The dinuclear precursors Fe-2(NBu)(2)Cl-2(NH(2)Su)(2), [Fe-2(NBu)(S)Cl-4](2-), and Fe-2(NHBu)(2)(S)(N{SiMe3}(2))(2) allowed the selective syntheses of the cubane clusters [Fe-4(NBu)(n)(S)(4-n)Cl-4](z) with [n, = [3, 1-], [2, 2-], [1, 2-]. Weak-field iron-sulfur clusters with heteroleptic, nitrogen-containing cores are of interest with respect to observed or conjectured environments in the iron-molybdenum cofactor of nitrogenase. In this context, the present iron-imide-sulfide clusters constitute a new class of compounds for study, with the Fe4NS3 core of the [1, 2-] cluster affording the first synthetic representation of the corresponding heteroligated Fe4S3X subunit in the cofactor.