Analysis of transition states for oxidative insertions of ¹Fe(CO)₄ into H₃C–H, H₃C–Cl and H₃C–CH₃ bonds^a.

	CH4	CH3Cl	C2H6
EDA (in kcal mol−1)
ΔEstrain[“Fe”]	6.1	5.2	4.0
ΔEstrain[“X”]	54.4	31.2	57.3
ΔEstrain	60.5	36.4	61.3
ΔVelstat	−104.9	−47.8	−63.6
ΔEPauli	151.8	87.8	104.7
ΔEσ	−37.4	−22.5	−22.8
ΔEπ	−49.7	−19.8	−23.4
ΔErest	−9.9	−8.6	−8.2
ΔEoi	−97.0	−50.9	−54.4
ΔEint	−50.1	−10.9	−13.3
ΔE	10.4	25.5	48.0
FMO energy (in eV)
“Fe”: dσ	−4.6	−4.6	−4.5
“X”: σc–x	−7.3	−8.9	−7.0
Δεdonation	2.7	4.3	2.5
“Fe”: dπ	−5.3	−5.3	−5.3
“X”: σc–x*	−1.3	−3.4	−0.9
Δεbackdonation	4.0	1.9	4.4
FMO overlap
〈Fe: dσ|X: σc–x〉	0.30	0.15	0.20
〈Fe: dπ|X: σc–x*〉	0.35	0.05	0.09
FMO population (in e)
“Fe”: dσ	0.42	0.37	0.25
“X”: σc–x	1.44	1.73	1.62
“Fe”: dπ	1.54	1.63	1.75
“X”: σc–x*	0.58	0.36	0.35

^aComputed at ZORA-OPBE/TZ2P.