Preparation and Structures of Rare Earth 3-Benzoylpropanoates and 3-Phenylpropanoates

Abstract

Rare earth (RE) complexes of 3-benzoylpropanoate (bp), [RE(bp)3(H2O)n] (RE=La, n=2; RE=Y, Ce, Pr, Nd, Yb, n=1) and 3-phenylpropanoate (pp), [RE(pp)3] (RE=Y, La, Ce, Nd, Yb), have been prepared by metathesis reactions between the corresponding rare earth chloride and the appropriate sodium carboxylate. Analysis by single-crystal X-ray diffraction finds that both RE bp and pp complexes favour formation of carboxylate-bridged 1-D coordination polymers in the solid state. Here, the former favours heteroleptic 9 or 10-coordinate complexes (splitting between Ce and La) with the carbonyl remaining uncoordinated but participating as a hydrogen bond acceptor with water in the coordination sphere. Lack of bp carbonyl coordination leaves this group available for surface interactions during corrosion inhibition and complex solubilization. The latter pp derivatives form eight-coordinate complexes for Y and Yb and are the first examples of homoleptic RE pp complexes to be reported.