[pi] in poly(
oxazines) and demonstrated that such bonds contribute to the improvement of their thermal properties, such as elevated glass transition temperatures [18-20].
Oxazines [14] and quinazolines [15] are natural products which exhibit a widespread spectrum of biological activity including antitumor [16-18], anti-inflammatory [19], and antiplatelet [20] properties.
Among the topics are organic building blocks for molecular engineering, the design and synthesis of organic molecules for molecular electronics, molecular storage systems for solar thermal energy storage and conversion, strategies to switch fluorescence with photochromic
oxazines, recognizing carbohydrates, the synthesis and function of cyclodextrin-based artificial enzymes, and dendrimers in biology and nanomedicine.
Antimalarial dyes revisited: Xanthenes, Azines,
Oxazines, and Thiazines.
Koycii, "Synthesis of new 1,3-disubstituted-2,3-dihydro-1H-naphth- [1,2e][1,3]
oxazines," Molecules, vol.
Additionally, the polymerization of N-allyl groups at lower temperature (17) before the ring-opening polymerization of
oxazines lead to a mild crosslinking state which would affect the mobility of reaction functional groups, which also could resulted in a higher E.
The large numbers of biologically active molecules that contain the
oxazine nucleus has play important roles in the drug discovery process and exhibit various biological activities [1, 2].
The reaction involves the use of a di-functional phenolic derivative and diamine, producing a linear polymer that contains
oxazine rings in its main-chain [20].
FTIR (KBr): v = 1498 (tri-substituted phenyl group); 1231 (s; [v.sub.as] (C-O-C of benzoxazine ring)), 1016 (s; [v.sub.s] (C-O-C of benzoxazine ring)); 1085 (s; vas (Si-O-C)); 931 (
oxazine ring).
According to Wang and Ishida 2000, the polymerization occurred at
oxazine structure via ring opening influence by distortion of its semichair structure above and below benzene ring plane.
1), the characteristic resonances of
oxazine ring at 3.97 and 4.84 ppm belonging to the -C[H.sub.2]-N--and 0-C[H.sub.2]-N- protons, respectively, were observed.