Comparison of the σ and π interaction energies in model complexes 10a and 10b, 17a and 17b, 16a and 16b, and 18a and 18b^a.

Model complex		ΔEorb of L → M	ΔEorb of ‖ M → L	ΔEorb of ⊥ M → L
		σ-Donationb	π-Backdonationb	π-Backdonationb
Rh–Cl	10a	−32.26	−21.04	−22.89
	10b	−31.13	−18.10	−21.30
	17a	−19.91	−30.00	−33.38
	17b	−18.17	−30.02	−29.08
Pt–Me	16a	−33.74	−8.62	−8.58
	16b	−32.84	−6.42	−7.11
	18a	−47.16	−17.55	−22.17
	18b	−45.02	−22.70	−18.87

^aFor the corresponding deformation density plots, see Tables S22 and S23.

^bAll energies are given in kcal mol⁻¹.