Mössbauer Effect of 129I in Pyridine Complexes of Iodine Monohalides

Abstract

Articles you may be interested inAn 129I Mössbauer spectroscopic study of iodine doped in poly(vinylpyridines) J. Chem. Phys. 75, 5155 (1981); 10.1063/1.441864 Mössbauer effect of 129I in n-σ and π-σ chargetransfer complexes of iodine in the frozen solution J. Chem. Phys. 72, 6192 (1980); 10.1063/1.439078 129I Mössbauer studies of iodine in the +1 and +3 oxidation states Wl(R) than that taken in Eq. (15) might be Wl(R) =E{b 1 exp[ -0:(R-R...)/R...]-2al(R.../R)7} , and for this choice Eq. (16) is modified by replacing the constant CN by C~3.12e" Ko( 1.0610:),Ko being the modified Bessel function of order 0; for x> 1, Ko(x) =e"'(7r/2x) 1/2 to within 10%.The information concerning the anisotropy is obtained most directly from the amplitude of the oscillatory part of the cross section; in all cases the frequency THE JOURNAL OF CHEMICAL PHYSICS of the oscillations is governed by the rainbow angle of the distorting potential. From Eqs. (11) and (16) we see that the amplitude of the oscillatory contribution is proportional to D (or 1/velocity), or normalized to Ub<.)O) it is proportional to ])3/6. To minimize the contributions from third-and higher-order terms in the cross section, it would be best to extrapolate a plot of the amplitude (normalized to u~(O» versus ])3/6 to ~ the slope of this plot giving the appropriate combination of anisotropy parameters. With the measurements analyzed in this manner, there should be no need to correct the high-energy approximations used in Sees. III and IV to evaluate the various quantities required.The values of isomer shift and quadrupole interaction at the 129 1 nucleus in IBr and ICI complexes with cyclic nitrogen bases have been measured. These have been used to estimate IT and'll" bondings in these complexes. All these complexes exhibit a linear N-I-X (X=CI, Br) linkage. Although the bromine complexes show a systematic dependence of the isomer shift on the basicity of the complexing cyclic amines, no such trend is observed in chlorine complexes.

Rapid Identification of Halogen Bonds in Co‐Crystalline Powders via 127I Nuclear Quadrupole Resonance Spectroscopy

“…These increases in C Q are in agreement with previously reported 129 I‐Mössbauer‐spectroscopic results obtained for iodine⋅⋅⋅nitrogen complexes, further supporting the trends. However, in contrast to our results, a 1968 report investigating complexes claimed to be formed between diiodoalkanes and amines by 127 I NQR reported a decrease in the NQR frequency by 6.8 MHz.…”

Rapid Identification of Halogen Bonds in Co‐Crystalline Powders via 127I Nuclear Quadrupole Resonance Spectroscopy

“…These increases in C Q are in agreement with previously reported 129 I-Mçssbauer-spectroscopic results obtained for iodine···nitrogen complexes, [60][61][62][63] further supporting the trends.H owever,i n contrast to our results,a1968 report investigating complexes claimed to be formed between diiodoalkanes and amines by 127 INQR reported ad ecrease in the NQR frequency by 6.8 MHz. Theauthors proposed aC À I···N motif resembling ah alogen bond.…”

The Halogen Bond

“…This technique allowed for measuring the values of the isomer shift and quadrupole interaction at the 129 I nucleus in complexes of BrI and ClI with pyridyl compounds, wherein the presence of a linear X–I···N bond was observed. 439 A dependence of the isomer shift on the base strength could be observed for BrI, but not for ClI.…”