Magnetic phase transitions of PM2. CoCl2, PM2. CoBr2, and PM2. FeCl2 (PM = pyrimidine) were observed at T-N = 4.4, 4.7, and 6.1 K, respectively, as defined by the peak of chi(ac)' They are characterized to be isomorphous, belonging to the space group I4(1)22, and canted antiferromagnets below TN The neutron diffraction study supports the principally antiferromagnetic structure.