Keggin‐type Polyoxometalates [PW₁₁O₃₉MCl]^5– with Noble Metals (M = Rh and Ir): Novel Synthetic Entries and ESI‐MS Directed Reactivity Screening

Everything flows

“…Individual highlights were, for instance, contributions on "[Bi 4 ] 6Ϫ Ϫ The Zintl Anion with the Highest Charge per Atom Obtained from Solution" by Thomas F. Fässler and coworkers, [1] "Silica-Based Nanoporous Materials" by Osamu Teresaki and co-workers, [2] "Non-innocent Redox Behavior of Amidinato Ligands: Spectroscopic Evidence for Amidinyl Complexes" by Wolfgang Kaim and co-workers, [3] and "Keggin-type Polyoxometalates [PW 11 O 39 MCl] 5Ϫ with Noble Metals (M ϭ Rh and Ir): Novel Synthetic Entries and ESI-MS Directed Reactivity Screening" by Maxim N. Sokolov and co-workers, [4] to name just a few.…”

Gas‐Phase Fragmentation Reactions of Keggin‐Type {PW11O39M} (M = Rh, Ir, and Ru) Polyoxometalates as Fingerprints of the Ligands Attached at the Noble Metal Site

“…The proton adducts [PW 11 O 39 MCl + 2H] 3– and [PW 11 O 39 MCl + 3H] 2– are observed from acetonitrile solutions of [Bu 4 N] 5 [PW 11 O 39 MCl] under soft ionization conditions 12b,14. The CID mass spectra of both [PW 11 O 39 MCl + 2H] 3– (M = Rh and Ir) trianions display two competitive dissociation channels, which evolve H 2 O (Δ m = 18) and HCl (Δ m = 36) at low collision energies below CE Elaboratory = 15 eV (Table 1, Entries 1 and 2).…”

“…For example, the CID mass spectra of [PW 11 O 39 M(SCN) + 2H] 3– (M = Rh and Ir) display a first liberation of H 2 O followed by a charge‐splitting process to afford the [PW 11 O 38 M] 2– dianion and the SCN – anion under identical CID conditions (Table 1, Entries 3 and 4) 12b. The gas‐phase fragmentation reactions of the [PW 11 O 39 RhCH 3 + 2H] 3– and [PW 11 O 39 IrCH 3 + 2H] 3– trianions under CID conditions (Table 1, Entries 6 and 7) comprise the competitive release of a methyl radical (Δ m = 15) followed by H 2 O (Δ m = 18) and the liberation of CH 3 · and H 2 O (Δ m = 33).…”

“…The compounds [Bu 4 N] 5 [PW 11 O 39 RhCl] and [Bu 4 N] 5 [PW 11 O 39 IrCl] are convenient starting materials for ligand‐substitution reactions at the noble metal site through Cl substitution 5c,12b. The Ir compound proved to be more substitutionally inert than the Rh compound 5c.…”

“…This finding could have implications for the identification of Keggin‐type POMs that are partially overlapped in their single‐stage ESI mass spectra. For example, we recently reported that the reaction of [Bu 4 N] 5 [PW 11 O 39 RhCl] with NaNO 2 gave a low conversion into [Bu 4 N] 5 [PW 11 O 39 Rh(NO 2 )] 12b. In this particular case, the ESI(–) mass spectrum of the resulting mixture displayed partially overlapped peaks because of the intrinsic wide envelope of the species and the close mass of the L = Cl – and NO 2 – anions.…”