also reflected in redox potentials. The furochlorophin 1 b oxidizes to its li cation radical at 0.47 V and reduces at -1.25 V to the anion radical (determined by cyclic voltammetry. versus Ag/AgCl, in CH,CI,). In comparison with etiochlorin I,1121 1 b is easier to oxidize as well as to reduce by about 180 mV. This smaller redox span correlates well with the observed first absorption band shift. Although the absorption bands of the furochlorophin derivatives have lower extinction coefficients, their bandwidths are broader than those found in chlorins; thus the difference in total oscillator strength between the two systems is less drastic. The decrease in absorption extinction coefficient may be attributable to the reduced rigidity of a macrocycle missing some of the peripheral carbons. Previously Flitsch reported the synthesis of "isobacteriophin", which has two pyrrolic B-p bonds removed; that chromophore also exhibits reduced absorption intensity as compared to isobacteriochlorins. [I 31 To our knowledge 1 a-1 d are the first porphyrinoids that possess a chlorophin core structure. A previous attempt to prepare such compound was not successful. ['41 The inherent simplicity of this serendipitous synthesis not only enriches the chemistry of corrinoids" 51 but may have potential applications in the emerging photodynamic cancer therapy because of the desirable long-wavelength absorption characteristics of these pigments.