Chemical Assembling of Heterometallic {Cd–M} (M=Li, Mg, Eu, Tb) Molecules with 3,5‐Di‐tert‐butylbenzoate Bridges and N‐Donor Ligands

Abstract

AbstractIt was shown that the reaction of potassium 3,5‐di‐tert‐butylbenzoate (Kbzo) and Cd(NO3)2 in EtOH gave the [Cd3(H2O)(EtOH)3(bzo)6]⋅EtOH complex (I). The use of Li(bzo) or Mg(bzo)2 salts in this reaction in the presence of excess 2,4‐lutidine or a stoichiometric amount of 1,10‐phenanthroline initiated the crystallization of the polymer [CdLi2(H2O)(EtOH)2(bzo)4]n (II) containing no N‐donor ligands or trinuclear complexes [Cd2Mg(bzo)6(L)2]⋅Solv (L, Solv=lut, 2EtOH (III); phen, 6CH2Cl2 (IV)) that included coordinated N‐donors. The use of Eu(bzo)3 as the source of Ln ions in the presence of a stoichiometric amount of lut gave trinuclear carboxylates [EuCd2(H2O)2(EtOH)2(bzo)7]⋅3EtOH (V) and [TbCd2(H2O)(EtOH)3(bzo)7]⋅2EtOH⋅2.7H2O (VI) containing no lut molecules. It was found that the incorporation of coordinated N‐donors was observed only if a 10‐fold excess of pyridine or a stoichiometric amount of 2,2’‐dipyridyl was added to the reaction medium in the presence of Ln(NO3)3⋅6H2O (Ln=Eu, Tb) or Ln(bzo)3, respectively. In these cases, trinuclear {Cd−Ln} complexes were formed, which contained a terminal N‐donor ligand, [LnCd2(bzo)6(NO3)(py)4]⋅1.5MeCN (Ln=Eu (VII), Tb (VIII)), [EuCd2(H2O)(bzo)7(bpy)2]⋅2THF⋅3H2O⋅MeCN (IX) and [TbCd2(H2O)(bzo)7(bpy)2] (X)). The structures of the new compounds were determined by single‐crystal X‐ray diffraction analysis. The complexes were characterized by luminescence spectroscopy, IR spectra, CHN‐analysis and fluorescence analysis.