Hemocompatible 3D Silver(I) Coordination Polymers: Synthesis, X‐ray Structure, Photo‐Catalytic and Antibacterial Activity

Abstract

Three new Ag(I) coordination polymers, namely, [Ag 3 (pyp) 3 (H 2 O) 2 ](bpydc)1.5(H 2 O) 6 (1), Ag 2 (dpe) 2 (phdac)](H 2 O) 5.4 (2), and [Ag 2 (azbpy) 3 (H 2 O) 2 ].(dga)(H 2 O) 5 (3) (where pyp = 1,3-bis(4-pyridylpropane), H 2 bpydc = 2,2'-bipyridine-5,5'-dicarboxylic acid, dpe = 1,2-di(4-pyridyl)ethylene, H 2 phdac = 1,4-phenylenediacetic acid, azpy = 4,4'-azobispyridine and H 2 dga = diglycolic acid) were synthesized and characterized using elemental analysis, IR, UV-vis, fluorescence spectroscopy, and single crystal X-ray diffraction. The most interesting aspect of these coordination polymers (CPs) in the solid state is represented by the number of lattice water molecules that, along with carboxylate ligands, play a crucial role in network formation through H-bonds to attain a 3D structure. The band gap energies of the CPs were calculated. Among the compounds studied CP 2 was proved to be the most efficient photocatalyst for the degradation of noxious organic dye methylene blue (MB) and in addition tendered better antibacterial activity. Finally, all three CPs showed to be hemocompatible.

Polymorphism in [Ag(bpetan)]n Coordination Polymers with Nitrate and Isophthalate Anions: Photocatalytic and Antibacterial Activity, Hemolysis Assay and Study of Cytotoxicity

“…In addition a water molecule is bound at each silver atom at longer distance (Ag(1)–O(8w)=2.895(3) Å, Ag(2)–O(7w)=2.780(3) Å), so that the metals adopt a non‐trigonal tri‐coordinated geometry. The Ag–N bond lengths (Table S3) are comparable to those noticed in related complexes, but slightly shorter by ca. 0.03 Å than those measured in CP 1 .…”

“…2). The Ag–N bond distances fall in the range 2.152(6)‐2.193(6) Å, while Ag–O interactions are significantly longer, in between 2.630(6)‐2.889(6) Å, as detected in similar complexes . As a matter of fact Ag(I) ions 1,3,4,6,8 are tri‐coordinated while 2,5,7 are tetra‐coordinated (Table S2).…”

“…Being Ag + ion a d 10 system, oxidation or reduction of this metal center is extremely difficult. In this context, comparing the emission profile of the free ligands and of the Ag complexes, we can conclude that the emission behavior of CP 1 and CP 2 is a cumulative effect of the metal perturbed intra ligand π*–π and π*–n CT transitions …”

“…In the present case the superior photocatalytic efficiency of CP 2 in comparison to CP 1 may be explained by facile charge separation and transfer in CP 2 for the presence of iph anions. As we know the activity of a photocatalyst is governed by a high content of π‐electrons in the aromatic moiety …”

Two 1D Silver(I) Coordination Polymers with 1,3‐Bis(4‐pyridyl) propane and Aromatic Carboxylate Anions: Synthesis, Structure and Photocatalytic Behavior

“…In CP 1 and 2, the photocatalytic activity gets influenced by aromatic moieties in these species. [39][40][41][42] Photocatalytic activity: The calculated optical band gap for the photocatalytic action of complexes 1 and 2 was 4.08 and 4 eV, respectively. So, the transfer of electrons from the valence band to the conduction band can occur upon irradiation with photon energy higher or equal than its band gap energy.…”