Neutral and anionic transition metal complexes supported by decafluorodiphenylamido ligands: X-ray crystal structures of {Na(THF)2}{Ti[N(C6F5)2]4}, {K(η6-C6H5Me)2}{ZrCl2[N(C6F5)2]3}, K{VCl[N(C6F5)2]3}, Fe[N(C6F5)2]2(THF)2 and Co[N(C6F5)2]2(py)2
摘要:
Reaction of MN(C6F5)(2) (M = Na, K) with transition metal halides results in the formation of transition metal complexes incorporating decafluorodiphenylamido ligands. TiCl3(THF)(3) reacts with 3 equiv. NaN(C6F5)(2) to yield the 'metallate' complex {Na(THF)(2)}{Ti[N(C6F5)(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. ZrCl4 reacts with 3 equiv. KN(C6F5)(2) to give {K(eta(6)-C7H8)(2)}{ZrCl2[N(C6F5)(2)](3)} (2). The F-19 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 pseudooctahedral 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 eta(6) fashion with two toluene rings in addition to a fluorine atom arising from one of the pentafluorophenyl groups. The reaction Of VCl3 with 3 equiv. KN(C6F5)(2) generates the 'metallate' complex K{VCl[N(C6F5)(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 FeCl3 to 3 ;equiv. KN(C6F5)(2) results in reduction of the metal center and the formation of the Fe(II) species Fe[N(C6F5)(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. COI2 reacts with 2 equiv. NaN(C6F5)(2) in the presence of pyridine to produce the expected product Co[N(C6F5)(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. (C) 2002 Elsevier Science Ltd. All rights reserved.