Quantum dot with zinc and copper substituted phthalocyanines. 1. Energy transfer in solution and in-situ light absorption in Langmuir monolayers

The paper deals with spectroscopic characterization of a core/shell CdSe/ZnS quantum dot and phthalocyanines substituted with butyl and octakis(octyloxy) peripheral groups: zinc (II) and copper (II) 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine, zinc (II) and copper (II) 2,3,9,10,16,17,23,24-octakis(octyloxy)-29H,31H-phthalocyanine in chloroform as well as in a form of 2D Langmuir monolayers. The isotherms of surface pressure as a function of the mean area per molecule are examined and the in-situ absorption study of the Langmuir monolayer is also studied. The influence of the substituents attached to the phthalocyanine macroring and of the presence of the quantum dot on dye spectroscopic properties (absorption and fluorescence) is shown. Molecular arrangement of the molecular skeleton of the phthalocyanines on water substrate is evaluated. A comparison of the in-situ absorption of the phthalocyanine monolayers and electronic absorption spectra of the dyes in chloroform supports the existence of dye aggregates in the monolayer. Interaction between the phthalocyanine dyes and CdSe/ZnS quantum dot observed as dot fluorescence quenching is also discussed. (C) 2013 Elsevier B.V. All rights reserved.