1329997-30-9Relevant academic research and scientific papers
Energetics of halogen bonding of group 10 metal fluoride complexes
Beweries, Torsten,Brammer, Lee,Jasim, Naseralla A.,McGrady, John E.,Perutz, Robin N.,Whitwood, Adrian C.
, p. 14338 - 14348 (2011)
A study is presented of the thermodynamics of the halogen-bonding interaction of C6F5I with a series of structurally similar group 10 metal fluoride complexes trans-[Ni(F)(2-C5NF 4)(PCy3)2] (2), trans-[Pd(F)(4-C 5NF4)(PCy3)2] (3), trans-[Pt(F){2-C5NF2H(CF3)}(PR 3)2] (4a, R = Cy; 4bR = iPr) and trans-[Ni(F){2-C 5NF2H(CF3)}(PCy3)2] (5a) in toluene solution. 19F NMR titration experiments are used to determine binding constants, enthalpies and entropies of these interactions (2.4 ≤ K300 ≤ 5.2; -25 ≤ ΔHo ≤ -16 kJ mol-1; -73 ≤ ΔSo ≤ -49 J K-1 mol-1). The data for -ΔHo for the halogen bonding follow a trend Ni PtF increases substantially with adduct formation. X-ray crystallographic data for Ni complexes 5a and 5c are compared to previously published data for a platinum analogue. We show by experiment and computation that the difference between Pt-X and Ni-X (X = F, C, P) bond lengths is greatest for X = F, consistent with F(2pπ)-Pt(5dπ) repulsive interactions. DFT calculations on the metal fluoride complexes show the very negative electrostatic potential around the fluoride. Calculations of the enthalpy of adduct formation show energies of -18.8 and -22.8 kJ mol -1 for Ni and Pt complexes of types 5 and 4, respectively, in excellent agreement with experiment.
