TY - JOUR AU - Lawson Daku, Latévi Max AU - Castaings, Anna AU - Marchon, Jean-Claude TI - Density-Functional Theory Study of the Stereochemistry of Chloroiron(III) and Chloromanganese(III) Complexes of a Bridled Chiroporphyrin PY - 2009 JF - Inorganic Chemistry JA - Inorg. Chem. SN - 0020-1669 VL - 48 IS - 12 SP - 5164 EP - 5176 L1 - http://pubs.acs.org/doi/pdf/10.1021/ic900031c L2 - http://pubs.acs.org/doi/full/10.1021/ic900031c L3 - http://pubs.acs.org/doi/abs/10.1021/ic900031c L4 - http://www.unige.ch/sciences/chifi/publis/pics/double/ref00994.png M3 - 10.1021/ic900031c UR - http://dx.doi.org/10.1021/ic900031c N2 - Transition metal complexes of chiroporphyrins, in which two adjacent meso substituents are linked by a strap of eightmethylene groups, [M(BCP8)], can exist as either an αααα or αβαβ atropisomer depending on the nature of thecoordinated metal cation. This remarkable conformational versatility was investigated by density-functional theorycalculations for the d5 chloroiron(III) complex in the low-spin and high-spin states and for the d4 high-spinchloromanganese(III) complex. The lowest-lying electronic state of all of the conformers of the chloroiron(III) bridledchiroporphyrin is found to be the high-spin state. For the chloroiron(III) complex in the low-spin or the high-spin stateand for the high-spin chloromanganese(III) complex, the most stable form is predicted to be the αααα conformer inwhich the chloride axial ligand is located within the cavity provided by the bridles. The predicted stereochemistries arecompared with those similarly obtained (i) for the chloroiron(III) and chloromanganese(III) complexes of thetetramethylchiroporphyrin, which is devoid of straps, and (ii) for the d10 zinc(II) and low-spin d8 nickel(II) BCP8complexes, on the basis of the effects tied to the occupancy of the stereochemically active dx2-y2-type antibondingorbital level, to the restraints imposed by the straps, and to the presence of the axial chloride ligand. ID - 994 ER -