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2 Polish Journal of Chemistry

2 1998

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Nonlinear optical properties of 1-alkyl-4(2-benzimidazolylidene)-1,4-dihydropyridines and their Langmuir film formation

100%

Janik R. , Kucharski S. , Prędota J.

1998

tom Vol. 72, nr 5

901-909

The nonlinear optical properties of a homologous series of heterocyclic betaines (1-alkyl-4(2-benzimidazolylidene)-1,4-dihydropyridines) with methtyl, n-butyl, n-octyl, n-dodecyl and n-hexadecyl alkyl groups were evaluated by determination of their first hyperpolarizability (beta) using solvatochromic method. The measurements showed that in static (beta(0)) and in external field (beta(1064)) first hyperpolarizability values for the betaines were 2.5-3.4 and 4-5 times higher than that for p-nitroaniline, respectively. The Langmuir monolayer formation of the compounds on aqueous surface was evaluated by the surface pressure (Pi) vs. molecular area per molecule (delta) isotherms. The betaines with n-dodecyl and n-hexadecyl chains were able to form a Langmuir film, although the shape of Pi-delta isotherms indicated that they would not be qualified as good film forming materials of single component films.

Langmuir-Blodgett film formation by polymeric materials

100%

Raźna J. , Kucharski S. , Bryjak M.

tom Vol. 72, nr 10

2312-2320

Polymeric materials such as: poly(n-octadecyl methacrylate), poly(n-octadecyl methacrylate-co-N-p-nitrophenylmaleimide) and poly(n-octadecyl methacrylate-co-N-p-nitrophrnylacrylamide) were synthesized to investigate their ability for monolayer film formation and deposition. It was found that polymerization of n-octadecyl methacrylateee yielded the material with improved ability of film formation as compared with the monomer, and the surface pressure-area isotherm showed a distinct solid film phase formation with a high value of film collapse pressure of ca. 56 mN/m. The incorporation of a co-monomer resulted in a shift of the surface pressure isotherm towards higher area values, still with a distinct solid film phase region and high film collapse pressure. The thickness of the poly(n-octadecyl methacrylate) film deposited onto a solid subphase was ca. 3 nm per monolayer (as determined by surface plasmon resonance) and this value corresponded to the lenght of the monomer molecule.