The dangler manganese center in the oxygen evolving complex (OEC) of photosystem II plays an important role in the oxidation of water to dioxygen. Inspired by the structure of the OEC, we synthesized a series of site-differentiated tetra-manganese clusters [LMn3(PhPz)(3)OMn][OTf](x) (2: x = 2; 3:x = 1) that features an apical manganese ion-distinct from the others that is appended to a trinuclear manganese core through an mu(4)-oxygen atom bridge. This cluster design was targeted to facilitate studies of high-valent Mn-oxo formation, which is a proposed step in the mechanism for water oxidation by the OEC. Terminal Mn-oxo species supported by a multinuclear motif were targeted by treating 2 and 3 with iodosobenzene. Akin to our previously reported iron complexes, intramolecular arene hydroxylation was observed to yield the C-H bond oxygenated complexes [LMn3(PhPz)(2)(OArPz)OMn][OTf](x) (5: x = 2; 6: x = 1). The fluorinated series [LMn3(F(2)ArPz)(3)OMn][OTf](x) (8: x = 2; 9: x = 1) was also synthesized to mitigate the observed intramolecular hydroxylation. Treatment of 8 and 9 with iodosobenzene results in intramolecular arene C-F bond oxygenation as judged by electrospray ionization mass spectrometry. The observed aromatic C-H and C-F hydroxylation is suggestive of a putative high-valent terminal metal-oxo species, and it is one of the very few examples capable of oxygenating C-F bonds.