Functionalization of Heteropolyanions—Osmium and Rhenium Nitrido Derivatives of Keggin‐ and Dawson‐Type Polyoxotungstates: Synthesis, Characterization and Multinuclear (¹⁸³W, ¹⁵N) NMR, EPR, IR, and UV/Vis Fingerprints

Abstract

Reaction of K(10)[alpha(2)-P(2)W(17)O(61)] or K(10)[alpha(1)-P(2)W(17)O(61)] or [Bu(4)N][OsCl(4)N] in a water/methanol mixture, and subsequent precipitation with (Bu(4)N)Br provided [alpha(2)-P(2)W(17)O(61){Os(VI)N}](7-) and [alpha(1)-P(2)W(17)O(61){Os(VI)N}](7-) Dawson structures as tetrabutylammonium salts. Reactions of [(Bu(4)N)(4)][alpha-H(3)PW(11)O(39)] with either [ReCl(3)(N(2)Ph(2))(PPh(3))(2)] or [Bu(4)N][ReCl(4)N] are alternatives to the synthesis of [(Bu(4)N)(4)][alpha-PW(11)O(39){Re(VI)N}]. (183)W and (15)N NMR, EPR, IR, and UV-visible spectroscopies and cyclic voltammetry have been used to characterize these compounds and the corresponding [(Bu(4)N)(4)][alpha-PW(11)O(39){Os(VI)N}] Keggin derivative.

Noble Metals in Polyoxometalates

“…[48] Additional calculations have compared the electronic structures and reactivities of hypothetical Al III -, P V -, and S VI -centered anions as well as the corresponding molybdates. [49] 4À [50] has been confirmed by the more extensive investigations of Maatta, Proust et al [51] in which this anion, together with both the a 1 and a analogues might be stabilized by the lacunary polytungstate, [45b] and another report discusses the possible variation in nitrogen-transfer reactivity caused by changing M (Ru, Os, Re) or the central tetrahedral atom (Al, Si, P, As).…”

“…The rigid structure in solution (no evidence of boat-chair interconversion) was confirmed by variable temperature 51 V NMR, 17 O NMR spectroscopy and was further characterized by ESI mass spectrometry. [9] Reaction of the heterometallic cuboidal clusters [Mo 3 À or pyridine) causes dissociation into the monomers with Pd-L coordination.…”

“…[18] Solutions of the vanadoplatinate(IV) anion yielded the anticipated four-line 51 5À were successfully modeled by DFT methods. [19] The crystal structure of the guanidinium salt (CH 6 N 3 ) 5 , in which the two Ag + ions are each coordinated to oxygen atoms of the {AsW 9 O 33 } units and the S atoms of two {Mo 3 S 4 } clusters located in different monomeric units of the parent supramolecular assembly.…”

A (Nitrido)chromium(V) Function Incorporated in a Keggin‐Type Polyoxometalate: [PW11O39CrN]5– – Synthesis, Characterization and Elements of Reactivity

“…[69] In the case of the d 1 system [PW 11 O 39 {Re VI N}] 4-, the lack of nitrogen superhyperfine coupling was ascribed to an odd electron primarily localized on the rhenium 5d x 2 -y 2 (d π ) orbital overlapping with 2p π orbitals of the inplane oxygen ligands. [54] The spectrum of 1 recorded at 77 K in a frozen solution revealed an axial system with g Ќ = 1.98 and g ʈ = 1.91. …”

“…[52] Moreover, by varying the POM structural type, and the identity or oxidation state of the metallic cation incorporated, one can expect to tune the reactivity of the metalnitrido function from nucleophilic to electrophilic. We recently reported osmium-, rhenium-and (nitrido)ruthenium derivatives of POMs [53][54][55] and we describe herein the syn- 2-, including nitrosyl, organoimido and organodiazenido species, have been described, [56] few examples are known in the Keggin family. Indeed, the higher reducibility of [PMo 12 O 40 ] 3-in comparison to [Mo 6 O 19 ] 2-precludes the direct functionalization of the latter by the amines or hydrazines commonly used in the functionalization of the former, [31,57] whereas the corresponding polyoxotungstates are not reactive under such conditions.…”