Ion Dynamics in Confined Spaces: Sodium Ion Mobility in Icosahedral Container Molecules

Abstract

Cation fluctuations within a molecular anionic ligand framework in crystals have rarely been observed. Veith et al. have studied local Li + ion fluctuations in crystalline lithium siloxyamides that contain either an anionic (N-Si-O-Si- ions has also been reported in the "onion"-type spherical cluster [Li 24 OI 2 (AsR) 10 ] (R = Me 2 (iPrMe 2 C)Si).[2] To date, ion fluctuations in crystallized "molecular boxes" have only been observed for Li + ions. We report herein on two compounds that are composed of a small central PH 2 À anion surrounded by a spherical outer shell consisting of twelve tert-butoxy anions. In this confined polyanionic space, that is, between the PH 2 À anion and the outer shell, 12 or 13 highly mobile sodium cations are embedded. One sodium ion can be reversibly added or removed to interconvert these aggregates.Brandsma et al. reported the synthesis of sodium dihydrogenphosphide, NaPH 2 , which uses the reduction of elemental phosphorus with sodium metal and subsequent addition of tert-butyl alcohol. This form of NaPH 2 is a versatile reagent for the preparation of organophosphorus compounds; [3] however, the nature of this "Brandsma reagent" was not known.We treated a solution of sodium in a 1:1 (by volume) mixture of ammonia and dimethoxyethane (dme) with red or white phosphorus. A yellow-brown suspension is obtained after approximately 1.5 h. After evaporation of the ammonia, the crude mixture, containing [NaPH 2 (solv) x ] and [NaNH 2 -(solv) x ] (solv = NH 3 or dme) suspended in dme, was treated with tert-butyl alcohol at À78 8C (Scheme 1 a). A clear solution is obtained at room temperature, which shows one triplet in the proton-coupled 31 P NMR spectrum at d = À307.7 ppm (J = 145.0 Hz) and a doublet at d = À2.24 ppm in the 1 H NMR spectrum (J = 145.0 Hz) for the PH 2 À ion. From this solution, colorless crystals of the composition Na 13 (dme) 3 (PH 2 )(OtBu) 12 (1) were obtained.When the crude NaPH 2 /NaNH 2 mixture is evaporated to dryness and toluene is used as solvent for the reaction with tBuOH, a new species 2 is detected by 31 P and 1 H NMR spectroscopy in the clear solution. The PH 2 À ion is identified through a triplet at d = À292.3 ppm (J = 142 Hz) in the proton-coupled 31 P NMR spectrum and a doublet at d = Scheme 1. Syntheses of 1 and 2.

PH3 as a Phosphorus Source for Phosphinidene–Carbene Adducts and Phosphinidene–Transition Metal Complexes

“…All reagents were used as received from commercial suppliers unless otherwise stated. The compounds Dipp NHC=PH (1a), [10] [ Mes NHC * -H]-[Cl] [21] and{[Na(OtBu)] x [Na(PH 2 )]} (x ≈ 2.5) [22] were synthesized following literature procedures. Reactions involving PH 3 gas were carried out in a setup and following a procedure described by Pringle and co-workers [23] and PH 3 electronic grade, > 99.9995% was used.…”

Simple One-Pot Syntheses of Water-Soluble Bis(acyl)phosphane Oxide Photoinitiators and Their Application in Surfactant-Free Emulsion Polymerization

“…Bis(mesitoyl)phosphinic acid, (MesCO) 2 P(O)OH = BAPO–OH, is easily accessible from red phosphorus and sodium metal in a one‐pot procedure according to Scheme . In dimethoxyethane (DME) as the solvent and with naphthalene, C 10 H 8 , as redox promoter, sodium and phosphorus are converted to sodium phosphide, Na 3 P. After in situ protonation to give NaPH 2 (NaOtBu) x (step 2), reaction with mesitoylchloride, MesCOCl (step 3) and treatment with acetic acid, HOAc (step 4), the phosphaenol 1 is cleanly obtained. Finally, aqueous H 2 O 2 is added (step 5) to afford the desired product BAPO–OH ( 2 ) at high yield (87% based on P).…”

Phosphorous‐Functionalized Bis(acyl)phosphane Oxides for Surface Modification

“…[20] Without prior isolation, the aggregate compound NaPH 2 (NaOtBu) x 1 was reacted with mesitoyl chloride to give sodium bis(mesitoyl)phosphide 2 in > 80 % yield as bright yellow crystals (Scheme 1). [20] Without prior isolation, the aggregate compound NaPH 2 (NaOtBu) x 1 was reacted with mesitoyl chloride to give sodium bis(mesitoyl)phosphide 2 in > 80 % yield as bright yellow crystals (Scheme 1).…”

“…2) Light in the visible region is absorbed by BAPOs (l = 360-440 nm), but the cleavage products are transparent. [20] Without prior isolation, the aggregate compound NaPH 2 (NaOtBu) x 1 was reacted with mesitoyl chloride to give sodium bis(mesitoyl)phosphide 2 in > 80 % yield as bright yellow crystals (Scheme 1). 3) BAPOs show a relatively high thermal stability (> 100 8C) and can be easily stored.…”

“…NaPH 2 is easily obtained from elemental phosphorus, sodium, and tert-butanol in the form of a sodium tert-butylate aggregate, which is a versatile starting material for functional phosphorus compounds. [20] Without prior isolation, the aggregate compound NaPH 2 (NaOtBu) x 1 was reacted with mesitoyl chloride to give sodium bis(mesitoyl)phosphide 2 in > 80 % yield as bright yellow crystals (Scheme 1). The structure of 2 ( Figure 1) was obtained from a X-ray diffraction study with crystals obtained from a hot toluene/THF mixture (10:1) that contained residual dimethoxyethane (DME).…”