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Updated: Jun 19, 2026

Interfacial Molecular-level Structures of Polymers and Biomacromolecules Revealed via Sum Frequency Generation Vibrational Spectroscopy
Published on: August 13, 2019
Theoretical study of nonlinear optical properties of "parallel connection" chromophores containing parallel
Chao-Zhi Zhang1, Hui Cao, Chan Im
1Department of Chemistry, Konkuk University, Seoul 143-701, Korea. chzhzhang@sohu.com
Abstract:
Chromophores containing two parallel nonconjugated D-pi-A units are effective chromophores with high hyperpolarizability and good optical transparency. It provides a method for the design and synthesis of effective chromophores. The semiempirical method ZINDO was employed to study the relationship between enhancement of the static first hyperpolarizabilities (beta0) per D-pi-A unit and the number of parallel nonconjugated D-pi-A units in a chromophore. The results show that the chromophores containing two parallel nonconjugated D-pi-A units would exhibit higher beta0 values than two times the beta0 value of the corresponding reference chromophore containing a D-pi-A unit. The chromophore containing three parallel nonconjugated D-pi-A units exhibits the highest enhancement of beta0 per D-pi-A unit, which is 10.1 times the beta0 value of the corresponding reference chromophore. However, the beta0 value of the chromophore containing four parallel nonconjugated D-pi-A units is very small, and the enhancement of beta0 value per D-pi-A unit decreases sharply, from 10.1 to 0.3, with increasing the number of parallel D-pi-A units in a chromophore from 3 to 4. It could give a useful suggestion for designing chromophores containing parallel nonconjugated D-pi-A units.
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