THE REACTION OF BROMO-PHOSPHORANES AND IODO-PHOSPHORANES WITH UNACTIVATED COARSE GRAIN MANGANESE METAL-POWDER TO YIELD [MNI2(PHOSPHINE)2] AND [(MNX2(PHOSPHINE))N] (X = BR OR I) BY INSERTION OF MN INTO THE P-X BOND - THE CRYSTAL-STRUCTURE OF [MNI2(PPH3)2]

The novel reaction of crude manganese metal powder with dibromo- and diiodo-phosphoranes, R3PX2, has been studied. Reaction of the phosphoranes R3PI2 (R = phenyl or substituted aryl) with manganese allows insertion of the metal into P-X bonds and gives the monomeric tetrahedral complexes [MnI2(PR3)2] and MnI2. However, reaction of R3PX2 (R3 = mixed aryl/alkyl, trialkyl; X = Br or I) with manganese, whilst once again proceeding via insertion into P-X bonds, now leads to the quantitative isolation of the polymeric complexes [{MnX2(PR3)}n], thus illustrating the subtle nature of these reactions. Examples of both types of complex have been crystallographically characterised and represent rare examples of such. There is some evidence that where R3 = Ph2Me an equilibrium exists and both types of complex, [MnI2(PPh2Me)2] and [{MnI2(PPh2Me)}n] can be detected from the same reaction.