The synthesis of sulfur-bridged Fe-Ni heterobimetallics was inspired by Nature's strategies to "trick" abundant first row transition metals into enabling 2-electron processes: redox-active ligands (including pendant iron-sulfur clusters) and proximal metals. Our design to have redox-active ligands on each metal, NO on iron and dithiolene on nickel, resulted in the observation of unexpectedly intricate physical properties. The metallodithiolate, (NO)Fe(NS), reacts with a labile ligand derivative of [Ni(SCPh)], Ni, yielding the expected S-bridged neutral adduct, , containing a doublet {Fe(NO)}.
View Article and Find Full Text PDFSearching for a connection between the two-electron redox behavior of Group-14 elements and their possible use as platforms for the photoreductive elimination of chlorine, we have studied the photochemistry of [(o-(Ph P)C H ) Ge Cl ]Pt Cl and [(o-(Ph P)C H ) ClGe ]Pt Cl , two newly isolated isomeric complexes. These studies show that, in the presence of a chlorine trap, both isomers convert cleanly into the platinum germyl complex [(o-(Ph P)C H ) ClGe ]Pt Cl with quantum yields of 1.7 % and 3.
View Article and Find Full Text PDFIn this work, heterostructures of coupled TiO@MoSwith different phases of MoSwere synthesized via hydrothermal technique. The prepared materials were thoroughly characterized using various techniques, including XRD, SEM, transmission electron microscopy, Brunauer-Emmet-Teller, XPS, Zeta potential and UV-vis spectroscopy. The optimized nanocomposites were tested for the photocatalytic degradation of methyl Orange (MO) under visible light as well as the adsorption of Rhodamine b (RhB) and methelene blue (MB) dyes.
View Article and Find Full Text PDFIncorporating radical ligands into metal complexes is one of the emerging trends in the design of single-molecule magnets (SMMs). While significant effort has been expended to generate multinuclear transition metal-based SMMs with bridging radical ligands, less attention has been paid to mononuclear transition metal-radical SMMs. Herein, we describe the first α-diiminato radical-containing mononuclear transition metal SMM, namely, [κ-PhTt]Fe(AdNCHCHNAd) (), and its analogue [κ-PhTt]Fe(CyNCHCHNCy) () (PhTt = phenyltris(butylthiomethyl)borate, Ad = adamantyl, and Cy = cyclohexyl).
View Article and Find Full Text PDFA series of -dicyanide vanadium(III) compounds based on acetylacetonate, (PPN)[V(acac)(CN)]·(PPN)Cl·2MeCN (), and salen ligands, (EtN)[V(salen)(CN)] (), (PPN)[V(MeOsalen)(CN)]·DMF·2MeCN (), and (PPN)[V(salphen)(CN)]·DMF () [salen = ,'-ethylenebis(salicyl-imine), MeOsalen = ,'-ethylenebis(methoxysalicylimine), salphen = ,'-phenylenebis(salicyl-imine), and PPN = bis(triphenylphosphine)iminium], were prepared and structurally characterized. High-field EPR studies reveal that the complexes exhibit moderate magnetic anisotropy with positive values of +5.70, +3.
View Article and Find Full Text PDFThe combined experimental and theoretical investigation of the magnetic properties of the cobalt(ii) NHC complexes (NHC = N-heterocyclic carbene); [Co(CH2SiMe3)2(IPr)] (1), [CoCl2(IMes)2] (2) and [Co(CH3)2(IMes)2] (3) revealed a large easy plane anisotropy for 1 (D = +73.7 cm-1) and a moderate easy axis anisotropy for 2 (D = -7.7 cm-1) due to significant out-of-state spin-orbit coupling.
View Article and Find Full Text PDFChem Commun (Camb)
July 2020
The geometry of cobalt(ii) ions in the axially distorted octahedral cation in [Co(MeCN)6](BF4)2 (1) was compared to the trigonal prismatic cation in [CoTppy]PF6 (2) which revealed significant differences in magnetic anisotropy. Combined experimental and ab initio CASSCF/NEVPT2 calculations support the observed zero field SMM behaviour for 2, with easy axis anisotropy, attributed to the rigidity of the trigonal prismatic ligand. Strong transverse anisotropy for 1 leads to significant quantum tunnelling processes.
