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DOI: 10.1039/A801093E (Paper) Reference Section for: Chem. Commun., 1998, 1081-1082

[{(dppe)Pt}2B7H11]: An arachno-bimetallanonaborane based on the uncommon n-B9H15 cluster framework

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Ramón Macías, Nigam P. Rath and Lawrence Barton

Abstract

The first bimetallanonaborane, [{(dppe)Pt}2B7B11], based on the uncommon n-B9H15 cluster framework, is prepared and characterized as a final product from the reaction of pentaborane (9) with [PtCl2(dppe)].

References

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  7. Full experimental details available as supplementary material upon request from the authors.
  8. (a) NMR data for [(dppe)PtB3H7], (CDCl3, 294–297 K){ordered as: relative intensity δ(11B)(rel. to BF3·Oet2)[δ(1H)]} 1BH 19.8 [3.28]; 2BH2 4.1 [4.20 (2 H); 2.80 (2 H), 1J(195Pt–1H)ca. 63 Hz]; additional cage δ(1H)–2.64 (2µ-H). δ(H)(dppe) 7.69–7.41 (4C6H5), 2.37 (m 2CH2). δ(31P)(CDCl3, 294–297 K, rel. 85% H3PO4) 55.4, 1J(195Pt–31P) 2541 Hz. Data compare very well with those for [(PPh3)2PtB3H7], in J. Bould, J. D. Kennedy and W. S. McDonald, Inorg. Chim. Acta., 1992, 196, 201 Search PubMed; (b) [(dppe)(BH3)2], (CDCl3, 294–297 K): 2BH3–39.9 [1.02; AA′ XX′ spin system, N= 15.77 Hz]; 1J(11B–1H) coupling constants not resolved due to the broadness of the boron resonances. δ(31P)(CDCl3, 294–297 K, rel. 85% H3PO4) 18.9 (br).
  9. Selected NMR data for [{(dppe)Pt}2B7H11], (CDCl3, 294–297 K){ordered as: relative intensity δ(11B)(rel. to BF3·OEt2)[δ(1H)]} 1BH 39.2 [3.98], 4B 15.2 [4.98, 4.80, 4.22, 4.12, 2.82 (endo)[2J(195Pt–1H)ca. 67 Hz], 1BH2–4.7 [2.07 (m, J 5.1 Hz; endo/exo)], 1BH –24.6 [1.34]; additional cage δ(1H)–0.23 (bridging), –1.74 (bridging). δ(1H)(dppe) 8.0–6.9 (4C6H5), 2.31 (m, CH2), 1.87 (m, CH2). The 11B spectra were too broad to observe coupling constants. δ(31P)(CDCl3, 228 K, rel. 85% H3PO4) 55.7 [d, P(3 or 4)], 53.1 [d of d, P(2)], 49.4 [s, P(1) and 45.3 d, P(4 or 3)]; 4J[31P(4 or 3)–31P(2)] 12.2 Hz, 1J[195Pt–31P(4 or 3)] 2658 Hz; 4J[31P(4 or 3)–31P(2)]+4J[31P(3 or 4)–31P(2)] 19.0 Hz, 1J[195Pt–31P(2)] 2534 Hz; 1J[195Pt–31P(1)] 2419 Hz; 4J[31P(2)–31P(3 or 4)] 22.6 Hz, 1J[195Pt–31P(3 or 4)] 2609 Hz. Low resolution MS (VG, ZAB-E: FAB in CH2Cl2, 3-nitrobenzyl alcohol matrix) overlapped with the M – H2 ion, gave an apparent cutoff at m/z 1280 (calc. for12C521H5911B731P4198Pt2 1280). Observed and calculated mass spectral parent profiles showing isotopic distribution for the [M–BH3] ion, with m/z(max.)= 1259, compare very well.
  10. Crystal data for C58H74B7O1.5P4Pt2, [(dppe)2Pt2B7H11], M= 1384.90 (includes 1.5 molecules of Et2O), triclinic, space group P[1 with combining macron], a= 12.8918(1), b= 13.7153(1), c= 17.8679(2)Å, α= 97.118(1), β= 94.409(2), γ= 108.92(1)°, U= 2942.44(5)Å3, Dc= 1.563 Mg m–3, Z= 2, F(000)= 1370, µ(Mo-Kα)= 4.897 mm–1, T= 223(2) K. Atotal of 11 509 (Rint= 0.07) independent reflections, 2θmax= 52.0° on a Siemens CCD single-crystal X-ray diffractometer using ω scans. The final wR(F2) for all unique reflections was 0.119 with a conventional R(F) of 0.049 [for 8526 reflections with I > 2σ(I)] for 677 parameters. CCDC 182/824.
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