Free energy values calculated by DFT for the formation of different metal–phosphine–halide coordination compounds.

Metal–phosphine–halide adduct formation	Calculated free energy (kcal mol−1)
PTA + GaCl3 → [(PTA)GaCl3]	ΔG = –16.0
(PTA-H) + GaCl3 → [(PTA-H)GaCl3]	ΔG = +2.2
P(Me)3 + GaCl3 → [(PMe)3GaCl3]	ΔG = –19.8
PTA + AuCl → [(PTA)AuCl]	ΔG = –43.3
(PTA-H) + AuCl → [(PTA-H)AuCl]	ΔG = –26.9