Hydrothermal reactions of Co(CH3COO)2·4H2O and 1,2,4,5-bezenetetracarboxylic acid (1,2,4,5-H4BTEC) with N‚N'-bis(3-methylpyridyl)oxalamide (L1), N‚N'-bis(3-methylpyridyl)adipoamide (L2) and N‚N'-bis(3-methylpyridyl)sebacoamide (L3) afforded [Co(L1)0.5(1,2,4,5-BTEC)0.5(H2O)]n, 1, {[Co(L1)(1,2,4,5-BTEC)0.5(H2O)]·H2O}n, 2, {[Co(L1)1.5(1,2,4,5-BTEC)0.5(H2O)]·3H2O}n, 3, [Co(L2)(1,2,4,5-BTEC)0.5(H2O)2]n, 4, [Co3(L3)(1,2,4,5-BTEC)1.5(μ2-OH2)2]n, 5, which have been...