Related Products of 16858-01-8, Catalysts are substances that increase the reaction rate of a chemical reaction without being consumed in the process. 16858-01-8, Name is Tris(2-pyridylmethyl)amine, molecular formula is C18H18N4. In a Article,once mentioned of 16858-01-8
Semiquinoid radical bridging ligands are capable of mediating exceptionally strong magnetic coupling between spin centers, a requirement for the design of high-temperature magnetic materials. We demonstrate the ability of sulfur donors to provide much stronger coupling relative to their oxygen congeners in a series of dinuclear complexes. Employing a series of chalcogen donor-based bis(bidentate) benzoquinoid bridging ligands, the series of complexes [(TPyA)2Cr2(RL4-)]2+ (OLH4 = 1,2,4,5-tetrahydroxybenzene, OSLH4 = 1,2-dithio-4,5-dihydroxybenzene, SLH4 = 1,2,4,5-tetrathiobenzene, TPyA = tris(2-pyridylmethyl)amine) was synthesized. Variable-temperature dc magnetic susceptibility data reveal the presence of weak antiferromagnetic superexchange coupling between CrIII centers in these complexes, with exchange constants of J = -2.83(3) (OL4-), -2.28(5) (OSL4-), and -1.80(2) (SL4-) cm-1. Guided by cyclic voltammetry and spectroelectrochemical measurements, chemical one-electron oxidation of these complexes gives the radical-bridged species [(TPyA)2Cr2(RL3-?)]3+. Variable-temperature dc susceptibility measurements in these complexes reveal the presence of strong antiferromagnetic metal-semiquinoid radical coupling, with exchange constants of J = -352(10) (OL3-?), – 401(8) (OSL3-?), and -487(8) (SL3-?) cm-1. These results provide the first measurement of magnetic coupling between metal ions and a thiosemiquinoid radical, and they demonstrate the value of moving from O to S donors in radical-bridged metal ions in the design of magnetic molecules and materials.
Sometimes chemists are able to propose two or more mechanisms that are consistent with the available data. Related Products of 16858-01-8, If a proposed mechanism predicts the wrong experimental rate law, however, the mechanism must be incorrect.Welcome to check out more blogs about 16858-01-8, in my other articles.
Reference:
Metal catalyst and ligand design,
Ligand Template Strategies for Catalyst Encapsulation – NCBI