselane derivatives (3 and 5) are synthesized and full heteronuclear NMR characterization of these compounds are reported. Interestingly, NMR spectrum of compounds 2-5 show coupling of H-1 and C-13 signals of groups involved in intramolecular nonbonding interactions with Se-77. The coupling constants J(H-se) and J(C-se) are in the range 13.6 21.6 Hz and 28-49 Hz, respectively. For compounds 4 and 5. J(H-se) coupling constants of formyl proton are smaller than their respective acetal CH protons for compounds 2 and 3. However, this trend is opposite for J(C-se) coupling constants, indicating that in formyl group containing compounds 4 and 5, Se...0 interactions are present while in compounds 2 and 3 with acetal fragments, Se...H interactions also could be present because of steric constraints. To confirm these interactions, quantum chemical analyses were performed for 2, 4 and 5. The minimal energy conformation for these compounds present Se...O/Se...H interactions and are at lower energy in comparison to different conformers which do not show any interaction. For compounds 4 and 5, minimal energy conformation present Se.0 interactions and for compound 2,Se...H is the favored conformation. These results are in accordance with the NMR data for these compounds. X-ray crystal structure of compound 1,3-bis(phenylselanylmethyl)benzene (1) was also determined during this work. In order to understand the effect of the Se...O/Se...H interactions and the position of phenylselanylmethyl groups, quantum chemical analyses were also carried out for 1,4-bis(phenylselanylmethyl)benzene derivatives (6 and 7). Interestingly, minimal energy conformers of 1,3-bis(phenylselanylmethyl)benzene derivatives 2 and 4 are more stable than their corresponding conformers of 1,4-bis-(phenylselanylmethyl)benzene derivatives 6 and 7.1,3-bisR(2-(diethoxymethyl) phenyOselanyl}methyllbenzene (2) with an energy barrier of 16.22 kcal/mol is more stable than corresponding 1,4-bis [(diethoxymethyl)phenyOselanyl)methylibenzene (7), while molecule 4 is 1.79 kcal/mol more stable than its corresponding 2'-[{1,4-phenylenebis(methylene)}bis(selanediy1)]clibenzaldehyde (6).
- 出版日期2018-3-5
