(MCl2)-Cl-II (M = Mn, Fe, Co) as their acetonitrile solvates were isolated, and their structural, spectroscopic, and magnetic properties were studied. MCl2(NCMe)(2) (M = Fe, Mn) form 1-D chains of octahedral M-II ions with four bridging chlorides and two axial MeCN's. The presence of an axial distortion for MFe causes a significant magnetic anisotropy that increases significantly below 150 K; however, chi(av) [=(chi(parallel to) + 2 chi)/3] almost coincides with the value obtained on a polycrystalline sample. MnCl2(NCMe)(2) is a paramagnet with a weak antiferromagnetic coupling. Annealing FeCl2(NCMe)(2) at 55 degrees C forms the monosolvate of FeCl2(NCMe) composition in which two chains collapse into a double chain with formation of Fe-Cl bonding such that half of the mu-Cl's becomes mu(3)-Cl's. This material orders magnetically below T-c = 4.3 K. For M = Co, paramagnetic tetrahedral [CoCl3(NCMe)](-) anions are isolated.