Synthesis and Structural Characterization of Lithium and Iron Complexes Containing a Chelating Phenolate Phosphane Ligand

✍ Scribed by Lan-Chang Liang; Yu-Ning Chang; Huan-Yu Shih; Sheng-Ta Lin; Hon Man Lee

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 332 KB
• Volume: 2011
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/ejic.201100260

✦ Synopsis

Abstract

The preparation and characterization of lithium and iron(II) complexes containing a potentially tridentate biphenolate phosphane ligand are reported. Deprotonation of 2,2′‐phenylphosphanyl‐bis(4,6‐di‐tert‐butylphenol) (H~2~L^Ph^) with one or two equivalents of __n__BuLi in diethyl ether solutions at –35 °C produces binuclear {Li(HL^Ph^)(OEt~2~)}~2~ or tetranuclear Li~4~(L^Ph^)~2~(OEt~2~)~3~, respectively. An X‐ray study of {Li(HL^Ph^)(OEt~2~)}~2~ showed it to be a C~i~‐symmetric dimer composed of two Li(HL^Ph^)(OEt~2~) units linked with dative O–Li bonds involving phenolate oxygen donor atoms whereas that of Li~4~(L^Ph^)~2~(OEt~2~)~3~ revealed a C~2~‐symmetric structure in which the two biphenolate phosphane ligands are linked with four lithium atoms that bind to three diethyl ether molecules. Treatment of FeCl~2~ with one or two equivalents of Na~2~(L^Ph^)(DME)~2~ in THF at –35 °C generates binuclear Fe~2~(L^Ph^)~2~(THF)~2~ or mononuclear Fe(HL^Ph^)~2~(THF)~2~, respectively. The two iron(II) centers in Fe~2~(L^Ph^)~2~(THF)~2~ are antiferromagnetically coupled.