Synthetic procedures are described that allow conversion of [Mn4O2(OAc)(6)(py)(2)(dbm)(2)] (1, dbmH = dibenzoylmethane) to [Mn(4)O(3)X(OAc)(3)(dbm)(3)] (X = Cl, 2; X = Br, 3). Treatment of 1 with NBu(4)(n)Cl in CH2Cl2 or hot MeCN leads to 2 in 5-8% and 35-43% yields (based on dbm), respectively. A higher yield (similar to 88%) is obtained by treating 1 with 4 equiv of Me(3)SiCl in CH2Cl2. An analogous procedure with 4 equiv of Me(3)SiBr in CH2Br2 gives 3 in 55% yield. Complexes 2 and 3 are isomorphous, monoclinic space group P2(1)/n, T = -155 degrees C, Z = 4. For 2, a = 13.900(3), b = 22.038(5), and c = 16.518(5) Angstrom and beta = 107.80(1)degrees; for 3, a = 13.644(2), b = 22.190(4), and c = 16.548(3) Angstrom, and beta = 106.64(1)degrees. The structures were solved by direct methods (MULTAN78) and refined on F to R(R(w)) values of 7.85 (7.38) and 7.37 (6.89)% using 2267 and 2809 unique reflections with F > 2.33 sigma(F) for 2 and 3, respectively. Treatment of [Mn3O(OAc)(6)(py)(3)](ClO4) in MeCN with Me(3)SiCl followed by addition of H2O and acetic acid results in crystallization of (pyH)(3)[Mn4O3Cl7(OAc)(3)]. 2MeCN (4) in 75% yield (based on Mn).