Dark transition of 1st level reduction products of porphyrins to 2d level

Transition of the products of the first restoration of porphyrines to the second one in the darkness and practically in the absence of a reducer and oxygen has been studied. Its cause is the disproportioning of dyhydroform into tetrahydro- and the initial pigment. Regeneration of porphyrines under these conditions is also shown. The rate of both reactions significantly increases in the light.