Summary of EDA-NOCV calculations on complex anions [rac-1]⁻, [rac-6]⁻, [rac-7]⁻, [meso-8]⁻. All energies are given in kcal mol⁻¹. E_int: total interaction energy between the two given fragments. E_L→M: interaction energy arising from donor interactions between the ligand fragment and the cobalt atom (a: σ–donor interactions, b: π–donor interactions). E_M→L: interaction energy arising from π backdonation from the cobalt atom to the ligand fragment.

	Fragments	E int	E L→M	E M→L
[rac-1]−	[Co{1,2-(PMes)2C2B10H10}]−, cod	190	29b	150
[rac-6]−	[Co{1,2-(PMes)2C2B10H10}]−, 2 CyNC	162	52a	93
[rac-7]−	[Co{1,2-(PMes)2C2B10H10}]−, tBu2C2P2	214	28b	161
[meso-8]−	[Co{1,2-(P3Mes2)C2B10H10}], P3−	175	66b	82