Synthesis of Cationic R₂P₅⁺ Cages and Subsequent Chalcogenation Reactions

Abstract

Cationic R2P5(+) cage compounds (1(+)) have been synthesized by the stoichiometric reaction of R2PCl, GaCl3 and P4. The reaction conditions depend on the substituent R. Alkyl-substituted derivatives (1 a-1 d[GaCl4]) are best synthesized under solvent-free conditions, whereas aryl-substituted derivatives (1 e-1 h[GaCl4]) are formed in C6H5F. All compounds have been prepared on a multi-gram scale in good to excellent yields and have been fully characterized with an emphasis on (31P NMR spectroscopy in solution and single-crystal structure determination. Subsequent chalcogenation reactions of cations R2P5(+) (1 a(+), 1 e(+)) and trication Ph6P7(3+) (3(3+)) with elemental sulfur (α-S8) or grey selenium (Se(grey)) yielded a series of unique polyphosphorus-chalcogen cations (4 a(+), 4 e(+), 5 a(+), 6(2+) and 7(2+)), possessing nortricyclane-type molecular structures. An in-depth study of the (31)P{(1)H} and (77)Se NMR spectroscopic parameters is presented, and correlations between the substitution pattern and the observed structural features have been investigated in detail.

Functionalization of Pentaphosphorus Cations by Complexation

“…As the cyclopentadienyl iron halide complex [Cp Ar Fe(μ‐Br)] 2 had been successfully used for white phosphorus activation, it was selected as the starting point for our investigation. To our surprise, the reaction of this Fe complex with [P 5 R 2 ][GaCl 4 ] salts (R= i Pr and Mes; Mes=2,4,6‐Me 3 C 6 H 2 ; Scheme a) afforded remarkable, unsymmetrically substituted bicyclo[1.1.0]pentaphosphanes 1‐R as the major product. The isopropyl‐substituted pentaphosphane 1‐ i Pr is formed in the reaction of [Cp Ar Fe(μ‐Br)] 2 and [P 5 i Pr 2 ][GaCl 4 ] and can be identified by an apparent AMXY 2 spin system with multiplets at δ =−38.9, −87.0, −251.9, and −325.0 ppm in the 31 P{ 1 H} NMR spectrum.…”

“…The 1 J PP coupling constants obtained by iterative fitting (−324.7 Hz to −400.2 Hz) are typical for P−P single bonds, while the 2 J PP coupling constants ( 2 J AE =−3.9 Hz, 2 J AM =−7.7 Hz, 2 J MY =80.3 Hz, 2 J EX =50.0 Hz, 2 J XY =−6.4 Hz) span a large range. Small 2 J PP couplings such as 2 J AE and 2 J AM are typical for tetracoordinate P atoms …”

“…[*] Dr.A.K.Adhikari, C. G. P. Ziegler [P 5 R 2 ] + cations (Scheme 1) seemed to be ideal candidates for such an investigation as they are readily accessible with aw ide range of substituents by insertion of carbene-analogous phosphenium cations [PR 2 ] + into P À Pb onds of white phosphorus. [21,22] Although their reactivity with elemental sulfur,s elenium, and N-heterocyclic carbenes has been studied, [23,24] their coordination behavior is completely unknown. Herein, we describe reactions of cyclopentadienyl iron, cobalt, and nickel complexes with such cations,w hich result in the formation of neutral bicyclo-[1.1.0]pentaphosphanes 1-R (R = iPr and Mes) and cationic P 5 R 2 complexes [(Cp Ar Co)(h 4 -P 5 R 2 )] + ([2-R] + ;C p Ar = C 5 (C 6 H 4 -4-Et) 5 ,R = iPr and Cy) and [(Cp Ar Ni) 2 (h 3:3 -P 5 R 2 )] ([3-R] + ).…”

Cationic Chains of Phosphanyl‐ and Arsanylboranes

“…[7] Apart from linear chains, other structural motifs were found. [10] Boron compounds otherwise tend to form higher aggregated clusters rather than linear chains. [10] Boron compounds otherwise tend to form higher aggregated clusters rather than linear chains.…”

Anorganische Chemie 2013

“…Die R2P+‐Einheit liegt zwischenzeitlich als Phosphanylphosphoniumion [R2ClPPR2]+ vor, und schiebt im Zug der Reaktion in eine Seite des P4‐Tetraeders ein; dabei wird R2PCl freigesetzt. Aufgrund der gespannten Natur der [R2P5]+‐Spezies reagieren diese bereitwillig mit Chalkogenen unter Bildung von kationischen [R2P5Ch2]+‐Käfigen 97. Die Umsetzung des verwandten Käfigs [ClDippP5]+ mit dem Carben :IMe2Dipp führt zur Fragmentierung des Kations in P2‐ und P3‐Fragmente unter Bildung der neutralen Spezies [ClDippP‐P:IMe2 Dipp] sowie dem Kation [IMe2 Dipp:P‐P‐P:IMe2Dipp]+.…”