Aspects of the coordination chemistry of rac-trans-1,2-diphosphinocyclohexane and the preparation of reinforced 9aneP3 and 9anePN2 macrocycles

Abstract

Racemic trans-1,2-diphosphinocyclohexane (t-chxnP₂) has been synthesised and its coordination chemistry to Cu(I), Ag(I), Mn(I) and Fe(II) investigated. Compounds of empirical formula [Cu(t-chxnP₂)₂]BF₄ and [Ag(t-chxnP₂)₂]BF₄ have been prepared as isomeric mixtures and the solid-state structure of both complexes determined by single-crystal techniques. The Cu(I) complex is a monomeric species which crystallises with one ligand bearing the R,R configuration and the other being the S,S isomer whereas the Ag(I) complex crystallises as a polymer containing both chelating and bridging t-chxnP₂ ligands with 3- and 4-coordinate Ag(I) centres and argentophilic bonds. The bidentate diprimary phosphine has been coordinated to Mn(I) and Fe(II) templates and used as a P₂ unit for the formation of chiral (albeit racemic) 1,4,7-triphosphamacrocycles (9aneP₃). In addition 1R,2R- and 1R,2S-diaminocyclohexane (chxn) have been coordinated to Mn(I) and Fe(II) templates and similarly employed for the formation of new 1,4-diamino-7-phosphamacrocycle (9anePN₂) complexes.