The synthesis is described of fixed distance triads consisting of zinc porphyrin ( ZP ), metal-free porphyrin ( HP ) and pyromellitimide (I) in which the ZP and HP moieties are bridged by a rigid 4,4'-biphenylene spacer and related spacers, being held with dihedral angles defined by the torsional angle (θ) of the 4,4'-biphenylene spacer varying from nearly coplanar (θ = 0°, phenanthrene spacer) to nearly orthogonal (θ = 90°, 2,2',6,6'-tetramethylbiphenylene spacer). Using these models, the effects of the dihedral angle of the two porphyrins have been examined for singlet–singlet excitation energy transfer from ZP to HP , hole transfer from HP ⁺ to ZP and charge recombination of ZP ⁺– HP – I ^– to the ground state. In the three processes examined, the observed rate constants are roughly in the order of 1d (coplanar)≥1c (nearly coplanar) >1a (tilted) >1b (orthogonal).