A series of three Mo2 dimers bridged by a meta‐phenylene group has been studied in terms of electronic coupling (EC) and electron transfer (ET) in comparison with the para isomers. Optical analyses on the mixed‐valence complexes indicate that by replacing a para‐phenylene bridge with a meta one, the EC between the two Mo2 centers is dramatically weakened; consequently, the ET rates (ket) are lowered by two to three orders of magnitude. In the para series, the EC parameters (Hab) and ET rates (ket) are greatly affected by O/S atomic alternation of the bridging ligand. However, for the meta analogues, similar EC and ET parameters are obtained, that is, Hab=300–400 cm−1 and ket≈109 s−1. These results suggest that through‐σ‐bond and/or through‐space coupling channels become operative as the π conjugation is disabled. DFT calculations reveal that destructive quantum interference features seen for the meta series arise from the cancellation of two π‐conjugated coupling pathways. Quantum constructive vs. destructive effects: Optical analysis of Mo2 mixed‐valence donor‐bridge‐acceptor systems indicates that a meta phenylene bridge lowers the electron‐transfer rate by two to three orders of magnitude with respect to the para analogues. DFT calculations reveal that the destructive quantum interference features arise from the cancellation of two coupling pathways. [ABSTRACT FROM AUTHOR]