Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2014-12-22T13:03:07Z No. of bitstreams: 1 Dissertação - Idney Resplandes Brandão Leite - 2014.pdf: 1973206 bytes, checksum: 4d3a96660c36dd1cef5779f1835a09e8 (MD5) / Approved for entry into archive by Cláudia Bueno (claudiamoura18@gmail.com) on 2014-12-23T13:22:42Z (GMT) No. of bitstreams: 1 Dissertação - Idney Resplandes Brandão Leite - 2014.pdf: 1973206 bytes, checksum: 4d3a96660c36dd1cef5779f1835a09e8 (MD5) / Made available in DSpace on 2014-12-23T13:22:42Z (GMT). No. of bitstreams: 1 Dissertação - Idney Resplandes Brandão Leite - 2014.pdf: 1973206 bytes, checksum: 4d3a96660c36dd1cef5779f1835a09e8 (MD5) Previous issue date: 2014-04-10 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Using Hartree-Fock (HF) and the second-order Møller-Plesset perturbation theory (MP2) methods with the 6-311++G(2d,2p) basis set, we have determined the dipole moment (𝜇), static linear polarizability ( 𝛼) and first hyperpolarizability (𝛽𝑡𝑜𝑡 and 𝛽𝐻𝑅𝑆) of the following linear chains : (HCN)𝑁, (HNC)𝑁, (LiCN)𝑁′ and (LiNC)𝑁′ (for 𝑁=1-10 and 𝑁′ = 1−15). The asymptotic MP2/6-311++G(2d,2p) values of 𝜇, 𝛼, 𝛽𝑡𝑜𝑡 and 𝛽𝐻𝑅𝑆 per unit ( 𝜇, 𝛼, 𝛽𝑡𝑜𝑡 and 𝛽𝐻𝑅𝑆) of the chains of HCN, HNC and LiNC have been estimated. For the chains of LiCN, at the same calculation level, we have estimated only the polymeric values (infinite chain values) of 𝜇 and 𝛼. For the chains of HCN and HNC, the obtained results shows that the effect of the structural isomerization on the polymeric values of 𝜇, 𝛼, 𝛽𝑡𝑜𝑡 and 𝛽𝐻𝑅𝑆 is significant, principally for these two latter properties. In the case of chains of LiCN and LiNC, the isomeric change practically does not affect the asymptotic values of 𝜇 and 𝛼. In the polymeric limit, the presented results also show that the effect of substitution of hydrogen atoms in linear chains of HCN and HNC for lithium atoms is an expressive increase of 𝜇 and 𝛼 and a substantial reduction of 𝛽𝑡𝑜𝑡 and 𝛽𝐻𝑅𝑆. / Utilizando os métodos ab initio de Hartree-Fock (HF) e de Møller-Plesset em segunda ordem (MP2) com o conjunto de funções-base 6-311++G(2d,2p), determinamos o momento de dipolo (𝜇), a polarizabilidade linear ( 𝛼) e a primeira hiperpolarizabilidade estática (𝛽𝑡𝑜𝑡 e 𝛽𝐻𝑅𝑆) das seguintes cadeias lineares: (HCN)𝑁, (HNC)𝑁, (LiCN)𝑁′ e (LiNC)𝑁′ (para 𝑁=1-10 e 𝑁′ = 1−15). Os valores assintóticos MP2/6-311++G(2d,2p) de 𝜇, 𝛼, 𝛽𝑡𝑜𝑡 e 𝛽𝐻𝑅𝑆 por unidade ( 𝜇, 𝛼, 𝛽𝑡𝑜𝑡 e 𝛽𝐻𝑅𝑆) das cadeias de HCN, HNC e LiNC foram estimados. Para as cadeias de LiCN, neste mesmo nível de cálculo, só foi possível estimar os valores poliméricos (valores para cadeias infinitas) de 𝜇 e 𝛼. Para as cadeias de HCN e HNC, os resultados obtidos mostram que o efeito da isomerização estrutural sobre os valores poliméricos de 𝜇, 𝛼, 𝛽𝑡𝑜𝑡 e 𝛽𝐻𝑅𝑆 é significativo, principalmente para estas duas últimas propriedades. No caso das cadeias de LiCN e LiNC, a mudança isomérica praticamente não afeta os valores poliméricos de 𝜇 e 𝛼. No limite polimérico, os resultados apresentados também mostram que o efeito da substituição dos átomos de hidrogênio das cadeias de HCN e HNC por átomos de lítio é um aumento expressivo dos valores de 𝜇 e 𝛼 e uma redução substancial de 𝛽𝑡𝑜𝑡 e 𝛽𝐻𝑅𝑆.

