02396nas a2200205   4500008004100000022001400041245011500055210006900170260000800239300001400247490000700261520167200268100001801940700002201958700001701980700001701997700002202014700002402036856013002060       2025                        eng d  a1528-748300aCocrystals of the green fluorescence protein chromophore analogue: coformer-induced switch between AIE and ACQ0 aCocrystals of the green fluorescence protein chromophore analogu  cSEP  a7473-74880 v253 a<p>
	Fluorescent organic solids hold great potential for advancing photonics applications. However, tuning their solid-state photoluminescent emissions remains a significant challenge. In this study, we report the synthesis and characterization of five cocrystals (two cocrystal polymorphs) derived from a pristine imidazolinone derivative (A) and the various coformer molecules, namely 1,2,4,5-tetrafluoro-3,6-diiodobenzene, 1,2,4,5-tetrafluoro-3,6-dibromobenzene, perfluoronaphthalene, and 3,4,5-trifluorobenzoic acid. The structural and optical properties of these cocrystals were examined by using single-crystal X-ray diffraction, absorption spectroscopy, photoluminescence spectroscopy, and photoluminescence decay spectroscopy. Cocrystals I, II, and III are isomorphous pairs and exhibit three-dimensional isostructurality, where the coformer molecules bridge adjacent helices of compound A, leading to aggregation-induced emission. In contrast, the cocrystal polymorphs IVA and IVB developed using coformer 3,4,5-trifluorobenzoic acid form two-dimensional sheet-like structures mediated by pi-stacking interactions between the coformers and molecule A, with interplanar distances ranging from 3.2 to 3.5 &amp; Aring;. These stronger pi-pi interactions promote nonradiative decay pathways, resulting in reduced or quenched fluorescence and an aggregation-caused quenching effect. To gain further insights into their electronic properties, theoretical analysis including frontier molecular orbitals, time-dependent density functional theory, Hirshfeld surface analysis, molecular electrostatic potential, and noncovalent interaction plots were performed.</p>
1 aSuresh, Sneha1 aDabke, Niteen, B.1 aPandya, Rinu1 aVanka, Kumar1 aDutta, Madhusudan1 aGonnade, Rajesh, G.  uhttps://library.ncl.res.in/content/cocrystals-green-fluorescence-protein-chromophore-analogue-coformer-induced-switch-between