Electromagnetic transitions from deformed structures based on $alpha$ configurations or on heavier clusters are discussed, drawing the link between multiparticle-multihole excited bands and cluster structures. Enhanced E2 and E1 transitions are revie
wed in the light nuclei, $^8$Be, $^{10}$Be, $^{12}$C, $^{16}$O, $^{18}$O and heavier ones like $^{212}$Po. Connections between cluster structures and superdeformed configurations in $^{36}$Ar and $^{40}$Ca are discussed. What the cluster states based on heavier substructures like $^{12}$C and $^{16}$O are concerned, recent results on the resonant radiative capture reaction $^{12}$C($^{16}$O,$gamma$)$^{28}$Si are presented, in particular the strong decay mode involving the feeding of low-lying $^{28}$Si 1$^+$ and 2$^+$ T=1 states by enhanced M1 isovector transitions.
The 12C+16O resonant radiative capture reaction has been studied at 5 bombarding energies between Elab = 15.4 and 21.4 MeV, around the Coulomb barrier, at the Triumf laboratory (Vancouver, Canada) using the Dragon 0{deg} spectrometer and the associat
ed BGO array. The most remarquable result is the previously unobserved decay path through 28Si doorway states of energies around 12 MeV leading to the measurement of new capture cross-sections. The feeding of specific, deformed states in 28Si from the resonances is discussed, as well as the selective feeding of 1^+ T=1 states around 11 MeV.
