Antimony(III) halide compounds of thioureas: Structures and biological activity

Dimension-Controlled Growth of Antimony-Based Perovskite-like Halides for Lead-Free and Semitransparent Photovoltaics

Antimony (Sb) has been identified as a promising candidate for replacing toxic lead (Pb) in perovskite materials because Sb-based perovskite-like halides exhibit not only intrinsic thermodynamic stability but also a unique set of intriguing optoelectronic characteristics. However, Sb-based perovskite-like halides still suffer from poor film morphology and uncontrollable halide constituents, which result from the disorder of the growth process. Herein, we propose a simple strategy to facilitate heterogeneous nucleation and control the dimension transformation by introducing bis(trifluoromethane)sulfonimide lithium (LiTFSI), which produces high-quality two-dimensional MA₃Sb₂I_9-xCl_x films. As the spacer molecule among Sb-based pyramidal clusters, LiTFSI plays a role in forming a zero-dimensional intermediate phase and retarding crystallization. The slower dimension transformation well stabilizes the band gap of perovskite-like films with a fixed Cl/I ratio (∼7:2) and avoids random "x" values in MA₃Sb₂I_9-xCl_x films prepared from the conventional method. Based on this method, Sb-based perovskite-like solar cells (PLSCs) achieve the highest recorded power conversion efficiency (PCE) of 3.34% and retain 90% of the initial PCE after being stored under ambient conditions for over 1400 h. More importantly, semitransparent Sb-based PLSCs with PCEs from 2.62 to 3.06% and average visible transparencies from 42 to 23% are successfully obtained, which indicates the great potential of the emerging Pb-free halide semiconductor for broad photovoltaic applications.

Synthesis, Structural Characterization, and Antibacterial Activity of Novel Erbium(III) Complex Containing Antimony

The novel 3D edta-linked heterometallic complex [Sb₂Er(edta)₂(H₂O)₄]NO₃·4H₂O (H₄edta = ethylenediaminetetraacetic acid) was synthesized and characterized by elemental analyses, single-crystal X-ray diffraction, powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermal analysis. The complex crystallizes in the monoclinic system with space group Pm. In the complex, each erbium(III) ion is connected with antimony(III) ions bridging by four carboxylic oxygen atoms, and in each [Sb(edta)]^- anion, the antimony(III) ion is hexacoordinated by two nitrogen atoms and four oxygen atoms from the edta^4- ions, together with a lone electron pair at the equatorial position. The erbium(III) ion is octacoordinated by four oxygen atoms from four different edta^4- ions and four oxygen atoms from the coordinated water molecules. The carboxylate bridges between antimony and erbium atoms form a planar array, parallel to the (1 0 0) plane. There is an obvious weak interaction between antimony atom and oxygen atom of the carboxyl group from the adjacent layer. The degradation of the complex proceeds in several steps and the water molecules and ligands are successively emitted, and the residues of the thermal decomposition are antimonous oxide and erbium(III) oxide. The complex was evaluated for its antimicrobial activities by agar diffusion method, and it has good activities against the test bacterial organisms.

Silver complex of salicylic acid and its hydrogel-cream in wound healing chemotherapy

The known metallotherapeutic [Ag(salH)]₂ (AGSAL-1) of salicylic acid (salH₂), was used for the development of new efficient silver based material for wounds healing. AGSAL-1 was characterized by spectroscopic techniques and X-ray crystallography. The wound healing epithelialization of AGSAL-1 was investigated by the means of scratch assay against immortalized human keratinocytes (HaCaT) cells. The anti-inflammatory activity of AGSAL-1 was evaluated by monitoring the catalytic peroxidation of linoleic acid to hydroperoxylinoleic acid by the enzyme lipoxygenase (LOX). The antibacterial activity of AGSAL-1 was evaluated against bacterial species which colonize wounds, such as: Pseudomonas aeruginosa (PAO1), Staphylococcus epidermidis and Staphylococcus aureus, by the means of Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and their Inhibition Zone (IZ). Moreover, the influence of AGSAL-1 against the formation of biofilm of PAO1 and St. aureus was also evaluated by the mean of Biofilm Elimination Concentration (ΒΕC). A hydrogel material CMC@AGSAL-1, based on the dispersion of AGSAL-1 in to carboxymethyl cellulose (CMC) was tested for its antimicrobial activity. Molecular Docking was performed, to explore the molecular interaction of AGSAL-1 with (i) the transcriptional regulator of PAO1, LasR. (ii) the mevalonate pathway for the biosynthesis of isoprenoids which is essential for gram-positive bacteria St. epidermidis and St. aureus. The toxicity of AGSAL-1 was examined against the HaCaT cells. Its genotoxicity was evaluated using Allium cepa model, in vivo. No genotoxicity was detected, indicating that AGSAL-1 is a candidate towards the development on a new efficient medication of the silver based metallodrugs.

