Magnesium clusters bonding state

Matrix isolation experiments showed that small clusters of magnesium and calcium are more reactive than atoms " . Thus, codeposition of CH3Br and magnesium, monitored by IR and UV visible spectra, indicated that Mg2 and Mgs were consumed while Mg atoms were not. It was proposed that Mg clusters reacted in a four-center transition state, and this is the first example of cr-bond breaking on a cluster but not an atom under the same experimental conditions. 

---