title: Theory-guided design and synthesis of multichromophore dendrimers: an analysis of the electro-optic effect.
abstract: Extensive experimental and theoretical study suggests that interchromophore electrostatic interactions are among the most severe impediments to the induction and stability of large electro-optic coefficients in electric-field-poled organic materials. In this report, multichromophore-containing dendritic materials have been investigated as a means to minimize unwanted attenuation of nonlinear optical (electro-optic) activity at high chromophore loading. The dendritic molecular architectures employed were designed to provide optimized molecular scaffolding for electric-field-induced molecular reorientation. Design parameters were based upon past experimental results in conjunction with statistical and quantum mechanical modeling. The electro-optic behavior of these materials was evaluated through experimental and theoretical analysis. Experimental data collected from the dendrimer structures depict a reasonably linear relationship between chromophore number density (N) and electro-optic activity (r(33)) demonstrating a deviation from the dipolar frustration that typically limits r(33) in conventional chromophore/polymer composite materials. The observed linear dependence holds at higher chromophore densities than those that have been found to be practical in systems of organic NLO chromophores dispersed in polymer hosts. Theoretical analysis of these results using Monte Carlo modeling reproduces the experimentally observed trends confirming linear dependence of electro-optic activity on N in the dendrimer materials. These results provide new insight into the ordering behavior of EO dendrimers and demonstrate that the frequently observed asymptotic dependence of electro-optic activity on chromophore number density may be overcome through rational design.
authors.affiliation: Department of Chemistry and Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98105, USA. psull76@u.washington.edu
authors.forename: Philip A
authors.initials: PA
authors.lastname: Sullivan
authors.forename: Harrison
authors.initials: H
authors.lastname: Rommel
authors.forename: Yi
authors.initials: Y
authors.lastname: Liao
authors.forename: Benjamin C
authors.initials: BC
authors.lastname: Olbricht
authors.forename: Andrew J P
authors.initials: AJ
authors.lastname: Akelaitis
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Firestone
authors.forename: Jae-Wook
authors.initials: JW
authors.lastname: Kang
authors.forename: Jingdong
authors.initials: J
authors.lastname: Luo
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Davies
authors.forename: Dong Hoon
authors.initials: DH
authors.lastname: Choi
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Eichinger
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Reid
authors.forename: Antao
authors.initials: A
authors.lastname: Chen
authors.forename: Alex K-Y
authors.initials: AK
authors.lastname: Jen
authors.forename: Bruce H
authors.initials: BH
authors.lastname: Robinson
authors.forename: Larry R
authors.initials: LR
authors.lastname: Dalton