REACTIONS OF COORDINATED LIGANDS .18. TEMPLATE SYNTHESES AND PERIPHERY REACTIONS OF MACROCYCLIC MULTIPHOSPHANE LIGANDS WITH FUNCTIONAL-GROUPS

Cyclisation of the tridentate phosphanes PhP([CH2]3PRH)2 (R = H, Me) with the divinyl components R'P(CH = CH2)2 [R' = Ph, NEt2, O(iPr)] within Ni(II) templates affords complexes NiBr2L (3a - f) of functionalised macrocyclic tetraphosphanes (L) in almost quantitative yields. An X-ray structural analysis of the cyano complex [Ni(CN)L]PF6 (5a), obtained by metathetical reactions, reveals a folded 14-membered macrocyclic ligand L. The P atoms occupy axial and equatorial positions within the trigonal-bipyramidal ligand arrangement with an equatorial CN group. By periphery reactions at the P - NEt2 function of the 14-membered ring system P - OH, P - O-, P - Cl, P - OR" derivatives (R" = Me, iPr, CH2CH = CH2) are formed. Addition of methyl acrylate to the P - H functions in 3d and 3f leads to macrocyclic diesters 12a, 12b. By cleavage of the P - N bond in 3a with concentrated aqueous HBr a complex of composition 7a . HBr . 3 H2O is obtained. An X-ray structural analysis of the latter shows a P - OH functionalised macrocyclic tetraphosphane occupying the four basal positions within a square pyramidal coordination geometry at Ni(II).