Di-and triphenylacetate complexes of yttrium and europium

The significant variety in the crystal structures of rare-earth carboxylate complexes is due to both the large coordination numbers of the rare-earth cations and the ability of the carboxylate anions to form several types of bridges between rare-earth metal atoms. Therefore, these complexes are represented by mono-, di- and polynuclear complexes, and by coordination polymers. The interaction of LnCl₃(thf)_x(Ln = Eu or Y; thf is tetrahydrofuran) with sodium or diethylammonium diphenylacetate in methanol followed by recrystallization from a DME/THF/hexane solvent mixture (DME is 1,2-dimethoxyethane) leads to crystals of the non-isomorphic dinuclear complexes tetrakis(μ-2,2-diphenylacetato)-κ⁴O:O′;κ³O,O′:O′;κ³O:O,O′-bis[(1,2-dimethoxyethane-κ²O,O′)(2,2-diphenylacetato-κ²O,O′)europium(III)], [Eu(C₁₄H₁₁O₂)₆(C₄H₁₀O₂)₂], (I), and tetrakis(μ-2,2-diphenylacetato)-κ⁴O:O′;κ³O,O′:O′;κ³O:O,O′-bis[(1,2-dimethoxyethane-κ²O,O′)(2,2-diphenylacetato-κ²O,O′)yttrium(III)], [Y(C₁₄H₁₁O₂)₆(C₄H₁₀O₂)₂], (II), possessing monoclinic (P2₁/c) symmetry. The [Ln(Ph₂CHCOO)₃(dme)]₂molecule (Ln = Eu or Y) lies on an inversion centre and exhibits three different coordination modes of the diphenylacetate ligands, namely bidentate κ²O,O′-terminal, bidentate μ₂-κ¹O:κ¹O′-bridging and tridentate μ₂-κ¹O:κ²O,O′-semibridging. The terminal and bridging ligands in (I) are disordered over two positions, with an occupancy ratio of 0.806 (2):0.194 (2). The interaction of EuCl₃(thf)₂with Na[Ph₃CCOO] in methanol followed by crystallization from hot methanol produces crystals of tetrakis(methanol-κO)tris(2,2,2-triphenylacetato)-κ⁴O:O′;κO-europium(III) methanol disolvate, [Eu(C₁₉H₁₅O₂)₃(CH₃OH)₄]·2CH₃OH, (III)·2MeOH, with triclinic (P\overline{1}) symmetry. The molecule of (III) contains twoO,O′-bidentate and oneO-monodentate terminal triphenylacetate ligand. (III)·2MeOH possesses one intramolecular and four intermolecular hydrogen bonds, forming a [(III)·2MeOH]₂dimer with two bridging methanol molecules.