01848nas a2200205   4500008004100000022001400041245010400055210006900159260000900228300001600237490000700253520111500260100001801375700003301393700002201426700002301448700002801471700002201499856012101521       2023                        eng d  a1144-054600aThe effect of substituents on the aggregation-induced emission of 9,10-phenanthraquinone-hydrazones0 aeffect of substituents on the aggregationinduced emission of 910  cAUG   a15066-150750 v473 a<p>
	Organic luminophores, particularly &amp; pi;-conjugated systems, have become crucial in modern optoelectronic devices that utilise luminescence as an output signal, requiring aggregate or solid-states, such as nanoparticles, thin films, or crystals. Herein, we report the one-step synthesis of six hydrazone derivatives using condensation reactions between 9,10-phenanthrenedione and different aromatic hydrazines, comprising electron-donating/electron-withdrawing groups and a quinoline moiety. The introduction of a conjugated &amp; pi;-system leads to complete co-planarization of molecules resulting in large bathochromic shifts in their absorption profile, the maximum red-shifts ever observed for the hydrazones. These hydrazones are weakly fluorescent in dilute acetonitrile solutions. However, they exhibit enhanced emissions of up to 300-fold in aggregated states. Dynamic light scattering (DLS) and scanning electron microscopy (SEM) studies support nanoaggregate formation. All the compounds exhibit red to NIR emissions in their crystalline state with as high as 75% quantum efficiency.</p>
1 aKumar, Naveen1 aLyngkhoi, Deikrisha, Lyngdoh1 aGaikwad, Sudhakar1 aSamanta, Debabrata1 aKhatua, Snehadrinarayan1 aPramanik, Susnata  uhttps://library.ncl.res.in/content/effect-substituents-aggregation-induced-emission-910-phenanthraquinone-hydrazones