In this work, we determine the crystal structure of
bis(acetato)(meso-tetraphenylporphyrinato)germanium(III),
Ge(tpp)(OAc)2. Experimental results indicate
that the germanium atom has an octahedral coordination
geometry.
The geometry around the germanium center of the
Ge(tpp)(OAc)2 molecule has Ge−O(1) =
1.874(5) Å and an
average Ge−N = 1.999 Å. The acetate groups are unidentately
coordinated to the germanium(IV) atom. In the
title compound,
(acetato)(meso-tetraphenylporphyrinato)indium(III),
In(tpp)(OAc), the coordination sphere of the
In3+ ion is an approximately square-based pyramid in
which the apical site is occupied by an asymmetric
(chelating)
bidentate OAc- group. The average In−N bond
distance is 2.173(3) Å, and the In atom is displaced 0.762
Å
from the porphyrin plane. The In−O(1) and In−O(2) distances
are 2.322(4) and 2.215(4) Å, respectively.
To
develop the correlations between the 13C chemical shifts of
the acetato ligand and types of carboxylate coordination,
this work also thoroughly examines the 13C NMR data of the
methyl and carbonyl carbons on 13 acetato
porphyrinato metal complexes M(por)(OAc)
n
with n = 1, 2, por = tpp, tmpp
(5,10,15,20-tetrakis(4-methoxyphenyl)porphyrinate), tpyp
(5,10,15,20-tetrakis(4-pyridyl)porphyrinate),
and M = Ga, In, Tl, Ge, Sn. According to these
results, the 13C methyl and carbonyl chemical shifts of the
acetato group at 24 °C are separately located at 20.5
± 0.2 and 168.2 ± 1.7 ppm for the acetate, which is unidentately
coordinated to the metal (i.e., the unidentate
case) and at 18.0 ± 0.7 and 175.2 ± 1.6 ppm for the chelating
bidentate case.