High valent Mn(O) species of a series of electron-rich and -deficient meso-tetra(aryl)porphyrins (aryl = phenyl, 2-Cl-phenyl, 2-nitrophenyl, 2-Me-phenyl, 2-Br-phenyl, 2,6-di-Cl-phenyl 4-OMe-phenyl, 4-Me-phenyl, 4-Cl-phenyl and 4-pyridyl) were prepared at 273 K.