Molecular Mechanism of Diaminomaleonitrile to
Diaminofumaronitrile Photoisomerization: An Intermediate Step
in the Prebiotic Formation of Purine Nucleobases

J 2014

Molecular Mechanism of Diaminomaleonitrile to Diaminofumaronitrile Photoisomerization: An Intermediate Step in the Prebiotic Formation of Purine Nucleobases

SZABLA, Rafal Kazimierz, Robert W. GÓRA, Jiří ŠPONER and Judit ŠPONEROVÁ

Basic information

Original name

Molecular Mechanism of Diaminomaleonitrile to Diaminofumaronitrile Photoisomerization: An Intermediate Step in the Prebiotic Formation of Purine Nucleobases

Authors

SZABLA, Rafal Kazimierz (616 Poland), Robert W. GÓRA (616 Poland), Jiří ŠPONER (203 Czech Republic, guarantor, belonging to the institution) and Judit ŠPONEROVÁ (348 Hungary, belonging to the institution)

Edition

Chemistry - A European Journal, Weinheim, WILEY- VCH VERLAG GMBH, 2014, 0947-6539

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10403 Physical chemistry

Country of publisher

Germany

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

URL

Impact factor

Impact factor: 5.731

RIV identification code

RIV/00216224:14740/14:00075641

Organization unit

Central European Institute of Technology

DOI

http://dx.doi.org/10.1002/chem.201304224

UT WoS

000331729700018

Keywords in English

isomerization; nucleobases; nucleotides; photochemistry; quantum chemistry

Abstract

V originále

The photoinduced isomerization of diaminomaleonitrile (DAMN) to diaminofumaronitrile (DAFN) was suggested to play a key role in the prebiotically plausible formation of purine nucleobases and nucleotides. In this work we analyze two competitive photoisomerization mechanisms on the basis of state-of-the-art quantum-chemical calculations. Even though it was suggested that this process might occur on the triplet potential-energy surface, our results indicate that the singlet reaction channel should not be disregarded either. In fact, the peaked topography of the S-1/S-0 conical intersection suggests that the deexcitation should most likely occur on a sub-picosecond timescale and the singlet photoisomerization mechanism might effectively compete even with a very efficient intersystem crossing. Such a scenario is further supported by the relatively small spin-orbit coupling of the S-1 and T-2 states in the Franck-Condon region, which does not indicate a very effective triplet bypass for this photoreaction. Therefore, we conclude that the triplet reaction channel in DAMN might not be as prominent as was previously thought.

Links

ED1.1.00/02.0068, research and development project

Name: CEITEC - central european institute of technology

Citovat

SZABLA, Rafal Kazimierz, Robert W. GÓRA, Jiří ŠPONER and Judit ŠPONEROVÁ. Molecular Mechanism of Diaminomaleonitrile to Diaminofumaronitrile Photoisomerization: An Intermediate Step in the Prebiotic Formation of Purine Nucleobases. Chemistry - A European Journal. Weinheim: WILEY- VCH VERLAG GMBH, 2014, vol. 20, No 9, p. 2515-2521. ISSN 0947-6539. Available from: https://dx.doi.org/10.1002/chem.201304224.

@article{1184820,
   author = {Szabla, Rafal Kazimierz and Góra, Robert W. and Šponer, Jiří and Šponerová, Judit},
   article_location = {Weinheim},
   article_number = {9},
   doi = {http://dx.doi.org/10.1002/chem.201304224},
   keywords = {isomerization; nucleobases; nucleotides; photochemistry; quantum chemistry},
   language = {eng},
   issn = {0947-6539},
   journal = {Chemistry - A European Journal},
   title = {Molecular Mechanism of Diaminomaleonitrile to Diaminofumaronitrile Photoisomerization: An Intermediate Step in the Prebiotic Formation of Purine Nucleobases},
   url = {http://onlinelibrary.wiley.com/doi/10.1002/chem.201304224/pdf},
   volume = {20},
   year = {2014}
}

TY  - JOUR
ID  - 1184820
AU  - Szabla, Rafal Kazimierz - Góra, Robert W. - Šponer, Jiří - Šponerová, Judit
PY  - 2014
TI  - Molecular Mechanism of Diaminomaleonitrile to Diaminofumaronitrile Photoisomerization: An Intermediate Step in the Prebiotic Formation of Purine Nucleobases
JF  - Chemistry - A European Journal
VL  - 20
IS  - 9
SP  - 2515-2521
EP  - 2515-2521
PB  - WILEY- VCH VERLAG GMBH
SN  - 09476539
KW  - isomerization
KW  - nucleobases
KW  - nucleotides
KW  - photochemistry
KW  - quantum chemistry
UR  - http://onlinelibrary.wiley.com/doi/10.1002/chem.201304224/pdf
L2  - http://onlinelibrary.wiley.com/doi/10.1002/chem.201304224/pdf
N2  - The photoinduced isomerization of diaminomaleonitrile (DAMN) to diaminofumaronitrile (DAFN) was suggested to play a key role in the prebiotically plausible formation of purine nucleobases and nucleotides. In this work we analyze two competitive photoisomerization mechanisms on the basis of state-of-the-art quantum-chemical calculations. Even though it was suggested that this process might occur on the triplet potential-energy surface, our results indicate that the singlet reaction channel should not be disregarded either. In fact, the peaked topography of the S-1/S-0 conical intersection suggests that the deexcitation should most likely occur on a sub-picosecond timescale and the singlet photoisomerization mechanism might effectively compete even with a very efficient intersystem crossing. Such a scenario is further supported by the relatively small spin-orbit coupling of the S-1 and T-2 states in the Franck-Condon region, which does not indicate a very effective triplet bypass for this photoreaction. Therefore, we conclude that the triplet reaction channel in DAMN might not be as prominent as was previously thought.
ER  -

SZABLA, Rafal Kazimierz, Robert W. GÓRA, Jiří ŠPONER and Judit ŠPONEROVÁ. Molecular Mechanism of Diaminomaleonitrile to Diaminofumaronitrile Photoisomerization: An Intermediate Step in the Prebiotic Formation of Purine Nucleobases. \textit{Chemistry - A European Journal}. Weinheim: WILEY- VCH VERLAG GMBH, 2014, vol.~20, No~9, p.~2515-2521. ISSN~0947-6539. Available from: https://dx.doi.org/10.1002/chem.201304224.

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