1ST SPHERE COORDINATION CHEMISTRY OF MODIFIED CYCLODEXTRINS .2. THE BIS(CIS-PTCL2) COMPLEX OF -6A,6B,6D,6E-TETRA-O-NICOTINOYL-ALPHA-CYCLODEXTRIN

The modified alpha-cyclodextrin system having four nicotinate groups w ith an ABDE symmetry presents two pairs of preferentially cis-coordina ting pyridyl ligands. The molecule in dmso-d6 has been shown by H-1 NM R to complex two cis-PtCl2 moieties. The observed non-equivalence of t he pyridyl ligands may be explained by a molecular graphics study whic h places the metal above and outside the rim of the alpha-cyclodextrin with the two coordinating ligands in sites parallel and antiparallel to the molcular axis.