cyclohexyl and the like in this embodiment 1 to 4 of the x 39 s in the above formula are no 2 0 to 3 of said x 39 s are hydrogen halogen cyano hydrocarbon or halocarbon and y is hydrogen nitro cyano halogen hydrocarbon or halocarbon the y 39 s may all be one atom or group or different atoms or groups the metalloporphyrins of this embodiment differ from the nickel magnesium or zinc complexes of mesonitrooctaethylporphyrin of the prior art in the metal component of the complex the nickel magnesium and zinc complexes being inactive for alkane oxidation and in some cases by having in beta positions of the porphyrin ring hydrogen halogen halocarbon cycloalkyl or aryl rather than the ethyl groups of the prior art compounds in another embodiment of the invention the metalloporphyrin has one or more nitro groups in beta positions and hydrogen or a substituent other than nitro in the remaining beta positions the substituent may be halo cyano hydrocarbon or halocarbon in this embodiment x in the above formula is hydrogen halogen nitro cyano alkyl cycloalkyl or halocarbon at least one of said y 39 s is nitro and the remaining y 39 s are hydrogen halogen nitro cyano hydrocarbon or halocarbon in a preferred embodiment the compound has either halogen atoms or nitro groups in all of the beta positions in this embodiment x in the above.