Thallium complexes of tetraphenylporphyrin: Tl(tpp-N-O)(OAc) and cis-acetato-N-p-tert-butylbenzensulfonylimido-meso-tetraphenylporphyrinatothallium(III) Tl(N-p-(NSO2C6H4Bu)-Bu-t-tpp)(OAc)

摘要

The crystal structures of Tl(tpp-N-O)(OAc) (3) and acetato-N-p-tert-butylbenzensulfonylimido-meso-tetraphenylporphyrinatothallium(III) Tl(N-p-(NSO2C6H4Bu)-Bu-t-tpp)(OAc) (5) have been determined. The coordination sphere around Tl3+ is a distorted square-based pyramid in which the apical site is occupied by a bidentate chelating OAc- group for 3 and 5. The plane of three pyrrole nitrogen atoms (i.e., N(1), N(2) and N(3)), strongly bonded to Tl3+ in 3 and 5, is adopted as a reference plane, 3N. The porphyrin ring is severely distorted and the pyrrole ring N(4) bonding to the oxygen and (NSO2C6H4Bu)-Bu-t group makes a dihedral angle of 46.5 degrees and 46.7 degrees with the 3N plane for 3 and 5, respectively. In 3, Tl3+ and O(1) are located on the same side at 1.11 and 1.34 angstrom from its 3N plane, and in 5, Tl3+ and N(5) are also located on the same side at 1.15 and 1.30 angstrom from its 3N plane. The free energy of activation at the coalescence T-c for the intermolecular acetate exchange process of 3 and 5 in CD2Cl2 is found to be Delta G(184)double dagger = 39.3 and Delta G(208)double dagger = 44.1 kJ/mol, respectively, through H-1 NMR variable temperature measurements.