Diamagnetic susceptibility measurement

The diamagnetic susceptibility measurements are consistent with the NMR properties of cycloheptatrienes. Pikulik and Childs compared the H NMR chemical shifts of the C(7) proton of 7-substituted cycloheptatrienes and the corresponding 1,4-cycloheptadienes and showed that there was a considerable upfield shift of the resonance of the former protons... 

The diamagnetic susceptibility measurements are consistent with the NMR properties of cycloheptatrienes. Pikulik and Childs compared the NMR chemical shifts of the C(7)... 

Other physical methods were also applied to the elucidation of the isomerism of diazocyanides, e. g., determination of diamagnetic susceptibility, the Faraday effect (optical rotation in a magnetic field), and electronic and infrared spectra. Hantzsch and Schulze measured ultraviolet spectra at a remarkably early date (1895 a). Unfortunately, their results and later work (Le Fevre and Wilson, 1949 Freeman and Le Fevre, 1950) did not allow unambiguous conclusions, except perhaps the observation that the molar extinction coefficients of the band at lowest frequency are consistently larger in all types of (i -compounds Ar — N2 - X than in the corresponding (Z)-iso-mers (Zollinger, 1961, p. 62). 

Simultaneous weight-change and diamagnetic-anisotropy measurements upon adsorption and desorption of bromine in PG have been carried out (M4). They showed that final susceptibility values are reached well before full bromine saturations, and remain until 80% desorption is attained. 

The W(IV) compounds W(Et2C c)4 (14) and [(CU.2)ndtc] (15) are characterised only by analytical data and magnetic susceptibility measurements. They are considered to be paramagnetic with moments of about 1.0 BM, which is in contrast with the diamagnetism of W(R2[Pg.94]

An additional, independent estimate of the concentration of paramagnetic superoxo and diamagnetic hydroperoxo-/peroxo-titanium species was made from magnetic susceptibility measurements using a Lewis coil force magnetometer (52). The gram-susceptibility of Ti in TS-1 + H2C>2 was estimated to be 5.5 X 10-6 emu/g, which corresponds to an effective magnetic moment of... 

Some of these quantities are experimentally measurable from scattering experiments [1,2] or relate to physically interesting quantities which appear in different problems. For example p ) gives the kinetic energy of any nonrelativistic system, (r ) is related to the diamagnetic susceptibility, (r ) relates to the electron-nucleus potential energy,... 

An understanding of the limitations of the Kirkwood-Vinti approximation should therefore lead to considerable advances in the theory of bonding. In its absence, we shall here use diamagnetic susceptibility as the principal method of measuring yms and use refractive index only as a secondary method. 

The first 10 powder diffraction lines for each phase are given in Table 1. Bulk magnetic susceptibility measurements (77-300°K) show that both platinum disulfide and platinum ditelluride are diamagnetic, with susceptibilities of -31(2) and -12(1) emu/mole respectively, as expected for low-spin d6 octahedral ions. Platinum disulfide shows semiconducting behavior between 77 and 300°K, with an activation energy of 0.10(1) eV, whereas platinum ditelluride is metallic. 

Step 2. Electron-transfer the decrease in the d-d absorption subsequent to the steep rise of the absorbance in Fig. 27(b) corresponds to the formation of Cu(I) ions, i.e. electron transfer from the substrate to Cu(II) ions. The d orbitals of Cu(I) are perfectly occupied, so that d-d absorption spectrum does not appear in the Cu(I) complex. The rate constant ke is obtained from the falling curve of the d-d absorption. The fraction of Cu(II) ions is also determined from the magnetic susceptibility of the reaction system. The Cu(II) ion contains an unpaired electron and is paramagnetic, while the Cu(I) ion is diamagnetic. Magnetic measurement is applicable particularly to an insoluble catalyst system155. ... 

Measured values of the diamagnetic susceptibility of the noble gases correspond to reasonable values of Sr2. For polyatomic molecules the interpretation of the diamagnetic susceptibility in terms of structural features is in general uncertain, and this property has not been found to be valuable in structural chemistry. 

The usefulness of magnetic susceptibility and diamagnetic susceptibility exaltation measurements as a means of assessing aromaticity has been outlined elsewhere (68JA811, 74AHC(17)255, B-75MI22206). 

The key underlying assumption of all the NMR studies of the homotropenylium systems is that there is an induced ring current when the ions are in a magnetic field and that this effects the two C(8) protons in a different manner. Dauben, Wilson and Laity measured the diamagnetic susceptibility of 11 and showed that it has a susceptibility exaltation which is similar in magnitude to that of the tropylium ion88. 

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