The crystal structure of the tetraimine macrocyclic Co(II) complex [Co(C10H20N8)Cl(H2O)]Cl.H2O has been determined. The space group is P2(1)/n, with a = 6.969(1), b = 22.077(3), c = 11.794(2) angstrom, beta = 107.44(1)-degrees and Z = 4. The Co(II) environment is nearly octahedral, unlike the analogous Ni(II) and Cu(II) complexes which have a square pyramidal structure. An extensive FT-IR investigation between 4000 and 50 cm-1 of all three tetraimine complexes and their N-D deuterated counterparts has been carried out. Some spectra of related perchlorate complexes are also reported. Detailed assignments of the observed transitions are proposed. The presence of NH...Cl- hydrogen bonds is clearly established.