An underexplored
reaction of pyrazine (rigid and linear) and succinic
acid (flexible) with Co(NO3)2·6H2O afforded four new coordination polymers (CPs): [Co(H2O)(pyz)(suc)] (1), [Co(H2O)2(pyz)(suc)]
(2), [Co(H2O)4(pyz)](suc) (3) and [Co2(H2O)2(pyz)(suc)2] (4), as well as [Co(HCO2)2(pyz)] (5) being lately reported along with well-known 6 and 7. The CPs were obtained as stable crystalline
materials and characterized by conventional solid-state techniques,
including X-ray crystallography. Hydrothermally produced compounds 1 and 2 were both 3D CPs. While 3 and 4 obtained under ambient/solvothermal conditions
in DMSO generated 1D and 3D structures, 5 isolated from
DMF under solvothermal conditions had a 3D structure. The topologies
of the coordination polymers 1–7 were
described by underlying nets 3D 5-c fet, 3D 4-c cds, 1D 2-c 2C1, 3D 5-c bnn, 3D
6-c rob, 1D 2-c 2C1, and 3D 6-c pcu, respectively. The plot of χM
–1 versus T was essentially linear in the entire temperature
range following the Curie–Weiss law with a Curie constant (C) of 2.525 and a negative Weiss constant (ϕ) of −46.24
K, suggesting weak antiferromagnetic (AF) exchange interactions. CO2 and N2 adsorption studies of 1–5 featured type III isotherms. 1 was found to
show remarkably higher quenching efficiencies for nitrophenols (η
= 98% for o-NP) over other NACs. The Stern–Volmer
plot exhibited deviation in linearity with K
sv values about 200 times greater than that for the simplest
nitroaromatic compound (NB), signifying its exclusive quenching ability
toward 1. The LOD for p-NP addition
to 1 was found to be 0.995 ppm.