Synthesis, characterization, and NLO properties of a phenothiazine-stilbazole monolayer

4-(trans-4-(4-(10-phenothiazinyl)butyramido)styryl)pyridine (PBSP) has been synthesized and covalently bound to a coupling layer of (p-(chloromethyl)p henyl)trichlorosilane (CPTS) on a quartz substrate to produce a polar-order ed thin film. The addition of the PBSP molecules on the coupling layer was monitored by FTIR spectroscopy, UV-visible spectroscopy, AFM, and second ha rmonic generation (SHG). The observation of an amine band and strong methyl ene 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, con sistent with the addition of the PBSP and quaternization of the pyridyl gro up. AFM shows that there is an incomplete coverage of the PBSP layer on the coupling layer. The nonlinear optical properties of the PBSP monolayers we re 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 choromophore was determined to be 55 degrees, and a value of chi(zzz) = chi(zxx) = 2.8 x 10(-8) esu was calculated.