3-Methyl-1-phenyl-4-[(phen­yl)(2-phenyl­hydrazin-1-yl)meth­ylidene]-1H-pyrazol-5(4H)-one

The title compound, C23H20N4O, is a heterocyclic phenyl­hydrazone Schiff base with a pyrazole moiety. In the crystal, a variety of inter­actions occur, including N—H⋯π and π–π stacking between the phenyl ring of the phenyl­hydrazinyl group and its symmetry-generated equivalent [centroid–centroid distance = 3.6512 (7) Å]

Novel palladium(II) complex derived from mixed ligands of dithizone and triphenylphosphine synthesis, characterization, crystal structure, and DFT study

ABSTRACT. A novel distorted square-planar palladium(II) complex of the type [Pd(Hdz)(PPh3)Cl], where (Hdz = dithizone mono deprotonate and PPh3 = triphenylphosphine), was synthesized in dichloromethane reactions between PdCl2 and a mixture of Hdz and PPh3. The new Pd(II) complex has been identified by FT-IR, electronic spectra, DFT calculations, molar conductivity, and single-crystal X-ray diffraction. An X-ray diffraction study revealed the structure of this complex, indicating distorted square planar coordination geometry around the Pd(II) ion by N, S, P, and Cl donor atoms. XRD analysis has also shown that the Pd(II) complex contains one five-membered ring formed by the coordination of the Hdz ligand through the nitrogen and sulfur atoms to the palladium metal center. To comprehend the strength of nucleophilic and electrophilic attack between the ligands and metal ions, the natural bond orbital (NBO) was used. Finally, density functional theory (DFT) was used to show the molecular reactivity and stability of the ligands and palladium complex.   KEY WORDS: Palladium(II), Dithizone mono deprotonated, Distorted square planar geometry, NBO analysis, DFT calculations Bull. Chem. Soc. Ethiop. 2022, 36(3), 617-626.                                                               \ DOI: https://dx.doi.org/10.4314/bcse.v36i3.11                                                     &nbsp

4-[(4-Meth­oxy­benzyl­idene)amino]­benzene­sulfonamide

The title Schiff base compound, C14H14N2O3S, is non-planar, with a dihedral angle of 24.16 (7)° between the benzene rings. In the crystal, N—H⋯O and N—H⋯N hydrogen bonds link the mol­ecules into a layer parallel to (011). Intra- and inter­layer C—H⋯O inter­actions and π–π inter­actions [centroid–centroid distances = 3.8900 (9) and 3.9355 (8) Å] are also present

1,5-Bis(2-methyl­phen­yl)-3-nitro­formazan

In the title compound, C15H15N5O2, the nitro O atoms are disordered over two sets of sites with an occupancy ratio of 0.75 (4):0.25 (4). Amine–imine tautomerism is observed in the formazan group. This was evident from the similar C—N bond distances in the formazan [1.319 (2) and 1.332 (3) Å], as well as the distribution of the imine proton in the Fourier difference map which refined to a 0.53 (3):0.47 (3) ratio. C—H⋯O and π–π inter­actions [centroid–centroid distances = 3.4813 (1) and 3.3976 (1) Å] are observed in the crystal packing

Photo-and thermoresponsive N-salicylideneaniline derivatives : solid-state studies and structural aspects

