Single‐Crystal ESR Spectrum of Bis(ethylenediamine) Copper(II) Nitrate; the Calculation of Molecular g Values for Rhombic Symmetry from Data on Crystals Containing Inequivalent Orientations

1969 ◽  
Vol 50 (3) ◽  
pp. 1476-1477 ◽  
Author(s):  
D. E. Billing ◽  
B. J. Hathaway
Keyword(s):  
Single Crystal ◽  
Esr Spectrum ◽  
Rhombic Symmetry

scholarly journals The ESR Spectrum of a π Cation Radical Trapped in a Single Crystal of Chloro(tetraphenylporphyrinato)cobalt(III)

1983 ◽  
Vol 56 (3) ◽  
pp. 822-826 ◽  
Author(s):  
Masahiro Kohno ◽  
Hiroaki Ohya-Nishiguchi ◽  
Kiyoko Yamamoto ◽  
Tosio Sakurai
Keyword(s):  
Single Crystal ◽  
Cation Radical ◽  
Esr Spectrum

TEMPERATURE DEPENDENCES OF Y2Cu2O5 ESR SPECTRA

1989 ◽  
Vol 03 (05) ◽  
pp. 427-435 ◽  
Author(s):  
A.A. GIPPIUS ◽  
V.V. MOSHCHALKOV ◽  
YU. A. KOKSHAROV ◽  
A.N. TIKHONOV ◽  
B.V. MILL ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Single Crystal ◽  
Room Temperature ◽  
Esr Spectra ◽  
Single Line ◽  
Néel Temperature ◽  
Esr Spectrum ◽  
Complicated Form ◽  
Temperature Dependences ◽  
G Factors

Temperature dependences of the ESR spectrum in Y 2 Cu 2 O 5 compound are studied for both polycrystalline and single crystal samples. The g-factors along the main axes are found to be ga=2.099, gb=2.048, and gc=2.21 at room temperature, T=293 K . As temperature decreases, the linewidth ΔH increases in agreement with the Huber’s formula ΔH=A(T N /(T−T N ))β+B(θ/T+1) with the following parameters: A=1513±10 Oe , B=509±10 Oe , T N =7±1 K , θ=18±2 K , β=1.3±0.3. In the vicinity of the Neel Temperature, T N , the ESR spectrum has a very complicated form indicating the existence of clusters with different internal magnetic fields. Below T N , a single line symmetrical ESR spectrum is recovered.

ESR spectrum of Mn(.eta.-C4H6)2PMe3 in a single crystal of Fe(.eta.-C4H6)2PMe3

1984 ◽  
Vol 3 (2) ◽  
pp. 238-240 ◽  
Author(s):  
J. M. McCall ◽  
J. R. Morton ◽  
K. F. Preston
Keyword(s):  
Single Crystal ◽  
Esr Spectrum

Low field ESR spectrum of trivalent gadolinium in single crystal throrium oxide

1968 ◽  
Vol 28 (4) ◽  
pp. 258-259 ◽  
Author(s):  
S.A. Marshall ◽  
G.A. Johnson
Keyword(s):  
Single Crystal ◽  
Esr Spectrum ◽  
Low Field

scholarly journals ESR Spectrum of the 9‐Molybdomanganate(IV) Ion in Dilute Single Crystal

1969 ◽  
Vol 50 (9) ◽  
pp. 3647-3648 ◽  
Author(s):  
P. G. Rasmussen ◽  
K. M. Beem ◽  
E. J. Hornyak
Keyword(s):  
Single Crystal ◽  
Esr Spectrum

Conformation-Controlled Trans-Effect of the Proximal Histidine in Haemoglobins. An Electron Spin Resonance Study of Monomeric Nitrosyl-57Fe-Haemoglobins

1976 ◽  
Vol 31 (9-10) ◽  
pp. 524-533 ◽  
Author(s):  
Matthias Overkamp ◽  
Hans Twilfer ◽  
Klaus Gersonde
Keyword(s):  
Magnetic Resonance ◽  
Spin Density ◽  
Hyperfine Splitting ◽  
Proton Magnetic Resonance ◽  
Binding Properties ◽  
Trans Effect ◽  
Esr Spectrum ◽  
Rhombic Symmetry ◽  
Haem Iron ◽  
Hyperfine Structures

