Peroxide Coordination of Tellurium in Aqueous Solutions

Abstract

Tellurium-peroxo complexes in aqueous solutions have never been reported. In this work, ammonium peroxotellurates (NH4 )4 Te2 (μ-OO)2 (μ-O)O4 (OH)2 (1) and (NH4 )5 Te2 (μ-OO)2 (μ-O)O5 (OH)⋅1.28 H2 O⋅0.72 H2 O2 (2) were isolated from 5 % hydrogen peroxide aqueous solutions of ammonium tellurate and characterized by single-crystal and powder X-ray diffraction analysis, by Raman spectroscopy and thermal analysis. The crystal structure of 1 comprises ammonium cations and a symmetric binuclear peroxotellurate anion [Te2 (μ-OO)2 (μ-O)O4 (OH)2 ](4-) . The structure of 2 consists of an unsymmetrical [Te2 (μ-OO)2 (μ-O)O5 (OH)](5-) anion, ammonium cations, hydrogen peroxide, and water. Peroxotellurate anions in both 1 and 2 contain a binuclear Te2 (μ-OO)2 (μ-O) fragment with one μ-oxo- and two μ-peroxo bridging groups. (125) Te NMR spectroscopic analysis shows that the peroxo bridged bitellurate anions are the dominant species in solution, with 3-40 %wt H2 O2 and for pH values above 9. DFT calculations of the peroxotellurate anion confirm its higher thermodynamic stability compared with those of the oxotellurate analogues. This is the first direct evidence for tellurium-peroxide coordination in any aqueous system and the first report of inorganic tellurium-peroxo complexes. General features common to all reported p-block element peroxides could be discerned by the characterization of aqueous and crystalline peroxotellurates.

Deciphering the Crystal Structure of a Scarce 1D Polymeric Thorium Peroxo Sulfate

“…Particularly, the band located at 859 cm −1 on the Raman spectrum (Figure ) and the very weak one observed at 818 cm −1 on FTIR spectrum (Figure S1) are assigned to the ν (O−O) symmetric stretching vibration mode of the peroxide ligand, in accordance with the bridging μ‐η 2 :η 2 coordination mode already observed for cerium(IV), uranium(VI) and plutonium(IV) compounds . The shift of the Raman band to lower wavenumber in comparison to free H 2 O 2 (around 880 cm −1 ) can be attributed to the coordinating Th IV cation . Raman bands positioned at 1128 and 1088 cm −1 ( ν 3 ); 979 cm −1 ( ν 1 ); 644 and 601 cm −1 ( ν 4 ); and 496 cm −1 ( ν 2 ) can be assigned to sulfate ligand in agreement with the literature and FTIR data (Figure S1) …”

“…1.486(7) ,w hich is slightly lower than those reported for m 3 -bridged Ln-peroxo compounds (1.52 to 1.55 ). [13b] However,i ti sc loser to those reported for the only two peroxides tructures resolved for tetravalenta ctinides,w here the peroxide ligands exhibit m 2 -h 2 :h 2 coordination (OÀOl ength is 1.496 (6) in the Pu IV peroxy-carbonate com-poundN a 8 Pu 2 (O 2 ) 2 (CO 3 ) 6 ·12 H 2 Oa nd 1.516-1.515 in [Th(O 2 )(terpy)(NO 3 ) 2 ] 3 cluster). [3, 7c] Such ad ifferencec an be attributed to the ionic radius of the tetravalent actinidesv ersus trivalent lanthanides and their relatedc harged ensity.T he ThÀ OP length in Th(O 2 )(SO 4 )(H 2 O) 2 ranges from 2.351(7) to 2.573 (6) ,w hich agrees with the literature data observed for Th (2.369(2) )a nd Pu peroxide clusters (2.33(1)-2.36(1) ) [3, 7c] but also with m 3 peroxo complexes (LnÀOP ranges from 2.311(3) to 2.408(2) for Ln = Sm, Eu, Gd;f rom 2.289 to 2.501 for Ln = Dy;and from 2.35 to 2.36 for Ln = Tb).…”

Effect of aluminum vacancies on the H2O2 or H2O interaction with a gamma‐AlOOH surface. A solid‐state DFT study

“…11 B NMR studies clearly demonstrate that boric acid does not interact with aqueous hydrogen peroxide and the peroxocoordination by B(III) occurs only at pH>7 . It was also shown that other p‐block elements, Sn(IV), Ge(IV), Te(VI) form peroxo derivatives only under basic conditions after deprotonation of the hydrogen peroxide and there is no coordination of the molecular hydrogen peroxide by these elements. Indeed, studies of the interaction of hydrogen peroxide and aluminum compounds have shown that the end product is a peroxosolvate of aluminum oxide in which the peroxide is bound by short (strong) hydrogen bonds (H‐bonds) and there is no H 2 O 2 direct coordination with aluminum atoms …”

Hydrogen Peroxide Coordination to Cobalt(II) Facilitated by Second‐Sphere Hydrogen Bonding

“…This shifted H 2 O 2 resonance is the first direct evidence that H 2 O 2 is binding to Co II in 1,a sthe 1 HNMR and electronic spectra demonstrate that Co II is five-coordinate under these conditions.The decay product of 1-H 2 O 2 was identified as 1-OH 2 by crystallization of the bulk material. [23][24][25][26][27] Thefirst-order decay of 1-H 2 O 2 contrasts the second-order decay mechanism of B,which bears the same ligand and counterion, and at the same starting concentration has ah alf-life of 10 4 s. [19] This comparison suggests that the redox-active nature of Mh as adramatic effect on the stability of M(H 2 O 2 )s pecies.…”

“…1-OH 2 ,which is very similar to acomplex reported by Borovik et al, [22] is an incommensurately modulated structure and is therefore represented as aball-and-stick model. [23][24][25][26][27] Thefirst-order decay of 1-H 2 O 2 contrasts the second-order decay mechanism of B,which bears the same ligand and counterion, and at the same starting concentration has ah alf-life of 10 4 s. [19] This comparison suggests that the redox-active nature of Mh as adramatic effect on the stability of M(H 2 O 2 )s pecies. For 1-OH 2 ,w hich only contains two second-sphere hydrogen bonds,t he Bu proton resonances overlap between 1and À1ppm.…”