Solvent-dependent structures of lanthanide–TCNQ coordination networks and their magnetic properties
Lanthanide complexes were prepared with 2,6-diacetylpyridinebis(benzoylhydrazone) (DAPBH2) and 7,7,8,8-tetracyano-p-quinodimethanide (TCNQ•−). The complexes adopted one of two structure types depending on the reaction solvent. The complexes were
categorized as Type I (i.e. bis{[2,6-diacetylpyridinebis(benzoylhydrazone)] methanollanthanide(III)}bis(µ2- 7,7,8,8-tetracyanoquinodimethanide(1−))bis(7,7,8,8-tetracyanoquinodimethanide(1−))bis(7,7,8,8-tetracyanoquinodimethanide(1−)) methanol disolvate, [Ln2(DAPBH2)2
(µ2-TCNQ•−)2(TCNQ•−)2(MeOH)2](TCNQ•−)2·2MeOH (Ln = Gd, Tb, or Dy) or Type-II (i.e. [Ln2(DAPBH2)2(µ2-TCNQ•−)2(TCNQ•−)2(EtOH)2]
(TCNQ•−)2·solvent (Ln = Tb and Dy, solvent =4EtOH for the Tb and 2EtOH·2CH2Cl2 for the Dy complexes). These two complexes exhibit dramatically different molecular structures and packings. In all complexes, the
strong intra- and intermolecular stacking interactions of the TCNQ•− radicals lead to the formation of 1D TCNQ chains. Magnetic susceptibility measurements for Type I and Type II complexes reveal that they exhibit paramagnetic behavior and that their magnetic properties
originate from the lanthanide ions alone, owing to the diamagnetic nature of the TCNQ•− stacks.
Keywords: 4f–2p spin system; Lanthanide complex; magnetic properties; solvent-dependent structure
Document Type: Research Article
Affiliations: 1: Department of Chemistry, Faculty of Science, Toho University, Miyama, Funabashi, Chiba, Japan; 2: Research Centre for Materials with Integrated Properties, Toho University, Miyama, Funabashi, Chiba, Japan;
Publication date: 02 November 2018
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