DESIGN AND SYNTHESIS OF TWO (PSEUDO)SYMMETRIC GIANT TRICHROMOPHORIC SYSTEMS CONTAINING THE C60 CHROMOPHORE

Diels−Alder reaction of C60 with the 1,3-dienes syn-5 and syn-20 affords the giant trichromophoric systems syn-C60-5-DMN-6-PZn and syn-C60-9-DMN-6-DMA, respectively, in which the three chromphores in each system are linked via rigid, hybrid saturated polynorbornane-bicyclo[2.2.0]hexane (“norbornylogous”) hydrocarbon bridges. The norbornylogous bridge is a strong mediator of electron and energy transfer via a through-bond coupling mechanism. Hence, the giant trichromophores described herein illustrate the necessary methodology for the synthesis of efficient molecular systems that are capable of generating long-lived charge-separated states. The 1,3-dienes syn-5 and syn-20 were prepared in a straightforward manner from two fragments containing a diene and a dienophile, and thus a simple building-block approach to such sophisticated systems is described. Semiempirical AM1 MO SCF calculations were carried out on the trichromophoric systems to quantify their ability to adopt two nondegenerate boat conformation...