Effective magnetic field parameter

HS-HS] pairs. The third component (relative intensity z=44.0%) with parameters <5Hs(bpym, S) and AEq(HS) (bpym, S) can be unambiguously assigned to the HS state in [HS-LS] pairs, because the measured effective magnetic field at the iron nuclei of 81 kOe clearly originates from a spin quintet ground state of iron(II) (S=2). As a result, the complete distinction of dinuclear units becomes possible. It follows from the area fractions of the subspectra intensities that at 4.2 K the sample (bpym, Se) contains 2z=88.0% [HS-LS],7=4.0% [HS-HS] and (x-z)=8.0% [LS-LS] pairs. 

Fig. 1 shows the Moessbaucr spectra of fresh and used (in an industrial apparatus) partially deactivated catalysts. The parameters of the spectra (isomer shift 5, quadrupole splitting A, effective magnetic field Hcff, and relative weight of components C) are presented in Table 2. 

The revised stracture of the tables in the present volume 1129 is introduced at the beginning of section 2.1.2, "List of tabulated rotational parameters". The parameters are listed separately for each isotopologue and each vibronic state of a molecule. Within this order, the magnetic field parameters considered here are placed at the very end, below the rotational and hfs constants or electric dipole moments and internal rotation parameters. The number of pubhcations employing Zeeman effects has decreased in recent years. The following symmetric top Zeeman and related parameters are included in the tables ... 

The Mossbauer spectral lineshapes in the case of thin absorbers can be represented fairly accurately by Lorentzian-type functions. The values of the isomer shift, quadrupole splitting, linewidth, strength of the effective magnetic field at the nucleus, and other parameters of interest can be determined by a statistical treatment of the data. A number of computer routines have become available which enable such analyses to be performed in a rather straightforward fashion. 

Optical detection of magnetic resonance (ODMR) was attempted for measurements of the pH effects on the triplet state of purine to investigate the protonation site of purine at low temperatures (78JA7131). The ODMR spectrum did not show the presence of more than one triplet state at liquid helium temperatures. Since the protonated tautomers 1H,9H (3a) and H,1H (3b) have similar bond structures, their triplets should have similar zero-field parameters and are thus not easy to distinguish by ODMR. 

Turro, N.J., Chow, M.-F., Rigaudyo, J., 1981. Mechanism of thermolysis of endoperoxides of aromatic compounds. Activation parameters, magnetic field, and magnetic isotope effects. J Am Chem Soc. 103, 7218-7222. 

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