Optical properties of inorganic polymers
The electronic structure of organic and inorganic polymeric systems are well described by their molecular symmetry, even with the large bond polarity shown by such systems as polyphosphazenes. We have performed calculations using semi-empirical Hamiltonians to determine the electronic structure and optical nonlinearities for a series of model phosphonitrilic and organic compounds. The optical transition energies for phosphonitrilic compounds are greater than their organic counterparts as a result of in-plane {pi}{prime} bonding interactions, and are modulated by the electronegativity of the substituent groups on the phosphorus atoms. We report values for the vertical ionization energy and electronic absorption wavelengths, and use molecular orbital contour analysis to show the effects of ligand electronegativity on the {pi}{prime} network. Hyperpolarizabilities were calculated from third order perturbation theory for a series of phosphonitrilic compounds, (X{sub 2}P-N){sub n}, as a function of bond length alternation and ligand substitution. In contrast to organic polyenes, the difference in {pi} orbital energy between phosphorus and nitrogen is critical to determining the onset of saturation and the magnitude of the hyperpolarizability.
- Research Organization:
- Pacific Northwest Lab., Richland, WA (USA)
- Sponsoring Organization:
- DOE/ER
- DOE Contract Number:
- AC06-76RL01830
- OSTI ID:
- 6664002
- Report Number(s):
- PNL-SA-18059; CONF-891119-139; ON: DE90017143
- Resource Relation:
- Conference: Materials Research Society fall meeting, Boston, MA (USA), 27 Nov - 2 Dec 1989
- Country of Publication:
- United States
- Language:
- English
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