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. 2022 Sep 9;8(36):eabq8613.
doi: 10.1126/sciadv.abq8613. Epub 2022 Sep 7.

Homoatomic cations: From [P5]+ to [P9]

Julia Frötschel-Rittmeyer  1 , Michael Holthausen  1 , Christian Friedmann  2 , David Röhner  2 , Ingo Krossing  2 , Jan J Weigand  1
Affiliations

Homoatomic cations: From [P5]+ to [P9]

Julia Frötschel-Rittmeyer et al. Sci Adv. .

Abstract

Recent synthetic approaches to a series of [P9]X salts (X = [F{Al(ORF)3}2], [Al(ORF)4], and (RF = C(CF3)3); Ga2Cl7) overcome limitations in classical synthesis methods that proved unsuitable for phosphorus cations. These salts contain the homopolyatomic cation [P9]+ via (I) oxidation of P4 with NO[F{Al(ORF)3}2], (II) the arene-stabilized Co(I) sandwich complex [Co(arene)2][Al(ORF)4] [arene = ortho-difluorobenzene (o-DFB) and fluorobenzene (FB)], or (III) the reduction of [P5Cl2][Ga2Cl7] with Ga[Ga2Cl7] as Ga(I) source in the presence of P4. Quantum chemical CCSD(T) calculations suggest that [P9]+ formation from [Co(arene)2]+ occurs via the nido-type cluster [(o-DFB)CoP4]+, which resembles the isoelectronic, elusive [P5]+. Apparently, the nido-cation [P5]+ forms intermediately in all reactions, particularly during the Ga(I)-induced reduction of [P5Cl2]+ and the subsequent pick up of P4 to yield the final salt [P9][Ga2Cl7]. The solid-state structure of [P9][Ga2Cl7] reveals the anticipated D2d-symmetric Zintl-type cage for the [P9]+ cation. Our approaches show great potential to bring other [Pn]+ cations from the gas to the condensed phase.

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Figures

Fig. 1.
Fig. 1.. Retrosynthesis concepts toward [P9]+ and preparation of salts [P9]X.
(I) X = [F{Al(ORF)3}2]: P4 (2.5 equivalents), NO[F{Al(ORF)3}2] (1.0 equivalents), RT, exclusion of light, 4FB, (68%). (II) X = [Al(ORF)4]: P4 (3.0 equivalents), [Co(o-DFB)2][Al(ORF)4] (1.0 equivalents), RT, FB, (21%). (III) X = [Ga2Cl7]: P4 (10.0 equivalents), [P5Cl2][Ga2Cl7] (1.0 equivalents), Ga[Ga2Cl7] (1.0 equivalents), RT, FB/CS2, (77%). RF, C(CF3)3.
Fig. 2.
Fig. 2.. Characterization of [P9][Ga2Cl7].
(I) 31P MAS NMR and liquid 31P{1H} NMR spectra of the separated crystals in CD2Cl2; asterisks (*) denote spinning sidebands in the MAS NMR. (II) Raman spectrum and assignment. (III) Molecular structure of cation [P9]+ including anion [Ga2Cl7]−.
Fig. 3.
Fig. 3.. Calculated mechanism toward the formation of [P9]+ starting from [P5Cl2][GaIIICl4], P4, and in situ formed [GaI(FB)2][(GaIII)2Cl7].
Geometry optimization was performed at the (RI-)B3LYP(D3BJ)/def2-TZVPP level of theory, and single-point energies were calculated at the DLPNO-CCSD(T)/QZVPP level with ORCA. Solvation corrections were calculated in FB:CS2 (v/v, 5:1), with the CPCM model (εr = 5.2) at the B3LYP(D3BJ)/def2-TZVPP level of theory.
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References

    1. Gillespie R. J., Passmore J., Polycations of group VI. Acc. Chem. Res. 4, 413–419 (1971).
    1. Bartlett N., Lohmann D. H., Fluorides of the noble metals. Part II. Dioxygenyl hexafluoroplatinate(V), O2+[PtF6]−. J. Chem. Soc. 1962, 5253–5261 (1962).
    1. Bartlett N., Lohmann D. H., Dioxygenyl hexafluoroplatinate(V) O2+[PtF6]−. Proc. Chem. Soc., 115–116 (1962).
    1. Ballone P., Jones R. O., Density functional study of phosphorus and arsenic clusters using local and nonlocal energy functionals. J. Chem. Phys. 100, 4941–4946 (1994).
    1. Martin T. P., Compound clusters. Z. Phys. D. 3, 211–217 (1986).