scholarly journals Temperature- and pressure-dependent structural study of {Fe(pmd)2[Ag(CN)2]2}nspin-crossover compound by neutron Laue diffraction

2014 ◽  
Vol 70 (3) ◽  
pp. 436-443 ◽  
Author(s):  
José Alberto Rodríguez-Velamazán ◽  
Laura Cañadillas-Delgado ◽  
Miguel Castro ◽  
Garry J. McIntyre ◽  
José Antonio Real
Keyword(s):  
High Spin ◽  
Ambient Pressure ◽  
Spin Transition ◽  
Group Symmetry ◽  
Bridging Ligands ◽  
Laue Diffraction ◽  
Structural Consequence ◽  
Distorted Octahedral ◽  
Moderate Sensitivity ◽  
Temperature And Pressure

The effect of pressure (up to 0.17 GPa) on the spin-crossover compound {Fe(pmd)2[Ag(CN)2]2}n[orthorhombic isomer (II), pmd = pyrimidine] has been investigated by temperature- and pressure-dependent neutron Laue diffraction and magnetometry. The cooperative high-spin ↔ low-spin transition, centred atca180 K at ambient pressure, is shifted to higher temperatures as pressure is applied, showing a moderate sensitivity of the compound to pressure, since the spin transition is displaced byca140 K GPa−1. The space-group symmetry (orthorhombicPccn) remains unchanged over the pressure–temperature (P–T) range studied. The main structural consequence of the high-spin to low-spin transition is the contraction of the distorted octahedral [FeN6] chromophores, being more marked in the axial positions (occupied by the pmd units), than in the equatorial positions (occupied by four [Ag(CN)2]−bridging ligands).

scholarly journals Thortveitite-type Tm2Si2O7

2014 ◽  
Vol 70 (7) ◽  
pp. i34-i35 ◽  
Author(s):  
Volker Kahlenberg ◽  
Paul Aichholzer
Keyword(s):  
Ambient Pressure ◽  
Point Group ◽  
Structure Type ◽  
Group Symmetry ◽  
Site Symmetry ◽  
Cation Site ◽  
Bond Lengths ◽  
Flux Synthesis ◽  
Distorted Octahedral ◽  
The Individual

Single crystals of dithulium disilicate, Tm2Si2O7, were obtained in flux synthesis experiments in the system SiO2–Tm2O3–LiF at ambient pressure. The compound belongs to the group of sorosilicates,i.e.it is based on [Si2O7]-units and crystallizes in the thortveitite (Sc2Si2O7) structure type. The Tm3+cation (site symmetry .2.) occupies a distorted octahedral site, with Tm—O bond lengths in the range 2.217 (4)–2.289 (4) Å. Each of the octahedra shares three of its edges with adjacent [TmO6] groups, resulting in the formation of layers parallel to (001). The individual [SiO4] tetrahedra are more regular,i.e.the differences between the bond lengths between Si and the bridging and non-bridging O atoms are not very pronounced. The layers containing the octahedra and the sheets containing the [Si2O7] groups (point group symmetry 2/m) form an alternating sequence. Linkage is provided by sharing common oxygen vertices.

Evidence for high-spin-to-low-spin transition under pressure in Fe 72 Pt 28 Invar alloy

2000 ◽  
Vol 80 (2) ◽  
pp. 155-163 ◽  
Author(s):  
S. Odin, F. Baudelet, E. Dartyge, J. P
Keyword(s):  
High Spin ◽  
Spin Transition ◽  
Invar Alloy

Structural, magnetic and Mössbauer spectroscopic studies of the [Fe(3-bpp)2](CF3COO)2 complex: role of crystal packing leading to an incomplete Fe(ii) high spin ⇋ low spin transition

CrystEngComm ◽  
2021 ◽  
Vol 23 (15) ◽  
pp. 2854-2861
Author(s):  
Kristian Handoyo Sugiyarto ◽  
Djulia Onggo ◽  
Hiroki Akutsu ◽  
Varimalla Raghavendra Reddy ◽  
Hari Sutrisno ◽  
...  
Keyword(s):  
High Spin ◽  
Crystal Packing ◽  
Spin Transition ◽  
Spectroscopic Studies ◽  
Mononuclear Complex

Mononuclear complex [Fe(3-bpp)2](CF3COO)2 exhibits a thermal (HS + HS) ⇋ (HS + LS) transition at ∼226 K which is not associated with any crystallographic transition.

