PMID- 29489369
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20180327
LR  - 20180327
IS  - 1520-5215 (Electronic)
IS  - 1089-5639 (Linking)
VI  - 122
IP  - 11
DP  - 2018 Mar 22
TI  - How Methylation Modifies the Photophysics of the Native All- trans-Retinal 
      Protonated Schiff Base: A CASPT2/MD Study in Gas Phase and in Methanol.
PG  - 3096-3106
LID - 10.1021/acs.jpca.8b00773 [doi]
AB  - A comparison between the free-energy surfaces of the all- trans-retinal 
      protonated Schiff base (RPSB) and its 10-methylated derivative in gas phase and 
      methanol solution is performed at CASSCF//CASSCF and CASPT2//CASSCF levels. 
      Solvent effects were included using the average solvent electrostatic potential 
      from molecular dynamics method. This is a QM/MM (quantum mechanics/molecular 
      mechanics) method that makes use of the mean field approximation. It is found 
      that the methyl group bonded to C10 produces noticeable changes in the solution 
      free-energy profile of the S(1) excited state, mainly in the relative stability 
      of the minimum energy conical intersections (MECIs) with respect to the 
      Franck-Condon (FC) point. The conical intersections yielding the 9- cis and 11- 
      cis isomers are stabilized while that yielding the 13- cis isomer is 
      destabilized; in fact, it becomes inaccessible by excitation to S(1). 
      Furthermore, the planar S(1) minimum is not present in the methylated compound. 
      The solvent notably stabilizes the S(2) excited state at the FC geometry. 
      Therefore, if the S(2) state has an effect on the photoisomerization dynamics, it 
      must be because it permits the RPSB population to branch around the FC point. All 
      these changes combine to speed up the photoisomerization in the 10-methylated 
      compound with respect to the native compound.
FAU - Barata-Morgado, Rute
AU  - Barata-Morgado R
AD  - Area de Quimica Fisica , University of Extremadura , Avda. Elvas s/n , Edif. Jose 
      Ma Viguera Lobo 3a, planta, Badajoz 06006 , Spain.
FAU - Sanchez, M Luz
AU  - Sanchez ML
AD  - Area de Quimica Fisica , University of Extremadura , Avda. Elvas s/n , Edif. Jose 
      Ma Viguera Lobo 3a, planta, Badajoz 06006 , Spain.
FAU - Munoz-Losa, Aurora
AU  - Munoz-Losa A
AD  - Dpto. Didactica de las Ciencias Experimentales y Matematicas, Facultad de 
      Formacion del Profesorado , University of Extremadura , Avda. Universidad s/n , 
      Caceres 10003 , Spain.
FAU - Martin, M Elena
AU  - Martin ME
AUID- ORCID: 0000-0002-5252-2893
AD  - Area de Quimica Fisica , University of Extremadura , Avda. Elvas s/n , Edif. Jose 
      Ma Viguera Lobo 3a, planta, Badajoz 06006 , Spain.
FAU - Olivares Del Valle, Francisco J
AU  - Olivares Del Valle FJ
AD  - Area de Quimica Fisica , University of Extremadura , Avda. Elvas s/n , Edif. Jose 
      Ma Viguera Lobo 3a, planta, Badajoz 06006 , Spain.
FAU - Aguilar, Manuel A
AU  - Aguilar MA
AUID- ORCID: 0000-0002-2586-859X
AD  - Area de Quimica Fisica , University of Extremadura , Avda. Elvas s/n , Edif. Jose 
      Ma Viguera Lobo 3a, planta, Badajoz 06006 , Spain.
LA  - eng
PT  - Journal Article
DEP - 20180312
PL  - United States
TA  - J Phys Chem A
JT  - The journal of physical chemistry. A
JID - 9890903
EDAT- 2018/03/01 06:00
MHDA- 2018/03/01 06:01
CRDT- 2018/03/01 06:00
PHST- 2018/03/01 06:00 [pubmed]
PHST- 2018/03/01 06:01 [medline]
PHST- 2018/03/01 06:00 [entrez]
AID - 10.1021/acs.jpca.8b00773 [doi]
PST - ppublish
SO  - J Phys Chem A. 2018 Mar 22;122(11):3096-3106. doi: 10.1021/acs.jpca.8b00773. Epub 
      2018 Mar 12.