A computational study of dimers and trimers of hypohalous acids

Ab initio calculations [MP2/6-311++G(2d,2p] were used to analyze the interactions between hypohalous acids (HOX) dimers and trimers, for X equal to F, Cl, and Br. Two minima for X = F and three minima for X = Cl and Br were located on the potential energy surface of the dimers. Eight different structures have been obtained for the trimers, six of them cyclic and two open structures. The six cyclic minima for X = F present similar interaction energies, while for X = Cl and Br, those with three O–H···O interactions are the most stable ones.