Construction of Pyrazine-Appended 1D and 3D Cobalt(II) Succinate Coordination Polymers: Influence of Solvent on Architectures and Applications in Gas Adsorption and NAC Detection.

An underexplored reaction of pyrazine (rigid and linear) and succinic acid (flexible) with Co(NO 3 ) 2 ·6H 2 O afforded four new coordination polymers (CPs): [Co(H 2 O)(pyz)(suc)] ( 1 ), [Co(H 2 O) 2 (pyz)(suc)] ( 2 ), [Co(H 2 O) 4 (pyz)](suc) ( 3 ) and [Co 2 (H 2 O) 2 (pyz)(suc) 2 ] ( 4 ), as well as [Co(HCO 2 ) 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 χ M -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. CO 2 and N 2 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.