(Phys.org)—A combined team of chemists from the University of Bath in the U.K. and Université Toulouse III–Paul Sabatier, UMR in France has found an instance of a calcium compound breaking the ‘like repels like’ chemistry rule. In their paper published in the journal Science, the group describes how they accidentally came upon the reaction while studying reactions between calcium hydride and terminal alkenes. Robert Emmet Mulvey with the University of Strathclyde in the U.K. offers a Perspective piece on the work done by the team in the same journal issue.