The Magnetic Properties and Structure of Hemoglobin, Oxyhemoglobin and Carbonmonoxyhemoglobin

Pauling, Linus; Coryell, Charles D.

doi:10.1073/pnas.22.4.210

Cited by 1,095 publications

(723 citation statements)

References 5 publications

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“…[38] Therefore, the formation of different Laves phases MgNi 2-x Ge x should be attributed to the difference of four electrons between Ni and Ge and, as a consequence, to the changing of the valence electron concentration (VEC). Starting with the binary Laves phase …”

Section: Discussionmentioning

confidence: 99%

The Influence of the Valence Electron Concentration on the Structural Variation of the Laves Phases MgNi_2–xGe_x

Siggelkow

Hlukhyy

Fässler

2017

Zeitschrift anorg allge chemie

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Abstract. The influence of the partial substitution of Ni atoms by the similarly sized but electron-richer Ge atoms with a similar electronegativity in the binary Laves phase MgNi 2 is investigated. A small degree of substitution in MgNi 2-x Ge x (x = 0.1) leads to the change of the hexagonal MgNi 2 -type structure (C36) to the cubic C15 type, whereas higher amounts of Ge lead to the formation of the two new Laves phases Mg 2 Ni 3 Ge and MgNi 1.30(5) Ge 0.70 , which were synthesized by the direct reaction of the elements in alumina and niobium crucibles using an induction furnace. The crystal structures of the two phases were determined by single-crystal X-ray diffraction. Mg 2 Ni 3 Ge (hR18-MgNi 2-x Ge x , x = 0.5) crystallizes in the Y 2 Rh 3 Ge-type structure, which

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Section: Discussionmentioning

confidence: 99%

The Influence of the Valence Electron Concentration on the Structural Variation of the Laves Phases MgNi_2–xGe_x

Siggelkow

Hlukhyy

Fässler

2017

Zeitschrift anorg allge chemie

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“…Difference density analysis as derived by highly resolved X-ray crystallography [1] and later modern quantum chemistry calculations (MO-theory -ab-initio, Morokuma [2], DFT [3] -or valence-bond theory, Pauling [4][5][6]) provide important insight into the nature of the metal-ligand bond. An extensive review on quantum chemical methods for analyzing the chemical bond and their applications to a wide range of closed shell TM complexes with organic ligands (carbene, carbyne, alkene, and alkyne -complexes) as well as complexes with CO, BF, BO À , BNH 2 , and H ligands has been published by Frenking and Fr€ o ohlich [7] and we refer the reader to their work.…”

Section: Introductionmentioning

confidence: 99%

Chemical Bonding in Molecules and Complexes Containing d-Elements Based on DFT

Atanasov

Daul

Fowe

2005

Monatshefte für Chemie

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Summary. Metal-ligand bonding in transition metal halide molecules and complexes with different central ions, oxidations states, and coordination numbers: Cr III X 6 3À , Cr IV X 4 , Cr II X 2 (X ¼ F,Cl,Br,I),3þ (M ¼ Cr,Co) and Re 2 Cl 8 2À has been studied in terms of the Extended Transition State (ETS) energy patitioning scheme within the DFT and electron density analysis (the Laplacian of the electron density and the electronic localization function). Bonding is found to be dominated by ionicity in all cases, especially so for complexes with higher coordination numbers. Covalent contributions to the metal-ligand bond are found to be mainly due to the ndelectrons and to lesser extent due to the metal (n þ 1)s and (n þ 1)p-orbitals, contributions from (n þ 1)s increasing when going to lower coordination numbers. Metal-ligand bonding analysis have been used in order to check some concepts emerging from ligand field theory when applied to the spectroscopy and magnetism of transition metal complexes. It is pointed out that for complexes of high symmetry (MX 6 , O h , MX 4 , T d , and MX 2 , D 1h ) electron density analyses gain interpretative power when partitioned into contributions from occupied orbitals of different symmetry.

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“…The basis of most fMRI studies is the blood oxygenation level dependent (BOLD) contrast (4 -6), which is derived from the fact that the magnetic property of hemoglobin depends on its oxygenation state (7). Because deoxygenated hemoglobin is paramagnetic, deoxygenated blood leads to a local decrease in T* 2 and T 2 .…”

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confidence: 99%

Imaging brain function in humans at 7 Tesla

Yacoub

Shmuel

Pfeuffer

et al. 2001

Magnetic Resonance in Med

419

333

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This article describes experimental studies performed to demonstrate the feasibility of BOLD fMRI using echo-planar imaging (EPI) at 7 T and to characterize the BOLD response in humans at this ultrahigh magnetic field. Visual stimulation studies were performed in normal subjects using high-resolution multishot EPI sequences. Changes in R* 2 arising from visual stimulation were experimentally determined using fMRI measurements obtained at multiple echo times. The results obtained at 7 T were compared to those at 4 T. Experimental data indicate that fMRI can be reliably performed at 7 T and that at this field strength both the sensitivity and spatial specificity of the BOLD response are increased. This study suggests that ultrahigh field MR systems are advantageous for functional mapping in humans. Magn Reson Med 45:588 -594, 2001.

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The Magnetic Properties and Structure of Hemoglobin, Oxyhemoglobin and Carbonmonoxyhemoglobin

Cited by 1,095 publications

References 5 publications

The Influence of the Valence Electron Concentration on the Structural Variation of the Laves Phases MgNi_2–xGe_x

The Influence of the Valence Electron Concentration on the Structural Variation of the Laves Phases MgNi_2–xGe_x

Chemical Bonding in Molecules and Complexes Containing d-Elements Based on DFT

Imaging brain function in humans at 7 Tesla

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The Magnetic Properties and Structure of Hemoglobin, Oxyhemoglobin and Carbonmonoxyhemoglobin

Cited by 1,095 publications

References 5 publications

The Influence of the Valence Electron Concentration on the Structural Variation of the Laves Phases MgNi2–xGex

The Influence of the Valence Electron Concentration on the Structural Variation of the Laves Phases MgNi2–xGex

Chemical Bonding in Molecules and Complexes Containing d-Elements Based on DFT

Imaging brain function in humans at 7 Tesla

Contact Info

Product

Resources

About

The Influence of the Valence Electron Concentration on the Structural Variation of the Laves Phases MgNi_2–xGe_x

The Influence of the Valence Electron Concentration on the Structural Variation of the Laves Phases MgNi_2–xGe_x