Energy Transport in Dichroic Metallo‐organic Crystals: Selective Inclusion of Spatially Resolved Arrays of Donor and Acceptor Dyes in Different Nanochannels

In this study, the precise positioning and alignment of arrays of two different guest molecules in a crystalline host matrix has been engineered and resulted in new optically active materials. Sub‐nm differences in the diameters of two types of 1D channels are sufficient for size‐selective inclusion of dyes. Energy transport occurs between the arrays of different dyes that are included in parallel‐positioned nanochannels by Förster resonance energy transfer (FRET). The color of individual micro‐sized crystals are dependent on their relative position under polarized light. This angular‐dependent behavior is a result of the geometrically constrained orientation of the dyes by the crystallographic packing of the host matrix and is concentration dependent.