The light absorption of vitamin B 12

Abstract

A calculation based on the one dimensional free electron model of the light absorption of vitamin B₁₂ and of similar compounds has been carried out. The model was applied in its simplest form and in three stages of refinement by using a standard procedure described in a recent paper (Kuhn 1964) and tested there on a great number of dyes. The calculation was thus straightforward and no adjustable parameters were introduced. The interaction of the chromophore with the axial ligands was neglected as well as any effect depending on the specific nature of the central atom or on the buckling of the resonating portion.