Crystal structure of a new monoclinic polymorph of 2,4-dihydroxybenzaldehyde 4-methylthiosemicarbazone

The title compound, C9H11N3O2S, is a second monoclinic (P21/c) polymorph of the previously reported Cc form [Tan et al. (2008b). Acta Cryst. E64, o2224]. The molecule is non-planar, with the dihedral angle between the N3CS residue (r.m.s. deviation = 0.0816 Å) and the benzene ring being 21.36 (4)°. The conformation about the C=N bond [1.292 (2) Å] is E, the two N-bound H atoms are anti, and the inner hydroxy O-bound and outer amide N-bound H atoms form intramolecular hydrogen bonds to the imine N atom. Crucially, the H atom of the outer hydroxy group is approximately syn to the H atom of the benzene C atom connecting the two C atoms bearing the hydroxy substituents. This arrangement enables the formation of supramolecular tubes aligned along [010] and sustained by N—H...O, O—H...S and N—H...S hydrogen bonds; the tubes pack with no specific interactions between them. While the molecular structure in the Cc form is comparable, the H atom of the outer hydroxy group is approximately anti, rather than syn. This different orientation leads to the formation a three-dimensional architecture based on N—H...O and O—H...S hydrogen bonds

Theoretical study to find the thermal stress and strain generated in the Wood silica using lasers

In this research study theory to find the stress and emotion gases in the glass as a result of exposure to pulses of the laser beam has been the study using vehicles three major on-system axes cylindrical (r, 0, z), where I took three models of glass silica glass soda glass fused and shedtwo types of lasers where the study showed that the thermal stresses and emotions ..

Organotin(IV) complexes with 2-hydroxynaphthaldehyde-<i>N</i>(4)-ethylthiosemicarbazone: Synthesis, characterization, and <i>in vitro</i> antibacterial activity

<p>Four new organotin(IV) complexes with 2-hydroxynaphthaldehyde-<i>N</i>(4)-ethylthiosemicarbazone [(H₂DNET), (<b>1</b>)] of the type [MeSnCl(DNET] (<b>2</b>), [BuSnCl(DNET)] (<b>3</b>), [PhSnCl(DNET)] (<b>4</b>), and [Ph₂Sn(DNET] (<b>5</b>) have been synthesized by the direct reaction of H₂DNET (<b>1</b>) with organotin(IV) chloride(s) in the presence of potassium hydroxide in absolute methanol. All the compounds were characterized by elemental analyses, molar conductivity, UV-Vis, IR, ¹H, ¹³C, and ¹¹⁹Sn NMR spectral studies. The molecular structure of ligand (<b>1</b>) has been confirmed by X-ray single crystal diffraction. Spectroscopic data clearly suggested that Sn(IV) center is coordinated with the ONS tridentate ligand (H₂DNET) and exhibits a five-coordinate geometry in solution. Antibacterial studies were carried out <i>in vitro</i> against four bacterial strains. All organotin(IV) compounds (<b>2–5</b>) showed good activity against various bacteria but lower activity than the reference drug (Ciprofloxacin). The results demonstrate that organic groups attached to tin(IV) moiety have significant effect on their biological activities. Among them, diphenyltin(IV) derivative <b>5</b> exhibits significantly good activity than the other organotin(IV) derivatives (<b>2–4</b>).</p

Bis-<i>N</i>-heterocyclic carbene silver(I) and palladium(II) complexes: Efficient antiproliferative agents against breast cancer cells

<p>A new Pd(II)-<i>N</i>-heterocyclic carbene (NHC) complex <b>2</b> was derived from a binuclear Ag(I)-NHC complex <b>1</b>. ¹H NMR spectra of complexes showed uniquely different characteristic behavior of bridging methylene protons than compared with the ligand. X-ray crystallography showed that palladium at the center of bis-NHC units in <b>2</b> was found in square-planar geometry. Ligand and complexes were tested against breast cancer cells (MCF-7). The ligand did not show considerable antiproliferative activity (IC₅₀ 181.0 ± 3.0 µM) whereas complexes showed significant activity (<b>1</b>: 0.5 ± 0.1 μM; <b>2</b>: 2.5 ± 0.2 μM) compared with the standard drug, tamoxifen (2.4 ± 0.2 μM).</p

