Novel One- and Two-Dimensional Ag(I) Networks Generated from Double Schiff Base Ligands with Disubstituted Quinoxaline Diazenes as the Terminal Binding Sites

The new double Schiff base ligand L7 (2,5-bis(2-benzodiazine)-3,4-diaza-2,4-hexadiene) with disubstituted quinoxaline diazenes was synthesized. Four new polymeric Ag(I) complexes based on L7, namely {Ag 3 ( L7 ) 3 (BF 4 ) 3 (CH 2 Cl 2 ) 3 (H 2 O)} n ( 1 ), {Ag 2.5 ( L7 ) 1.5 (ClO 4 ) 2.5 (H 2 O) 2 } n ( 2 ), {Ag 4 ( L7 ) 3 (PF 6 ) 4 } n ( 3 ), and {Ag 4 ( L7 ) 3 (SbF 6 ) 4}n ( 4 ), have been synthesized successfully. They were fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. In compound 1, two Ag(I) atoms are held together by two L7 ligands through the inside middle chelating N donors to generate a binuclear “X-shaped” helical secondary building block. In compounds 2 − 4, three Ag(I) atoms are held together by three L7 ligands through the inside middle chelating N donors to afford a trinuclear crownlike secondary building block. These spontaneous self-organized supramolecular secondary building blocks were further linked together into the higher extended hierarchy through outside N−Ag(I) coordination interactions. Compound 1 features a two-dimensional net containing a molecular cage, and compounds 2 − 4 feature two- ( 2 and 3 ) and one-dimensional ( 4 ) molecular crown-containing polymeric complexes in the solid state, respectively.