98331-71-6Relevant academic research and scientific papers
Complexes of hybrid ligands. Synthesis of a fluoro-alcohol diarylphosphino ligand and its complexes with Pt2+, Pd2+, Ni2+, Co2+, Cu+, and Rh3+: Crystal and molecular structure of a trans square-planar Ni2+ complex with two bidentate ligands showing cis-trans isomerism in solution
Boeré, René T.,Montgomery, Craig D.,Payne, Nicholas C.,Willis, Christopher J.
, p. 3680 - 3687 (2008/10/08)
The first example of a fluorinated alcohol containing a tertiary phosphino function, PPh2CH2C(CF3)2OH (HL1), has been synthesized. In the ionized form, this compound acts as a uninegative, bidentate, chelating, hybrid ligand, capable of forming stable complexes with both hard and soft transition-metal ions. We have made Pt(L1)2, Pd(L1)2, Ni(L1)2, Co(L1)2, Cu(L1)(PPh3)2, and K[RhCl2(L1)2]. NMR data show that Pt(L1)2 and Pd(L1)2 are cis square-planar compounds in solution. In solution, Ni(L1)2 is a mixture of cis and trans isomers, and values of ΔH, ΔG, and ΔS for their interconversion in different solvents are derived from variable-temperature NMR spectra. The CH2 1H and CF3 19F NMR signals in the ligand appear as pseudotriplets in both cis and trans isomers of Ni(L1)2, through coupling to 31P nuclei in the two ligand molecules. This virtual coupling is the result of large 2J(P,P′) values in both isomers. A complete determination of the crystal and molecular structure has been made for Ni(L1)2, C32H24F12NiO2P2. Crystals are orthorhombic, space group P212121, with a = 18.145 (2) A?, b = 33.269 (3) A?, c = 10.945 (1) A?, V = 6607 (2) A?3, and Z = 8. Least-squares refinement on F of 407 variables using 5922 observations converged at a conventional agreement factor R = 0.072. The complex is trans square planar in configuration, but there are two significantly different molecular conformations present. In one of these, there are close approaches to nickel from the CF3 groups of the ligand; this interaction distorts the ligand field around the metal and produces a difference in color between the solid and the solution of this complex.
