Executive Summary : | Non-covalent short and long-range molecular interactions play a major role in supramolecular organic crystals.[1] Synthetic control over these interactions would modify the physio-chemical properties of these plastic and elastic crystals.[2-3] Thus, very significant research is going on towards modulating these interactions in flexible crystals through plastic (irreversible) and elastic (reversible) deformations towards several applications such as light emitting diodes, detectors, optical waveguide, organic solid state lasers, optoelectronic devices, semiconductors, and sensors etc.[4-15] It is quite challenging to predict the influence of mechanical deformation on the spectral and temporal optical properties of crystals. Very recently it has been shown that fluorescence intensity gets enhanced because of bending in GFP chromophore crystals.[16] However, the nanoscopic understanding of structure-property relationship in this direction is at its nascent stage. This is because it is not possible to obtain such information using state of the art fluorimeters. There is no report regarding how the mechanical deformation affects the excited state dynamics and hence influence the spectral behaviour in flexible crystals. (A) How the nanoscopic supramolecular interactions get modified in the flexible crystal because of physical deformation (say bending) and (B) its correlation with the modification of fluorescence intensity and fast excited state dynamics, are unknown and hence would be quite interesting to investigate. |