Comparison of two Mn(IV)Mn(IV)-bis-μ-oxo complexes {[Mn(IV)(N(4)(6-Me-DPEN))](2)(μ-O)(2)}(2+) and {[Mn(IV)(N(4)(6-Me-DPPN))](2)(μ-O)(2)}(2).

The addition of tert-butyl hydro-peroxide ( (t) BuOOH) to two structurally related Mn(II) complexes containing N,N-bis-(6-methyl-2-pyridyl-meth-yl)ethane-1,2-di-amine (6-Me-DPEN) and N,N-bis-(6-methyl-2-pyridyl-meth-yl)propane-1,2-di-amine (6-Me-DPPN) results in the formation of high-valent bis-oxo complexes, namely di-μ-oxido-bis-{[N,N-bis-(6-methyl-2-pyridylmeth-yl)ethane-1,2-di-amine]-manganese(II)}(Mn-Mn) bis-(tetra-phenyl-borate) dihydrate, [Mn(C(16)H(22)N(4))(2)O(2)](C(24)H(20)B)(2)·2H(2)O or {[Mn(IV)(N(4)(6-Me-DPEN))](2)(μ-O)(2)}(2BPh(4))(2H(2)O) (1) and di-μ-oxido-bis-{[N,N-bis-(6-methyl-2-pyridylmeth-yl)propane-1,3-di-amine]-manganese(II)}(Mn-Mn) bis-(tetra-phenyl-borate) diethyl ether disolvate, [Mn(C(17)H(24)N(4))(2)O(2)](C(24)H(20)B)(2)·2C(4)H(10)O or {[Mn(IV)(N(4)(6-MeDPPN))](2)(μ-O)(2)}(2BPh(4))(2Et(2)O) (2). Complexes 1 and 2 both contain the 'diamond core' motif found previously in a number of iron, copper, and manganese high-valent bis-oxo compounds. The flexibility in the propyl linker in the ligand scaffold of 2, as compared to that of the ethyl linker in 1, results in more elongated Mn-N bonds, as one would expect. The Mn-Mn distances and Mn-O bond lengths support an Mn(IV) oxidation state assignment for the Mn ions in both 1 and 2. The angles around the Mn centers are consistent with the local pseudo-octa-hedral geometry.