Magnetic moments variable temperature

Fe(6-Mepy)2(py)tren] (004)2 Doped in PSS. Magnetic susceptibilities measured for a microcrystalline sample of the complex produce a magnetic moment value = 0.36 pg at 10 K and 0.61 pg at 150 K, followed by a gradual increase to Peff = 2.80 pe at 311 K [138]. Thus 26% of the complexes are in the HS state at 300 K if a magnetic moment of 5.1 Pe is assumed for the pure HS compound. On the other hand, the complex doped into a polystyrene sulfonate (PSS) film does not provide any evidence for a thermal population of the HS state up to 340 K as demonstrated by variable-temperature UV-VIS and Mossbauer spectra. In fact, all the complexes doped into the PSS film are in the LS state at temperatures below 340 K. However, if irradiated by a single pulse of a Q-switched Nd/YAG laser (532 mp), the complex is excited from the LS ground state to the HS J2 states via an intermediate MLCT state and the metal states. The subsequent back relaxation from the excited T2 state to the... 

From variable-temperature 57Fe Mossbauer spectra Konig and Ritter82) determined the Debye-Waller factors f over the temperature range of 298-4.2 K in III (on polymorph one with 0.9 B.M. at 77 K). Whereas the magnetic moment and other physical properties show an abrupt change with temperature near Tc ( 213 K), they found a continuous change of -Inf. 

Comparative variable-temperature magnetic susceptibility studies have been undertaken for [MnCl(TPP)] and [MnCl(TPP)(py)]676,617 and accurate estimates ( — 2.3 and - 3.0cm 1 respectively) of the zero-field splitting of the ground state of Mn111 in these compounds obtained. As expected the magnetic moments of both compounds at room temperature are close to the spin-only value for S = 2. 

In order to understand the charge transfer features of the Blue Copper site, the variable-temperature optical absorption, room-temperature circular dichroism, and magnetic circular dichroism spectra of plastocyanin, stellacyanin, and azurin were studied355. As can be seen for plastocyanin in Fig. 12, the relative intensities (and signs, in the case of CD and MCD) of these transitions vary among the different types of spectra. This is a result of the difference in selection rules for absorption, CD, and MCD spectra, as mentioned in the Introduction. A careful comparison of the three types of spectra and the absorption bandshape temperature dependence (see moment analysis in Ref. 35, pp. 176-177)... 

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