Novel PNN' & P2NN' ligands based on 2-aminopyridine (APyPNN-R) R = Ph (1a), Cy (1b), iBu (1c), 8-aminoquinoline (AQPNN-R) R = Ph (2a), Cy (2b), iBu (2c), iPr (2d), and 2-picolylamine (P2NN-R) R = Ph (3a), Cy (3b), iBu (3c), have been synthesized via a versatile, one-pot, single-step, reductive amination of tertiary phosphine acetaldehydes with the amine by reaction with STAB (where STAB is sodium(triacetoxy)borohydride). Ligands 1b and 1c bridge between paramagnetic Co(ii) and form dimeric complexes Co2Cl4(APyPNN-R)2 (4 and 5) when reacted with cobalt dichloride. Ligands 2a-c coordinate in a tridentate fashion forming chelate complexes MCl2(AQPNN-R) M = Co(ii) (6-8), and, for 2d, the Fe(ii) complex FeCl2(AQPNN-iPr) (9). A solution magnetic susceptibility value for 9 of 3.9μB is consistent with a monomer-dimer equilibrium. The synthesis of the dimeric complex [FeCl2(AQPNN-Ph)]2 (10) using 2a as well as solid state magnetic susceptibility measurements on 9 and 10 confirm this phenomenon. Ligand 3a coordinates to Fe(ii) in an interesting tetradentate fashion despite bearing a tertiary amine moiety giving octahedral FeCl2(P2NN') (11). All of the metal complexes have been characterized by elemental analysis, paramagnetic 1H NMR spectroscopy, solution magnetic susceptibility, and single crystal X-ray diffraction (XRD).
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http://dx.doi.org/10.1039/c8dt04058c | DOI Listing |
Dalton Trans
January 2025
Department of Chemistry, Handique Girls' College, Guwahati 781001, Assam, India.
Photoactive complexes of bioessential 3d metals, activable within the phototherapeutic window (650-900 nm), have gained widespread interest due to their therapeutic potential. Herein, we report the synthesis, characterization, and light-enhanced anticancer and antibacterial properties of four new dinuclear Co(II) complexes: [Co(phen)(cat)] (Co-1), [Co(dppz)(cat)] (Co-2), [Co(phen)(esc)] (Co-3), and [Co(dppz)(esc)] (Co-4). In these complexes, phen (1,10-phenanthroline) and dppz (dipyrido[3,2-:2',3'-]phenazine) act as neutral N,N-donor ligands, while cat and esc serve as O,O-donor catecholate ligands derived from catechol (1,2-dihydroxybenzene) and esculetin (6,7-dihydroxy coumarin).
View Article and Find Full Text PDFJ Neurol
January 2025
Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy.
Background: In multiple sclerosis (MS), susceptibility-weighted imaging (SWI) may reveal white matter lesions (WML) with a paramagnetic rim ("paramagnetic rim lesions" [PRLs]) or diffuse hypointensity ("core-sign lesions"), reflecting different stages of WML evolution.
Objective: Using the soma and neurite density imaging (SANDI) model on diffusion-weighted magnetic resonance imaging (MRI), we characterized microstructural abnormalities of MS PRLs and core-sign lesions and their clinical relevance.
Methods: Forty MS patients and 20 healthy controls (HC) underwent a 3 T brain MRI.
Dalton Trans
January 2025
Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany.
Two Co(II) mixed-ligand metal-organic frameworks (MOFs) based on 2-methylimidazole and trimesate were synthesised at room temperature. The structure and properties of the two MOFs, named material Deutsches Elektronen Synchrotron-1 and -2 (mDESY-1 and mDESY-2), were verified by single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), SQUID magnetic susceptibility and N adsorption. The structural analysis indicates that mDESY-1 is a 3D ionic framework with 2-methyl-1-imidazol-3-ium counterions residing in its pores, while mDESY-2 is a 2D neutral framework isostructural to ITH-1, with water as a co-crystallising solvent.
View Article and Find Full Text PDFJ Psychiatry Neurosci
January 2025
From the Department of Psychiatry, Yale University School of Medicine, New Haven, Conn., USA (Chen, Luo, Ide, C.-S. Li); Yale University, New Haven, Conn., USA (H.-T. Li); the Department of Biomedical Engineering, College of Chemistry and Life Science, Beijing University of Technology, Beijing, China (G. Li); the Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Beijing, China (G. Li); the Department of Neuroscience, Yale University School of Medicine, New Haven, Conn., USA (C.-S Li); the Interdepartment Neuroscience Program, Yale University, New Haven, Conn., USA (C.-S. Li); the Wu Tsai Institute, Yale University, New Haven, Conn., USA (C.-S. Li).
Background: Genetic variants may confer risk for depression by modulating brain structure and function; evidence has underscored the key role of the subgenual anterior cingulate cortex (sgACC) in depression. We sought to examine how the resting-state functional connectivity (rsFC) of the sgACC was associated with polygenic risk for depression in a subclinical population.
Methods: Following published protocols, we computed seed-based whole-brain sgACC rsFC and calculated polygenic risk scores (PRS) using data from healthy young adults from the Human Connectome Project.
Adv Sci (Weinh)
January 2025
Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, 400076, India.
Stabilizing large easy-axis type magnetic anisotropy in molecular complexes is a challenging task, yet it is crucial for the development of information storage devices and applications in molecular spintronics. Achieving this requires a deep understanding of electronic structure and the relationships between structure and properties to develop magneto-structural correlations that are currently unexplored in the literature. Herein, a series of five-coordinate distorted square pyramidal Co complexes [Co(L)(X)].
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