On September 6, 2007, Kistler, Kurt A.; Matsika, Spiridoula published an article.COA of Formula: C6H5N3O The title of the article was Cytosine in Context: A Theoretical Study of Substituent Effects on the Excitation Energies of 2-Pyrimidinone Derivatives. And the article contained the following:
The ultrafast radiationless decay mechanism for cytosine has been shown to be in part dependent upon high vertical excitation, while slower fluorescence displayed in some cytosine analogs is generally linked to lower vertical excitation energies. To probe how excitation energies relate to pyrimidine structure, substituent effects on the vertical excitation energies for a number of derivatives of 2-pyrimidin-(1H)-one (2P) have been calculated using multireference configuration-interaction ab initio methods. Substitutions using groups with 蟺 electron donating, withdrawing and conjugation-extending properties at the C4 and C5 positions on the 2P system give predictive trends for the first three singlet excited-state energies. The S1 蟺蟺* energies of 2P derivatives involving C4 substitution vary linearly with the Hammett substituent parameter 蟽P+. Cytosine is shown to have the highest bright 蟺蟺* energy of the 2P derivatives presented, with that energy being strongly dependent on the position, orientation, and geometry of the C4-amino. A simple description of the predictive energetic trends for the bright 蟺蟺* energies using frontier MO theory is presented, based on the character of the HOMO and LUMO orbitals for each derivative The results of this study expand the current understanding of the photophys. behavior of the DNA pyrimidine bases and could be useful in the design of analogs where particular spectral properties are desired. The experimental process involved the reaction of Imidazo[1,2-c]pyrimidin-5(6H)-one(cas: 55662-66-3).COA of Formula: C6H5N3O
The Article related to cytosine theory substituent effect excitation energy pyrimidinone, Physical Organic Chemistry: Theoretical Organic Chemical Concepts, Including Quantum and Molecular Mechanical Studies and other aspects.COA of Formula: C6H5N3O
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem