The reaction of a sterically less hindered tetrapropyl[24]dithiaamethyrin(1.0.0.1.0.0) (with antiaromatic character) and [Rh(CO)2Cl]2 synthesized a unique anti isomer of the bis(dicarbonylrhodium(I)) product, with two rhodium ions on the opposite faces of the macrocyclic ligand, and the corresponding syn isomer. Structural analyses by single‐crystal X‐ray diffraction, 1H nuclear magnetic resonance, and density functional theory calculations indicated that the anti isomer exhibited a stronger paratropic ring current and a more planar structure than the syn isomer. More information can be found in the Research Article by Yoshihiro Ishimaru et al.

From the reaction of sterically less hindered tetrapropyl[24]dithiaamethyrin(1.0.0.1.0.0) 5, with [Rh(CO)2Cl]2, a unique anti form of the bis(dicarbonylrhodium(I)) complex (6‐anti), where two rhodium ions are on the opposite faces of the macrocyclic ligand, was isolated for the first time in 12% yield along with the corresponding syn isomer (6‐syn, 61% yield). These structures were characterized in detail by single‐crystal X‐ray structure analysis. Compound 6‐syn exhibited a bowl‐shaped structure with the two rhodium atoms separated by a distance of ∼4.5 Å. In contrast, 6‐anti contained a wave‐shaped macrocycle with a distance of ∼5.3 Å between the two rhodium atoms. Furthermore, the 1H nuclear magnetic resonance spectra and density functional theory calculation results revealed that 6‐anti had a stronger paratropic ring current and a more planar structure than 6‐syn. The isolation of both 6‐anti and 6‐syn enabled detailed discussion of the structure‐property relationship.