摘要
Hydro(solvo)thermal reactions of N,N′-di(3-methylpyridyl)oxalamide (L 1 ) and N,N′-di(4-methylpyridyl)oxalamide (L 2 ) with angular dicarboxylic acids and Zn(ii) and Co(ii) metal salts afforded six coordination polymers (CPs), namely, [Zn(L 1 ) 0.5 (FIPBB)·H 2 O] n [H 2 FIPBB = 4,4′-hexafluoroisopropylidenebis(benzoic acid)] (1), [Zn(L 2 )(OBA)·CH 3 OH] n [H 2 OBA = 4,4′-oxybis(benzoic acid)] (2), [Co(L 2 ) 0.5 (FIPBB)·0.25CH 3 OH] n (3), [Co(L 1 )(OBA)·2H 2 O] n (4), [Co(L 1 ) 0.5 (FIPBB)] n (5), and [Co 2 (L 1 ) 2 (FIPBB) 2 (H 2 O) 5 ·4H 2 O] n (6), which have been structurally characterized by using single-crystal X-ray diffraction. CPs 1 to 6 form a two-dimensional (2D) net with the bey, a polycatenated 2D net with the sql, a three-dimensional (3D) framework with the 6T9, a 2D net with the 3,5L2, 2D net with the bey and a one-dimensional (1D) looped chain with the 2,2,2,4C10 topologies, respectively. The distinct topological switch between 5 and 6 in the presence and absence of coordinated/cocrystallized water molecules was triggered under various temperatures through coordination and breakage of Co-O bonds. CPs 1 and 2 exhibit sustained porosities indicated by CO 2 adsorption and exhibit high selectivity toward detection of pesticides such as 2,6-dichloro-4-nitroaniline (2,6-DCNA) and 4-nitroaniline (4-NA) with low detection limits and good recyclability up to five cycles. Integrating 1-octadecene with a long alkyl chain into 1-5 to modify the surface wettability induces hydrophobicity, which was verified by the measurement of water contact angles.