(a) Crystal structures of H-HexNet motifs of Tp-1, T12-1, T18-1, and Ex-1. Normalized solid state fluorescence spectra of (b) Tp-apo (solid line) and Tp-2Ds (dashed line), (c) T12-apo (solid line) and T12-1 (dashed line), (d) T18-apo-II (solid line) and T18-1 (dashed line), and (e) Ex-apo (solid line) and Ex-1 (dashed line). Reprinted with permission.97 Copyright 2016 American Chemical Society.