Calculated geometries [side view (Upper) and projected view (Lower)] for 4 (a) and 4-Intd (b). Critical points are superimposed as transparent blue spheres. Atom key: C, green; H, pale blue; Rh, brown; P, red. Selected distances (Å) and angles (°) are as follows. 4: PRhC(15) 90.1, dihedral PRhC(13)–C(16) −0.4. 4-Intd: RhC(21) 2.050, RhC(25) 2.043, RhC(11) 2.054, RhC(15) 2.063, C(11)···C(15) 2.169, PRhC(15) 135.5, dihedral PRhC(13)–C(16) 56.0.