01575nas a2200193   4500008004100000022001400041245016200055210006900217260000900286300001600295490000700311520081500318100002201133700001901155700002401174700002601198700002801224856012901252       2023                        eng d  a0022-326300aCarbamate-Protected (BOC and O-NB) 2-Aminopyrimidinedione-based janus G-C nucleobase motifs as building blocks for supramolecular assembly and smart polymers0 aCarbamateProtected BOC and ONB 2Aminopyrimidinedionebased janus   cOCT   a14953-149590 v883 a<p>In this paper, we report ``carbamate protected'' 2-aminopyrimidinedione-based Janus G-C nucleobases (2-APD Janus G-C nucleobases) featuring polymerizable groups and self-complementary triple H-bonding motifs DDA and AAD as building blocks for developing smart polymers and self-healing materials. The carbamate-masked H-bonding motif, cleavable under acidic (BOC group) or photocleavable (O-nitrobenzyl group) conditions, would facilitate the synthesis of smart polymers by alleviating aggregation during polymerization which in turn would exclude self-assembly-assisted solubility issues. Ready accessibility in excellent yields coupled with the possibility for facile introduction of polymerizable groups would make these building blocks excellent candidates for diverse polymerization applications.</p>
1 aSingh, Dharmendra1 aLakshmi, Durga1 aMeena, Chhuttan, L.1 aKrishna, Gamidi, Rama1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/carbamate-protected-boc-and-o-nb-2-aminopyrimidinedione-based-janus-g-c-nucleobase-motifs02417nas a2200241   4500008004100000022001400041245010900055210006900164260000800233300001400241490000700255520158900262100001901851700002301870700001901893700002001912700002101932700001701953700001901970700002801989700002702017856013102044       2026                        eng d  a0897-475600aDynamic janus hydrogen bond mimicry unlocks tough, flexible supramolecular elastomers for strain sensing0 aDynamic janus hydrogen bond mimicry unlocks tough flexible supra  cMAR  a2699-27110 v383 a<p>
	Flexible and wearable electronics demand stretchable sensors with polymer elastomers as key matrixes for mechanical flexibility and durability. However, despite their excellent elasticity, their limited mechanical strength remains a challenge. To address this limitation, in this study, we report the rational design of supramolecular polyurethane elastomers (SPUs) incorporating nucleobase-inspired aminopyrimidinedione with DDA-AAD (G-C mimic) reversible triple hydrogen bonds. This dual-domain architecture gives rise to a durable supramolecular network with enhanced mechanical properties, yielding elastomers that are soft, stretchable, and tough. By tuning of the density of dynamic cross-links, mechanical properties were systematically modulated. SPU-0.5 exhibited a maximum tensile strength of 16.14 MPa, representing a 67-fold strength enhancement over that of SPU-0. Although increasing the aminopyrimidinedione (APD) content reduced elongation, SPU-0.2 retained a high elongation of 1060% and showed the lowest residual strain during cyclic tests. To be of great interest, the activation energy increased with increasing hydrogen bonding content up to SPU-0.1, whereas beyond SPU-0.2 it decreased, likely due to extensive hydrogen bond formation. Furthermore, SPU-0.2-SP, a conductive variant, demonstrated a promising strain-sensing performance even after hundreds of cycles. Overall, the insights gained from this study advance the development of intelligent soft materials and lay the groundwork for next-generation flexible and wearable electronic devices.</p>
1 aLakshmi, Durga1 aWagh, Mahendra, A.1 aSharma, Aakash1 aAlam, Md, Shafi1 aSelvan, Muthamil1 aTorris, Arun1 aMondal, Titash1 aSanjayan, Gangadhar, J.1 aNair, Kiran, Sukumaran  uhttps://library.ncl.res.in/content/dynamic-janus-hydrogen-bond-mimicry-unlocks-tough-flexible-supramolecular-elastomers-strain