Complexes of 2,2',2 -Nitrilotriphenol. Part 3. Crystal and Molecular Structures of Three Aluminium Complexes

Article abstract of DOI:10.1002/hlca.19870700305

Crystal and molecular structures of three Al(III) complexes of the tripod ligand 2,2',2 -nitrilotriphenolate (I) are presented.They all show 5-coordinate Al in approximately trigonal bipyramidal geometry, with an external nucleophile X occupying the second axial position.X is OH^- in ^-+ (quin = quinuclidine), N in (py = pyridine), and one of the O-atoms of a second molecule in the dimeric <(Al(I))₂>.Correlated variations in the axial bond lengths of the trigonal bipyramid are observed: <(Al(I))₂> Al-N_int. = 2.094 Angstroem, Al-O_ext. = 1.850 Angstroem; : Al-N_int. = 2.153 Angstroem, Al-N_ext. = 1.992 Angstroem; ^-: Al-N_int. = 2.278 Angstroem, Al-O_ext. = 1.765 Angstroem.They are interpreted in terms of a dissociative reaction path at the Al(III) centre.