Facile construction of lanthanide metallomacrocycles with the bridging imidazolate and triazolate ligands and their ring expansions.
Four novel tri- or tetranuclear organolanthanide metallomacrocycles [Cp2Ln(mu-Im)(THF)3 (Cp = C5H5, Ln = Yb (1), Er (2)], [Cp2Dy(mu-Im)]4(THF)]3 x 2THF (3), and [Cp'2Yb(mu-eta1:eta2-Tz)]4 x 2THF (Cp' = CH3C5H4) (4) have been synthesized through protolysis of Cp3Ln or Cp'3Yb with imidazole or triazole, indicating that both the bridge-ligand size and the lanthanide-ion radii can be applied in the modulation of the metallomacrocycles. Further investigations on the reactivity of complexes 1, 3, and 4 toward phenyl isocyanate reveal that PhNCO inserts readily into the simple bridge Ln-N bonds of 1 and 3 to yield the corresponding insertion products [Cp2Ln(mu-eta1:eta2-OC(Im)NPh)]3 (Ln = Yb (5), Dy (6)) but cannot insert into the Ln-N bond with a mu-eta1:eta2-bonding mode in 4. The novel bridge ligand [OC(Im)NPh] can expand the numbers of the ring members from 12 to 18 in 5 or 16 to 18 in 6. The number of metal atoms in the metallacycles with the ligand [OC(Im)NPh] is independent of the lanthanide-ion size; both trinuclear lanthanide macrocycles are observed in 5 and 6. All of these new complexes have been characterized by elemental analysis and spectroscopic properties, and their structures have also been determined through X-ray single-crystal diffraction analysis.
Zhang
Jie
J
Department of Chemistry, Fudan University, Shanghai 200433, People's Republic of China. zhangjie@ fudan.edu.cn
Cai
Ruifang
R
Chen
Zhenxia
Z
Zhou
Xigeng
X
D018360:Crystallography, X-Ray; D007093:Imidazoles / Q000737:chemistry*; D017953:Isocyanates / Q000737:chemistry; D028581:Lanthanoid Series Elements / Q000737:chemistry* / Q000378:metabolism; D008024:Ligands; D047028:Macrocyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D014230:Triazoles / Q000737:chemistry*
D007093:Imidazoles; D017953:Isocyanates; D028581:Lanthanoid Series Elements; D008024:Ligands; D047028:Macrocyclic Compounds; D009942:Organometallic Compounds; D014230:Triazoles; C025319:phenyl isocyanate