SYNTHESIS OF NEW TETRADENTATE OLIGOPHOSPHINE LIGANDS

The synthesis of a series of symmetrical and unsymmetrical tripodal te tradentate alkylphosphine ligands is described. Me2PCH2CH2P(CH2CH2CH2P Me2)2 was synthesized by the photochemical reaction of (2-(dimethylpho sphino)ethyl) phosphine with excess allyldimethylphosphine, and Me2PCH 2CH2CH2P(CH2CH2PMe2)2 was synthesized by the photochemical reaction of (3-(dimethylphosphino)propyl)phosphine with excess dimethylvinylphosp hine. The known ligand P(CH2CH2PMe2)3 was synthesized in a one-step re action by the photochemical addition of dimethylphosphine (3 equiv) to trivinylphosphine. The tetradentate ligands form one-to-one complexes Fe(PP3)Cl2 with iron by displacement of weaker phosphine ligands.