Marigold Flower‐Like Assemblies of Phosphorescent Iridium–Silver Coordination Polymers

Abstract

Racemic and enantiopure phosphorescent iridium(III)-silver(I) coordination polymers are reported. The polymers rac-, Λ-, and Δ-IrAg were formed, respectively, by the assembly of the chiral iridium metalloligands rac-, Λ-, and Δ-[Ir(mesppy) (qpy)]PF (rac-, Λ- and Δ-Ir) where mesppy is 2-phenyl-4-mesitylpyridinato and qpy is 4,4':2',2'':4'',4'''-quaterpyridine, and Ag ions through N -Ag linear coordination. The polymers have been characterized in MeNO solution by H and H DOSY NMR and CD spectroscopies and in the solid-state by scanning electron microscopy (SEM). The crystal structures of the racemic polymer rac-IrAg has been obtained by X-ray diffraction. The polymers rac-, Λ-, and Δ-IrAg exhibited orange/red emission in solution, in films and as crystals, with intensities comparable to those of the corresponding iridium metalloligands rac-, Λ-, and Δ-Ir. The morphology of the enantiopure polymers in the solid-state resembles marigold flower-like nano-porous assemblies while the racemic polymer possesses an irregular morphology formation.

A Luminescent 1D Silver Polymer Containing [2.2]Paracyclophane Ligands

“…The weakly coordinated acetonitrile molecules are nearly perpendicular to the Ag-Npy bonds, with a Npy-Ag1-NMeCN angle of 87.6(3)°. The Ag1-N distance in Ag-pCp is similar to the 2.141 and 2.156 Å observed in rac-IrAg (Rota Martir et al, 2018) and also similar to the Ag-N distances of between 2.123 and 2.133 Å seen in a series of linear two-coordinate [Ag(pyridine)2] + structures. (Chen et al, 2007) This is a provisional file, not the final typeset article…”

A Luminescent 1D Silver Polymer Containing [2.2]Paracyclophane Ligands

“…In the extended coordination sphere, there are two weakly bound acetonitrile molecules, with longer Ag to N distances of 2.833(10) Å. The weakly coordinated acetonitrile molecules are nearly perpendicular to the Ag-N py bonds, with a N py -Ag1-N MeCN angle of 87.6(3) The Ag1-N distance in Ag-pCp is similar to the 2.141 and 2.156 Å observed in rac - IrAg ( Rota Martir et al, 2018 ) and also similar to the Ag-N distances of between 2.123 and 2.133 Å seen in a series of linear two-coordinate [Ag (pyridine) 2 ] + structures. ( Chen et al, 2007 ).…”

“…Ag1 is located at an inversion center, this results in a perfect 180° N-Ag1-N bond angle and identical Ag1-N distances of 2.141(4) Å. A linear N-Ag-N bond has been observed in some Ag-coordination polymers, for example in rac- IrAg ( Rota Martir et al, 2018 ); however, in many cases the linear coordination is distorted by the presence of anions and solvent molecules ( Chen et al, 2006 ). In the extended coordination sphere, there are two weakly bound acetonitrile molecules, with longer Ag to N distances of 2.833(10) Å.…”

“…Co-crystallization of Ag(I) complexes with bipyridine and benzimidazole was reported by Cai and coworkers ( Cai et al, 2011 ) to yield 1D infinite coordination polymer chains with both intraligand emission and ligand-to-metal charge transfer contribution. We reported the first example of a phosphorescent Ag(I) coordination polymer that incorporated iridium (III) metalloligands ( Rota Martir et al, 2018 ).…”

Coordination Polymers Based on Highly Emissive Ligands: Synthesis and Functional Properties

“…The first examples of phosphorescent coordination polymers formed through the self-assembly between the iridium complexes rac-, Λand ∆-[Ir(mesppy) 2 (qpy)]PF 6 (mesppy-2-phenyl-4-mesitylpyridine, qpy-4,4 :2 ,2 :4 ,4 -quaterpyridine) and Ag + ions through qpy-Ag coordination were reported by Martir et al [226]. Enantiopure Λand ∆-IrAg formed porous nanospheres resembling the shape of marigold flowers.…”