A Comparative Study on the Thermodynamics of Halogen Bonding of Group 10 Pincer Fluoride Complexes

The thermodynamics of halogen bonding of a series of isostructural Group 10 metal pincer fluoride complexes of the type [(3,5‐R 2 ‐ t Bu POCOP t Bu )MF] (3,5‐R 2 ‐ t Bu POCOP t Bu = κ 3 ‐C 6 HR 2 ‐2,6‐(OP t Bu 2 ) 2 with R=H, t Bu, COOMe; M=Ni, Pd, Pt) and iodopentafluorobenzene was investigated. Based on NMR experiments at different temperatures, all complexes  1‐ t Bu (R= t Bu, M=Ni), 2‐H (R=H, M=Pd), 2‐ t Bu (R= t Bu, M=Pd), 2‐COOMe (R=COOMe, M=Pd) and 3‐ t Bu (R= t Bu, M=Pt) form strong halogen bonds with Pd complexes showing significantly stronger binding to iodopentafluorobenzene. Structural and computational analysis of a model adduct of complex  2‐ t Bu with 1,4‐diiodotetrafluorobenzene as well as of structures of iodopentafluorobenzene in toluene solution shows that formation of a type I contact occurs.