Structural, photolysis and biological studies of novel mixed metal Cu(I)-Sb(III) mixed ligand complexes

Direct reaction of copper(I) halides with triphenylstibine (tpSb) and 2-mercapto-thiazolidine (tzdtH) in 1:1:1 molar ratio, results in the formation of the [CuX(μ2-S)-tzdtH)(tpSb)]2 (X=Cl (1), Br (2) and I (3)) complexes. The complexes have been characterized by melting point, FT-IR, UV-vis, (1)H NMR spectroscopic data and X-ray crystallography. Complexes 1-3 are di-nuclear and they are the first examples of mixed metals (CuSb), mixed ligand (thioamide, stibine and halogen) containing complexes. Two μ2-S (1-3) atoms bridge the two copper(I) ions with tetrahedral geometry. The coordination sphere around copper atoms is completed by one Sb from tpSb and one halogen (chlorine, bromine or iodine) atom. Intermolecular via N-H⋯X (Cl (1) and Br (2)) interactions stabilized the assembly. The short coppercopper bond distances of 3.103 (1), 3.061 (2) and 3.110, 3.108 (3) Ǻ found in 1-3 indicates d(10)-d(10) interaction between metal centers. The complexes exhibit high photo-sensitivity to UVB light. The complexes 1-3 and the already known [Cu(μ2-I)(tpSb)2]2 (4) were tested for their in vitro cytotoxic activity against human cancer cell lines: MCF-7 (breast, estrogen receptor (ER) positive), MDA-MB-231 (breast, estrogen receptor (ER) negative) and MRC-5 (normal human fetal lung fibroblast cells) with sulforhodamine B (SRB) colorimetric assay. Since estrogen receptors (ERs) are located in MCF-7, in contrast to MDA-MB-231 cells, the estrogenic effect of 1-4 on MCF-7 cells was studied by the mean of methylene blue assay. Compound 4 exhibits the highest estrogenic effect. None of 1-4 exceeds the activity of cisplatin against MCF-7 cells, but they are more active than cisplatin towards MDA-MB-231 cells. UVB light increases the effectiveness of complexes on MCF-7 cells which in the case of 4 is up to 28% higher than the corresponding initial complex (without irradiation).

Structural Characterization of Thermochromic and Spin Equilibria in Solid-State Ni(detu)4Cl2 (detu = N,N'-Diethylthiourea)

Consecutive thermochromic lattice distortional and spin crossover equilibria in solid-state Ni(detu)4Cl2 (detu = N,N'-diethylthiourea) are investigated by variable-temperature X-ray crystallography (173-333 K), DFT calculations, and differential scanning calorimetry. Thermochromism and anomalous magnetism were reported previously (S. L. Holt, Jr., et al. J. Am. Chem. Soc. 1964, 86, 519-520); the latter was attributed to equilibration of a singlet ground state and a thermally accessible triplet state, but structural data were not obtained. A crystal structure at 173(2) K revealed [Ni(detu)4](2+) centers with distorted planar ligation of nickel(II) to the four sulfur atoms, with an average Ni-S bond length of 2.226(3) Å. The nickel ion was displaced out-of-plane by 0.334 Å toward a proximal apical chloride at a nonbonding distance of 3.134(1) Å. Asymmetry in the trans S-Ni-S angles was coupled to a monoclinic ↔ tetragonal lattice distortion (T(1/2) = 254 ± 11 K), resulting in thermochromism. Spin crossover occurs by tetragonal modulation of nickel(II) with approach of the proximal chloride at higher temperatures (T(1/2) = 383 ± 18 K), which is consistent with a contraction of -0.096(4) Å in the Ni···Cl separation observed at 293 K. A high-spin (S = 1) square-pyramidal [Ni(dmtu)4Cl](+) model (dmtu = N,N'-dimethylthiourea) was optimized by DFT calculations, which estimated limiting equatorial Ni-S bond lengths of 2.45 Å and an apical Ni-Cl bond of 2.43 Å. Electronic spectra of the spin isomers were calculated by TD-DFT methods. Assignment of the FTIR spectrum was assisted by frequency calculations and isotope substitution.

Novel bismuth compounds: synthesis, characterization and biological activity against human adenocarcinoma cells

Novel bismuth(iii) halide compounds were synthesized. Molecules with lower H-all atoms inter-molecular interactions tend to exhibit the higher activity against MCF-7 and HeLa cells.

Experimental and DFT studies for selective separation of Sb(iii) and Sb(v) from mixtures with Zr(iv)/Co(ii) using thiourea grafted polystyrene adsorbent

The ‘S’ atom of thiourea functionalized polystyrene adsorbent exhibited very strong interaction with excellent separation of antimony(iii and v) ions in presence of large concentration of cobalt and zirconium ions.