Six novel Co(II) coordination polymers, namely, [Co10L6(OH)2(H2O)9]·10.5H2O (1) [Co3L2(3-abpt)2]·2H2O (2), [Co3L2(4-azpy)2(H2O)2(EtOH)] (3), [Co3L2(4,4'-bipy)2(H2O)2(MeCN)] (4), [Co3L2(4,4'-bipy)2] (5), and [Co5L2(OH)2(ina)2(H2O)2] (6) (H3L = 2,2'-phosphinico-dibenzoic acid, 3-abpt = 4-amino-3,5-bis(3-pyridyl)-1,2,4-triazole, 4-azpy = 4,4?-azobispyridine, 4,4'-bipy = 4,4'-bipyridine, Hina = isonicotinic acid), have been hydrothermally synthesized and their magnetic properties have been...