View Article and Find Full Text PDFHerein, different phases of MoS nanosheets were synthesized, characterized and tested for dye removal from water. The influence of the MoS phases as well as the 1T concentration on the adsorption performance of organic dyes MO, RhB and MB was deeply investigated. The results revealed that the 1T-rich MoS nanosheets have superior adsorption performance compared to other 2H and 3R phases.
View Article and Find Full Text PDFChem Commun (Camb)
February 2019
A new cyclic molecule incorporating [MoIII(CN)7]4- has been characterized by single crystal X-ray methods, SQUID magnetometry and theoretical calculations. The wheel molecule [MoIII(CN)7]6[Ni(L)]12(H2O)6 exhibits ferromagnetic Mo-Ni coupling which did not exist for the previously reported octacyanometallate analogue [MoIV(CN)8]6[Ni(L)]12(H2O)6. These results indicate that known supramolecular architectures incorporating octacyanometallates can be used as platforms for making new molecules incorporating seven-coordinate cyanide precursors.
View Article and Find Full Text PDFMoS is a very attractive material and has been well studied for potential applications in various areas. However, due to the wide variety of factors affecting the molecular and electronic structure of MoS, several contradictory reports about the adsorptive and photocatalytic properties of such materials have been published. In most of these reports, the effect of the actual phase of the materials on the properties was neglected.
View Article and Find Full Text PDFThe iron(II) semiquinonate character within the iron(III) catecholate species has been proposed by numerous studies to account for the O reactivity of intradiol catechol dioxygenases, but a well-characterized iron(II) semiquinonate species that exhibits intradiol cleaving reactivity has not yet been reported. In this study, a detailed electronic structure description of the first iron(II) o-semiquinonate complex, [PhTt]Fe(phenSQ) [PhTt = phenyltris(tert-butylthiomethyl)borate; phenSQ = 9,10-phenanthrenesemiquinonate; Wang et al. Chem.
View Article and Find Full Text PDFThe air-stable mononuclear Co(ii) compounds [Co(Tpm)][ClO] (, Tpm = tris(pyrazol-1-yl)methane), [Co(Tpm)][BPh]·2MeCN () with trigonal antiprismatic geometry (trigonally elongated octahedral geometry) are reported. Magnetic and theoretical studies reveal that the complexes exhibit single-molecule magnet behavior with uniaxial anisotropy and a huge energy difference between ground and first excited Karmers' doublets (∼200 cm). Under applied DC fields, compounds and exhibit frequency and temperature dependence of the imaginary susceptibility.
View Article and Find Full Text PDFGiven the recent advent of mononuclear single-molecule magnets (SMMs), a rational approach based on lanthanides with axially elongated f-electron charge cloud (prolate) has only recently received attention. We report herein a new SMM, [Li(THF)4[Er{N(SiMe3)2}3Cl]⋅2 THF, which exhibits slow relaxation of the magnetization under zero dc field with an effective barrier to the reversal of magnetization (ΔEeff/kB =63.3 K) and magnetic hysteresis up to 3 K at a magnetic field sweep rate of 34.
View Article and Find Full Text PDFChem Commun (Camb)
October 2014
The effect of ligands with heavy donor atoms on the magnetic anisotropy of the pseudo-tetrahedral cobalt complexes, Co(quinoline)2I2 (1) and Co(EPh3)2I2 (2-3) (E = P, As) has been investigated. The axial zero-field splitting parameter D was found to vary from +9.2 cm(-1) in 1 to -36.
View Article and Find Full Text PDFA family of magnetic metal-organic frameworks, (Ph3PMe)2[M2(TCNQ)3] {M=Fe(2+), Co(2+), Ni(2+) and Zn(2+)} have been prepared and structurally characterized. The honeycomb-like "layers" consist of M(II) ions doubly bridged with dinitrilomethane moieties of two 7,7,8,8-tetracyanoquinodimethane (TCNQ) dianions which are further connected through phenyl rings to form a 3D dianionic framework [M2TCNQ3](2-) with Ph3PMe(+) cations filling cavities that run along the c axis. Studies of the magnetic coupling through the TCNQ dianion in these structures revealed that it can promote long-range magnetic ordering despite the long coupling pathway.
View Article and Find Full Text PDFA family of trigonal bipyramidal (TBP) 5d-4f cyanide bridged aggregates were synthesized that exhibit slow relaxation of the magnetization below 4 K as indicated by a signal in the out-of-phase ac susceptibility data under zero field.
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