Synthesis, structure, and reactivity of doubly trans-spanning bis(dialkyl selenide) complexes; a new route to diselenamacrocycles via alkene metathesis in metal coordination spheres

The title compounds are accessed by the reaction of Grubbs' first generation catalyst and platinum(II) dichloride complexes with trans dialkyl selenide ligands Se((CH2)6CH = CH2)2, and subsequent substitution of the chloride ligands. They are isolated as mixtures of easily interconverted syn/anti isomers with respect to the selenium lone pairs; the latter orientation is found in crystal structures. Attempted hydrogenations release the novel diselanamacrocycle Se(C14H28)2Se.218