Abstract
Two novel isostructural compounds containing multi-component co-crystals [M(C6H4NO2)(2)(-H2O)(2)](C9H6O6)(2) (M = Co (1), Zn (2), C6H4NO2 = Picolinic acid, C9H6O6 = Trimesic acid) have been synthesized. The compounds were characterized by elemental analysis, FT-IR, UV-Visible and H-1 NMR spectroscopies as well as thermal and single crystal X-ray diffraction analyses. Single crystal X-ray diffraction analysis reveals that 1 and 2 are isostructural. Compound 1 crystallizes in triclinic space group (P-1, with a = 5.154 (10) angstrom, b = 11.125 (2) angstrom, c = 14.113 (3) angstrom, alpha = 91.01 (3)degrees, beta = 100.54 (3)degrees, and gamma = 102.71 (3)degrees). In a similar fashion, compound 2 crystallizes in triclinic space group (P-1, with a = 5.1735 (3) angstrom, b = 11.0930 (10) angstrom, c = 14.1554 (8) angstrom, alpha = 91.70 (3)degrees, beta = 100.26 (3)degrees, gamma = 102.90 (3)degrees). The metal (II) cation presents distorted MN2O4 octahedral geometry with H2O molecules coordinated to the metal in equatorial position while the picolinic acid molecules are axially coordinated through the pyridine N atom. The two trimesic acid molecules are not part of the first coordination sphere. Compounds 1 and 2 constitute an example of a class of coordination compound of multicomponent crystals having trimesic acid outside the coordination sphere where it is neither protonated or deprotonated. The two compounds were investigated for luminiscence properties. (C) 2017 Elsevier B.V. All rights reserved.