Complexes of the (1R)-(+)-camphor azine diphosphines Z,Z-3,3′-Ph2PnC10H15N–NC10H15PxPh2 and Z,Z-3,3′-Ph2PxC10H15N–N C10H15PxPh2 (x = exo, n = endo) with Group 6 metal carbonyls: crystal structures of the ligands and fac-[W(CO)3(E,Z-Ph2PxC10H15 N–NC10H15PxPh2)]

Abstract

Treatment of (1R)-(+)-camphor azine with 2 mole equivalents of butyllithium, followed by chlorodiphenylphosphine, gave the azine diphosphines Z,Z-3,3′-Ph₂PⁿC₁₀H₁₅N–NC₁₀H₁₅P^xPh₂ I and Z,Z-3,3′-Ph₂P^xC₁₀H₁₅ N–NC₁₀H₁₅P^xPh₂ II (x = exo, n = endo); the structures of these were determined by X-ray diffraction. On boiling an ethanol solution of the exo,exo-diphosphine II with sodium ethoxide or a propan-2-ol solution containing hydrazine hydrate and acetic acid the diphosphine isomerised to the corresponding exo,endo-diphosphine I. The corresponding diphosphine dioxides III and IV were prepared by treating I or II with H₂O₂, respectively. Treatment of I with [Mo(CO)₄(nbd)] (nbd = norbornadiene) or with [Mo(CO)₃(cht)] (cht = cyclohepta-1,3,5-triene) gave fac-[Mo(CO)₃(Ph₂PⁿC₁₀H₁₅N–NC₁₀H₁₅P^xPh₂)] 1a. Treatment of I with [W(CO)₄(nbd)] gave the tricarbonyltungsten(>0>) complex fac-[W(CO)₃(Ph₂PⁿC₁₀H₁₅N–NC₁₀H₁₅P^xPh₂)] 1b and the analogous mer complex mer-[W(CO)₃(Ph₂PⁿC₁₀H₁₅N–NC₁₀H₁₅P^xPh₂)] 2. Treatment of II with [W(CO)₆] gave the mer,exo,endo tricarbonyl complex 2, and the fac,endo,endo complex fac-[W(CO)₃(Ph₂PⁿC₁₀H₁₅N–NC₁₀H₁₅PⁿPh₂)] 3. Treatment of II with [M(CO)₄(nbd)] (M = Mo, W or Cr) gave mainly a complex of type fac-[M(CO)₃(Ph₂P^xC₁₀H₁₅N–N C₁₀H₁₅P^xPh₂)] (M = Mo 4a, W 4b or Cr 4c). The crystal structure of the tricarbonyltungsten(>0>) complex 4b was determined by X-ray diffraction and the chirality around tungsten shown to be C, i.e. clockwise. Treatment of 4b with 1 mole equivalent of bromine gave the tricarbonyltungsten(II) bromide salt [WBr(CO)₃(Ph₂P^xC₁₀H₁₅N–N C₁₀H₁₅P^xPh₂)]Br 5. Infrared, proton, phosphorus-31 and some carbon-13 NMR data are given.