PMID- 19809672
OWN - NLM
STAT- MEDLINE
DCOM- 20091125
LR  - 20131121
IS  - 1463-9076 (Print)
IS  - 1463-9076 (Linking)
VI  - 11
IP  - 30
DP  - 2009 Aug 14
TI  - Acceleration of the Z to E photoisomerization of penta-2,4-dieniminium by 
      hydrogen out-of-plane motion: theoretical study on a model system of retinal 
      protonated Schiff base.
PG  - 6406-14
LID - 10.1039/b900882a [doi]
AB  - We report the result of comparison between two reaction coordinates [on the 
      potential energy surface of the first excited state (S(1))] produced by CASSCF 
      and these energies recalculated by MRMP2 in the Z to E photoisomerization of 
      penta-2,4-dieniminium (PDI) as the minimal model of the retinal protonated Schiff 
      base (RPSB). One coordinate is the S(1) state minimum-energy-path (MEP) in 
      mass-weighted coordinates from the S(1) vertically excited point, where a strong 
      hydrogen-out-of plane (HOOP) motion is not exhibited. The energy profile of the 
      S(1) MEP at the MRMP2//CASSCF level shows a barrier for the rotation around the 
      reactive C-C and hits the S(1)/S(0) degeneracy space where the central C-C-C-C 
      dihedral angle is distorted by 65 degrees . The other coordinate is an S(1) 
      coordinate obtained by the relaxed scan strategy. The relaxed coordinate along 
      the central C-C-C-C dihedral angle, which we call the HOOP coordinate, shows 
      strong HOOP motion. According to the MRMP2//CASSCF calculation, there is no 
      barrier on the HOOP coordinate. Furthermore, the S(1) to S(0) transition may be 
      possible without the large skeletal deformation by HOOP motion because the HOOP 
      coordinate encounters the S(1)/S(0) degeneracy space where the central C-C-C-C 
      dihedral angle is distorted by only 40 degrees . Consequently, if PDI is a 
      suitable model molecule for the RPSB as often assumed, the 11-cis to all-trans 
      photoisomerization is predicted to be accelerated by the HOOP motion.
FAU - Sumita, Masato
AU  - Sumita M
AD  - Department of Chemistry, Graduate School of Pure and Applied Sciences, University 
      of Tsukuba, Tsukuba, 305-8571, Japan.
FAU - Ryazantsev, Mikhail N
AU  - Ryazantsev MN
FAU - Saito, Kazuya
AU  - Saito K
LA  - eng
PT  - Journal Article
DEP - 20090609
PL  - England
TA  - Phys Chem Chem Phys
JT  - Physical chemistry chemical physics : PCCP
JID - 100888160
RN  - 0 (Schiff Bases)
RN  - 7YNJ3PO35Z (Hydrogen)
RN  - 9009-81-8 (Rhodopsin)
RN  - RR725D715M (Retinaldehyde)
SB  - IM
MH  - Computer Simulation
MH  - Hydrogen/chemistry
MH  - Models, Chemical
MH  - Models, Molecular
MH  - Molecular Conformation
MH  - Molecular Structure
MH  - Motion
MH  - Photochemistry/*methods
MH  - Retinaldehyde/*chemistry
MH  - Rhodopsin/*chemistry
MH  - Schiff Bases
MH  - Spectrum Analysis, Raman/methods
EDAT- 2009/10/08 06:00
MHDA- 2009/12/16 06:00
CRDT- 2009/10/08 06:00
PHST- 2009/10/08 06:00 [entrez]
PHST- 2009/10/08 06:00 [pubmed]
PHST- 2009/12/16 06:00 [medline]
AID - 10.1039/b900882a [doi]
PST - ppublish
SO  - Phys Chem Chem Phys. 2009 Aug 14;11(30):6406-14. doi: 10.1039/b900882a. Epub 2009 
      Jun 9.