| Full text | |
| Author(s): |
Orenha, Renato P.
;
Vessecchi, Ricardo
;
Galembeck, Sergio E.
Total Authors: 3
|
| Document type: | Journal article |
| Source: | STRUCTURAL CHEMISTRY; v. 29, n. 3, p. 11-pg., 2018-06-01. |
| Abstract | |
We have studied prop-2-en-1-imine (1), prop-2-enal (2), ethane-1,2-diimine (3), ethanedial (4), and 2-iminoacetaldehyde (5) to investigate the influence of the negative hyperconjugation in pi-pi* interaction with the substitution of =CH2 by =NH and/or =O in trans-buta-1,3-diene (6). The analyzes of the pi-pi* interaction performed from evaluation of the pi molecular orbital diagrams and electron localization function method demonstrated, that compared to 6, the substituted compounds 1-5 presented lower electron conjugation, especially in the structures bearing =O. The geometric parameters, natural bond orders, and topological analysis realized by quantum theory of atoms in molecules method indicated a predominant C-C and C=C character for the simple and double C-C bonds in the substituted compounds, 1-5, as compared to 6. Compound 4 had the highest enthalpy of formation, which reflected the lowest pi-pi* interaction, maintained by the two =O conjugated groups. The natural bond orbital (NBO) and natural resonance theory (NRT) methods revealed that the pi-pi* electron delocalization in substituted compounds, 1-5, is lower than in 6 from, firstly, of the less favorable interactions: pi(X=C) -> pi*(C=C) and pi(X=C) -> pi*(C=X), despite of the larger pi(C=C) -> pi*(C=X) conjugation, with X = N and/or O, of 1-5 than pi(C=C) -> pi*(C=C) of 6. But, most importantly, the weight of the interaction: n(pi)(O) -> sigma*(C-C), was determined from NBO and NRT methods as proportional to the pi-pi* conjugation and thus demonstrating be decisive to establish the level of pi electronic delocalization. (AU) | |
| FAPESP's process: | 08/02677-0 - Computational Study of the interaction between HIV-1 reverse transcriptase non-nucleoside inhibitors with amino acids of the inhibitory site |
| Grantee: | Sergio Emanuel Galembeck |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 09/08712-4 - The resonance in compounds with conjugated multiple bonds |
| Grantee: | Renato Pereira Orenha |
| Support Opportunities: | Scholarships in Brazil - Scientific Initiation |
| FAPESP's process: | 14/50265-3 - Distribution and metabolism of natural and synthetic xenobiotics: from the comprehension of reactional process to tissue imaging generation |
| Grantee: | Norberto Peporine Lopes |
| Support Opportunities: | BIOTA-FAPESP Program - Thematic Grants |
| FAPESP's process: | 15/15176-2 - How to tune the Ru-NO coordination bond: insight from Kohn-Sham molecular orbital theory and energy decomposition analyses |
| Grantee: | Renato Pereira Orenha |
| Support Opportunities: | Scholarships abroad - Research Internship - Doctorate (Direct) |
| FAPESP's process: | 14/23604-1 - Computational chemistry: a tool to studies of mass spectrometry, reactivity and fragmentation/reaction mechanisms of organic compounds |
| Grantee: | Ricardo Vessecchi Lourenço |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 11/20351-7 - Computational study of ruthenium-nitosyl compounds |
| Grantee: | Renato Pereira Orenha |
| Support Opportunities: | Scholarships in Brazil - Doctorate (Direct) |