TY - CHAP
T1 - Formamide as the Model Compound for Photodissociation Studies of the Peptide Bond
AU - Eckert-Maksić, Mirjana
AU - Antol, Ivana
AU - Vazdar, Mario
AU - Barbatti, Mario
AU - Lischka, Hans
N1 - Publisher Copyright:
© Springer Netherlands 2010.
PY - 2010
Y1 - 2010
N2 - Dynamics simulations are an essential step in exploring ultrafast phenomena in photochemistry and photobiology. In this chapter we present results of photodynamics studies for some model compounds for the peptide bond using the on-the-fly surface hopping method. The mechanism of photodissociation of formamide, its protonated forms and methyl substituted derivatives in their lowest singlet excited states in the gas phase is discussed in detail. Merits and demerits of using these simple molecules as models in exploring photochemical and photophysical properties of more complex systems, like peptides and proteins, are emphasized. It is found that in all examined model molecules the major deactivation process after excitation to the S1 state is dissociation of the peptide C–N bond. The same holds for the deactivation path from the S2 state, with exception of the O- protonated formamide in which C–O dissociation becomes the major deactivation process. Furthermore, it is shown that substitution by the methyl group(s), as well as protonation, strongly influence the lifetime of both excited states. In the last section application of the newly developed hybrid nonadiabatic photodynamics QM/MM approach in calculating photodissociation of formamide in argon matrix is illustrated.
AB - Dynamics simulations are an essential step in exploring ultrafast phenomena in photochemistry and photobiology. In this chapter we present results of photodynamics studies for some model compounds for the peptide bond using the on-the-fly surface hopping method. The mechanism of photodissociation of formamide, its protonated forms and methyl substituted derivatives in their lowest singlet excited states in the gas phase is discussed in detail. Merits and demerits of using these simple molecules as models in exploring photochemical and photophysical properties of more complex systems, like peptides and proteins, are emphasized. It is found that in all examined model molecules the major deactivation process after excitation to the S1 state is dissociation of the peptide C–N bond. The same holds for the deactivation path from the S2 state, with exception of the O- protonated formamide in which C–O dissociation becomes the major deactivation process. Furthermore, it is shown that substitution by the methyl group(s), as well as protonation, strongly influence the lifetime of both excited states. In the last section application of the newly developed hybrid nonadiabatic photodynamics QM/MM approach in calculating photodissociation of formamide in argon matrix is illustrated.
KW - Environmental effects
KW - Excited state
KW - Formamide
KW - Nonadiabatic dynamics
KW - Peptide bond
KW - Photodissociation
KW - QM/MM
KW - Substituted formamides
KW - Surface hopping
UR - http://www.scopus.com/inward/record.url?scp=84873983665&partnerID=8YFLogxK
U2 - 10.1007/978-90-481-3034-4_3
DO - 10.1007/978-90-481-3034-4_3
M3 - Chapter
AN - SCOPUS:84873983665
T3 - Challenges and Advances in Computational Chemistry and Physics
SP - 77
EP - 106
BT - Challenges and Advances in Computational Chemistry and Physics
PB - Springer
ER -