In this issue's Perspective, Andrea Pace and Paola Pierro (University of Palermo, Italy) review recent research into 1,2,4-oxadiazoles, including their synthesis, chemical and photochemical activity and their applications in materials and bioactive compounds. 

On the outside front cover of the issue (above), and also a Hot article, Fraser Stoddart (Northwestern University, US) and colleagues report a predictive thermodynamic approach to designing and tuning pseudorotaxane mechanically interlocked  molecular (MIM) switches. The researchers hope that this approach could lead to more complex mechanically interlocked molecules with advanced properties and applications. 

The inside front cover (above) also features a Hot article. The work by Michael Smietana and colleagues (University of Montpellier 2, France) shows the synthesis of borono-analogues of nucleotides that form di-nucleotides through a borate ester bond rather than the phosphate linkage found in their natural counterparts. The authors claim that this finding opens the possibility of boron playing a role in pre-biotic chemistry or could form the basis of an artificial genetic code.