Chiral supramolecules:: Organometallic molecular loops made from enantiopure R-[cis-Rh2(C6H4PPh2)2(CH3CN)6](BF4)2

Two enantiopure molecular loops, RR-[cis-Rh-2(C6H4PPh2)(2)(py)(2)O2C(CF2)(n)CO2](2) (1, n = 2 and 2, n = 3) have been made from the reaction in CH2Cl2 and CH3OH of the inherently chiral dirhodium compound, R-[cis-Rh-2(C6H4- PPh2)(2)(CH3CN)(6)](BF4)(2), and HO2C(CF2)(n)CO2H in the presence of an excess of pyridine. Single-crystal structure analyses reveal that each of these compounds is composed of two R-cis-Rh-2(C6H4PPh2)(2)(ax-py)(2)(2+) units, and two equatorial perfluorodicarboxylate linkers, which form a loop oligomer. The H-1, F-19, and P-31{H-1} NMR spectra in CDCl3 and C5D5N indicate that only one type of highly symmetric species exists in each solution, which is consistent with the solid-state structures.