Some properties of semiempirical Hamiltonians was written by Koutecky, Jaroslav. And the article was included in Journal of Chemical Physics in 1967.Application of 253-50-9 This article mentions the following:
The Hamiltonian used in semiempirical Pariser-Parr-Pople (P.P.P)-type treatments is put in a form such that (a) the parameters on which correlation effects depend become obvious and (b) the part of the Hamiltonian responsible for deviations from pairing properties of conjugated heterocycles with alternant topology is isolated. A set of approx. rules based on this analysis is derived. The rules concerning the extent of correlation effects are compared for some conjugated hydrocarbons with computations by full configuration interaction in the π-electron approximation Generalizations are derived of known conditions under which heterocyclic systems are paired. The character of the two first excited states of heteroanalogs and heteroderivs. of alternant hydrocarbons is discussed, and rules determining deviations from the behavior of parent alternant hydrocarbons are formulated. This makes it possible to predict the polarizations of the first two transitions in these compounds in the P.P.P. approximation with limited configuration interaction. The predictions are compared with some results of calculations on azines and amines. In the experiment, the researchers used many compounds, for example, 2,6-Naphthyridine (cas: 253-50-9Application of 253-50-9).
2,6-Naphthyridine (cas: 253-50-9) belongs to naphthyridine derivatives. Six naphthyridine isomers are white solids with a surprisingly wide span of melting points: 1,6-Naphthyridine’s is the lowest at <40 ºC; 2,6-naphthyridine’s is the highest at 114–115 ºC. Enoxacin, nalidixic acid, and trovafloxacin are 1,8-naphthyridine derivatives with antibacterial properties related to the fluoroquinolones.Application of 253-50-9
Referemce:
1,8-Naphthyridine – Wikipedia,
1,8-Naphthyridine | C8H6N2 – PubChem