TY - JOUR
T1 - The application of molecular modelling techniques in the prediction of the photochromic behaviour of spiroindolinonaphthoxazines
AU - Christie, Robert M.
AU - Chi, Li J.
AU - Spark, Roger A.
AU - Morgan, Keith M.
AU - Boyd, A. S F
AU - Lycka, Antonin
PY - 2005/1/1
Y1 - 2005/1/1
N2 - Two isomeric photochromic compounds, spiroindolinonaphth[2,1-b] [1,4] oxazine 1 and spiroindolinonaphth[1,2-b] [1,4] oxazine 2, were synthesised. During the synthesis of spirooxazine 2, a coloured, non-photochromic spirooxazine 6 was isolated as an associated product and characterised as a mixture of geometric isomers. A range of readily available molecular modelling techniques were applied to provide an account of the behaviour of the photochromic materials. Heats of formation calculated using AM1, following MM2 geometry optimisation, for ring-closed and ring-opened spirooxazines, provide a method for assessing whether a spirooxazine might be expected to show photochromic behaviour. ZINDO calculations based on the molecular geometry optimised in this way provide a reasonable account of the UV-vis absorption profile of the ring-closed forms 1 and 2. An approach that uses MM2 calculations to predict the most stable of the isomer(s) of the transient ring-opened photomerocyanines, used in combination with PPP-MO calculations using optimised parameterisation, may be used to provide a prediction of the ?max values, although the method may not produce an unequivocal result when the energies of the geometrical isomers are similar. © 2004 Elsevier B.V. All rights reserved.
AB - Two isomeric photochromic compounds, spiroindolinonaphth[2,1-b] [1,4] oxazine 1 and spiroindolinonaphth[1,2-b] [1,4] oxazine 2, were synthesised. During the synthesis of spirooxazine 2, a coloured, non-photochromic spirooxazine 6 was isolated as an associated product and characterised as a mixture of geometric isomers. A range of readily available molecular modelling techniques were applied to provide an account of the behaviour of the photochromic materials. Heats of formation calculated using AM1, following MM2 geometry optimisation, for ring-closed and ring-opened spirooxazines, provide a method for assessing whether a spirooxazine might be expected to show photochromic behaviour. ZINDO calculations based on the molecular geometry optimised in this way provide a reasonable account of the UV-vis absorption profile of the ring-closed forms 1 and 2. An approach that uses MM2 calculations to predict the most stable of the isomer(s) of the transient ring-opened photomerocyanines, used in combination with PPP-MO calculations using optimised parameterisation, may be used to provide a prediction of the ?max values, although the method may not produce an unequivocal result when the energies of the geometrical isomers are similar. © 2004 Elsevier B.V. All rights reserved.
KW - Molecular modelling
KW - Photochromism
KW - Photomerocyanine
KW - Spirooxazine
UR - http://www.scopus.com/inward/record.url?scp=8744287542&partnerID=8YFLogxK
U2 - 10.1016/j.jphotochem.2004.06.006
DO - 10.1016/j.jphotochem.2004.06.006
M3 - Article
VL - 169
SP - 37
EP - 45
JO - Journal of Photochemistry and Photobiology A: Chemistry
JF - Journal of Photochemistry and Photobiology A: Chemistry
IS - 1
ER -