Syntheses, Structural Characterization, and Properties of Mixed‐valent Co^IICo^III and Zn^II Coordination Polymers from 5‐(4‐Carboxybenzylamino)isophthalic Acid

Abstract

The reaction of cobalt(II) and zinc(II) salts with 5‐(4‐carboxybenzylamino)isophthalic acid (H3L) in the presence of 1,2‐bis(pyridin‐4‐yl)ethane (bpa) as auxiliary co‐ligand under hydrothermal synthetic condition led to the formation of two complexes, {[(CoII)0.25(CoIII)0.5(HL)(H2O)0.5(bpa)0.25]·2.5H2O}n (1) and [Zn(HL)(bpa)0.5]n (2), which were characterized by single crystal and powder X‐ray diffraction, IR spectroscopy as well as elemental and thermogravimetric analyses. Complex 1 displays uninodal 4‐connected 2D sql network with (44.62) topology, complex 2 is binodal (3, 6)‐connected 2D (4.62)2(42.610.83) network. Interestingly, complex 1 shows structural features consistent with the Jahn‐Teller distortions, whereas in 2 adjacent 2D networks are interpenetrated to show 2D + 2D → 3D parallel interpenetration of slabs. Furthermore, it is noteworthy that the oxidation of CoII to CoIII occurred in the preparation of 1 to give rise to a mixed‐valent cobalt coordination polymer, which can be confirmed by magnetic measurement. Magnetic property of 1 and luminescence of 2 were investigated.