scispace - formally typeset
Search or ask a question
Author

A.K. Gregson

Bio: A.K. Gregson is an academic researcher from University of Melbourne. The author has contributed to research in topics: Paramagnetism & Magnetic anisotropy. The author has an hindex of 4, co-authored 4 publications receiving 74 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: The magnetic anisotropy of binuclear copper(II) acetate monohydrate has been determined by a null deflexion method at temperatures between 80 and 300 K.
Abstract: The magnetic anisotropy of binuclear copper(II) acetate monohydrate has been redetermined by a null deflexion method at temperatures between 80 and 300 K. The new data establish that all previously reported anisotropy measurements have been seriously in error, presumably due to difficulties in correctly identifying the principal crystal axes. The previous necessity to invoke temperature-dependent values for the exchange integral J$\_{\text{eff}}$ and the g-factors now disappears and the new experimental anisotropies conform closely to Bleaney & Bowers (1952 b) theory with constant values for the disposable parameters. The magnetic anisotropy is especially sensitive to anisotropy in the high-frequency term of the susceptibility expressions. This enables the controversial electronic spectrum to be assigned in terms of the ligand field transitions 11 000 cm$^{-1}$ (d$\_{z^{2}}$ $\leftarrow $ d$\_{x^{2}-y^{2}}$); 14 400 cm $^{-1}$ (d$\_{xz,yz}$ $\leftarrow $ d$\_{x^{2}-y^{2}}$); 17 000 cm $^{-1}$ (d$\_{xy}$ $\leftarrow $ d$_{x^{2}-y^{2}}$). The nature of the chemical bonding and exchange interaction is discussed.

45 citations

Journal ArticleDOI
TL;DR: In this paper, paramagnetic anisotropy and electron spin resonance data on the planar S = 12 bis(dithioacetyl-acetonato)cobalt(II) are discussed and intepreted assuming the unpaired electron lies in the dz2 orbital.

19 citations

Journal ArticleDOI
TL;DR: In this article, the effect of the axial ligand field parameter δ on the average magnetic moment and the magnetic anisotropy of 2 T 2g cubic field ground term complexes is illustrated in relation to trisacetylacetonatoruthenium (III).

7 citations

Journal ArticleDOI
TL;DR: In this paper, the magnetic anisotropies and principal susceptibilities of ferrous ammonium sulphate hexahydrate were investigated to remove the existing discrepancies in the sign of its molecular magnetic aisotropic and the nature of ligand field and electronic structure.

4 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: A combination of structural, spectroscopic, and computational studies were conducted and provided definitive evidence for bis(arylimidazol-2-ylidene)pyridine radicals in reduced cobalt chemistry, and suggest that a wide family of pyridine-based pincers may also be redox-active.
Abstract: The bis(arylimidazol-2-ylidene)pyridine cobalt methyl complex, (iPrCNC)CoCH3, was evaluated for the catalytic hydrogenation of alkenes. At 22 °C and 4 atm of H2 pressure, (iPrCNC)CoCH3 is an effect...

176 citations

Journal ArticleDOI
TL;DR: In this article, the maximum amounts of absorption of gases were found to be 1.8, 1.9, 2.2, and 0.9 mole per one mole of the copper(II) salt for N2, Ar, O2 and Xe, respectively.
Abstract: Copper(II) terephthalate absorbs a large amount of gases such as N2, Ar, O2, and Xe. The maximum amounts of absorption of gases were 1.8, 1.9, 2.2, and 0.9 mole per one mole of the copper(II) salt for N2, Ar, O2, and Xe, respectively, indicating that the gases were not adsorbed on the surface but occluded within the solid. The porous structure of copper(II) terephthalate, in which the gas is occluded, is deduced from the temperature dependence of magnetic susceptibilities and the linear structure of terephthalate.

130 citations

Journal ArticleDOI
TL;DR: In this paper, it was shown that rhodium(II) monocarboxylate bridged by pyrazine form stable micropores by self-assembly of infinite linear chain complexes.

94 citations

Journal ArticleDOI
TL;DR: It is shown here how the kinetics and mechanisms of the mechanochemical synthesis of HKUST-1 can be influenced by milling conditions and additives, yielding on occasion two new and previously undetected intermediate phases containing a mononuclear copper core, and that finally rearrange to form the HKust-1 architecture.
Abstract: We have applied in situ monitoring of mechanochemical reactions by high-energy synchrotron powder X-ray diffraction to study the role of liquid additives on the mechanochemical synthesis of the archetypal metal–organic framework (MOF) HKUST-1, which was one of the first and is still among the most widely investigated MOF materials to be synthesized by solvent-free procedures It is shown here how the kinetics and mechanisms of the mechanochemical synthesis of HKUST-1 can be influenced by milling conditions and additives, yielding on occasion two new and previously undetected intermediate phases containing a mononuclear copper core, and that finally rearrange to form the HKUST-1 architecture On the basis of in situ data, we were able to tune and direct the milling reactions toward the formation of these intermediates, which were isolated and characterized by spectroscopic and structural means and their magnetic properties compared to those of HKUST-1 The results have shown that despite the relatively lar

89 citations