SURFACE-ENHANCED RAMAN-SPECTRA OF LANGMUIR-BLODGETT MONOLAYERS OF (HEXADECAMETHYLTETRALINO)PORPHYRAZINES

Langmuir monolayers of metal-free tra(1,1,4,4-tetramethyl-6,7-tetralin o)porphyrazine (HDMTLPH2) and its copper complex (HDMTLPCu) were forme d on a water subphase. The surface pressure-area isotherms were measur ed and the floating monolayers were transferred to various substrates. The spectra of Langmuir-Blodgett (LB) films deposited on metal surfac es were studied. Surface-enhanced Raman spectra of a single LB monolay er of HDMTLPH, and HDMTLPCu deposited on rough surfaces (silver-coated tin spheres and island films of silver and gold) are reported. Reflec tion absorption Fourier transform IR spectra of LB films on smooth sil ver are also presented. The spectroscopic characterization includes th e UV-visible spectra of multilayer films on glass slides, solutions an d the bulk materials. Characteristic vibrational wavenumbers are liste d and used to discuss molecular orientation in the LB assemblies.