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

It 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.