Αντικείμενο της παρούσης διδακτορικής διατριβής αποτελεί ο υπολογισμός των ηλεκτρικών πολυπολικών ροπών (διπολική έως και δεκαεξαπολική) ακετυλενικών αλυσίδων οι οποίες υπάγονται στους γενικούς τύπους H-(C≡C)n-H, Χ-(C≡C)n-H και Χ-(C≡C)n-X, n=1–7, X=F, Cl, Br, I, CN, NC, η συστηματική μελέτη των (υπερ)πολωσιμοτήτων των μη υποκατεστημένων ακετυλενικών αλυσίδων Η-(C≡C)n- H, n=3–7 και τέλος ο υπολογισμός των ηλεκτρικών ιδιοτήτων αλληλεπίδρασης συστημάτων του τύπου Η-(C≡C)n-H…Ηe, n=1–7. Σε όλες τις περιπτώσεις χρησιμοποιήθηκαν οι ab initio μέθοδοι SCF και MP2 καθώς και οι ευρέως χρησιμοποιούμενες DFT μέθοδοι B3LYP, B3PW91 και mPW1PW91. Στους υπολογισμούς των ηλεκτρικών πολυπολικών ροπών χρησιμοποιήθηκε η βάση ccpVDZ σε όλες τις περιπτώσεις και ιδιαίτερη έμφαση δόθηκε στον τρόπο μεταβολής των υπό μελέτη ιδιοτήτων με την μεταβολή του υποκαταστάτη στα άκρα της αλυσίδας. Στους υπολογισμούς των ηλεκτρικών (υπερ)πολωσιμοτήτων των μη υποκατεστημένων ακετυλενικών αλυσίδων Η-(C≡C)n-H χρησιμοποιήθηκαν ελάχιστα πολωμένα σύνολα βάσης και πραγματοποιήθηκε σύγκριση με τα αποτελέσματα που προέκυψαν από την χρήση μεγαλύτερων συνόλων βάσης. Για τον υπολογισμό των εν λόγω ιδιοτήτων χρησιμοποιήθηκε η μέθοδος του πεπερασμένου πεδίου. Τέλος πραγματοποιήθηκαν υπολογισμοί των ηλεκτρικών ιδιοτήτων αλληλεπίδρασης συστημάτων Η-(C≡C)n-H…Ηe για δυο συγκεκριμένες διαμορφώσεις ενώ για την αποφυγή του σφάλματος υπέρθεσης συνόλου βάσης χρησιμοποιήθηκε η υπερμοριακή προσέγγιση των Boys-Bernardi. / The purpose of the present doctoral dissertation is the calculation of the electric multipole moments (dipole up to hexadecapole) of acetylenic chains under the general formulas H-(C≡C)n-H, Χ-(C≡C)n-H and Χ-(C≡C)n-X, n=1–7, X=F, Cl, Br, I, CN, NC, the systematic study of the (hyper)polarizabilities of the non substituted acetylenic chains Η-(C≡C)n-H, n=3–7 and finally the calculation of interaction induced electric properties of systems of the general formula Η-(C≡C)n-H…Ηe, n=1– 7. In all cases considered the ab initio SCF and MP2 methods have been used along with the very popular DFT methods B3LYP, B3PW91 and mPW1PW91. For the electric multipole moment calculations the cc-pVDZ basis set has been used in all cases and special attention has been paid in the way the properties of interest change by changing the substituent at the ends of the acetylenic chains. For the electric (hyper)polarizability calculations on the non substituted acetylenic chains H-(C≡C)n- H minimally polarized basis sets have been used and comparison was made with the results obtained by using larger basis sets. In order to calculate the above mentioned properties the finite field method was applied. Finally, calculations were performed in order to calculate the interaction induced electric properties of the systems Η-(C≡C)n- H…Ηe for two particular configurations while in order to avoid the basis set superposition error the Boys-Bernardi counterpoise method has been applied.