98%
921
2 minutes
20
We present the synthesis of two new novel tetradentate ligands based on 1,3,4-oxadiazole, 2-(2-pyridyl)-5-[,-bis(2-pyridylmethyl)aminomethyl]-1,3,4-oxadiazole (LTetraPy-ODA) and 2-(2-phenyl)-5-[,-bis(2-pyridylmethyl)aminomethyl]-1,3,4-oxadiazole (LTetraPh-ODA). The ligands were used to prepare six mononuclear complexes [Fe(LTetraPy-ODA)(NCE)] (C1-C3) and [Fe(LTetraPh-ODA)(NCE)] (C4-C6) where E = S, Se or BH. In addition, the ligand LTetraPy-ODA was employed in the synthesis of a new di-nuclear complex [FeII2(LTetraPh)](ClO)·1 CHNO·1.5 HO (C7). Characterization of all complexes was carried out using single-crystal X-ray crystallography, elemental analysis, and infrared spectroscopy. Magnetic susceptibility measurements, performed in the temperature range of 2-300 K using a SQUID magnetometer, revealed spin crossover behaviour exclusively in the mononuclear complexes C3 and C6, in which two monodentate NCBH co-ligands coordinate. The presence of the lattice solvent was found to be crucial to the spin transition property, with complex C3 exhibiting a switching temperature () of approximately 165 K and C6 approximately 194 K. The other four mononuclear complexes C1, C2, C4, C5, as well as the dinuclear complex C7 are locked in the high spin state over the measured temperature range. Density Functional Theory (DFT) calculations were performed on complexes C1-C6 to rationalise the observed magnetic behaviour, demonstrating the significant effect of the NCS, NCSe and NCBH co-ligands ligands on the spin-crossover behaviour of the [Fe(L)(NCE)] complexes.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/d4dt01141d | DOI Listing |
RSC Adv
September 2025
Department of Chemistry, University of Guelph Guelph ON N1G 2W1 Canada
In the context of the importance of manganese β-diketonates as precursors for the preparation of manganese oxide thin films and nanostructured materials, we report synthetic protocols and pitfalls encountered in the preparation of a family of Mn(ii) complexes of two fluorinated β-diketonates, 1,1,1-trifluoroacetylacetonato- (tfac) and 1,1,1,5,5,5-hexafluoroacetylacetonato- (hfac). The synthetic conditions and crystal structures of six new complexes are reported, including a coordination polymer {K[Mn(tfac)]}, an unusual trinuclear complex Mn(tfac)(OH), and a series of mononuclear complexes with coordinated solvents tetrahydrofuran, 1,2-dimethoxyethane, water, and acetonitrile. The crystal structures of two known Mn(ii) complexes are also reported for completeness.
View Article and Find Full Text PDFDalton Trans
September 2025
Department of Chemistry, Indian Institute of Technology Guwahati, Assam 781039, India.
Motivated by copper's essential role in biology and its wide range of applications in catalytic and synthetic chemistry, this work aims to understand the effect of heteroatom substitution on the overall stability and reactivity of biomimetic Cu(II)-alkylperoxo complexes. In particular, we designed a series of tetracoordinated ligand frameworks based on iso-BPMEN = (,-bis(2-pyridylmethyl)-','-dimethylethane-1,2-diamine) with varying the primary coordination sphere using different donor atoms (N, O, or S) bound to Cu(II). The copper(II) complexes bearing iso-BPMEN and their modified heteroatom-substituted ligands were synthesized and structurally characterized.
View Article and Find Full Text PDFACS Omega
September 2025
Laboratory of Materials, Nanotechnology, and Environment, Faculty of Sciences, Mohammed V University in Rabat, Av. Ibn Battuta, P.O. Box 1014, Rabat 10000, Morocco.
In this study, we describe the synthesis and characterization of the mononuclear complexes [ )], [ ], and [ ], where = (2-((2-hydroxybenzylidene)-amino)-phenol). The structural analysis of these complexes was carried out utilizing mass spectrometry, H NMR, C NMR, P NMR, UV-visible, and FT-IR. All three complexes were investigated as corrosion inhibitors for mild steel in 1 M HCl.
View Article and Find Full Text PDFFront Immunol
September 2025
Center for Cellular Immunotherapies, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States.
Background: Multiplex gene-edited chimeric antigen receptor (CAR) T-cell therapies face significant challenges, including potential oncogenic risks associated with double-strand DNA breaks. Targeted microRNAs (miRNAs) may provide a safer, functional, and tunable alternative for gene silencing without the need for DNA editing.
Methods: As a proof of concept for multiplex gene silencing, we employed an optimized miRNA backbone and gene architecture to silence T-cell receptor (TCR) and major histocompatibility complex class I (MHC-I) in mesothelin-directed CAR (M5CAR) T cells.
J Immunother Cancer
September 2025
Department of Pediatrics, Center for Childhood Cancer and Blood Disorders, Division of Heme/Onc and Bone Marrow Transplant, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, Colorado, USA
Background: Diffuse midline glioma (DMG) and glioblastoma (GBM) are aggressive brain tumors with limited treatment options. Macrophage phagocytosis is a complex, tightly regulated process governed by competing pro-phagocytic and anti-phagocytic signals. CD47-SIRPα signaling inhibits macrophage activity, while radiotherapy (RT) can enhance tumor immunogenicity.
View Article and Find Full Text PDF