Electronic supplementary information (ESI) available. CCDC 1899401, 1902658, 1966932, 1989369, 1989398, 1989403, 2014911, 2014914, 2019418, 2049690, 2049691, 2062423, 2157376, 2156456–2156467 and 2191107–2191119. For ESI and crystallographic data in CIF or other electronic format see DOI: https://doi. org/10.1039/d1nj03056f.N-Salicylideneaniline (SA) and its derivatives are known to possess chromism upon exposure to external stimuli. Herein, we present mechanochemical synthesis of a series of photo-and thermoresponsive SA-derivatives and report on solid-state stabilisation of their tautomeric forms either by change in temperature or by photoirradiation. The influence of UV light on proton transfer between the enol-imine (EI) and keto-amine (KA) forms was investigated at λ1 = 254 and λ2 = 365 nm. Differential scanning calorimetry (DSC) measurements provided extra information on the thermodynamic relationship between the prototropic tautomers, and their exposition to liquid nitrogen, combined with variable temperature single-crystal X-ray diffraction (VT-SCXRD) and spectroscopic data, ascertained structural reasons for the intrinsic thermo-optical properties of the compounds. A series of structural determinations between 150 and 300 K further shed light on the thermomechanical behaviour exhibited by the thermoresponsive compounds. By virtue of calorimetry we were able to demonstrate proton transfer via the intramolecular O⋯N hydrogen bond over the temperature range 193–453 K. This present work demonstrates the importance of applying complementary analytical techniques and appropriate approaches for understanding the switching behaviour between the EI and KA forms. Furthermore, the assertion that it is predominantly the planarity (φ < 25°) that determines thermochromaticity is questioned.The National Research Foundation (NRF), South Africa and Rhodes University Research Council.http://rsc.li/njchj2023Chemistr

The crystal structure of 2-oxo-2H-chromen-4-yl acetate, C11H8O4

C11H8O4, monoclinic, P21/c (no. 14), a = 4.5947(2) Å, b = 10.5414(3) Å, c = 19.1611(7) Å, β = 94.084(2)°, V = 925.70(6) Å3, Z = 4, Rgt(F) = 0.0376, wRref(F 2) = 0.1109,T = 200(2) K.CCDC no.: 190638

Reaction of Perrhenate with Phthalocyanine Derivatives in the Presence of Reducing Agents and Rhenium Oxide Nanoparticles in Biomedical Applications

A novel alternative route to access rhenium(V)−phthalocyanine complexes through direct metalation of metal-free phthalocyanines (H2Pcs) with a rhenium(VII) salt in the presence of various two-electron reducing agents is presented. Direct ion metalation of tetraamino- or tetranitrophthalocyanine with perrhenate (ReO4−) in the presence of triphenylphosphine led to oxidative decomposition of the H2Pcs, giving their respective phthalonitriles. Conversely, treatment of H2Pcs with ReO4− employing sodium metabisulfite yielded the desired ReVO−Pc complex. Finally, reaction of H2Pcs with ReO4− and NaBH4 as reducing agent led to the formation of rhenium oxide (RexOy) nanoparticles (NPs). The NP synthesis was optimised, and the RexOy NPs were capped with folic acid (FA) conjugated with tetraaminophthalocyanine (TAPc) to enhance their cancer cell targeting ability. The cytotoxicity profile of the resultant RexOy−TAPc−FA NPs was assessed and found to be greater than 80 % viability in four cell lines, namely, MDA−MB-231, HCC7, HCC1806 and HEK293T. Non-cytotoxic concentrations were determined and employed in cancer cell localization studies. The particle size effect on localization of NPs was also investigated using confocal fluorescence and transmission electron microscopy. The smaller NPs (≈10 nm) were found to exhibit stronger fluorescence properties than the ≈50 nm NPs and exhibited better cell localization ability than the ≈50 nm NPs

Novel genetic loci associated with hippocampal volume

The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (rg =-0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness

Novel genetic loci underlying human intracranial volume identified through genome-wide association

Intracranial volume reflects the maximally attained brain size during development, and remains stable with loss of tissue in late life. It is highly heritable, but the underlying genes remain largely undetermined. In a genome-wide association study of 32,438 adults, we discovered five novel loci for intracranial volume and confirmed two known signals. Four of the loci are also associated with adult human stature, but these remained associated with intracranial volume after adjusting for height. We found a high genetic correlation with child head circumference (ρgenetic=0.748), which indicated a similar genetic background and allowed for the identification of four additional loci through meta-analysis (Ncombined = 37,345). Variants for intracranial volume were also related to childhood and adult cognitive function, Parkinson’s disease, and enriched near genes involved in growth pathways including PI3K–AKT signaling. These findings identify biological underpinnings of intracranial volume and provide genetic support for theories on brain reserve and brain overgrowth

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder