The ZINDO-computed quadratic hyperpolarizability (beta) of p-nitroaniline (PNA) is compared
with that of its carbomer in its molecular mechanics (MM) optimized geometry. Complete
carbomerization of PNA leads to a new molecule with a static beta0 value of 941.3 x 10-30 cm5
esu-1 which is 2 orders of magnitude better than that of PNA. Within the model of pushpull
molecular topography, an empirical five-parameter formula is proposed in order to
estimate the beta value of 32 partial carbomer structures of p-nitroaniline. A compromise
between high beta values and a priori synthetic feasability is achieved for structures with three
carbomerized domains only: the carbon skeleton of the p-phenylene ring, the nitro group,
and the phenylene-nitro bond. The results are discussed within the framework of the two level
model on the basis of an orbital analysis.
Revised: January 23, 2012 |
Published: August 1, 2002
Citation
Ducere J., C. Lepetit, P.G. Lacroix, J. Heully, and R. Chauvin. 2002.Quadratic Hyperpolarizability of Carbomeric Structures.Chemistry of Materials 14, no. 8:3332-3338.