Optical and magnetic properties of the lowest triplet state of pyrido(2,3-b)pyrazine. An example of 3nπ* azanaphthalene was written by Yamauchi, Seigo;Hirota, Noboru. And the article was included in Journal of Physical Chemistry in 1987.Name: Pyrido[2,3-b]pyrazine This article mentions the following:
The lowest excited triplet (T1) states of pyrido(2,3-b)pyrazine (PP; 1,4,5-triazanaphthalene) in 3 kinds of environments were studied by using various spectroscopic and magnetic resonance techniques. Phosphorescence emission and excitation spectra, triplet lifetimes, zero field splittings (zfs), and triplet sublevel properties were obtained. From the anal. of the results T1 is 3nπ* in character in a single crystal of durene and in EtOH, but it is 3ππ* in trifluoroethanol. Observation of the 3nπ* phosphorescence was made for the 1st time in azanaphthalenes, which provides direct information about 3nπ* azanaphthalene. The 0-0 band and vibronic bands involving a’ vibrations are dominant in the phosphorescence spectrum. Large zfs and neg. D (≡ -3112x; -3.1 GHz) were obtained. As for the sublevel properties Tz is the most active and Tx is inactive in both radiative and nonradiative processes, whereas Ty is moderately active in the T1 ∼→ S0 nonradiative decay process. These 3nπ* properties are discussed in comparison with those of 3ππ* PP and azanaphthalenes and 3nπ* azabenzenes. Possible mechanisms to explain the radiative and nonradiative properties are given. In the experiment, the researchers used many compounds, for example, Pyrido[2,3-b]pyrazine (cas: 322-46-3Name: Pyrido[2,3-b]pyrazine).
Pyrido[2,3-b]pyrazine (cas: 322-46-3) belongs to pyrazine derivatives. Pyrazine derivatives have antitumor, antibiotic, anticonvulsant, antituberculous and diuretic effects as well as kinase, enzymatic and potent tubulin and FtsZ polymerization inhibitory activities. Pyrazine and a variety of alkylpyrazines are flavor and aroma compounds found in baked and roasted goods. Tetramethylpyrazine (also known as ligustrazine) is reported to scavenge superoxide anion and decrease nitric oxide production in human Granulocytes.Name: Pyrido[2,3-b]pyrazine