TY - JOUR
T1 - Theoretical insight into the second-order NLO response of the bis{4-[2-(4-pyridyl)ethenyl]benzoato}-zinc(II) metal-organic framework
AU - Zhang, Y.
AU - Champagne, B.
PY - 2012/10/18
Y1 - 2012/10/18
N2 - Ab initio wavefunction and density functional theory calculations have been performed to investigate the second-order nonlinear optical (NLO) properties of the bis{4-[2-(4-pyridyl)ethenyl]benzoato}-zinc(II) metal-organic framework (MOF). This has been carried out by adopting the supramolecular or cluster approach, which consists in analyzing the evolution of the first hyperpolarizability as a function of the number of units of the system. In a first step, the impact of the method of calculation has been assessed, evidencing that the exchange-correlation functional has a stronger impact on the first hyperpolarizability (β) values than the basis set. Still, the first hyperpolarizability values related to the hyper-Rayleigh scattering (HRS) (β ) are slightly more sensitive to the Zn basis set than to that of the other atoms, but the combination of the LANL2DZ basis for Zn with the 6-31G* basis set for the other atoms provides stable results with respect to adding supplementary valence, polarization, and diffuse functions as demonstrated by the variations of β that remain smaller than 6%. Several structure/property relationships have then been deduced for the β of this MOF: (i) the lack of coordination of the ligands extremities enhances β because their donor/acceptor characters are not damped by the Zn cations, (ii) the β of clusters expanding in one direction increases almost linearly with the cluster size, (iii) the deviations with respect to linearity are smaller than 25%, which differ from organic molecular crystals, and (iv) the octupolar component of the β response is of the same order of magnitude as its dipolar counterpart, and its relative importance generally increases with the cluster size.
AB - Ab initio wavefunction and density functional theory calculations have been performed to investigate the second-order nonlinear optical (NLO) properties of the bis{4-[2-(4-pyridyl)ethenyl]benzoato}-zinc(II) metal-organic framework (MOF). This has been carried out by adopting the supramolecular or cluster approach, which consists in analyzing the evolution of the first hyperpolarizability as a function of the number of units of the system. In a first step, the impact of the method of calculation has been assessed, evidencing that the exchange-correlation functional has a stronger impact on the first hyperpolarizability (β) values than the basis set. Still, the first hyperpolarizability values related to the hyper-Rayleigh scattering (HRS) (β ) are slightly more sensitive to the Zn basis set than to that of the other atoms, but the combination of the LANL2DZ basis for Zn with the 6-31G* basis set for the other atoms provides stable results with respect to adding supplementary valence, polarization, and diffuse functions as demonstrated by the variations of β that remain smaller than 6%. Several structure/property relationships have then been deduced for the β of this MOF: (i) the lack of coordination of the ligands extremities enhances β because their donor/acceptor characters are not damped by the Zn cations, (ii) the β of clusters expanding in one direction increases almost linearly with the cluster size, (iii) the deviations with respect to linearity are smaller than 25%, which differ from organic molecular crystals, and (iv) the octupolar component of the β response is of the same order of magnitude as its dipolar counterpart, and its relative importance generally increases with the cluster size.
UR - http://www.scopus.com/inward/record.url?scp=84867520076&partnerID=8YFLogxK
U2 - 10.1021/jp307283m
DO - 10.1021/jp307283m
M3 - Article
AN - SCOPUS:84867520076
SN - 1932-7447
VL - 116
SP - 21973
EP - 21981
JO - Journal of Physical Chemistry C: Nanomaterials and interfaces
JF - Journal of Physical Chemistry C: Nanomaterials and interfaces
IS - 41
ER -