Electron paramagnetic resonance spectra of the Group 4 hexafluoride anion radicals

Abstract

Publication costs assisted by the National Research Council of CanadaAnisotropic EPR spectra detected at 30 K in y-irradiated powdered BaGeF6, KzSnF6, and BaPbF, have been assigned to the hexafluoride anion radicals GeFl-, SnFl-, and PbFl-, respectively. These species are members of a series of paramagnetic hexafluorides of the elements of groups 4-7 which constitutes one of the largest known groups of isoelectronic free radicals. The nature of the semioccupied orbital in this type of radical is discussed in the light of unpaired electron spin densities computed from the measured hyperfine interactions for the hexafluorides.

Spectroscopy of the ns1‐Centers in Ionic Crystals

“…Due Table 24 Position (in nm) and width (in eV, between brackets) of the optical absorption bands from the IVA group of ns'-centers in crystals center to the complexity of the shf structure only the shf parameters from the first shell of eight Fligands could be determined. Pb3 + centers, which seem to represent self-trapped holes at cation sites, have been also reported in PbCO, crystals [183] and BaPbF, crystals [173].…”

“…Sn3' centers, which seem to represent self-trapped holes at cationic sites, were reported in SnCI,, Snl,, and SnSO, crystals [183] after X-ray irradiation at 77 K and in K,SnF, powder after y-irradiation [173]. The Sn3 ' center observed in K,SnF, exhibits the largest reported hf constant for this center, suggesting a strongly ionic compound.…”

“…A Ge3+ center, exhibiting the largest reported hf constant, has been observed [173] in y-ray irradiated powders of BaGeF,. The center, which seems to be a self-trapped hole, exhibits a shf structure from a regular octahedron of six NN Fligands.…”

Photochemical reactions involving matrix-isolated atoms

“…HCO, HOz, ClCO) are also suitable for testing for atom production by ESR (see section IVA).122J23 Curiously, there seems to be no record of the ESR spectra of KrF and XeF in matrices although they are well established in crystals (see ref 113). When fluorine atoms are generated photochem- Reaction with Nz to form Nz0132 or with COO to form C 0 3 could be used as a test for production of O(1D).138 Another characteristic reaction of O(lD) in fluid phases, the insertion into alkanes, does not seem to have been investigated in matrices at all, although the reaction with CHI to give CH30H and CHz0139 seems suitable for matrix application.…”

Understanding Lead Chemistry from Topological Insights: The Transition between Holo‐ and Hemidirected Structures within the [Pb(CO)n]2+ Model Series

“…complex is octahedral. [136] In the currently investigated [Pb(CO) 6 ] 2 + structure, the six n(CO) values differ by less than 2.2 cm À1 and average to 2294 cm…”