Studies on the composite Langmuir-Blodgett films of tetracationic porphyrazine cobalt and methyl orange

Citation
Xs. Feng et al., Studies on the composite Langmuir-Blodgett films of tetracationic porphyrazine cobalt and methyl orange, LANGMUIR, 16(24), 2000, pp. 9385-9389
Citations number
43
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
LANGMUIR
ISSN journal
0743-7463 → ACNP
Volume
16
Issue
24
Year of publication
2000
Pages
9385 - 9389
Database
ISI
SICI code
0743-7463(20001128)16:24<9385:SOTCLF>2.0.ZU;2-8
Abstract
By spreading the amphiphilic cobalt tetrahexadecyl-tetrapyridinoporphyrazin ium bromide (TA(16)PyPzCo) on the air/aqueous methyl orange (MO) solution i nterface, composite monolayer of TA(16)PyPzCo/MO was formed. Composite Lang muir Blodgett(LB) films have been fabricated and characterized by means of UV-vis spectra, IR spectra, and X-ray diffraction (XD). The molecular orien tation was estimated by using polarized UV-vis and polarized IR absorption measurements. The orientation angles of the hydrocarbon chains of TA(16)PyP zCo, the macrocycle, and the MO with respect to the normal of the substrate were estimated to be 49.5 degrees, 56.9 degrees, and 46.2 degrees, respect ively. The XD patterns of the LB films showed a well-defined lamella struct ure, and the d value was 6.04 nm. Based on these results, a possible film s tructure was proposed, in which the MO unit was under the macrocycle in the composite monolayer, and the long alkyl chains were interpenetrated in the adjacent TA(16)PyPzCo layer in the LB films. The trans to cis photoisomeri zation of the azobenzene group in MO molecules in LB films has been investi gated.