Synthesis and structural characterization of LiI, ZnII, CdII, and HgII complexes containing a fluorinated β-diketiminate ligand

The reaction of a fluorinated beta-aminoimine compound ArN]C(Me)CHIC(Me)NHAr (1) (Ar = 2,6-F2C6H3) with n-BuLi in coordinating solvents (Et2O and THF) leads to the solvated complexes [HC(CMeNAr)(2)] Li(Et2O) (2) and IFIC(CMeNAr)(2)]Li(THF) (3), respectively. They exist as momonuclear complexes featuring lithium atoms in a distorted trigonal planar environment. The same reaction, which was then carried out in a non-coordinated solvent (pentane), provided complex [HC(CMeNAr)(2)](2)Li-2 (4). It crystallized as a dinuclear complex in the solid state, featuring lithium atoms in a pseudo-tetrahedral coordination environment. Notably, one fluorine atom of each ligand was involved to stabilize the lithium center. Taking complex 2 as the precursor, a series of group 12 metal complexes were prepared via the reaction with MX2 (M = Zn, Cd, Hg; X = Br, I). The diketiminate zinc complexes [HC(CMeNAr)(2)]Zn(mu-I)(2)Li(Et2O)(2) (5) and IHC(CMeNAr)(2)] Zn(mu-Br)(2)Li(Et2O)(2) (6) were successfully synthesized and characterized by single crystal X-ray diffraction analysis. When 2 reacted with CdI2, the expected double iodide bridging product (FIC(CMeNAr)(2)]Hg(mu-1)(2)Li(Et2O)(2) (7a) was only generated in a small amount, with the single iodide bridging complex [HC(CMeNAr)(2))Cd(I)(mu-I)Li(Et2O)(3) (7b) as the major product. These results were unambiguously confirmed by NMR spectroscopy and X-ray crystallography. Next, a mercury complex (HC)-H-1(CMeNAr)(2)]Hg(mu-1)(2)Li(Et2O) (8) was prepared by using Hgl(2) as the metal source. Additionally, [HC(CMeNAr)(2)]ZnEt (9) was also obtained by mixing ligand 1 with Et2Zn. (C) 2012 Elsevier BA/. All rights reserved.