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The mixed-valence double salt K3(MnO4)(sub 2) crystallizes in space group P2(sub 1)/m with Z=2. The results of the polarized neutron diffraction study of K3 (MnO4)(sub 2) are discussed.

The dynamics of the polyaromatic cores are of vital importance as they help in examining the electrical conductivities of the columns. It is found that the dynamics of the inner core and the alkyl tails of discotics are strongly correlated.

A direct, sensitive inelastic neutron scattering spectroscopic study enables the quantitative determination of magnetic transitions in exchange-coupled oxo-centered triiron(III) complexes. The complex, (Fe3O(O2CCD3)6(C5D5N)3)NO3, has isosceles triangular cluster, while the clusters in K5(Fe3O(SO4)6(D2O)3). 6H2O and (Fe3O(O2CC(CD3)3)6(DOCD3)3)Cl are described as scalene. Magnetic Jahn-Teller effect accounts for the deviation of clusters from equilateral symmetry.

The Heisenberg-Dirac-Van Vleck (HDVV) spin-only magnetic coupling scheme was used to compare the inelastic incoherent neutron scattering (IINS) spectra of the series of trinuclear complexes (Fe(sub 2)(super III)M(II)O(OOCMe)6(py)3)(py), where (M = Mn, Ni). Major differences in the electronic interactions between the mixed-valence and mixed-metal ion clusters were revealed. If a 2-fold molecular symmetry is assumed, then the HDVV framework can be used to understand the spectrums of both complexes.

Theoretical Density Functional Theory calculations and neuron diffraction studies were used to investigate the exchange mechanisms and magnetic structure in the 2D cyano-bridged molecule based magnet [K.sub.2][[Mn[([H.sub.2]O).sub.2].sub.3][[Mo[(CN).sub.7]].sub.2].6[H.sub.2]O. Studies reveal the predominance of the spin polarization mechanism in the Mo-C-N-Mn sequence and the antiferromagnetic nature of the interaction is due to the overlap between the magnetic orbits relative to Mn and Mo in the cyano bridging region.

Research has been conducted on Fe(C (sub)3 H (sub)4 N (sub)2) (sub)6 (NO (sub)3) (sub)2. The authors describe the structural, magnetic and spectroscopic data of this compound which facilitate the molecular and electronic structure of [Fe(imidazole) (sub)6] (super)2+ cation.

We report the magnetic structure of two of the mag-netically ordered phases of Co3(OH)2(C4O4)2·3H2O, a coordination polymer that consists of a triangular framework decorated with anisotropic Co(II) ions. The combination of neutron diffraction experiments and magnetic susceptibility data allows us to identify one phase as displaying spin idle behavior, where only a fraction of the moments order at intermediate temperatures, while at the lowest temperatures the system orders fully. This novel magnetic behavior is discussed within the framework of a simple Hamiltonian and representational analysis and rationalizes this multiphase behavior by considering the combination of frustration and anisotropy [ABSTRACT FROM AUTHOR]

We report the magnetic structure of the two magnetically ordered phases of Co3(OH)2(C4O4)2, a coordination polymer that consists of a triangular framework decorated with anisotropic Co(II) ions. Neutron diffraction experiments allow us to confirm that the magnetic behavior changes upon dehydration and reveal the complex phase behavior of this system, relative to the hydrated compound Co3(OH)2(C4O4)2·3H2O. One phase is shown to display spin idle behavior, where only a fraction of the moments order at intermediate temperatures, while at the lowest temperatures the system orders fully, in this case with a net magnetic moment. This novel magnetic behavior is discussed within the framework of a simple Hamiltonian and representational analysis and rationalizes this multiphase behavior by considering the combination of frustration and anisotropy. The change in behavior on dehydration is also rationalized with respect to the changes in the single-ion anisotropy of the cobalt. [ABSTRACT FROM AUTHOR]

The mixed-valence double salt K3(MnO4)2 crystallizes in space group P21/m with Z = 2. The manganese centers Mn1 and Mn2 constitute discrete "permanganate", [MnVIIO4]-, and "manganate", [MnVIO4]2-, ions, respectively. There is a spin-ordering transition to an antiferromagnetic state at ca. T = 5 K. The spin-density distribution in the paramagnetic phase at T = 10 K has been determined by polarized neutron diffraction, confirming that unpaired spin is largely confined to the nominal manganate ion Mn2. Through use of both Fourier refinement and maximum entropy methods, the spin on Mn1 is estimated as 1.75 ± 1% of one unpaired electron with an upper limit of 2.5%. [ABSTRACT FROM AUTHOR]

