New rhodium(I) supramolecular structures containing pyridyl and bipyridyl ligands

The use of dimeric [RhCl(CO)2]2 as acceptor unit in the construction of mono-, bi- and three-dimensional metallosupramolecular structures is reported. The reaction of the dimer with the alkynylgold complex [Au(Ctriple bond; length of mdashCC5H4N)(CNC6H4O(O)CC6H4OC10H21)] resulted in the mononuclear rhodium complex 1, through an unexpected transfer of the isonitrile ligand from the gold to the rhodium centres. The reaction of the linear unit [RhCl(CO)2]2(μ-4,4′-bipy) (3) with the diphosphine 1,4-bis(diphenylphosphino)butane (dppb) yielded the simultaneous formation of both metallomacrocycles [RhCl(CO)(dppb)]2 (4) and {[RhCl(CO)]2(μ-4,4′-bipy)}2(μ-dppb)2 (5). The use of a diphosphine with smaller bite angle, 1,1′-bis-(diphenylphosphino)methane, (dppm) formed the three-dimensional {[RhCl(CO)]2(μ-4,4′-bipy)}2(μ-dppm)4 complex (6) that incorporates four diphosphine units connecting two [RhCl(CO)2]2(μ-bipy) linear edges. PM3 semi-empirical method has been used to calculate the optimised geometry of compound 6.