The metal-influenced halogen bonds between C6F5I and a series of transition metal monohalides trans-[M(X)(2-C5NF4)-(PR3)2] (M=Ni, Pd, and Pt; X=F, Cl, and Br; R=Me, Cy) (Fig.) have been studied with quantum chemical calculations in toluene solution.The optimized geometries of halogen-bonded complexes exhibit that angles C-I…X is near linear angles (178°-180°) and angles M-X…I is much smaller angles (92 °-147°).The strength of metal-influenced halogen bonds is not a monotonic dependence on the group 10 metal M atomic number.Electrostatic potential and natural bond orbital (NBO) analysis show that the electrostatic interaction, orbital interaction and charge-transfer interaction make a contribution to the formation of all metal-influenced halogen bonds.The electrostatic term plays a dominant role in the formation of halogen-bonded complexes.Furthermore, the AIM analysis has been performed to further elucidate the nature of metal-influenced halogen-bonding interaction.All results show that metal centers and metal-bound halogen atoms have significant influences on the geometries of complexes and strength of halogen bonds.