Tetrahedral manganese(II) complexes having formulae [MnX2{O = PR(NMe2)2}2] (X = Br, I; R = NMe2, Ph) were isolated and characterized, and in the case of [MnBr2{O = PPh(NMe2)2}2] the structure was ascertained by means of single crystal X-ray diffraction. All the complexes showed intense green emission assigned to the Mn(II) 4T1(4G) → 6A1(6S) transition upon excitation with UV light, with photoluminescence lifetimes in the range 100–1000 μs. Bromo-complexes maintain their luminescence features once dispersed in polycaprolactone matrix.
