In pursuit of natural occurring chiral dienes {(R/S)-carvone} as bidentate ligands for coordination to rhodium(I).

Bis-rhodium-mu-chlorido dinuclear complexes with natural occurring limonene-type enantiomeric diene nucleophiles, (S)- and (R)-carvone [SCar and RCar], are presented and their single crystal structures reported. Utilizing the diolefinic bonds of the carvones, mu-[Rh(I)(SCar)Cl](2) (IA/B) and mu-[Rh(I)(RCar)Cl](2) (IIA/B) were obtained in ca. 80% yields in clean reactions with reactant RhCl(3)(H(2)O)(x). The "structured" chiral nanomaterials (IA/B and IIA/B > 1.1 nm) crystallize as two independent, dinuclear chiral molecules Syn-mu-[Rh(I)(SCar)Cl](2) (IA), Anti-mu-[Rh(I)(SCar)Cl](2) (IB), and Syn-mu-[Rh(I)(RCar)Cl](2) (IIA, Anti-mu-[Rh(I)(RCar)Cl](2) (IIB), respectively (based on the relative orientation of the carvone ring, oxo and methyl groups). Principal differences between the IA/IIA vs IB/IIB complexes in the solid state include the relative orientation of the two carvones, inducing a significant distortion in the µ (2)-Rh(2)Cl(2) core, with the dihedral angles of 49.7(1)°/49.73(6)° in IA/IIA (Syn-mu geometry), versus 23.8(1)°/24.00(6)° in IB/IIB (Anti-mu geometry), respectively. The presence of the two structurally independent complexes in the solid state is also inferred from (1)H NMR spectra.