The reaction of a Rh-2(5+) cationic radical salt, 2,2-cis-[Rh-2-(acam)(4)(H2O)(2)]ClO4 (Hacam = acetamide), with sodium halides in aqueous solution gave crystals of [Rh-2(acam)(4)Cl](n). 7nH(2)O and [Rh-2(acam)(4)Br](n), both of which consist of zigzag chain of (-Rh-Rh-X)(n), which is supported by hydrogen bond between amidato-NH and amidat-O atoms for the chain of the bromide and between O atoms of amidato bridges through interstitial water molecules for the chloride chain.