A new 3D silver(I) coordination polymer with croconate ligand displaying green luminescent

Croconic Acid Doped Triglycine Sulfate: Crystal Structure, UV-Vis, FTIR, Raman, Photoluminescence Spectroscopy, and Dielectric Properties

Triglycine sulfate (TGS) single crystals doped with croconic acid (CA) were grown by evaporation from aqueous solutions. X-ray diffraction analysis shows a slight reduction in unit cell volume in TGS:CA compared to pure TGS crystals. The polarized Raman and near-infrared absorption spectra show that the positions of most lines resulting from inter- and intramolecular vibrations are in good agreement with those in spectra of undoped TGS crystals. The inclusion of CA in TGS is confirmed by the presence of bands characteristic of CA in the infrared-Fourier transform spectra. The ultraviolet-visible absorption spectra of TGS:CA are characterized by the presence of additional absorption bands (compared to the spectra of pure TGS) located in the transparent region of pure TGS. In the photon energy region 1.6–3.6 eV, a strong “green” luminescence band is present in TGS:CA upon excitation at λ = 325 nm. The position of the emission band depends on the wavelength of the exciting light. Doping of TGS with CA causes pinning of domain walls, which is accompanied by a decrease in amplitude and frequency dispersion of the dielectric anomaly at the phase transition, a decrease in the switchable polarization and an increase in the coercive field of hysteresis loops.

Synthesis, crystal structure and studies on the interaction with albumin of a new silver(I) complex based on 2-(4-nitrobenzenesulfonamido)benzoic acid

In the present work, the two-dimensional (2D) polymer poly[[μ₄-2-(4-nitrobenzenesulfonamido)benzoato-κ⁴O¹:O¹:O^1':N⁶]silver(I)] (AgL), [Ag(C₁₃H₉N₂O₆S)]_n, was obtained from 2-(4-nitrobenzenesulfonamido)benzoic acid (HL), C₁₃H₁₀N₂O₆S. FT-IR, ¹H and ¹³C{¹H} NMR spectroscopic analyses were used to characterize both compounds. The crystal structures of HL and AgL were determined by single-crystal X-ray diffraction. In the structure of HL, O-H...O hydrogen bonds between neighbouring molecules result in the formation of dimers, while the silver(I) complex shows polymerization associated with the O atoms of three distinct deprotonated ligands (L^-). Thus, the structure of the Ag complex can be considered as a coordination polymer consisting of a one-dimensional linear chain, constructed by carboxylate bridging groups, running parallel to the b axis. Neighbouring polymeric chains are further bridged by Ag-C monohapto contacts, resulting in a 2D framework. Fingerprint analysis of the Hirshfeld surfaces show that O...H/H...O hydrogen bonds are responsible for the most significant contacts in the crystal packing of HL and AgL, followed by the H...H and O...C/C...O interactions. The Ag...Ag, Ag...O/O...Ag and Ag...C/C...Ag interactions in the Hirshfeld surface represent 12.1% of the total interactions in the crystal packing. Studies of the interactions of the compounds with human serum albumin (HSA) indicated that both HL and AgL interact with HSA.

An experimental and theoretical study on the interaction of DNA and BSA with novel Ni2+, Cu2+ and VO2+ complexes derived from vanillin bidentate Schiff base ligand

In this investigation, the structure of bidentate N,N-Schiff base ligand of vanillin, (E)-4-(((2-amino-5-nitrophenyl)imino)methyl)-2-methoxyphenol (HL) was determined by single crystal X-ray diffraction. The interaction of new [CuL₂], [NiL₂] and [VOL₂] complexes with DNA and BSA was explored through UV-Vis and fluorescence spectroscopy. The electronic spectra changes displayed an isosbestic point for the complexes upon titration with DNA. The K_b values for the complexes [CuL₂], [NiL₂] and [VOL₂] were 2.4×10⁵, 1.9×10⁵ and 4.2×10⁴, respectively. [CuL₂] complex was bound more toughly than [NiL₂] and [VOL₂] complexes. These complexes had a significant interaction with Bovine Serum Albumin (BSA) and the results demonstrated that the quenching mechanism was a static procedure. Also, the complexes interacted with BSA by more than one binding site (n>1). Finally, the theoretical studies were performed using the docking method to calculate the binding constants and recognize the binding site of the DNA and BSA with the complexes. The ligand and complexes including Ni²⁺, Cu²⁺ and VO²⁺ ions were colonized by fungal growth.