A novel fully conjugated polymer containing 1,10-phenanthroline (DAPcDOD) was first synthesized by the polycondensation of 2,7-dimethyl-2,4,6-octatriene-1,8-dial with 5,6-diamine-1,10-phenanthroline. Three polymeric complexes were first prepared by the reaction of DAPcDOD with NiSO4, CoCl2, and FeSO4, respectively. The structures of the polymer and the complexes were characterized by IR, H-1-NMR, and elemental analysis. The magnetic behaviors of these complexes were measured as a function of magnetic field strength (0-50 kOe) at 5 K and as a function of temperature (5-300 K) at a magnetic field strength of 30 kOe. The results show that DAPcDOD-Ni2+ and DAPcDOD-Co2+ were soft ferromagnets, whereas DAPcDOD-Fe2+ exhibited the features of an antiferromagnet. (C) 2008 Wiley Periodicals, Inc.