Organotin(IV) complexes with 2-hydroxynaphthaldehyde-<i>N</i>(4)-ethylthiosemicarbazone: Synthesis, characterization, and <i>in vitro</i> antibacterial activity

<p>Four new organotin(IV) complexes with 2-hydroxynaphthaldehyde-<i>N</i>(4)-ethylthiosemicarbazone [(H₂DNET), (<b>1</b>)] of the type [MeSnCl(DNET] (<b>2</b>), [BuSnCl(DNET)] (<b>3</b>), [PhSnCl(DNET)] (<b>4</b>), and [Ph₂Sn(DNET] (<b>5</b>) have been synthesized by the direct reaction of H₂DNET (<b>1</b>) with organotin(IV) chloride(s) in the presence of potassium hydroxide in absolute methanol. All the compounds were characterized by elemental analyses, molar conductivity, UV-Vis, IR, ¹H, ¹³C, and ¹¹⁹Sn NMR spectral studies. The molecular structure of ligand (<b>1</b>) has been confirmed by X-ray single crystal diffraction. Spectroscopic data clearly suggested that Sn(IV) center is coordinated with the ONS tridentate ligand (H₂DNET) and exhibits a five-coordinate geometry in solution. Antibacterial studies were carried out <i>in vitro</i> against four bacterial strains. All organotin(IV) compounds (<b>2–5</b>) showed good activity against various bacteria but lower activity than the reference drug (Ciprofloxacin). The results demonstrate that organic groups attached to tin(IV) moiety have significant effect on their biological activities. Among them, diphenyltin(IV) derivative <b>5</b> exhibits significantly good activity than the other organotin(IV) derivatives (<b>2–4</b>).</p

Structures, DNA binding, DNA cleavage, and antitumor investigations of a series of molybdenum(VI) complexes with some N(4) methyl and ethyl thiosemicarbazone ligands

<div><p>Four dioxomolybdenum(VI) complexes were synthesized by reaction of [MoO₂(acac)₂] with thiosemicarbazones derived from 5-allyl-2-hydroxy-3-methoxybenzaldehyde (<b>1</b>), 2-hydroxynaphthaldehyde (<b>2</b>), 2,3-dihydroxybenzaldehyde (<b>3</b>), or 5-tert-butyl-2-hydroxybenzaldehyde (<b>4</b>). The ligands were coordinated to molybdenum as tridentate ONS donors. X-ray crystallography showed that the distorted octahedral coordination of molybdenum is completed by methanol (D) in <b>1a</b>, <b>3a</b>, and <b>4a</b> or H₂O in <b>2a</b>. The molecular structures of <b>1</b>, <b>3</b>, and <b>4</b>, and the complexes were determined by single-crystal X-ray crystallography. Binding of the ligand and complexes with calf thymus DNA were investigated by UV, fluorescence titrations, and viscosity measurements. Gel electrophoresis revealed that all the complexes can cleave pBR322 plasmid DNA. The cytotoxic properties of the complexes against human colorectal (HCT 116) cell line showed strong antiproliferative activities in relative order <b>4a </b>> <b>3a </b>> <b>1a </b>> <b>2a</b> with IC₅₀ values of 1.6, 4.0, 4.8, and 6.7 μM, respectively. The complexes exhibited more activity than the standard reference drug, 5-fluorouracil (IC₅₀ 7.3 μM). These studies show that dioxomolybdenum(VI) complexes have potential use in chemotherapy.</p></div

Asynthesis, Crystal Structures and in Vitro Anticancer Studies of New Thiosemicarbazone Derivatives

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