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Abstract Reactions of (O=)PH(OCH2CH3)2and BrMg(CH2)mCH=CH2(4.9–3.2 equiv;m=4 (a), 5 (b), 6 (c)) give the dialkylphosphine oxides (O=)PH[(CH2)mCH=CH2]2(2 a–c; 77–81 % after workup), which are treated with NaH and then α,ω‐dibromides Br(CH2)nBr (0.49–0.32 equiv;n=8 (a′), 10 (b′), 12 (c′), 14 (d′)) to yield the bis(trialkylphosphine oxides) [H2C=CH(CH2)m]2P(=O)(CH2)n(O=)P[(CH2)mCH=CH2]2(3 ab′,3 bc′,3 cd′,3 ca′; 79–84 %). Reactions of3 bc′and3 ca′with Grubbs’ first‐generation catalyst and then H2/PtO2afford the dibridgehead diphosphine dioxides(4 bc′,4 ca′; 14–19 %,n′=2m+2);31P NMR spectra show two stereoisomeric species (ca. 70:30). Crystal structures of two isomers of the latter are obtained,out,out‐4 ca′and a conformer ofin,out‐4 ca′that features crossed chains, such that the (O=)P vectors appearout,out. Whereas4 bc′resists crystallization, a byproduct derived from an alternative metathesis mode, (CH2)12P(=O)(CH2)12(O=)P(CH2)12, as well as3 ab′and3 bc′, are structurally characterized. The efficiencies of other routes to dibridgehead diphosphorus compounds are compared.
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Solid‐State Investigation, Storage, and Separation of Pyrophoric PH 3 and P 2 H 4 with α‐Mg Formate
Abstract Phosphane, PH3—a highly pyrophoric and toxic gas—is frequently contaminated with H2and P2H4, which makes its handling even more dangerous. The inexpensive metal–organic framework (MOF) magnesium formate, α‐[Mg(O2CH)2], can adsorb up to 10 wt % of PH3. The PH3‐loaded MOF, PH3@α‐[Mg(O2CH)2], is a non‐pyrophoric, recoverable material that even allows brief handling in air, thereby minimizing the hazards associated with the handling and transport of phosphane. α‐[Mg(O2CH)2] further plays a critical role in purifying PH3from H2and P2H4: at 25 °C, H2passes through the MOF channels without adsorption, whereas PH3adsorbs readily and only slowly desorbs under a flow of inert gas (complete desorption time≈6 h). Diphosphane, P2H4, is strongly adsorbed and trapped within the MOF for at least 4 months. P2H4@α‐[Mg(O2CH)2] itself is not pyrophoric and is air‐ and light‐stable at room temperature.
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- Award ID(s):
- 2105495
- PAR ID:
- 10397654
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 62
- Issue:
- 13
- ISSN:
- 1433-7851
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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