High Spin-Low Spin Transition in MnAs1-xPx(x=0.075)

1977 ◽  
Vol 42 (1) ◽  
pp. 31-35 ◽  
Author(s):  
Satoshi Haneda ◽  
Noriaki Kazama ◽  
Yasuo Yamaguchi ◽  
Hiroshi Watanabe
Keyword(s):  
High Spin ◽  
Spin Transition

Electron spin resonance and Moessbauer study of the high-spin-low-spin transition in [Fe(phen)2(NCS)2] and [Fe(pic)3]Cl2.EtOH

1981 ◽  
Vol 20 (1) ◽  
pp. 204-207 ◽  
Author(s):  
P. Sambasiva. Rao ◽  
Amikam. Reuveni ◽  
Bruce R. McGarvey ◽  
Prabuddha. Ganguli ◽  
Philipp. Guetlich
Keyword(s):  
Electron Spin Resonance ◽  
High Spin ◽  
Electron Spin ◽  
Spin Transition ◽  
Spin Resonance

scholarly journals Tetrakis(μ-2-phenylacetato-κ2O:O′) bis{(DMSO κO′)]copper(II)}(Cu-Cu)]

2014 ◽  
Vol 70 (a1) ◽  
pp. C1709-C1709
Author(s):  
Meriem Benslimane ◽  
Yasmine Kheira Redjel ◽  
Georges Denes ◽  
Hocine Merazig
Keyword(s):  
Transition Metals ◽  
Bond Length ◽  
Phenylacetic Acid ◽  
Inversion Center ◽  
Polymeric Complex ◽  
Dimeric Complex ◽  
Bridging Ligands ◽  
Carboxylate Groups ◽  
Distorted Octahedral ◽  
Hydrolysis Of

Carboxylate groups may interact as bridging ligands with divalent transition metals present in biological environments, thereby altering the bioavailability of drugs. Moreover, it is well known that many complexes of divalent transition metals are capable of catalyzing the hydrolysis of RNA (Stem et al., 1990; Kimura, 1994). The coordination chemistry of Cu2+ complexes bridged by phenylacetate has been reported. We have found only two reports of a dinuclear Co2+ complexes, namely tetrakis (phenylacetato)bis[(quinoline-N)-cobalt(II)](Cui et al.,1999),μ-aqua-κ2O:O-di-μ-phenylacetato-κ4O:O′-bis[(1,10-phenanthroline-κ2N,N′) (phenyl acetato-κO)cobalt(II)](Kong et al., 2005) and dinuclear Cu2+ complex, namely tetrakis (phenylacetato)bis-[(N,N-dimethylformamide)copper(II)], in which all phenylacetate groups are in bidendate bridging modes. In this presentation, the crystal structure of a new dimeric complex obtained by reaction of phenylacetic acid with copper(II) acetate is described. Each Cu(II) atom is six-coordinated by five O atoms from carboxylate groups of the phenylacetate and DMSO ligands and is completed by a Cu-Cu bond in a strongly distorted octahedral coordination, in which an inversion center is located at the mid-point of the Cu-Cu bond with a Cu...Cu distance of 2.6321(4) Å. This is longer than the 2.251(2)Å distance found in the polymeric complex [Cu2(C8H7O2)4]n. However, it is similar to the 2.6414(8) Å and 2.6261(8)Å distances found in the complex [Cu2(C8H7O2)4(C3H7NO)2] (Kong et al., 2005). The Cu-O phenylacetate bond length lies in the range 1.9644(14) to 1.9734 (14) Å and the Cu-ODMSO bond length is 2.1319(13) Å.

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