Solvothermal synthesis of enneanuclear [Cu II7Ln III2] clusters

Abstract

Employment of H₃L (= 2-(β-naphthalideneamino)-2-hydroxymethyl-1-propanol) in mixed-metal copper-lanthanide cluster chemistry has led to the isolation of four new enneanuclear heteronuclear isostructural [Cu^II₇Ln^III₂] complexes. More specifically, the solvothermal reaction of Cu₂(OAc)₄·2H₂O with H₃L and the corresponding lanthanide nitrate salt in MeCN in the presence of a base, NEt₃, yielded three complexes with the general formula [Cu^II₇Ln^III₂(L)₄(HL)₂(OAc)₄]·2MeCN (Ln: Gd, 1·2MeCN; Tb, 2·2MeCN; Dy, 3·2MeCN), while in addition the Y^III analogue, [Cu^II₇Y^III₂(L)₄(HL)₂(OAc)₄]·2MeCN (4·2MeCN), was also synthesized in the same manner. The structure of the cluster describes two corner-sharing [Cu₃Ln] cubane metallic units, each one further connected to one Cu^II ion. Dc magnetic susceptibility studies in the 5–300 K range for complexes 1–4 reveal the presence of both ferromagnetic and antiferromagnetic exchange interactions within the metallic clusters.