A new synthesis of acetato porphyrinato indium(III) from indium(III) oxide and X-ray crystal structures of In(tpyp)(OAc) and In(tmpp)(OAc)

Abstract

The indium porphyrin complexes [In(tpp)(OAc), In(tpyp)(OAc), In(tmpp)(OAc)] were prepared in good yields by refluxing the respective porphyrin (tpp, tpyp, tmpp) with In 2O 3 in acetic acid containing sodium acetate. The structures of In(tpyp)(OAc) and In(tmpp)(OAc) were determined by a single-crystal X-ray structure analysis. The indium atom is displaced 0.731 Å from the mean porphyrin plane (C 20N 4). The geometry around the indium centre of the In(tpyp)(OAc) molecule has In(1)-O(l) = 2.185(6), In(1)-O(2) = 2.412(6) and average In(l)-N p= 2.177(5) Å. This indicates that an asymmetric-bidentate acetato group is coordinated to the indium(III) atom in In(tpyp)(OAc). In the structure of In(tmpp)(OAc) the indium(1)-oxygen distances are In(l)-O(6) = 2.31(1) and In(1)-O(5) = 2.31(1) Å, whereas the indium(l) atom lies 0.697 and 0.758 Å from the four porphyrin nitrogens (4 N p) and the 24-atom porphyrin plane (C 20N 4), respectively. This indicates that In(1)(tmpp)(OAc) contains a symmetric bidentate binding of the acetate ligand.