A new supramolecular isomer of p-aminobenzoate Zn(II) coordination polymer: Structure and photoluminescent property

Abstract A new supramolecular isomer of hydrated Zn(II) coordination polymer {[Zn(pABA)2(H2O)]·H2O}n (1) was prepared by a combination of multifunctional p-aminobenzoic acid (pABAH) with hydrated zinc tetrafluoroborate and then structurally compared with two previously known isomers IWORET and YIWDEO (refcodes in the Cambridge Structural Database). The new compound was characterized by FT-IR spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction method. The crystallographic investigation shows that pABA anions bind the metal atoms in 1 and IWORET through the amine nitrogen and the carbonyl oxygen in a double-stranded bridge fashion giving rise a 1D coordination chain (1) and 2D layer (IWORET). In YIWDEO isomer, pABA− presents two different coordination modes (monodentate and bridging bidentate) extending the structure to 1D coordination polymer. The new solid reveals blue-violet and green photoluminescence, while IWORET crystals show violet emission upon excitation with ultraviolet light.