We propose a novel view on efficient packet forwarding in wireless mesh networks based on a molecular analogy in which mesh routers are either nuclei or electrons in an atom that corresponds to a 802.11 cell. In this view, a mesh network appears as a collection of spatially distributed 802.11 cells operating on different channels. We define Molecular MAC that uses dynamic channel switching at neighbor mesh routers to efficiently forward packets over multiple hops. To avoid deafness, nuclei notify electrons about pending packets before electrons pull them from nuclei for reception or further forwarding. We evaluate the proposed scheme through simulation and compare with other proposals. Our results show that Molecular MAC obtains much better performance in terms of throughput, packet delivery rate, end-to-end delay, and fairness.