STUDIES ON ORGANOLANTHANIDE COMPLEXES .56. FORMATION OF ION-PAIR COMPLEXES [NA.3PHEN]-.PHEN (LN=LA, PR OR ND, PHEN = 1,10-PHENANTHROLINE) AND CRYSTAL-STRUCTURE FOR LN=PR([LN(C5H5)3CL])

In the presence of 1,10-phenanthroline (phen), lanthanide chlorides Ln Cl3 reacted with cyclopentadienylsodium to give the novel complexes [N a.3phen]+[Ln(C5H5)3Cl]-.phen (Ln = La, Pr or Nd). In the praseodymium case, crystal structure analysis showed that the complex was an organo lanthanide ion pair. In the anion the central metal is co-ordinated to three cyclopentadienyl rings and a chlorine atom, forming a distorted tetrahedron. In the cation the sodium atom is co-ordinated to six nit rogen atoms from three phenanthrolines, to form a distorted octahedron .