Organic guests inclusion by tungsten-calix[4]arene hosts

The binding mode of a series of lower rim tungsten-calix[4]arenes toward different neutral organic guests has been investigated in the solid state and through ab initio computational studies. From the structure of the inclusion compounds examined it emerges that the metal can be employed as a control element to confer different cone shapes to the calixarene cavity and to act as an additional binding site.