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. 2021 Aug 30;12(42):14024-14032.
doi: 10.1039/d1sc04230k. eCollection 2021 Nov 3.

Synthesis, structure and bonding nature of heavy dipnictene radical anions

Hanns M Weinert  1 , Christoph Wölper  1 , Julia Haak  1   2 , George E Cutsail 3rd  1   2 , Stephan Schulz  1
Affiliations

Synthesis, structure and bonding nature of heavy dipnictene radical anions

Hanns M Weinert et al. Chem Sci. .

Abstract

Cyclic voltammetry (CV) studies of two L(X)Ga-substituted dipnictenes [L(R2N)GaE]2 (E = Sb, R = Me 1; E = Bi; R = Et 2; L = HC[C(Me)NDipp]2; Dipp = 2,6-i-Pr2C6H3) showed reversible reduction events. Single electron reduction of 1 and 2 with KC8 in DME in the presence of benzo-18-crown-6 (B-18-C-6) gave the corresponding dipnictenyl radical anions (DME)[K(B-18-C-6)][L(R2N)GaE]2 (E = Sb, R = Me 3; E = Bi, R = Et 4). Radical anions 3 and 4 were characterized by EPR, UV-vis and single crystal X-ray diffraction, while quantum chemical calculations gave deeper insight into the nature of the chemical bonding.

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Conflict of interest statement

There are no conflicts to declare.

Figures

Scheme 1
Scheme 1. Structurally characterized heavy dipnictene radical cations and anions (E = As, Sb, Bi).
Fig. 1
Fig. 1. CV curves of saturated solutions of 1 and 2 in THF with [n-Bu4N][PF6] (100 mM) as electrolyte. Experiments were performed at 45 °C due to the low solubility of 1 and 2.
Scheme 2
Scheme 2. Synthesis of dipnictene radical anions 3 and 4 by reduction of dipnictenes 1 and 2; Ar = Dipp.
Fig. 2
Fig. 2. UV-vis spectra of dipnictenes 1 and 2 in benzene and dipnictene radical anions 3 and 4 in THF solution. To illustrate the colour change, pictures of solutions of 10 mg of 1 and 2 before and after addition of one equivalent of KC8 in NMR tubes are depicted.
Fig. 3
Fig. 3. Molecular structure of 3 in the crystal. H-atoms and solvent molecules are omitted for clarity. Displacement ellipsoids are drawn at the 50% probability level.
Fig. 4
Fig. 4. Molecular structure of 4 in the crystal. H-atoms and minor part of the disorder are omitted for clarity. Displacement ellipsoids are drawn at the 50% probability level.
Fig. 5
Fig. 5. Continuous-wave EPR spectra of 3 (a) as solution in THF collected at X-band frequency (∼9.43 GHz) and (b) as frozen solution (77 K) collected at X-band frequency (∼9.45 GHz) in black with simulated spectrum in red. The asterisk indicates a small organic radical impurity. The frozen solution EPR (b) shows a broad signal with broad hyperfine features, due to the coupling of the unpaired electron with two Sb atoms, each of which possess NMR-active nucleotides (121Sb 57.21%, I = 5/2; 123Sb 42.79%, I = 7/2). EPR simulation parameters: g = [2.401, 2.051, 2.000], 2 × A(121Sb) = [120, 200, 560] MHz, lw (linewidth, peak-to-peak) = 13 mT; spectrometer conditions are described in the Experimental section.
Fig. 6
Fig. 6. (left) LUMO of [L(Me2N)GaSb]21 (isovalue 0.05). (right) Spin density of (DME)[K(B-18-C-6)][L(Me2N)GaSb]23.
Fig. 7
Fig. 7. (left) LUMO of [L(Et2N)GaBi]22 (isovalue 0.05). (right) Spin density of (DME)[K(B-18-C-6)][L(Et2N)GaBi]24.
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References

    1. Fischer R. C. Power P. P. Chem. Rev. 2010;110:3877–3923. doi: 10.1021/cr100133q. - DOI - PubMed
    2. Yadav S. Saha S. Sen S. S. ChemCatChem. 2016;8:486–501. doi: 10.1002/cctc.201501015. - DOI
    3. Schulz S. Chem.–Eur. J. 2010;16:6416–6428. doi: 10.1002/chem.201000580. - DOI - PubMed
    1. Yoshifuji M. Shima I. Inamoto N. Hirotsu K. Higuchi T. J. Am. Chem. Soc. 1981;103:4587–4589. doi: 10.1021/ja00405a054. - DOI
    1. West R. Fink M. J. Michl J. Science. 1981;214:1343–1344. doi: 10.1126/science.214.4527.1343. - DOI - PubMed
    1. Sharma M. K. Blomeyer S. Neumann B. Stammler H. G. Ghadwal R. S. Chem.–Eur. J. 2019;25:8249–8253. doi: 10.1002/chem.201901857. - DOI - PubMed
    2. Majhi P. K. Ikeda H. Sasamori T. Tsurugi H. Mashima K. Tokitoh N. Organometallics. 2017;36:1224–1226. doi: 10.1021/acs.organomet.7b00147. - DOI
    3. Sasamori T. Tokitoh N. Dalton Trans. 2008:1395–1408. doi: 10.1039/B715033D. - DOI - PubMed
    4. Sasamori T. Arai Y. Takeda N. Okazaki R. Furukawa Y. Kimura M. Nagase S. Tokitoh N. Bull. Chem. Soc. Jpn. 2002;75:661–675. doi: 10.1246/bcsj.75.661. - DOI
    5. Twamley B. Sofield C. D. Olmstead M. M. Power P. P. J. Am. Chem. Soc. 1999;121:3357–3367. doi: 10.1021/ja983999n. - DOI
    6. Tokitoh N. Arai Y. Sasamori T. Okazaki R. Nagase S. Uekusa H. Ohashi Y. J. Am. Chem. Soc. 1998;120:433–434. doi: 10.1021/ja973295y. - DOI
    7. Tokitoh N. Arai Y. Okazaki R. Nagase S. Science. 1997;277:78–80. doi: 10.1126/science.277.5322.78. - DOI
    1. Schwamm R. Coles M. P. Chem.–Eur. J. 2019;25:14183–14191. doi: 10.1002/chem.201903175. - DOI - PubMed