화학공학소재연구정보센터
Inorganic Chemistry, Vol.34, No.16, 4062-4068, 1995
Tripodal Amido Ligands Containing an Active Ligand Periphery
The trifunctional trisilylmethane-derived amine HC{SiMe(2)NH(2-FC6H4)}(3) (1) has been prepared which contains fluorine atoms in the ligand periphery which may act as additional donor functions in its amido complex derivatives. Lithiation with n-BuLi and reaction with YCl3 yields the seven-coordinate yttrium complex HC{SiMe(2)N(2-FC6H4)}Y-3(OEt(2)) (3) which has been structurally characterized by X-ray crystallography : triclinic, P ($) over bar 1 (No. 2), alpha = 9.4244(2) Angstrom, b = 10.5951(3) Angstrom, c = 16.6929 Angstrom, alpha = 93.280(8)degrees, beta = 91.918(7)degrees, gamma = 93.465(8)degrees, Z = 2, V = 1659.9(1) Angstrom(3), and R = 0.062. AU three fluorine donor atoms are coordinated to the yttrium center ((1)J(Y-89-F-19) = 5,3 Hz at 295 K). Rapid dynamic processes in solution which cannot be frozen out at 180 K confer an effective 3-fold symmetry upon the molecule at ambient temperature. Reaction of lithiated 1 with ZrCl4 in diethyl ether yields the (mu-Cl)(2)-bridged complex HC{SiMe(2)N(2-FC6H4)}3ZrCl2Li(OEt(2))(2) (4) which has one peripheral F-atom weakly coordinated to the Zr-center as established analytically and by an X-ray structure analysis : monoclinic, P2(1)/alpha (No. 14), alpha = 13.4123(2) Angstrom, b = 18.0086(3) Angstrom, c 17.3750(3) Angstrom, beta = 90.391(7)degrees, Z = 4, V = 4196.6(2) Angstrom(3), and R = 0.048, Reaction of 4 with MeLi gives the methyl-zirconium compound HC{SiMe(2)N(2-FC6H4)}3ZrCH3 (5) while upon condensation with [CpFe(CO)(2)](-), the dinuclear Zr-Fe-bonded complex HC{SiMe(2)N(2-FC6H4)}3ZrFe(CO)(2)Cp (6) is obtained. The spectroscopic data and structural considerations indicate that in 5 all three F-donors are bonded to Zr whereas in 6 all are uncoordinated, demonstating the coordinative flexibility of the ancillary donor functions in the tripodal amido complexes derived from 1.