Use of Molecular Scaffolding for the Stabilization of an Intramolecular Dative P^III‐P^V System

Abstract

The reaction of NapP 2 S 4 (1; Nap = naphthalene-1,8-diyl) with chlorine gas gave [Nap(PCl 2 )(PCl 4 )] (2), displaying a rare σ 4 P-σ 6 P bonding interaction. An X-ray structure analysis confirmed the PCl 5 -like, P−P bond containing phosphoniumphosphoride structure of 2 in the crystal, which was also found in solution at low temperature. At ambient and higher temperatures, dynamic behaviour on the NMR time-scale was observed, which was assigned to interchange of the ionic phosphonium-phosphoride form 2 and the molecular bis(phosphorane) Nap(PCl 3 ) 2 form 3, rather than to the ionic phosphonium salt-phosphorane form [Nap(PCl 3 )(PCl 2 )][Cl] 4. Electronic structure calculations were performed at the

1,2‐Diphosphaacenaphthene 1,2‐Dications: Synthetic, Stereochemical and Computational Study of the Stabilising Role of Naphthalene‐1,8‐diyl Backbone

“…The signals of the methyl groups in 7 are part of an A 12 A' 12 XX' spin system (A = H, X, X' = P). They appear as a virtual triplet in the 1 H NMR spectrum due to the considerably larger magnitude of 1 JA C H T U N G T R E N N U N G (P,P) coupling as compared to 3 JA C H T U N G T R E N N U N G (H,P) and 4 JA C H T U N G T R E N N U N G (H,P) couplings. Electrospray mass spectra showed the presence of dication 7 (m/z 180, in positive mode), as well as counteranions I À and I 3 À (in negative mode) when sampled as a solution in dry MeCN.…”

“…[2] We are interested in phosphorus-centred bonding environments and have been studying applications of the naphthalene-1,8-diyl frameworks in the stabilisation of unusual phosphorus containing systems for some time. [3] Highlights of our activity include an intramolecular P III -P V Lewis acidbase system stable to the attack of chlorine gas, [4] and the first room temperature stable phosphine-phosphine complex where the two phosphine moieties act as a donor and acceptor. [5] During our recent investigations we have come across phosphorus 1,2-dicationic species.…”

Crystal structures and molecular modeling of 1,8 chalcogenide‐substituted naphthalenes

“…There are a number of species available including Nap(PCl 2 ) 2 [6], Nap[P(OMe) 2 ] 2 [7], and Nap[P(NR 2 ) 2 ] 2 (R = Me, Et) [6,8]. We have used NapP 2 S 4 for the generation of a range of new heterocycles [9,10], and we have recently discovered a relatively simple preparation of NapP 2 Cl 6 [11].…”

How Not to Discover a New Reagent. The Evolution and Chemistry of Woollins' Reagent

“…31 Removal of the chlorine to give Nap(PCl 2 ) 2 was surprisingly difficult until we used (MeO)PCl 2 which eliminates PCl 3 and MeCl to give the desired bis phosphine chloride in quantitative yield. 32 This material represents the ideal synthon for making a wide range of alkyl and aryl substituted naphthalene bis phosphines.…”