Metal−organic coordination polymers are modular systems whose structures can be modified in numerous ways to introduce and influence non-linear optical and electrical properties. However, their full potential as piezoelectric nanogenerators for self-powered electronics is yet to be uncovered. Here, we report a Zn(II)-based ferroelectric one-dimensional coordination network {and 2,2′-bipyridine as a co-ligand. The origin of polarization in 1, despite its neutral structure, is due to the polyhedral distortions around the Zn(II) center as revealed by ab initio calculations. The presence of polarizable domains was visualized by piezoresponse force microscopy (PFM) experiments. Also, from the PFM studies, a sizable converse piezoelectric coefficient (d 33 ) value of 19.4 pm/V was noticed for 1, which is unprecedentedly high for the class of neutralnetwork coordination polymers. Furthermore, flexible composite devices comprising a thermoplastic polyurethane (TPU) polymer with different weight percentages (wt %) of 1 were prepared and examined for application as piezoelectric nanogenerators. Notably, the champion device of this series (poled 5 wt % 1-TPU composite) exhibits a highest open-circuit voltage of 5.6 V and power density output of 14.6 μW/cm 2 .

Upon treating the enantiomerically pure Schiff base ligand (R-H2L1 or S-H2L1) with equimolar copper nitrate led us to isolate two chiral tetranuclear Cu(II) cubane complexes with the general molecular formula...

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Supramolecular systems hold great potential as ferroelectric materials because they are easy to prepare and do not require toxic and environmentally damaging elements. However, directing the self-assembly process of a supramolecular array to yield polarizable solids is still challenging. Here, we describe induced ferroelectricity in a supramolecular framework of metal-organic cages that are supported by a flexible tripodal ligand (NHCH 2-(3-Py)) 3 PO (TPPA). Ferroelectric responses on the discrete cage [Cu 6 (H 2 O) 12 (TPPA) 8 ](NO 3) 12 • 45H 2 O (1) and its 2D-connected framework [{Cu 6 Cl 4 (H 2 O) 6 (TPPA) 8 }(NO 3) 8 • 60H 2 O] n (2) yielded well-resolved rectangular hysteresis loops at room temperature with remnant polarization values of 27.27 and 29.09 μC/cm 2 , respectively. Thermal hysteresis measurements (THM) and capacitance-voltage (CÀ V) plots further corroborate the ferroelectric behavior in these compounds. The polarization in them is due to the displacements of solvated molecules and nitrate ions in the pockets of these frameworks.

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