Reaction of the β-diketiminate ytterbium dichloride LYbCl2（THF）2（L=2,6-Pri2C6H3）NC（Me）CHC（Me）N（C6H3-2,60Pri2）（1）with 2equiv off C5H5Na in THF gave rise to the title complex LYb（C5H5）2（2）,and the crystal structure of the complex 2 was determined by single-crystal X-ray diffraction.The crystal belongs to orthorhombic,space group P21212 with a=4.3219（6）,b=1.6602（2）,c=0.9604（1）nm,V=6.891（2）nm3,Z=8,Dc=1.390 Mg·m-3,R=0.0331,wR=0.0535.In the molecular structure of the title complex,the central metal atom Yb is coordinated by two cyclopentadienyl rings and two nitrogen atomes of β-diketiminate group to form an eight-coordinate distorted tetrahedral geometry.
A polynuclear yttrium trifluoroethoxide was synthesized and its activity for the oligomerization of phenyl isocyanate was tested. Reaction of anhydrous YCl3 with CF3CH2ONa in a 1∶3 molar ratio in THF at room temperature, after workup, gave complex STHZ1 as colorless crystals. The composition of complex STHZ1 is Y（OCH2CF3）36ONa2（THF） 12 , which was identified by elemental analysis and 1H NMR. Further X-ray structure determination reveals that complex STHZ1 is a polynuclear ion pair compound, Y6（μ6-O）（OCH2CF3） 18 2- Na（THF）6+2 （STHZ1）. The crystal data of complex STHZ1 are trigonal, P-3 space group, a=1.78440（14） nm, b=1.78440（14） nm, c=1.27395（12） nm, γ=120°, V=3.5129（5） nm3, Z=1, Dc=1.607 mg·m -3 , μ=2.591 mm -1 （Mo Kα）, F（000）=1710, R=0.067, wR=0.182. Preliminary results demonstrated that complex STHZ1 is a highly effective catalyst for the oligomerization of phenyl isocyanate.
Divalent β-diketiminate lanthanide complexes LYbR（THF）（L=｛（2,6-Me2C6H3）NC（Me）｝2CH;R=C9H7（1）,CH3C5H4（2）,OC6H2-But2-2,6-Me-4（32））were synthesized by reducing the mixed-ligand trivalen（t） β-diketiminate ytterbium chlorides synthesized in situ with Na-K alloy.These divalent lanthanide complexes exhibit good catalytic activity for the ring opening polymerization of ε-caprolactone.
An unexpected carbon-oxygen bond cleavage of THF (THF = tetrahydrofuran) promoted by guanidinate titanium complex was described. Guanidinate lithium [Pr2iNC(NCy)2]Li (Cy = cyclohexyl) formed in situ reacted with TiCl4(THF)2 in a 2:1 molar ratio to produce the gua- nidinate titanium chloride [Pr2iNC(NCy)2]2TiCl2 (1) in good yield. The reaction of [Pr2iNC(NCy)2]2TiCl2 with lithium diisopropylamide in THF afforded an unexpected [Pr2iNC(NCy)2]2Ti(OBun)2 (2), which was formed by the cleavage of carbon-oxygen bond of THF. Complexes 1 and 2 were fully characterized by elemental analysis, NMR and IR spectroscopies, and X-ray crystal structure determination for complex 2.
Lanthanide methoxides supported by carbon-bridged bis(phenolate) ligands 2,2′-methylene-bis(6-tert- butyl-4-methylphenoxo) (MBMP2-) [(MBMP)Ln( μ-OMe)(THF)2]2 (Ln = Nd (1), Yb (2)) were synthesized in high yields by the protolysis reaction using (C5H5)3Ln(THF) as starting materials, and complex 1 was structurally characterized. The coordination geometry around the center metal can be best described as a distorted octahedron. Complexes 1 and 2 were shown to be efficient initiators for the ring-opening polymerization of 2,2-dimethyltrimethylene carbonate (DTC) and L-lactide. The mechanism of DTC polymerization was explored by the end group analysis of the oligomer.
The lanthanide coordination polymers bearing a 13-membered macrocycle, [(13-EDTA-pnOH)H2] were synthesized. The products [Ln(13-EDTA-pnOH)(H2O)2·NO3]n (Ln = Eu(1), Tb(2), Dy(3)) have been obtained by MS, IR and element analyses. The solid-state structure of 1 was established by single-crystal X-ray analysis. The coordination geometry around the central metal atom in complex 1 is a nine-coor-dinated, tricapped-trigonal prism having six donor atoms (two amine nitrogen atoms, two amide oxygen atoms and two carboxymethyl oxygen atoms) from one ligand, one oxygen atom from a neighboring ligand, and two more oxygen atoms from two water molecules. The europium atoms are linked by―Eu―O―C―O―Eu―bridges to form an infinite chain.
(C5H5)3Ln(THF) reacted with amine bis(phenol) LH2[L=Me2NCH2CH2N{CH2-(2-O-C6H2-But-3-Me-5)}2] in a 1:1 molar ratio in THF to generate the amine bis(phenolato) cyclopentadienyl lanthanide complexes LLn(C5H5)(THF)·(THF)n (Ln=La (1), n=0; Ln=Sm(2), n=1) in high yields. Complexes 1 and 2 were fully characterized by elemental analysis, NMR (for 1) and IR spectra, and X-ray structural determination. The crystal data of complex 1 are monoclinic, P21/c space group, a=1.1595(1) nm, b=1.8588(2) nm, c=1.6647(1) nm, β= 98.490(2)°, V=3.5486(5) nm3, Z=4, Dc=1.338 mg·m-3, μ=1.240 mm-1, F(000)=1488, R=0.0249, wR=0.0568. The crystal data of complex 2 are monoclinic, P21/c space group, a=0.9692(1) nm, b=1.4583(2) nm, c=2.8192(3) nm, β=96.805(2)°, V=3.9584(7) nm3, Z=4, Dc=1.340 mg·m-3, μ=1.524 mm-1, F(000)=1668, R=0.0346, wR=0.0756. The attempts failed to synthesize the amine bis(phenolate) lanthanide alkoxides by the reactions of complexes 1 and 2 with alcohols. The preliminary results revealed that complex 1 can initiate ε-caprolactone polymerization.
