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| Author(s): |
Caio Ricardo Faiad da Silva
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Química |
| Defense date: | 2011-12-16 |
| Examining board members: |
Roberto Rittner Neto;
Alvaro Cunha Neto;
Paulo Cesar Muniz de Lacerda Miranda
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| Advisor: | Roberto Rittner Neto |
| Abstract | |
In the Introduction section, there are short descriptions of the: a) rationalization of spin-spin couplings JCH (n = 1, 2 e 3); b) the steps of theoretical calculations; and c) two NMR experiments recently implemented at IQ-UNICAMP: HSQC-TOCSY-IPAP and IPAP-HSQMBC. The first part of Results and Discussion approaches the experimental determination of the spin-spin coupling constants (SSCC) in adamantane derivatives. The second part approaches theoretical spin-spin coupling constants. In this part is shown that isnft necessary high precision in theoretical calculations of geometry optimization for studies of spin-spin coupling constants in rigid molecules. The optimizated structures at PM3 and B3LYP level of theory present no difference geometrical parameters as well as the theoretical values of SSCC. The results lead a decrease in the computational efforts. The last part of Results and Discussion is about rationalization of JCH. The substituent in adamantane doesnft cause structural changes, so the variations in JCH are attributed to hyperconjugation. The increase in JCßHß for all derivatives is due to interaction between substituent and C-C bond (sCC or sCC*). For the JCaHb and JCaHg is observed that for the CN, C(O)CH3 and C(O)NH2 substituents the interaction sCaCb n*CO ou sCaCb n*CN, which removes electronic density in coupling pathway, doesnft allow no increase in these constants. For the others substituents interactions NXs*CaCb, which increases electronic density in coupling pathway, are responsible for the increase in these spin-spin coupling constants (AU) | |
| FAPESP's process: | 09/11662-9 - Experimental and theoretical study of nJCH coupling constants in substituted adamantane. |
| Grantee: | Caio Ricardo Faiad da Silva |
| Support Opportunities: | Scholarships in Brazil - Master |