Anion-controlled assembly of Ag(I) coordination polymers based on cis/trans-bis(acetylacetone)-1,4-cyclohexanediimine ligands: syntheses, structures, and solid-state luminescence

Abstract

Two isomorphic acetylacetone-based complexes: trans-bis(acetylacetone)-1,4cyclohexanediimine (TBAC) and cis-bis(acetylacetone)-1,4-cyclohexanediimine (CBAC) were designed to promote complex formation on reaction with AgX (X = , , , , and ) and were employed to generate nine silver coordination polymers (CPs), {[Ag(TBAC)]·2H₂O·BF₄}_n (1), [Ag(TBAC)_0.5(NO₃)]_n (2), [Ag₂(TBAC)₂(ClO₄)₂]_n (3), [Ag(TBAC)(CF₃SO₃)(H₂O)]_n (4), {[Ag(TBAC)₂]·SbF₆}_n (5), {[Ag(CBAC)]·BF₄}_n (6), {[Ag(CBAC)(H₂O)]·ClO₄}_n (7), {[Ag(CBAC)(H₂O)]·CF₃SO₃}_n (8), and {[Ag(CBAC)(H₂O)]·SbF₆}_n (9) that exhibit structural and topological diversity as determined by single-crystal X-ray diffraction analyses. The complexes were further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. Complex 1 exhibited a 3-D (4,4)-connected pts topology with the Schläfli symbol of (4²·8⁴). The anions in 2 are μ₂-bridging linkers, connecting the 1-D [Ag(TBAC)_0.5]_n chains to 2-D (3,4)-connected nets. In 3, TBAC is a tridentate ligand to bind Ag(I) ions to form a 1-D ladder-like supramolecular structure. Complex 4 has 2-D (3,3)-connected nets where both Ag(I) ions and TBAC ligands are 3-connected nodes. Complex 5 has a 1-D fishbone chain structure where some of the TBAC moieties are bidentate. The cis-isomer, CBAC, gives similar (3,3)-connected networks where the Ag(I) ions and CBAC ligands are 3-connected nodes in the resultant 6–9. Although the host networks in 6–9 are supramolecular isomers, structural comparisons revealed that use of cis- and trans-isomers of the ligand and different counterions significantly influence the structures. The luminescent properties of all complexes and ligands were investigated.

Keywords:

• Bis(acetylacetone)cyclohexanediimine
• silver coordination polymers
• luminescent property
• ion-controlled
• structure diversity

Acknowledgments

The Australian partnership are gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.

Funding

The work was supported by the Natural Science Foundation of China [grant number 21061003]; Joint fund of Guizhou Province of PR China [grant number [2014]7090]; Youth Foundation of Guizhou Provincial Department of Education [grant number [2015]415].