A novel sandwich N-fused porphyrin rhodium complex (Rh-1-Br) comprising a brominated N-fused porphyrin (1-Br) and an isomerized cyclooctadiene ligand was synthesized and characterized. X-ray crystallographic analysis revealed a 1,5-cyclooctadiene isomerization into allylic C-H activated k(1), eta(3)-C8H12 unit bound to the Rh center. The rotational dynamics of k(1), eta(3)-C8H12 ring in Rh-1-Br was discussed using (HNMR)-H-1 spectroscopic analysis and DFT calculation.