Synthesis, structure, and photoluminescent properties of lanthanide (Ln = Dy, Tb) chlorides and thiophenolates supported by formamidinate ligands

Abstract

The [Dy(DippForm)2Cl(THF)] (1a) and [Tb(DippForm)2Cl(THF)2] (1b) complexes are syn­thesized using salt metathesis reactions between lanthanide chlorides and K(DippForm) (DippForm = N,N'-bis(2,6-diisopropylphenyl)formamidinate). In contrast to K(DippForm), a reaction of its less sterically demanding analogue K(MesForm) (MesForm = N,N'-bis(me­sityl)formamidinate) with LnCl3 at any ratio of the reagents leads to the formation of the ho­moligand [Ln(MesForm)3] (Ln = Dy (2a), Tb (2b)) complexes. The [Ln(MesForm)2Cl(THF)] compounds are not isolated. Compounds 1a and 1b are successfully used as starting reagents for the preparation of new thiophenolate complexes [Ln(DippForm)2(SPh)(THF)] (Ln = Dy (3a), Tb (3b)). Crystal structures of compounds 1—3 are determined by single crystal X-ray diffraction. Photoluminescent properties of the complexes obtained are studied. The analysis of the spectra of both DippForm– and SPh– ligands shows an antenna effect for both Dy(III) and Tb(III). However, MesForm– acts as an efficient antenna for Tb(III) rather than Dy(III).