TY - JOUR
T1 - Distinguishing the effects of bond-length alternation versus bond-order alternation on the nonlinear optical properties of conjugated chromophores
AU - Gieseking, Rebecca L.
AU - Risko, Chad
AU - Brédas, Jean Luc
N1 - Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/6/18
Y1 - 2015/6/18
N2 - Understanding the relationships between the molecular nonlinear optical (NLO) properties and the bond-length alternation (BLA) or π-bond-order alternation (BOA) along the molecular backbone of linear π-conjugated systems has proven widely useful in the development of NLO organic chromophores and materials. Here, we examine model polymethines to elucidate the reliability of these relationships. While BLA is solely a measure of molecular geometric structure, BOA includes information pertaining to the electronic structure. As a result, BLA is found to be a good predictor of NLO properties only when optimized geometries are considered, whereas BOA is more broadly applicable. Proper understanding of the distinction between BLA and BOA is critical when designing computational studies of NLO properties, especially for molecules in complex environments or in nonequilibrium geometries.
AB - Understanding the relationships between the molecular nonlinear optical (NLO) properties and the bond-length alternation (BLA) or π-bond-order alternation (BOA) along the molecular backbone of linear π-conjugated systems has proven widely useful in the development of NLO organic chromophores and materials. Here, we examine model polymethines to elucidate the reliability of these relationships. While BLA is solely a measure of molecular geometric structure, BOA includes information pertaining to the electronic structure. As a result, BLA is found to be a good predictor of NLO properties only when optimized geometries are considered, whereas BOA is more broadly applicable. Proper understanding of the distinction between BLA and BOA is critical when designing computational studies of NLO properties, especially for molecules in complex environments or in nonequilibrium geometries.
KW - bond length alternation
KW - bond order alternation
KW - cyanines/polymethines
KW - nonlinear optics
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U2 - 10.1021/acs.jpclett.5b00812
DO - 10.1021/acs.jpclett.5b00812
M3 - Article
AN - SCOPUS:84934947946
SN - 1948-7185
VL - 6
SP - 2158
EP - 2162
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
IS - 12
ER -