Synthesis, characterization, and NLO properties of a phenothiazine-stilbazole monolayer
- and others
Engineering highly nonlinear optically (NLO) active assemblies can lead to thin films with potentially useful properties. For instance, materials with electron donor and acceptor groups bridged by a conjugated system have potential application as molecular wires, where electrons can tunnel or hop through the conjugated bridge. Phenothiazine and its derivatives are of widespread chemical interest. For example, they have useful pharmacological properties and can potentially be used in solar energy conversion. There is also interest in these systems as charge-transfer complexes with several acceptors due to their low ionization potentials. 4-(trans-4-(4-(10-phenothiazinyl)butyramido)styryl)pyridine (PBSP) has been synthesized and covalently bound to a coupling layer of (p-(chloromethyl)phenyl)trichlorosilane (CPTS) on a quartz substrate to produce a polar-ordered thin film. The addition of the PBSP molecules on the coupling layer was monitored by FTIR spectroscopy, UV--visible spectroscopy, AFM, and second harmonic generation (SHG). The observation of an amine band and strong methylene bands in the infrared spectra indicates the presence of the PBSP layer. The UV-visible spectrum shows a red shift in the charge-transfer band, consistent with the addition of the PBSP layer on the coupling layer. The nonlinear optical properties of the PBSP monolayers were measured by SHG. The second harmonic (SH) signal increased by 1 order of magnitude after the addition of the PBSP chromophore layer. The dependence of the SH intensity on incident angle and input polarization was modeled. The average molecular orientation angle of the chromophore was determined to be 55{degree}, and a value of {chi}{sub zzz}= {chi}{sub zxx} = 2.8 x 10 {sup {minus}8} esu was calculated.
- Research Organization:
- New Mexico Highlands Univ., Las Vegas, NV (US)
- OSTI ID:
- 20000010
- Journal Information:
- Langmuir, Vol. 15, Issue 19; Other Information: PBD: 14 Sep 1999; ISSN 0743-7463
- Country of Publication:
- United States
- Language:
- English
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