One-Directional Antenna Systems: Energy Transfer from Monomers to J-Aggregates within 1D Nanoporous Aluminophosphates

Authors: Sola-Llano, R; Fujita, Y; Gomez-Hortiguela, L; Alfayate, A; Uji-i, H; Fron, E; Toyouchi, S; Perez-Pariente, J; Lopez-Arbeloa, I; Martinez-Martinez, V

Article.
ACS Photonics. vol: 5. page: 2330-4022.
Date: JAN. 2018.
Doi: 10.1021/acsphotonics.7b00553.

Abstract:
A cyanine dye (PIC) was occluded into two 1D-nanopoporus Mg-containing aluminophosphates with different pore size (MgAPO-5 and MgAPO-36. with AFI and ATS zeolitic structure types, with cylindrical channels of 7.3 angstrom diameter and elliptical channels of 6.7 angstrom X 7.5 angstrom, respectively) by crystallization inclusion method. Different J-aggregates are photophysically characterized as a consequence of the different pore size of the MgAPO frameworks, with emission bands at 565 nm and at 610 nm in MgAPO-5 and MgAPO-36, respectively. Computational results indicate a more linear geometry of the J-aggregates inside the nanochannels of the MgAPO-36 sample than those in MgAPO-5, which is as a consequence of the more constrained environment in the former. For the same reason, the fluorescence of the PIC monomers at 550 nm is also activated within the MgAPO-36 channels. Owing to the strategic distribution of the fluorescent PIC species in MgAPO-36 crystals (monomers at one edge and J-aggregates with intriguing emission properties at the other edge) an efficient and one-directional antenna system is obtained. The unidirectional energy transfer process from monomers to J-aggregates is demonstrated by remote excitation experiments along tens of microns of distance..