Get access

Naphthalene-1,8-diyl Bis(Halogenophosphanes): Novel Syntheses and Structures of Useful Synthetic Building Blocks



A series of new bay region disphospha-functionalised naphthalenes is reported. The reduction of ylidic phosphonium phosphoride NapP2Cl6 (1) (Nap=naphthalene-1,8-diyl) with MeOPCl2 gives the important synthon Nap(PCl2)2 (2) in nearly quantitative yield. Reaction of 1 with magnesium metal affords (NapP2)n (3), which reacts with Br2 and I2, yielding Nap(PBr2)2 (4) and Nap(PI)2 (5), respectively. X-ray structure determinations reveal a twisted geometry of the naphthalene ring in sterically strained 2 and 4, whilst the presence of a P[BOND]P bond in 5 results in the release of the steric strain and generation of the planar NapP2 moiety. Although the tetrahedral P environments are severely distorted the σ3P[BOND]σ3P bonding in 5 represents a new type of P[BOND]P bonding environment in 1,8-diphosphanaphthalenes. Compounds 1, 4 and 5 each represent the highest coordination, achievable by direct halogenation. The new compounds 25 were fully characterised by NMR, IR, and Raman spectroscopy, mass spectrometry, and elemental analysis.

Get access to the full text of this article