Polymer, Vol.75, 109-118, 2015
Synthesis of triptycene based non-conjugated polytriazole: Temperature dependent regioselectivity and host-guest interaction with nitroaromatics
We report facile synthesis of a new triptycene based monomeric building block 2,6-diazidotriptycene (DAZT) that has been utilized to synthesize a series of triptycene based and triazole linked alternate co-polymer (TPT1-TPT4) via Cu(I)OAc catalyzed Sharpless "Click reaction". The effect of reaction temperature on regioselective incorporation of 1,2,3-triazole motif in the polymer backbone has been studied. The newly synthesized triptycene-polytriazole (TPT) polymers (having 1,4-regioregular 1,2,3-triazole units) have been characterized using NMR, FTIR, and UV-vis spectroscopic techniques. Interestingly, TPTs possess moderately high molecular weight, are organosoluble, amorphous in nature and have reasonably high thermal stability with T-g > 400 degrees C. Additionally, selected polymers are fluorescent in nature. These fluorescent TPTs interact strongly with nitroaromatics (NACs), as evident from the binding constants values obtained from Benesi - Hildebrand fluorescence plots (assuming complexation 1: 1). The extent of fluorescence quenching of these TPTs in presence of NACs was also estimated from Stern-Volmer (SV) plots. It was observed that polymer backbone which is richer in nitrogen, exhibited superior sensitivity towards NACs. Amongst the three NACs, PA is the most efficient quencher. K-SV values of TPTs for various NACs are comparable with those of previously reported polymers. (C) 2015 Elsevier Ltd. All rights reserved.