New routes to the preparation of the aquamolybdenum(IV) ion by comproportionation reactions

Abstract

The fluoride also coprecipitates from halogen fluoride solutions with XeF2 and complexes of XeF2 but not with XeF4.7,8 Recently, Avrorin et al.1 23456789 have reported the preparation of a higher fluoride of radon, either RnF4 or RnF6, and a water-soluble oxide, Rn03, in tracer experiments with isotope 222Rn. They hydrolyzed complex mixtures of products that had been obtained by heating radon, xenon, fluorine, bromine pentafluoride, and either sodium fluoride or nickel fluoride. Part of the radon volatilized on hydrolysis and part remained in the aqueous phase, suggesting the formation of Rn03. However, Avrorin et al. failed to closely examine the contents of the aqueous phase. In this note we report the results of experiments that we have carried out, using larger amounts of reagents and similar conditions, in an effort to confirm their findings. Experimental SectionA Monel reactor (9.05-mL volume) attached to a Monel valve was loaded at room temperature with either NiF2 (16.8-27.7 mmol) or NaF (39.3-42.9 mmol), cooled to -195 °C, and charged with BrFs (15.5-46.4 mmol), 222Rn (49-221 µ ), xenon (0.54-0.57 mmol), and fluorine (54.7-57.1 mmol). Each mixture was heated at 250-265 °C for approximately 40 h. The excess fluorine was pumped off at -195 °C, and BrF5 and uncomplexed XeF6 were vacuum distilled from the reactor at 0 °C. (The XeF6 product was complexes by NaF but not by NiF2). Products remaining in the reactor were then hydrolyzed with 8-15 mL of 0.10 M aqueous Xe03 solution at 0 °C. Radon in the hydrolysate was analyzed by measuring the emissions of its daughters, 214Pb and 214Bi, in equilibrium with their parent.4 The hydrolysate was centrifuged and the supemate transferred to a separate container; the radon was then analyzed in each fraction. The supemate was flushed with nitrogen for 5-10 min and the residue stirred with 10 mL of either water, 0.10 M Xe03 solution, or 1 KI solution; after 4 h, the analyses were repeated.To determine the behavior of radon in simpler mixtures, several experiments were carried out with only radon, fluorine, and NiF2 or with only radon, fluorine, and NaF. Each mixture was heated at

Synthesis, Characterization, and Structure Determination of a New Heterometallic Oxoalkoxide: Er2Ti4O2(OC2H5)18(HOC2H5)2

“…The behavior at higher temperatures was the same as already described, however. 18 (HOEt) 2 The packing sequence of the molecules can be considered as dense and body centered. The obtained molecular geometry is shown in Fig.…”

“…This fragment is also observed in other M>-containing alkoxides. e.g., Zr (16), Ce (17), and U (18).…”

Comparative Study of f-Element Electronic Structure across a Series of Multimetallic Actinide and Lanthanoid-Actinide Complexes Possessing Redox-Active Bridging Ligands

“…For example, actinyl "cation-cation" complexes, resulting from metal···oxo [O=An=O] n+ ···AnO 2 interactions, are considered important in this context. [9][10][11] A few examples of mixed-valent uranium complexes have appeared in the literature and include the uranium bimetallic systems [N{CH 2 CH 2 N(Si t BuMe 2 )} 3 U] 2 (μ-Cl) (1), 12 U 2 (O t Bu) 9 (2), 13 and [K(18-crown-6)(Et 2 O)][UO{µ 2 -NCH 2 CH 2 N(CH 2 CH 2 N(Si t BuMe 2 )) 2 }] 2 (3), 14 which reportedly exhibit canonical U III /U IV , U IV /U V , and U V /U VI valences, respectively (Chart 1). The chloride ligand of complex 1 resides on a crystallographic inversion center with a U-Cl distance uranium(IV)-chloride distances; the complex was assigned as a species with intermediate uranium valencies.…”

“…The authors described the valence of 2 as "trapped" U IV /U V on the basis of these crystallographic differences and optical spectroscopic evidence. 13 As such, the presence of an inversion center in 1 nominally indicates delocalization, but the similar uranium-alkoxide bond lengths for the valence-localized 2 demonstrate that crystallographic distances are neither reliable nor precise for unambiguous determination of the presence and extent of electronic communication for multimetallic uranium complexes.…”

Unprecedented 2-D hydrated proton encapsulated in supramolecular framework built of [Mo3O4(C2O4)(H2O)3]2−

“…To our knowledge, extended hydrated proton, which is the most close to the aqueous acid, has not been reported in the literature. Fortunately, by using the protonated trimolybdenum ( [12,13]. X-ray structural analysis [14] [16,17], suggesting that the cluster dianion is deprotonated.…”