Reaction of Naphthalenedithiadiphosphetanedisulphide with Ethylene Glycol

Abstract

Reaction of the title compounds (molar ratio 1:30) in refluxing toluene results in cleavage of one of the P-S-P bridges in naphthalenedithiadiphosphetanedisulphide 1 and formation of a new heterocycle 2 which contains a C₃P₂S ring with the phosphorus atoms substituted by OCH₂CH₂OH groups; reaction at 140 °C results in complete desulphuration of napthalenedithiadiphosphetanedisulphide 1 and formation of the new heterocycle l,8-naphthodiphosphonic acid anhydride 3 which contains a C₃P₂O ring. 2 and 3 were characterised by microanalysis, IR, ³¹P NMR and X-ray crystallography: 2, monoclinic, space group C2/c with a = 17.564(4), b = 12.475(2) and C = 16.423(3) Å, β = 102.98(3.), calculated density 1.54 g/cm³, Z = 8, reflections collected 1089, final R valus 0.0501; 3, monoclinic, space group P2_1/c with a = 7.961 (2), b = 8.275(2) and c = 16.192(5) Å, β = 96.93(3), calculated density 1.694 g/cm³, Z = 4, reflections collected 1837, final R value 0.044. No reaction occurred when 3 was heated with H₂O.