Wang Jitao

Pentakis(triphenylphosphine oxide)chlorolanthanide bis(feric tetrachloride) complexes

Abstract Twelve new complexes with the general formula [(Ph 3 P=O) 5 LnCl][FeCI 4 ] 2 where Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er and Y were synthesized. The X-ray diffraction crystal structural analysis of [(Ph 3 P=O) 5 LaCl] [FeCl 4 ] 2 showed that the [(Ph 3 P=O) 5 LaCl] 2+ cation was of six coordinated distorted octahedral geometry and the [FeCl 4 ] − anion was of tetrahedral geometry. The INDO method study revealed that the coordination of PO groups to the lanthanide made the LnCl bond more reactive than that in LnCl 3 , so that Lewis acids, such as FeCl 3 , could abstract chloride to give the title complexes.

Synthesis, characterization and electrochemical behaviour of 1′-formyl [(2,2-diferrocenyl)propane]isonicotinoyl hydrazone and its lanthanide complexes

Abstract One new diferrocene Schiff base was prepared by condensing 1′-formyl[(2,2-diferrocenyl)propane] with isonictinoyl hydrazine. 1′-formyl[(2,2-diferrocenyl)propane]isonicotinoyl hydrazone (HL) and its chelates with lanthanide ions, Ln(HL) 2 Cl 3 (H 2 O) n (Ln=La, Dy, Yb, Gd, Sm, Nd; n =1–5.) were prepared, isolated and characterized by elemental analysis, IR and 1 H NMR spectra. In these chelates the ligand coordinates to lanthanide ions in the keto form, and some chloride ions and water molecules participate in coordination to the metal ion. The redox properties of the ligand and its complexes were investigated using cyclic voltammetric method. Both the ligand and its lanthanide complexes exhibit two distinct pairs of redox peaks displaying electrochemical characteristics of multi-component system.

Asymmetric aldol condensation of acetyl ferrocene with aromatic aldehydes via the formation of the β-cyclodextrin inclusion complexes

Abstract By the formation of β-cyclodextrin (β-CD) inclusion complex, the aldol condensation of the acetyl ferrocene (FcCOCH 3 ) with aromatic aldehyde was investigated. The study reveals that the definite asymmetry-inducing ability of β-CD gives optical yields of the products in the range 6.0–30.4%. Also, alkali metal halides at a lower reaction temperature, can also give different results on the stereoselectivity of the reaction system. When the experiment was carried out in the solid state condition, an enhanced optical yield was obtained.

INVESTIGATION OF REACTION BETWEEN FULVENES AND α-NAPHTHYLLITHIUM

The steric structure and solvent effect of 6,6-dialkylfulvenes in reaction with α-naphthyllithium is studied. It is found for the first time that organolithium causes fulvenes to undergo reductive coupling reaction. In ether-THF, α-naphthyllithium also adds on the exo-cyclic double bond on 6, 6-dimethyl-, diethyl-and 6-methyl-6-ethylfulvene and abstracts α-hydrogen from the side chain of the fulvene in competition with the reduction and reductive coupling reaction. The reductive coupling reaction takes place when α-naphthyllithium reacts with 6-methyl-6-n-propyl-, -n-butyl-, and -i-butylfulvenes. There are various ways of activating 6, 6-polymethylene-fulvenes including tetra-, penta-, and hexamethylenefulvenes, all related with their structures. In ether-petroleum ether (1: 1), except that the 6, 6-tetramethylene-fulvenes undergoes α-hydrogen abstraction reaction, all the other 6, 6-dialkylfulvenes, 6, 6-penta- and hexamethylenefulvenes with α-naphthyllithium mainly undergo addition reaction.From the active fulvenes, some novel substituted or bridged titanocenes and zirconocenes are prepared.