DFT-optimized structures (Jaguar 5.0, B3LYP/LACVP**) for (A) singlet [PhBPiPr3]Mn(NtBu) and (B) triplet [PhBPiPr3]Mn(NtBu). Selected bond distances (Å) and angles (deg) for (A): Mn–N 1.63; Mn–P 2.28, 2.36, 2.36; Mn–N–C 144.8; P–Mn–P 96.8, 97.2, 97.7; N–Mn–P 104.7, 126.2, 127.2. For (B): Mn–N 1.66; Mn–P 2.40, 2.44, 2.45; Mn–N–C 179.2; P–Mn–P 89.5, 89.8, 91.5; N–Mn–P 121.9, 126.2, 127.0.