metal-organic compounds
The N atom in each complex is located on the opposite side of
the plane defined by the complexed benzene ring with respect
to the Fe atom attached to this ring. These values and the long
Fe1—C2 distances prompted examination of additional
selected angles and planes to discern possible deformations of
a complexed aromatic ring. Examination of the Fe—Csubst—X
angles (where X is the atom of a substituent bonded to the
complexed benzene ring and Csubst is the atom in the complex
ring to which substituent X is attached) revealed that for the
two different substituents present in the studied complexes,
the angles have quite different values. It was expected that a
longer Fe—N (bonded to aromatic C) distance may be
reflected in a smaller Fe1—C2—N1 angle. For (II), the values
are 135.4 (2)ꢀ for Fe1—C1—C7 and 133.8 (2)ꢀ for Fe1—C2—
N1, which is in agreement with the expected order. For (I),
however, these values are 133.1 (5)ꢀ for Fe1—C1—Cl1 and
135.2 (6)ꢀ for Fe1—C2—N1, thus the expectations were not
substantiated in the case of this complex. As the N atoms are
found above the complexed benzene-ring plane, on the side
opposite to Fe, in both complexes, the dihedral angles between
the planes formed by each substituted C atom and its direct
neighbors in a ring versus planes of other ring C atoms were
also examined. For (I), a plane centered at C1 and defined by
atoms C2/C1/C6 intersects the C2/C3/C4/C5/C6 plane at a
dihedral angle of 6.4 (5)ꢀ and intersects the plane formed by
the unsubstituted ring C atoms C3/C4/C5/C6 at a dihedral
angle of 5.1 (6)ꢀ, the angles being essentially the same. The C1/
C2/C3 plane, centered upon C2, which is an N-bound C atom,
intersects the C3/C4/C5/C6/C1 plane at an angle of 9.7 (8)ꢀ
and intersects the plane defined by unsubstituted ring C atoms
C3/C4/C5/C6 at an angle of 10.2 (9)ꢀ. For (II), the values
between planes are as follows: 2.8 (2)ꢀ between C2/C1/C6 and
C2/C3/C4/C5/C6, 2.5 (2)ꢀ between C2/C1/C6 and C3/C4/C5/
C6, 5.6 (2)ꢀ between C1/C2/C3 and C3/C4/C5/C6/C1, and
6.2 (2)ꢀ between C1/C2/C3 and C3/C4/C5/C6. These angles
seem to suggest that a longer Fe1—C2 distance and a larger
dihedral angle between the C1/C2/C3 planes and a plane
defined by the ring C atoms excluding atom C2 observed for
(I) may be a result of the electronic influence of the chlorine
neighbor and, for (II), steric crowding exerted by the second,
directly linked, benzene ring. Similar values, viz. 6.0 (5) and
7.1 (6)ꢀ, have been reported for phenylhydrazine complexes
studied by Manzur et al. (2000). The pyrrolidine ring of (I) in
the solid state adopts a twisted conformation with C12 and
C13 located out of the plane defined by the remaining three
atoms. In comparison with C12, atom C13 is further away from
the o-chloro substituent and from the Fe atom. A similar
situation is observed for (II), with C22 and C23 located out of
the C21/N1/C24 plane. In comparison with C22, atom C23 is
further away from the uncomplexed ring of the biphenyl
skeleton and from the Fe atom. Bond lengths in the pyrroli-
dine rings of both complexes are similar and in line with
literature values (Allen et al., 1987). The N atoms in both
complexes show similar bond lengths to ring atom C2
Figure 2
View of complex (II), showing the labeling of the non-H atoms and
displacement ellipsoids at the 50% probability level. H atoms have been
omitted for clarity.
value of 5.34 (13)ꢀ given previously by Jenkins et al. (2009).
This is also similar to the value of 5.4ꢀ reported for the
hexaethylbenzene–CpFe complex (Dubois et al., 1989),
although lower than the value of 7ꢀ reported for the 1,10-
trimethylenebenzene–CpFe cation (Nesmeyanov et al., 1977).
No standard uncertainties were provided by these authors in
their reports.
For (I), the average Fe—C(benzene) distance is
˚
2.098 (10) A, while the distances to the substituted atoms C1
˚
and C2 are 2.085 (10) and 2.237 (8) A, respectively. For (II),
˚
the corresponding values are 2.107 (4) A for the average, and
˚
2.139 (3) and 2.218 (3) A for the Fe1—C1 and Fe1—C2
distances, respectively. The distances from atom Fe1 to atom
C2, which carries a pyrrolidin-1-yl substituent in both
complexes, are among the largest reported for similar
˚
complexes, along with the value of 2.252 (2) A reported
previously for one of the substituted ring C atoms of a
dipyrrolidinyl complex (Jenkins et al., 2009). Other reports
with similar Fe—Csubst distances include the structure of an
Fe(Me5Cp)phenoxide–water complex [Csubst bonded to O;
2.269 (9) A; Moulines et al., 1995; Djakovitch et al., 1996], a p-
methylphenylhydrazine FeCp fragment in a tungsten complex
˚
[2.24 (1) A; Ishii et al., 1994] and an N -isopropylidene
˚
hydrazone of p-methylphenylhydrazine [2.201 (5) A; Manzur
et al., 2000]. Many of the Cp and pentamethyl-Cp complexes
examined in a series of studies by Carrillo and coworkers (see,
for example, Fuentealba et al., 2007; Manzur et al., 2000, 2007,
2009) have an Fe—Csubst (bonded to N) distance shorter than
that found in our work.
˚
0
˚
˚
[1.344 (11) A for (I) and 1.356 (4) A for (II)] and to the
methylene C atoms of the pyrrolidine rings [range 1.476 (4)–
The distance of the pyrrolidine N atom from the C1–C6 ring
˚
plane is 0.099 (13) and 0.034 (4) A, respectively, in (I) and (II).
˚
1.484 (12) A]. The C2—N1 bond length in each complex,
ꢁ
m392 Hendsbee et al. [Fe(C5H5)(C10H12ClN)]PF6 and [Fe(C5H5)(C16H17NO)]PF6
Acta Cryst. (2011). C67, m391–m394
Hendsbee, Arthur D.
