Showing papers on "Spin states published in 1979"
TL;DR: Spin state changes seem to have little influence on the porphyrin stereochemistry; it is determined primarily by the chemical properties of the ligand and its interaction with the haem and the globin.
290 citations
218 citations
TL;DR: In this article, a stoichiometric strontium cobaltite oxide was prepared at 910°C in air and characterized by chemical analysis and X-ray diffraction.
106 citations
TL;DR: The crystal structure of the spin crossover complex [Fe(2-pic) 3 ]Cl 2 ·EtOH in its high spin state (298, 150 K) and low spin state(90 K) has been determined as discussed by the authors.
71 citations
TL;DR: In this paper, an extension of the level scheme of 78Kr is proposed; four bands connected by stretched E2 transitions have been identified, and the β-decay half-lives of the 103 keV isomeric state and ground state of 78Rb have been remeasured.
51 citations
TL;DR: In contrast to the proteins, the 2-methyl model exhibits spectra at 4.2 K which imply that the lowest spin state has high susceptibility in a single direction, and the spectra differ, suggesting different detailed structure within the quintet.
39 citations
TL;DR: In this paper, the level schemes of odd Sn isotopes (A = 109-117) have been studied by an in-beam spectroscopy method through (α, xn) reactions.
39 citations
TL;DR: In this paper, the effects of atomic distance and electronegativity of ligand make comparable contributions to the isomer shift of a divalent iron in low spin state and high spin state, respectively, and the lattice term of electric field gradient gives a large contribution to the quadrupole splitting.
Abstract: The isomer shift and the quadrupole splitting of 57Fe in the pyrite‐type dichalcogenides, FeS2–CoS2–NiS2–NiSe2 and CoSe2, were measured at room temperature. It is concluded that the effects of atomic distance and electronegativity of ligand make comparable contributions to the isomer shift of a divalent iron in low spin state. In high spin state, the contribution of atomic distance is smaller than that of electronegativity. The lattice term of electric field gradient gives a large contribution to the quadrupole splitting. The isomer shift and the quadrupole splitting of Fe1–yCoyS2 change around y=0.5 where the concentration dependence of resistivity changes. In NiS2–xSex, the quadrupole splitting of 57Fe becomes small with increasing x at the metal–semiconductor phase boundary.
37 citations
TL;DR: In this article, the energy of Ni-N interactions for low-spin complexes with 12- to 15-membered macrocycles is related to the size of the aperture in the cyclic ligand.
Abstract: Nickel(II) complexes with 13- and 14-membered tetra-aza macrocycles exist in aqueous solution as an equilibrium mixture of a blue high-spin and a yellow low-spin species: the blue-to-yellow conversion is endothermic and predominance of the yellow form stems from a large positive entropy term, due to the release of two or more water molecules. The energy of the in-plane Ni–N interactions for low-spin complexes with 12- to 15-membered macrocycles is related to the size of the aperture in the cyclic ligand.
34 citations
TL;DR: In this paper, the inverse reaction 24 Mg( 136 Xe, 4n) 156 Dy at 595 MeV has been used to populate high spin states in 156 Dy.
31 citations
TL;DR: In this article, a general symmetry analysis of reductive elimination from transition metal alkyls has been carried out and it has been shown that concerted reaction is permitted for various complexes with the configurations d1−d8.
TL;DR: In this paper, the decay chains and lifetimes of high spin sub-nanosecond isomers have been measured using a solenoid spectrometer with Si(Li) detectors.
TL;DR: In this paper, a new theoretical model is presented, in which the EuS conduction band consists of pure spin states and mixed spin states, each weighted with a temperature dependent spectral weight (reduced density of states).
TL;DR: In this article, the transition from the low-to the high-spin state in Fe2+ and Co3+ compounds has been examined by X-ray and UV photoelectron spectroscopy.
TL;DR: In this article, the spin relaxation time of ·OH radicals is shown to depend on viscosity, and a variety of effects of magnetic fields and deuteration on reaction rates in pairs and on yields of radiolysis products are predicted.
Abstract: Dissociation and ionisation in condensed phases produce pairs of radicals (and electrons) or radical ions. Recombination of such pairs into ground state molecules depends on their spin state: singlets can recombine, triplets separate; theoretical work on ions in hydrocarbons is extended here to other substances, especially aqueous solutions. Single pairs are usually singlet initially. Recombination in spurs containing two or more pairs gives a mixture of singlets (S) and triplets (T). The cross-reactions in spurs, which in water give H2 and H2O2, normally have S:T = 1:3. Generation of a pair in a large spur via a triplet intermediate and Heisenberg spin exchange both transfer singlet character from the back reactions to the cross reactions. In mobile liquids, two processes are fast enough to cause correlation decay before recombination in the spurs: coherent (oscillatory) decay due to the hyperfine interaction in free hydrogen atoms and spin relaxation in hydroxyl and other cylindrically symmetrical radicals. Calculations of the spin relaxation time of ·OH radicals are presented : the mechanism is shown to depend on viscosity. Correlation effects on recombination of solvated electrons in viscous and glasses are discussed.It is shown that studies of spur dynamics must include spin effects. A variety of effects of magnetic fields and of deuteration on reaction rates in pairs and on yields of radiolysis products are predicted. Quantitative predictions are not attempted for lack of information, but effects will be small in liquid water, larger in organic liquids.
