3099-28-3Relevant articles and documents
A comparative study of magnetization dynamics in dinuclear dysprosium complexes featuring bridging chloride or trifluoromethanesulfonate ligands
Burns, Corey P.,Wilkins, Branford O.,Dickie, Courtney M.,Latendresse, Trevor P.,Vernier, Larry,Vignesh, Kuduva R.,Bhuvanesh, Nattamai S.,Nippe, Michael
, p. 8419 - 8422 (2017)
We utilized a rigid ligand platform PyCp22- (PyCp22- = [2,6-(CH2C5H3)2C5H3N]2-) to isolate dinuclear Dy3+ complexes [(PyCp2)Dy-(μ-O2SOCF3)]2 (1) and [(PyCp2)Dy-(μ-Cl)]2 (3) as well as the mononuclear complex (PyCp2)Dy(OSO2CF3)(thf) (2). Compounds 1 and 2 are the first examples of organometallic Dy3+ complexes featuring triflate binding. The isolation of compounds 1 and 3 allows us to comparatively evaluate the effects of the bridging anions on the magnetization dynamics of the dinuclear systems. Our investigations show that although the exchange coupling interactions differ for 1 and 3, the dynamic magnetic properties are dominated by relaxation via the first excited state Kramers doublet of the individual Dy sites. Compounds 1 and 3 exhibit barriers to magnetization reversal (Ueff = 49 cm-1) that can be favorably compared to those of the previously reported examples of [Cp2Dy(μ-Cl)]2 (Ueff = 26 cm-1) and [Cp2Dy(thf)(μ-Cl)]2 (Ueff = 34 cm-1).
Cobalt complexes of an OSNSO-tetrapodal pentadentate ligand: Synthesis, structures and reactivity
Thevenin, Lucas,Daran, Jean-Claude,Poli, Rinaldo,Fliedel, Christophe
, (2021)
The novel pentadentate tetrapodal proligand 2,6-bis[(2-hydroxyphenyl)sulfanylmethyl]pyridine (1·H2) and its cobalt(II) complex [Co(1)] (2) were synthesized and characterized by several analytical (EA, ESI-MS) and spectroscopic methods (NMR or EPR, FT-IR), including X-ray crystallography for 1·H2. Cyclic voltammetry studies showed that 2 undergoes a reversible metal-based oxidation (CoII/CoIII). Complex 2 was designed to be applied to organometallic mediated radical polymerization (OMRP), however it exhibited an extremely poor solubility in non-coordinating solvents and several vinyl monomers (styrene, vinyl acetate and tert-butyl acrylate), which hampers its potential as moderator. Complex 2 has a high affinity towards Lewis bases, such as pyridine, leading to the clean formation of the mono-pyridine adduct 2·py, as confirmed by X-ray crystallography. In 2·py, ligand 1 is pentacoordinated to the CoII center, with the two thioether-phenolate (S,O) moieties oriented anti to each other, and the only free coordination site of the octahedron is completed by the additional pyridine, trans to the central pyridine linker of 1. The equilibrium between 2 and 2·py could be studied by 1H NMR. Complex 2 could be cleanly and quantitatively oxidized to its diamagnetic iodo cobalt(III) analog [Co(1)I] (3), by simple reaction with iodine. The latter could then be subjected to a halide abstraction reaction, mediated by K[B(C6F5)], affording the cationic complex [Co(1)][B(C6F5)], 4.
Steric Effect on the Nucleophilic Reactivity of Nickel(III) Peroxo Complexes
Kim, Jalee,Shin, Bongki,Kim, Hyunjeong,Lee, Junhyung,Kang, Joongoo,Yanagisawa, Sachiko,Ogura, Takashi,Masuda, Hideki,Ozawa, Tomohiro,Cho, Jaeheung
, p. 6176 - 6183 (2015)
A set of nickel(III) peroxo complexes bearing tetraazamacrocyclic ligands, [NiIII(TBDAP)(O2)]+ (TBDAP = N,N′-di-tert-butyl-2,11-diaza[3.3](2,6)pyridinophane) and [NiIII(CHDAP)(O2)]+ (CHDAP = N,N′-dicyclohexyl-2,11-diaza[3.3](2,6)pyridinophane), were prepared by reacting [NiII(TBDAP)(NO3)(H2O)]+ and [NiII(CHDAP)(NO3)]+, respectively, with H2O2 in the presence of triethylamine. The mononuclear nickel(III) peroxo complexes were fully characterized by various physicochemical methods, such as UV-vis, electrospray ionization mass spectrometry, resonance Raman, electron paramagnetic resonance, and X-ray analysis. The spectroscopic and structural characterization clearly shows that the NiO2 cores are almost identical where the peroxo ligand is bound in a side-on fashion. However, the different steric properties of the supporting ligands were confirmed by X-ray crystallography, where the CHDAP ligand gives enough space around the Ni core compared to the TBDAP ligand. The nickel(III) peroxo complexes showed reactivity in the oxidation of aldehydes. In the aldehyde deformylation reaction, the nucleophilic reactivity of the nickel(III) peroxo complexes was highly dependent on the steric properties of the macrocyclic ligands, with a reactivity order of [NiIII(TBDAP)(O2)]+ III(CHDAP)(O2)]+. This result provides fundamental insight into the mechanism of the structure (steric)-reactivity relationship of metal peroxo intermediates. (Figure Presented).
A New Oxygen Containing Pyclen-Type Ligand as a Manganese(II) Binder for MRI and 52Mn PET Applications: Equilibrium, Kinetic, Relaxometric, Structural and Radiochemical Studies
Csupász, Tibor,Fekete, Anikó,Hollóczki, Oldamur,Kálmán, Ferenc Krisztián,Szücs, Dániel,Szikra, Dezs?,Tóth, éva,Tóth, Imre,Tircsó, Gyula
supporting information, (2022/01/31)
A new pyclen-3,9-diacetate derivative ligand (H23,9-OPC2A) was synthesized possessing an etheric O-atom opposite to the pyridine ring, to improve the dissociation kinetics of its Mn(II) complex (pyclen = 3,6,9,15-tetraazabicyclo(9.3.1)pentadeca
Fast and Efficient Nickel(II)-catalysed Transfer Hydrogenation of Quinolines with Ammonia Borane
Vermaak, Vincent,Vosloo, Hermanus C. M.,Swarts, Andrew J.
supporting information, p. 5788 - 5793 (2020/12/01)
Herein we report the first Ni(II)-catalysed transfer hydrogenation of quinolines using ammonia borane (AB) as hydrogen (H2) source. An in situ generated Ni(II)-bis(pyrazolyl)pyridine pre-catalyst could hydrogenate quinoline and its derivatives in excellent yields of up to 90% at 25 °C in 30 minutes. Spectroscopic studies revealed that a Ni(II)-hydride is responsible for the transfer hydrogenation of quinoline to 1,2,3,4-tetrahydroquinoline via a 1,4-dihydroquinoline intermediate. (Figure presented.).
