Neutral and anionic transition metal complexes supported by decafluorodiphenylamido ligands: X-ray crystal structures of {Na(THF) 2}{Ti[N(C 6F 5) 2] 4}, {K(η 6-C 6H 5Me) 2}{ZrCl 2[N(C 6F 5) 2] 3}, K{VCl[N(C 6F 5) 2] 3}, Fe[N(C 6F 5) 2] 2(THF) 2 and Co[N(C 6F 5) 2] 2(py) 2

Abstract

Reaction of MN(C 6F 5) 2 (M=Na, K) with transition metal halides results in the formation of transition metal complexes incorporating decafluorodiphenylamido ligands. TiCl 3(THF) 3 reacts with 3 equiv. NaN(C 6F 5) 2 to yield the ‘metallate’ complex {Na(THF) 2}{Ti[N(C 6F 5) 2] 4} ( 1). Single crystal X-ray diffraction studies reveal a tetrahedral titanium center complexed by four decafluorodiphenylamido ligands; while two THF ligands and four fluorine atoms coordinate the sodium cation. ZrCl 4 reacts with 3 equiv. KN(C 6F 5) 2 to give {K(η 6-C 7H 8) 2}{ZrCl 2[N(C 6F 5) 2] 3} ( 2). The 19F NMR spectrum of 2 reveals phenyl resonances in a 2:1 ratio, consistent with a trigonal bipyramidal structure being maintained in solution. The crystal structure of 2 reveals a pseudo-octahedral structure, with the sixth-coordination site being completed by a weak ZrF interaction with a pentafluorophenyl group of an amido ligand. The potassium counterion interacts in an η 6 fashion with two toluene rings in addition to a fluorine atom arising from one of the pentafluorophenyl groups. The reaction of VCl 3 with 3 equiv. KN(C 6F 5) 2 generates the ‘metallate’ complex K{VCl[N(C 6F 5) 2] 3} ( 3); the solid state structure of 3 reveals a distorted trigonal bipyramid with the coordination sphere being completed by a weak V–F interaction with the ortho-fluorine of one of the fluorophenyl amido ligands. Exposure of FeCl 3 to 3 equiv. KN(C 6F 5) 2 results in reduction of the metal center and the formation of the Fe(II) species Fe[N(C 6F 5) 2] 2(THF) 2 ( 4). Compound 4 is tetrahedral in the solid state with none of the weak MF contacts observed for 1, 2, 3 and 5. CoI 2 reacts with 2 equiv. NaN(C 6F 5) 2 in the presence of pyridine to produce the expected product Co[N(C 6F 5) 2] 2(py) 2 ( 5); X-ray crystallography reveals a five-coordinate species in the solid state which is additionally stabilized by a weak CoF interaction.