A monomeric allosteric haemoglobin from Chironomus thummi thummi was reconstituted with 57Fe-haem. This reconstituted haemoglobin was found to be identical to the non-reconstituted material with regard to the O2-binding properties and the visible spectra. The 270 MHz proton magnetic resonance of the bis(cyano)-57Fe-haemin shows that the reconstituted haem is identical with the non-reconstituted haem. Furthermore it has been proved by proton magnetic resonance that in Chironomus haemoglobins the prosthetic group is proto-haem IX. The ESR spectrum of the native nitrosyl haemoglobin demonstrates rhombic symmetry of the haem iron (gxx = 2.086, gyy=1.981, gzz=2.005) and hyperfine structures at gyy (aNε = 1.35 mT) and at gzz (a15NO = 3.05 mT, a14NO = 2.19 mT, aNε=0.715mT, a57Fe = 0.38 mT). The spectrum is independent of pH and can be classified as a type II spectrum following the classification of ref. 2. NO-binding obviously stabilizes the tertiary structure of this haemoglobin in a “tense” conformation with a relatively strong o bond of the 5th ligand (Nε of imidazole) and a relatively weak o bond of the 6th ligand (NO). Reaction of this haemoglobin with anionic, cationic and non-ionic detergents, respectively, leads to a transformation of the NO-ligated form into a “relaxed” conformation with a stretched or broken a bond of the 5th ligand (Nε of imidazole) and a strong σ bond of the 6th ligand (NO). The ESR spectrum of this modified NO-haemoglobin shows again a rhombic symmetry of the haem iron (gxx = 2.10, gyy = 2.06, gzz=2.010), but dramatically changes in the g tensors (low field shift), hyperfine structures and hyperfine splitting constants (a15NO=2.32 mT, a14 NO = 1.66 mT, a57Fe = 0.48 mT). The hyperfine splitting is isotropic. Transition from the “tense” conformation to the “relaxed” conformation corresponds with an increase of the spin density at the iron atom by 26% and a decrease of the spin density at the NO ligand by 25%. The spin density at the Nε of imidazole strongly decreases in the “relaxed” conformation, so that a hyperfine splitting of this ligand is not any more resolved. These results demonstrate the trans-effect of the proximal imidazole which in haemoglobins controls the binding properties of the external ligand in trans-position.

A Preparation of High Resolution Standards for Electron Microscopy. Part II

1971 ◽  
Vol 29 ◽  
pp. 160-161
Author(s):  
Akira Tanaka ◽  
David F. Harling
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Carbon Black ◽  
Single Crystal ◽  
Dark Field ◽  
Graphitized Carbon Black ◽  
Graphitized Carbon ◽  
Dark Field Imaging ◽  
Crystal Films ◽  
Micro Holes

In the previous paper, the author reported on a technique for preparing vapor-deposited single crystal films as high resolution standards for electron microscopy. The present paper is intended to describe the preparation of several high resolution standards for dark field microscopy and also to mention some results obtained from these studies. Three preparations were used initially: 1.) Graphitized carbon black, 2.) Epitaxially grown particles of different metals prepared by vapor deposition, and 3.) Particles grown epitaxially on the edge of micro-holes formed in a gold single crystal film.The authors successfully obtained dark field micrographs demonstrating the 3.4Å lattice spacing of graphitized carbon black and the Au single crystal (111) lattice of 2.35Å. The latter spacing is especially suitable for dark field imaging because of its preparation, as in 3.), above. After the deposited film of Au (001) orientation is prepared at 400°C the substrate temperature is raised, resulting in the formation of many square micro-holes caused by partial evaporation of the Au film.

Structure of Palladium Single-Crystal Films Prepared by Flash Evaporation onto (001) NaCl Substrates

1970 ◽  
Vol 28 ◽  
pp. 456-457
Author(s):  
L. E. Murr ◽  
G. Wong
Keyword(s):  
Single Crystal ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
High Rate ◽  
Flash Evaporation ◽  
Optimum Load ◽  
Single Crystal Films ◽  
Crystal Films ◽  
A Current

Palladium single-crystal films have been prepared by Matthews in ultra-high vacuum by evaporation onto (001) NaCl substrates cleaved in-situ, and maintained at ∼ 350° C. Murr has also produced large-grained and single-crystal Pd films by high-rate evaporation onto (001) NaCl air-cleaved substrates at 350°C. In the present work, very large (∼ 3cm2), continuous single-crystal films of Pd have been prepared by flash evaporation onto air-cleaved (001) NaCl substrates at temperatures at or below 250°C. Evaporation rates estimated to be ≧ 2000 Å/sec, were obtained by effectively short-circuiting 1 mil tungsten evaporation boats in a self-regulating system which maintained an optimum load current of approximately 90 amperes; corresponding to a current density through the boat of ∼ 4 × 104 amperes/cm2.

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