TL;DR: In this article, high spin states in 105 Ag have been studied using the 103 Rh(α, 2nγ) 105 Ag reaction and a comparison of the experimental results with theoretical calculations indicates that the properties of most of the positive parity states are reasonably well described by the cluster-vibrational model as well as by the triaxial rotator model.
TL;DR: In this paper, high-spin states in 91 Nb populated by the 89 Y(α, 2nγ) reaction were studied at 24.0 MeV and 35.7 MeV incident α-particle energy.
Journal Article•
TL;DR: From the experiments as well as from the model it can be concluded that P-450 works in the first reaction step in two states (different in structural and functional properties) being in equilibrium with each other.
Abstract: Based on the existence of a spin equilibrium of P-450 LM a thermodynamic model including the first two elementary steps has been developed. This model has been compared with a modified model of P-450 CAM first presented by SLIGAR [1]. For the quantitative description of the model of P-450 LM seven necessary constants have been calculated. In the model a 5-coordinated ferric heme complex as intermediate and precursor of the reduced state is included. The model is based on experimental data of the spin equilibrium and the binding of benzphetamine to P-450 LM2, on the redox potential of P-450 LM and further on the assumption of a structure of the precursor well adapted to reduction. The dissociation constant (KD) of the 6th heme iron ligand is calculated to be 0.03 meaning that only 3% of the high spin ferric state are 5-coordinated. From the thermodynamic parameters of the model the sequential order of the reaction process can be derived and conclusions can be drawn on possibly reaction controlling steps. Experimentally it is shown that the substrate induced spin shift is correlated with the reduction rate. This has been shown to be valid in dependence on the degree of saturation with only one substrate as well as with different substrates indicating that independent of the individual substrate only the shift of the spin state controls the reduction. From the experiments as well as from the model it can be concluded that P-450 works in the first reaction step in two states (different in structural and functional properties) being in equilibrium with each other. Different affinities of these two states towards the substrate shift the equilibrium. This shift increases the concentration of the reducible intermediate and by this the reduction as second elementary step is regulated.
TL;DR: In this article, a second collective band of positive parity is proposed to be based on a configuration [( f 5 2 ) J≠O 2 π g 9 2 ] 15 2 +.
TL;DR: In this article, the (n, γ) and (n e − ) reactions at thermal and resonance energies were studied and the transition multipolarities were deduced from the measured conversion coefficients and from L- and M-subshell ratios.
TL;DR: In this article, high-spin states in 109In have been investigated using the 107Ag(α, 2nγ)109In reaction using Ge(Li) detectors to establish the level scheme.
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TL;DR: In this paper, the internal conversion electron spectrum has been studied using a trochoidal spectrometer, and internal conversion coefficients of transitions between 240 and 410 keV have been determined, viz. those at 243.15, 255.76, 277.10, and 407.80 keV.
TL;DR: In this paper, one-, two-and three-particle transfer reactions induced by 115 MeV 11B and 12C, 126 MeV 18O and 105 MeV 13C ions on gas targets of 15N and 16O were studied.
TL;DR: The fine structure splitting constants for the perturbed T1 state are D = -3Y/2 = ± 15.508 GHz and E = (Z - X)/2 = ‡.643 GHz.
TL;DR: In this article, single-neutron transfer reactions on even-even Se nuclei have been studied using 33 MeV incident proton energy from the ANU cyclograaff facility.
TL;DR: In this article, negative parity bands of the low lying high spin states in the odd-odd Au nuclei ( 190,192,194 Au) are explained in the framework wherein the two odd quasi-particles ( π h 1 1 2 −v i 1 3 2 ) are coupled to the gamma deformed core.
TL;DR: In this paper, energy levels in 149Tb have been studied by the 142Nd (10B,3n) reaction using 54MeV 10B beams from the McMaster University FN accelerator.
Abstract: Energy levels in 149Tb have been studied by the 142Nd (10B,3n) reaction using 54 MeV 10B beams from the McMaster University FN accelerator Excitation functions, angular distributions, prompt γ–γ coincidence, electron conversion, and linear polarization measurements were obtained On the basis of these measurements we have identified two rotaition-aligned πh11/2 bands, a negative parity band up to spin 27/2−, and a positive parity band up to spin 27/2+ The energy spacings between levels in these bands strongly resemble those in the ground state and the 3− octupole band of the adjacent 148Gd core nucleus Other high spin positive parity states up to spin of 41/2 are also observed These high spin states show some evidence of rotational structure in 14 9Tb
TL;DR: In this article, the free induction decay signal of the Tz-Ty zero-field transition at 859.5 MHz of tetramethylpyrazine-d12 in durene following flash excitation at 266 nm in the singlet manifold was observed.