Orientation Dependence of Energy Transfer in an Anthracene–Porphyrin Donor–Acceptor System This work was supported by CSIR and DST (New Delhi, India). We thank Dr. T. P. Radhakrishnan for many helpful discussions.

“Equatorial” energy transfer: Orientation control of intramolecular energy transfer (EnT) is found in the donor–acceptor system shown, light absorbed by the “peripheral” anthracene is efficiently transferred to the porphyrin, but that by the “axial” anthracene subunits is not.