Mossbauer Table

FeHMA Octahedral Fe + tetrahedral Fe + after thermal treatment EXAFS/XANES, Mossbauer (Table 10) (152)... 

Platinum ammine complexes have been a fertile area for studying transinfluence. Table 3.21 lists data for a range of ammines showing how /(195Pt-15N) depends upon the trans-atom [153]. (A further selection of data can be found in R.V. Parish, NMR, NQR, EPR and Mossbauer Spectroscopy in Inorganic Chemistry, Ellis-Horwood, Chichester, 1991, pp. 76, 87.) Possibly the most detailed study (of complexes of tribenzylphosphine) examined over a hundred neutral and cationic complexes [154] (Table 3.22). 

Table 3. Mossbauer data of iron silylene complexes (Fe as standard)...

Comparison of the Mossbauer I Agxp I values with those calculated on the basis of the pqs formalism revealed that the organotin(IV) moiety has Tbp geometry, and in certain cases geometry too. Some of the complexes contain the organotin(IV) cation in two different environments. Finally, the local structure of the maleic acid complex formed with [Bu2Sn(IV)l was determined by an EXAFS method.The structural data are collected in Table 6. Similar studies... 

The various, solid-state stereochemistries just described may often be distinguished fairly readily by " Sn Mossbauer spectroscopy 5-9, 452), particularly from the value of the quadrupole splitting parameter, AEq (see Table II). 

Table 1. The 72-atom model examined by different theoretical methods. The energy differences (AE in kcal/mol) are calculated with respect to the lowest SCF energy. q(Fe) stands for Mulliken population charges on the Fe atoms q(S) and SS(b.i.) are the Mulliken population charges and the bond index for the bridging S atoms, respectively AEq is the calculated Mossbauer quadrupole splitting constant [mm/sec]. The PUHF spin states are those projected from the UHF wavefunction with 5 = 5,. 

Table 15.4 and Fe Mossbauer parameters of Cu5.47Fe2.9Sn13.1S32. 

Table IV. Mossbauer Parameters for Sulfided C0-M0/AI2O3 Catalysts.

Typical Mossbauer spectra for the fresh, reduced, carblded and used Fe/ZSM-5 system are shown in a composite Fig. 5. Similar spectra were obtained for the Fe-Co/ZSM-5 system. The product distribution for the F-T reaction, using the Fe and Fe-Co systems, are shown in Table 1. The gasoline range hydrocarbon yield increased from 75 to 94%, when the Fe-Co clusters were used in place of Fe only. In a typical CEMS (Conversion Electron Mossbauer Spectroscopy) of the Fe-Co system, no spectrum for 57pg vas observed even after one week from this. It was concluded that in the Fe-Co clusters Co was predominantly in the "mantle" and Fe species were In their "core," in the parlance of metallurgy/geophysics. This model Is sometimes referred to as the cherry model. 

Table I. Samples Used for MOssbauer Spectroscopy and Magnetic Susceptibility Studies...

Table III. Particle Size Determined Using Both MOssbauer...

Table 9. High-spin populations, rate constants fcm for the intersystem crossing in [Fe(acpa)2]BPh4-H20 according to a numerical simulation of the Mossbauer spectra"...

Structural and Bonding Aspects in Phosphorus Chemistry Table 6. Mossbauer spectra of halophosphates of tin and " tron... 

Fig. 1.1 Periodic table of the elements those in which the Mossbauer effect has been observed are marked appropriately. (Taken from the 1974 issue of [10])...

Interestingly, the correct polarity of the Mossbauer drive can be checked by using the isomer shift of oc-iron with respect to the materials in Table 3.1. After folding of the raw data, the center of the calibration spectrum without further correction must be at —0.12 mm s relative to the Co/Rh source material. 

Table 3.2 Properties of detectors commonly used in Mossbauer spectroscopy...

For a comparison of experimental Mossbauer isomer shifts, the values have to be referenced to a common standard. According to (4.23), the results of a measurement depend on the type of source material, for example, Co diffused into rhodium, palladium, platinum, or other metals. For Fe Mossbauer spectroscopy, the spectrometer is usually calibrated by using the known absorption spectrum of metallic iron (a-phase). Therefore, Fe isomer shifts are commonly reported relative to the centroid of the magnetically split spectrum of a-iron (Sect. 3.1.3). Conversion factors for sodium nitroprusside dihydrate, Na2[Fe(CN)5N0]-2H20, or sodium ferrocyanide, Na4[Fe(CN)]6, which have also been used as reference materials, are found in Table 3.1. Reference materials for other isotopes are given in Table 1.3 of [18] in Chap. 1. 

Table 4.1 Quadrupole moments for the ground state (g) and the excited state (e) of some Mossbauer nuclei quoted in millibam (1 mb = 10 m )...

If one pursues the calibration approach, one has to stick to a given combination of density functional and basis set, since the calibration will change for each such combination. Calibration curves have been reported for a number of widely used density functionals and basis sets. The results of a relatively comprehensive study are collected in Table 5.4. The standard deviation of the best fits is on the order of 0.08 mm s which appears to be the intrinsic reliability of DFT for predicting Mossbauer isomer shifts. 

Table 5.4 Linear fit data for Fe Mossbauer isomer shift predictions using the linear equation 5 = h (p - c) + a. A collection of 21 iron complexes with varying charge, oxidation- and spin-states have been studied (taken from [11])...

C. Occupation pattern. Finally, the third important factor - and the one that is often assumed to be the only important factor - is the occupation pattern of the if-orbitals. This concerns the angular integrals in (5.52). Their values are well known and listed in many textbooks on Mossbauer or EPR spectroscopy and here in Table 5.6. Using these tables, one simply multiplies gf with the occupation number of the orbital in question and the value and sums over aU... 

In Table 7.1 at the end of the book), nuclear data are collected for those Mdssbauer transitions of transition metal nuclides that are used in Mossbauer spectroscopy. The symbols used in this table have the following meaning ... 

In the last column of Table 7.1, the most popular radioactive precursor nuclide is given together with the nuclear decay process (EC = electron capture, = beta decay) feeding the Mossbauer excited nuclear level. 

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