Synthesis and Crystal Structure of Phosphorus(V) Nitride α‐P₃N₅

Abstract

12] Results with 20 molY0 of other catalysts at -20 "C: LaNa,tris(binaphthoxide) (LSB)[4a] inTHF(t6%, 13% ee), LaK,tris(binaphthoxide) (LPB)[4c]inTHF (49%, 0% er), AILibis(binaphth0xide) (ALB) [4b] in THF (quite low yield), LLB in toluene (25'Yo. 31 % ee), LLB in CH,CI, (33%, 15% ee), LnLB where Ln = Pr. Sm. Gd, Dy. or Yb in THF (low ee values), LLB* in THF (B* = 6,6'-bis((triethylsilyl)ethynyl(binaphthoxide)) (low ee), 6,6'-dibromo(binaphthoxide) (low ee), 6,6'-dimethoxy(binaphthoxide) (low ee)).[I31 The moderate yield is mainly due to the low reactivity of LLB. A small amount of dehydrated product was detected.[14] A trace amount of 4-hydroxy-3.5,5-trimethyl-6-phenyl-2-hexanone was detected.[15] The reaction of benzaldehyde and 8 equiv of 2a in the presence of 20 mol% of (R)-LLB at 198 h gave the desired aldol adduct with only 3% ee ( S ) in 41 % yield. but the reaction under the same conditions except in the presence of YbLi,tris((R)-binaphthoxide) ((R)-YbLB) instead of (R)-LLB gave the aldol product with 36% m (R) in 47% yield.[16] Review: A. F. Cockerill, L. 0 Davies, R. C. Harden, D. M. Rackham. Chem. Rer. 1973. 73. 553 -588, and references therein. [I 71 It is unlikely. even if the aldehyde coordinates to a Li atom of the Pr complex, that proximity to the Pr or the positioning of the formyl C-H in the shielding region of the naphthyl ring could produce a shift of such magnitude, as no such chemical shift is observed in the presence of LLB.Polymeric nonmetal nitrides are of considerable interest for the development of inorganic materials.['I Among the binary members of this class of compounds dimorphic boron nitride (BN) and silicon nitride (Si,N,) have gained significance. Their potential applications include use as substrate for semiconductors (Si,N,) and as high-temperature materials (for example crucibles made of hexagonal BN or valve tappets and turbochargers made of Si,N,).Chemically and structurally related phosphorus(v) nitride P,N, was assumed to be built up by a polymer network structure of connected TN, tetrahedra (T = B, Si, P) similar to that of cubic BN and Si,N,. The crystal structures of BN and Si,N, have already been investigated in detail."] However, no structural model of P,N, was available in spite of many intensive efforts,12. because neither monocrystalline nor pure polycrystalline samples of P3N5 had been obtained. In our recently developed synthesis of phosphorus(v) nitride [Eq. (l)] we always obtained mixtures of the polymorphs a-and B-P3N5, which were characterized by electron diffraction (ED), high-resolution transmission electron microscopy (HRTEM), EXAFS (extended X-ray absorption tine structure) spectroscopy, and 31P and ' ,N solid-state NMR spectr~scopy.~~] (PNCI,), + 2NH,CI --P3NS + 8HC1(1 1

Li+ Ion Conductors with Adamantane‐Type Nitridophosphate Anions β‐Li10P4N10 and Li13P4N10X3 with X=Cl, Br

“…[22,24] The 31 PNMR spectra of Li 13 P 4 N 10 X 3 (X = Cl, Br) feature one signal at d = 4.71 (X = Cl) and d = 4.74 ppm (X = Br), in accordance with one crystallographically independent Ps ite. The 6 Li NMR spectra feature three different signals, which also correspondt ot he three different Li sites and coordination spheres.T he 7 Li NMR spectrad on ot show this arrangement (X = Cl: d = À1.11and 0.18 ppm; X = Br: d = À1.32 ppm).…”

“…[37][38][39][40][41][42] Upon further heating these samples to about 600 8C, an irreversible phase transition to a-Li 10 P 4 N 10 was observed. Heating of b-Li 10 P 4 N 10 at this temperature also led to a-Li 10 P 4 N 10 .A ccordingt oE quations (10) and (11), a-Li 10 P 4 N 10 was obtained together with an unknown side phase (black body color), which could not be removed by washing with dry ethanol (Supporting Information, FigureS16). Thus, the phaset ransition from bLi 10 P 4 N 10 to a-Li 10 P 4 N 10 is reversible below 600 8Ca nd irreversible above this temperature.…”

“…Solid-state MAS (magic-angle spinning) NMR methods: 6 Li, 7 Li, and 31 Ps olid-state MAS NMR spectra of both polymorphs were recorded on aD SX Advance spectrometer (Bruker) with am agnetic field of 11.7 T. The sample was placed in aZ rO 2 rotor with an outer diameter of 4, 2.5, or 1.3 mm, which was mounted in ac ommercial MAS probe (Bruker) under inert conditions. The rotor was spun at ar otation frequency of 10, 20, or 50 kHz.…”

“…For successful reactions, excesses of LiCl/LiBra nd Li 3 Nw ere used for Equations (5) and (7). Thes ide phases Li 3 Pa nd LiCl/ LiBr werer emoved by washing with dry ethanol.…”

“…[1][2][3][4][5][6] Nitridophosphates are of particular interest due to their structural variability.T he ability to form different linking patterns of corner-and/oredge-sharing PN 4 tetrahedra as primary building units leads to av ariety of complex structures and allows materials to be optimized for many purposes. [7][8][9][10][11] Synthetic approaches to nitridophosphates are somewhat challenging due to the limited thermal stability of the starting materials (e.g.,P 3 N 5 decomposes above 850 8C). [12] To prevent thermald issociation at higher temperatures, the multi-anvil technique has emerged as apowerful tool, and has led to nitridophosphates with unprecedented topologies and properties.…”