02533nas a2200277   4500008004100000245016800041210006900209260000800278300001200286490000700298520154600305653003001851653001901881653002101900653002201921653001601943653001501959100002401974700002501998700002402023700002402047700001702071700002402088700002402112856011902136       2020                        eng d00aFive concomitant polymorphs of a green fluorescent protein chromophore (GFPc) analogue: understanding variations in photoluminescence with pi-stacking interactions0 aFive concomitant polymorphs of a green fluorescent protein chrom  cOCT  a850-8640 v763 a<p>The synthetically modified green fluorescent protein chromophore analogue 3,4,5-trimethoxybenzylidene imidazolinone (1) yielded five polymorphs (I, II, III, IV, V) concomitantly irrespective of the solvent used for crystallization. The pentamorphic modification of 1 is solely due to the interplay of iso-energetic weak intermolecular interactions in molecular associations as well as the conformational flexibility offered by a C-C single bond, which connects the electron-deficient moiety imidazolinone with the electron-rich trimethoxybenzylidene group. A common structural feature observed in all the polymorphs is the formation of a `zero-dimensional' centrosymmetric dimeric unit through a short and linear C-H center dot center dot center dot O hydrogen bond engaging phenyl C-H and imidazolinone carbonyl oxygen. However, the networking of these dimeric units showed a subtle difference in all the polymorphs. The 2D isostructurality was observed between polymorphs I, II and III, while the other two polymorphs IV and V revealed only `zero-dimensional' isostructurality. The different fluorescence emissions of Form I (blue) and Forms II to V (yellow) were attributed to the differences in pi-stacking interactions. It shows that one can modulate the photophysical properties of these smart materials by slightly altering their crystal structure. Such an approach will aid in developing new multi-colour organic fluorescent materials of varying crystal structures for live-cell imaging and fluorescent sensing applications.</p>
10agreen fluorescent protein10ahydrogen bonds10aisostructurality10aphotoluminescence10api-stacking10aPolymorphs1 aMali, Bhupendra, P.1 aDash, Soumya, Ranjan1 aNikam, Shrikant, B.1 aPuthuvakkal, Anisha1 aVanka, Kumar1 aManoj, Kochunnoonny1 aGonnade, Rajesh, G.  uhttps://library.ncl.res.in/content/five-concomitant-polymorphs-green-fluorescent-protein-chromophore-gfpc-analogue