Interlayer energy transport in Langmuir-Blodgett polymer films of poly[2-(9-carbazolyl)ethyl methacrylate-co-isobutyl methacrylate]

Abstract

Excitation energy transport through an ultrathin film has been investigated with a designed structure of copolymers containing carbazole and anthracene chromophores. Poly(isobutyl methacrylate) gives a stable monolayer at the air-water interface, and it is transferrable to a solid substrate. Various kinds of chromophores can be incorporated into this monolayer in the form of methacrylate esters. Using the Langmuir-Blodgett (LB) technique with these copolymers, artificial arrangements of the chromophoric units can be realized in a layered structure of the LB film. The carbazole chromophore exhibited simple monomer emission, and no excimer was detected. This spectroscopic property enabled us to carry out quantitative analyses of the interlayer energy-transfer process. Time-resolved fluorescence spectroscopy clearly showed efficient energy migration among carbazole chromophores. After several steps of interlayer migration, the excitation energy transfers to the anthracene layer coated on the carbazole layers. Although some unknown traps exist in this LB film, statistically random distribution of both the donor and acceptor moieties in each layer results in a high quenching yield of the carbazole excitons. Besides the uniform distribution, an advantage of polymer LB films is the thinness of each layer. These properties make possible the efficient energy transport through the layered structure.

Nano-structure of polyimide and poly(isobutyl methacrylate) monolayer films studied by interlayer electron transfer between porphyrin and pyromellitic diimide moieties

“…As shown in this figure, ln(Q 0 /Q) was linearly proportional to the C PMDI and from its slope the value of R was evaluated to be 1.13 nm. As reported previously, the monolayers of PI and PiBMA after transfer were 0.40 [18] and 1.06 nm, respectively [26]. Therefore, the electron transfer reaction from the photo-excited TPP in the poly(iBMA-co-AOTPP) layer (TPP layer) to the PMDI moieties in the neighboring PI layer can occur with a high probability depending on the mutual location of TPP and PMDI moieties in lateral and vertical directions.…”

“…The TPP layer and the PI layer were estimated to have a thickness of 1.06 and 0.40 nm, respectively [18,26]. Therefore, the center-to-center distance between the TPP layer and the neighboring PI layer is 0.73 nm and shorter than the radius of the active sphere, R = 1.13 nm.…”

Crystal structures, optical properties and theoretical calculation of novel two-photon polymerization initiators

“…These bands can be assigned to the excimer emission of the compounds due to the interactions between the molecules. Most carbazole compounds emit at wavelengths >400 nm in solid state [45][46][47] due to the aromatic p-p stacking. One sees that the fluorescence peak in Fig.…”

Synthesis and characterization of multifunctional polymers via atom transfer radical polymerization of N‐(ω′‐alkylcarbazolyl) methacrylates initiated by Ru(II) polypyridyl chromophores

“…Carbazole derivatives, known hole‐conducting materials, were chosen as basic building blocks for our study. Thus, side‐chain carbazole containing precursors N ‐( ω ′ ‐hydroxyethyl) carbazole ( 1 ) and N ‐( ω ′ ‐bromoalkyl) carbazoles ( 3– n ) and their corresponding N ‐( ω ′ ‐carbazolylalkyl) methacrylates ( 4– n ) monomers were synthesized as shown in Scheme with some modifications to the literature procedures 36–38. Neither N‐alkylation of the carbazole by the reaction of sodium carbazole with appropriate alkylating agents nor esterification of hydroxyalkyl carbazoles with methacryloyl chloride was adopted because of the inherent low yield of the long chain alkylated products and the tedious purification procedures.…”