Dinuclear arene ruthenium dichloro complexes designed for host–guest propensity

The synthesis and the crystal structures of several wheel-and-axle metal–organic (waamo) complexes are studied. The design of such systems is basically constituted by the binding between two Ru(II)(p-cymene)Cl2 units (wheels) and an organic spacer (axle), bearing pyridinic and/or cyano functions. Particular attention is given to the solid-state organization of the waamo complexes and to their propensity to create acceptors sites for guest species The inverted piano-stool motif, a characteristic synthon of half-sandwich ruthenium units, is always observed here, generating well defined layers of host molecules. Both polycatenated and host–guest systems were generated in order to achieve a compact packing.