Breakdown and utilization of cellulose are critical for the bioenergy sector; however, current cellulose-to-energy conversion schemes often consume large quantities of unrecoverable chemicals, or are expensive, due to the need for enzymes or high temperatures. In this paper, we demonstrate a new method for converting cellulose into soluble compounds using a mixture of Fe 2+ and Fe 3+ as catalytic centers for the breakdown, yielding Fe 3 O 4 nanoparticles during the hydrothermal process. Iron precursors transformed more than 61% of microcrystalline cellulose into solutes, with the composition of the solute changing with the initial Fe 3+ concentration. The primary products of the breakdown of cellulose were a range of aldaric acids with different molecular weights. The nanoparticles have concentration-dependent tuneable sizes between 6.7 and 15.8 nm in diameter. The production of value-added nanomaterials at low temperatures improves upon the economics of traditional cellulose-to-energy conversion schemes with the precursor value increasing rather than deteriorating over time., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

Kagomé lattice types have been of intense interest as idealized examples of extended frustrated spin systems. Here we demonstrate how the use of neutron diffraction and inelastic neutron scattering coupled with spin wave theory calculations can be used to elucidate the complex magnetic interactions of extended spin networks. We show that the magnetic properties of the coordination polymer Mn 3 (1,2,4-(O 2 C) 3 C 6 H 3 ) 2 , a highly distorted kagomé lattice, have been erroneously characterized as a canted antiferromagnet in previous works. Our results demonstrate that, although the magnetic structure is ferrimagnetic, with a net magnetic moment, frustration persists in the system. We conclude by showing that the conventions of the Goodenough-Kanamori rules, which are often applied to similar magnetic exchange interactions, are not relevant in this case.

We report the magnetic structure of the two magnetically ordered phases of Co3(OH)2(C4O4)2, a coordination polymer that consists of a triangular framework decorated with anisotropic Co(II) ions. Neutron diffraction experiments allow us to confirm that the magnetic behavior changes upon dehydration and reveal the complex phase behavior of this system, relative to the hydrated compound Co3(OH)2(C4O4)2·3H2O. One phase is shown to display spin idle behavior, where only a fraction of the moments order at intermediate temperatures, while at the lowest temperatures the system orders fully, in this case with a net magnetic moment. This novel magnetic behavior is discussed within the framework of a simple Hamiltonian and representational analysis and rationalizes this multiphase behavior by considering the combination of frustration and anisotropy. The change in behavior on dehydration is also rationalized with respect to the changes in the single-ion anisotropy of the cobalt.

Here, we present the first muon spectroscopy investigation of graphene, focused on chemically produced, gram-scale samples, appropriate to the large muon penetration depth. We have observed an evident muon spin precession, usually the fingerprint of magnetic order, but here demonstrated to originate from muon-hydrogen nuclear dipolar interactions. This is attributed to the formation of CHMu (analogous to CH(2)) groups, stable up to 1250 K where the signal still persists. The relatively large signal amplitude demonstrates an extraordinary hydrogen capture cross section of CH units. These results also rule out the formation of ferromagnetic or antiferromagnetic order in chemically synthesized graphene samples.

We report the magnetic structure of two of the magnetically ordered phases of Co(3)(OH)(2)(C(4)O(4))(2)·3H(2)O, a coordination polymer that consists of a triangular framework decorated with anisotropic Co(II) ions. The combination of neutron diffraction experiments and magnetic susceptibility data allows us to identify one phase as displaying spin idle behavior, where only a fraction of the moments order at intermediate temperatures, while at the lowest temperatures the system orders fully. This novel magnetic behavior is discussed within the framework of a simple Hamiltonian and representational analysis and rationalizes this multiphase behavior by considering the combination of frustration and anisotropy.

Spectroscopic, structural, and magnetic data are presented for Fe(C(3)H(4)N(2))(6)(NO(3))(2), which facilitate a precise definition of the electronic and molecular structure of the [Fe(Im)(6)](2+) cation. The structure was determined at 120(1) K by X-ray diffraction methods. The salt crystallizes in the trigonal space group R3 with unit-cell parameters a = 12.4380(14) A, c = 14.5511(18) A, and Z = 3. All the imidazole ligands are equivalent with an Fe-N bond distance of 2.204(1) A. Variable-temperature inelastic neutron scattering (INS) measurements identify a cold magnetic transition at 19.4(2) cm(-1) and a hot transition at 75.7(6) cm(-1). The data are interpreted using a ligand field Hamiltonian acting in the weak-field (5)D basis, from which the diagonal trigonal field splitting of the (5)T(2g) (O(h)) term is estimated as approximately 485 cm(-1), with the (5)A(g) (S(6)) component lower lying. High-field multifrequency (HFMF) EPR data and measurements of the magnetic susceptibility are also reported and can be satisfactorily modeled using the energies and wave functions derived from analysis of the INS data. The electronic and molecular structures are related through angular overlap model calculations, treating the imidazole ligand as a weak pi-donor.