masterThesis
Síntese de aza-heterociclos com conjugação π estendida alquilados para aplicações em materiais moleculares
Fecha
2018-07-25Registro en:
OLIVEIRA, André Herculano de. Síntese de aza-heterociclos com conjugação π estendida alquilados para aplicações em materiais moleculares. 2018. 77f. Dissertação (Mestrado em Química) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2018.
Autor
Oliveira, André Herculano de
Resumen
In recent years advanced molecular materials such as OLEDs (Organic Light
Emitting Diodes), and Liquid Crystals derived from heterocyclic compounds have
propelled the branch of the Organic-Electronics for their applications as organic
semiconductors. In this context, this work aims to synthesize, characterize and evaluate
the potential of new organic materials for applications such as semiconductors, derived
from the azaheterocyclic nuclei benzimidazole, quinoxaline and phenazine,
functionalized with alkyl side chains. The benzimidazole, quinoxaline and phenazine
nuclei acting as building blocks were: 4- (1H-benzo [d] imidazol-2-yl) -phenol, 1,4-
dihydroquinoxaline-2,3-dione, phenazine-2,3 diol. The side chain insertions in these
nuclei occurred via alkylation reactions (N, N, N, N, O and O, alkylations), the dodecyl
bromide was used as the source of the alkyl units. As alkylated functionalized
derivatives, 1-Dodecylquinoxaline-2,3 (1H) dione, 1-4-didodecylquinoxaline-2,3 (1H,
4H) -dione, 2- (4- (dodecyloxy) phenyl) -1H-benzo [ d] imidazole, 1-dodecyl-2- (4-
(dodecyloxy) phenyl) 1H-benzo [d] imidazole, and 2,3-bis (dodecyloxy) -phenazine. All
derivatives were suitably characterized by IV-ATR, 1 H and 13 C nuclear magnetic
resonance. As expected, after addition of the alkyl chains the novel derivatives had
lower melting points than the starting compounds. Regarding the synthetic step, the
methodologies used were satisfactory and with good yields. Analyzes were also carried
out to verify the liquid-crystalline properties of the derivatives obtained by polarized
light optical microscopy (MOLP) technique. For the alkylated derivatives that exhibited
crystalline liquid behavior visualized by MOLP and their thermal properties were
investigated by DSC in order to determine their phase transition temperatures.