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Although a great number of single-ion magnets (SIMs) and spin-crossover (SCO) compounds have been discovered, multifunctional materials with the combination of SCO and SIM properties are extremely scarce. Here magnetic studies have been carried out for a mononuclear, five-coordinate cobalt(ii) complex [Co(3,4-lut)4Br]Br (1) with square pyramidal geometry. Direct-current magnetic measurement confirms the spin transition between the S = 1/2 and 3/2 states in the range of 150-290 K with a small hysteresis loop. Frequency- and temperature-dependent alternating-current magnetic susceptibility reveals slow magnetization relaxation under an applied dc field of 3000 Oe. The work here presents the first instance of the five-coordinate mononuclear cobalt(ii)-based SIM exhibiting the thermally induced complete SCO.
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http://dx.doi.org/10.1039/c8dt03783c | DOI Listing |
Dalton Trans
September 2025
University of Patras, Department of Chemistry, 26504 Patras, Greece.
With the aim of assessing the role and impact of pseudohalides on the molecular and supramolecular structures of copper(II)/heavily substituted imidazole complexes, the synthesis and characterization of the complexes {[Cu(N)(HL)]} (1), {[Cu{N(CN)}(HL)]·MeCO} (2·MeCO) and [Cu(NCO)(HL)]·MeCN (3·MeCN) have been carried out; HL is the 4,5-diphenylimidazole ligand. The organic molecule behaves as a monodentate ligand through the pyridine-type nitrogen atom of the imidazole ring. The 1D polymer 1 is made up of undulating {-Cu-(N)-Cu-(N)-} chains, with the HL ligands extending from both sides of the chains.
View Article and Find Full Text PDFChem Asian J
August 2025
Department of Chemistry & Chemical Biology, Indian Institute of Technology (Indian School of Mines) Dhanbad, Dhanbad, Jharkhand, 826004, India.
We report the synthesis of six mononuclear organotin(IV) compounds, [RSn(L)] [R = Ph (1), t-Bu (2), and Me (3)] and [RSn(L)] [R = Ph (4), t-Bu (5), and Me (6)] supported by two polydentate pro-ligands, (E)-2,4-dichloro-6-(((2-hydroxy-5-nitrophenyl)imino)methyl)phenol (HL) and (E)-2,4-dichloro-6-(((2-hydroxyphenyl)imino)methyl)phenol (HL). HR-MS, multinuclear (H, C, and Sn) NMR spectroscopy, and FT-IR spectroscopy were used to characterize all compounds (1-6). Structural investigation via single-crystal X-ray diffraction confirmed a mononuclear geometry for all compounds, each featuring a five-coordinate tin(IV) center.
View Article and Find Full Text PDFDalton Trans
May 2025
Department of Applied Science, National Taitung University, Taitung 950, Taiwan.
A solution of six-coordinate [Mn(PS2)] (1) is inert towards nitric oxide (NO) at room temperature. In the presence of a proton source such as -toluenesulfonic acid or perchloric acid, however, the treatment of 1 with NO in the dark leads to the formation of {MnNO} [Mn(NO)(SPS-SPS)] (2) with a metal-diaryldisulphide ligand, as confirmed by several spectroscopy investigations, including single-crystal X-ray diffraction. A possible pathway for the formation of 2 was determined through theoretical studies and involves the following: (i) the thiolato sulphur in 1 interacts with H to generate an intermediate [Mn(PS2)(PS2H)] (A) with an S⋯H interaction; (ii) the reaction of A with NO yields HNO and an Mn(IV)-bound-thiyl radical species (B); and (iii) the nucleophilicity of the thiyl radical B to an adjacent thiolato sulphur produces a five-coordinate Mn(III)-diaryldisulphide species (C), which reacts with the generated HNO to yield 2.
View Article and Find Full Text PDFJ Biol Chem
May 2025
Department of Physiology & Biophysics, University of California, Irvine School of Medicine, Irvine, California, USA; Research Service, VA Long Beach Healthcare System, Long Beach, California, USA. Electronic address:
Carotenoid cleavage dioxygenases (CCDs) are non-heme Fe enzymes that catalyze the oxidative cleavage of alkene bonds in carotenoids, stilbenoids, and related compounds. How these enzymes control the reaction of dioxygen (O) with their alkene substrates is unclear. Here, we apply spectroscopy in conjunction with X-ray crystallography to define the iron coordination geometry of a model CCD, CAO1 (Neurospora crassa carotenoid oxygenase 1), in its resting state and following substrate binding and coordination sphere substitutions.
View Article and Find Full Text PDFDalton Trans
July 2024
Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education, School of Chemistry and Material Science Heilongjiang University, 74 Xuefu Road, Harbin 150080, P. R. China.
Two lanthanide complexes with formulae [Dy(L)(pentafluoro-PhO)] (1) and [Dy(L)(2,6-difluoro-PhO)](BPh) (2) (L = 2,14-dimethyl-3,6,10,13,19-pentaazabicyclo[13.3.1]nonadecal (19),2,13,15,17-pentaene) were structurally and magnetically characterized.
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