metal-organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
The coordination sphere of the Rh metal in (I) can be
described as pseudo-tetrahedral. The two Cp (cyclopenta-
dienyl) rings of the dppf ligand are not perfectly parallel, but
are twisted from each other with a dihedral angle of 3.4 (1)ꢀ.
The P1ÐC11Á Á ÁC16ÐP2 pseudo-torsion angle is 3.0 (4)ꢀ,
indicating that the two Cp rings adopt an eclipsed conforma-
tion. For comparison, the ideal torsion angle for a gauche (or
staggered) conformation is 36ꢀ. Both FeÐCg (Cg is the
ISSN 0108-2701
Azido[1,10-bis(diphenylphosphino)-
ferrocene](pentamethylcyclopenta-
dienyl)rhodium(III) hexafluoro-
phosphate
Ê
centroid of a Cp ring) distances are 1.63 A, and the Cg1ÐFeÐ
Cg2 angle (Cg1 is the centroid of the C11±C15 ring and Cg2 is
the centroid of the C16±C20 ring) is 177.5ꢀ. The Cg*Á Á ÁRh1Ð
P1, Cg*Á Á ÁRh1ÐP2 and Cg*Á Á ÁRh1ÐN1 angles (Cg* is the
centroid of the C1±C5 ring) are 125.5, 127.01 and 126.8ꢀ,
respectively. The P1Á Á ÁFeÁ Á ÁP2 bite angle is 60.68 (5)ꢀ, and the
Won Seok Han and Soon W. Lee*
Ê
P1Á Á ÁP2 distance is 3.526 (3) A. These bonding parameters
Department of Chemistry (BK21), Institute of Basic Science, Sungkyunkwan
University, Natural Science Campus, Suwon 440-746, South Korea
Correspondence e-mail: soonwlee@skku.edu
within a ferrocene moiety are consistent with those found in
the chloro analogue [Cp*RhCl(dppf)]PF6 (Ma & Yamamoto,
1999).
Received 19 February 2004
Accepted 2 March 2004
Online 31 March 2004
In the title compound, azido-2ꢀN-bis[ꢁ-(1ꢂ5:2ꢀP)-diphenyl-
phosphinocyclopentadienyl][2(ꢂ5)-pentamethylcyclopentadi-
enyl]iron(III)rhodium(III) hexa¯uorophosphate, [{Rh(C10-
H15)(N3)}{Fe(ꢁ-C17H14P)2}]PF6 or [FeRh(C10H15)(ꢁ-C17H14-
P)2(N3)]PF6, the coordination sphere of RhIII can be described
as pseudo-tetrahedral, composed of two P atoms from a 1,10-
bis(diphenylphosphino)ferrocene (dppf) ligand, an azido N
atom and the centroid of the ring of a C5Me5 (Cp*) ligand. The
two cyclopentadienyl rings in the dppf moiety adopt an
Ê
eclipsed conformation. The RhÁ Á ÁFe distance is 4.340 (2) A.
Comment
Various redox-active ligands are employed to control the
reactivities of transition-metal complexes (Gan & Hor, 1995).
The dppf ligand [1,10-bis(diphenylphosphino)ferrocene,
Fe(C5H4PPh2)2] and its derivatives are well known redox-
active ligands, and their complexes usually exhibit a ferrocene-
based oxidation process, together with additional redox
Figure 1
The molecular structure of (I), showing 50% probability displacement
ellipsoids. H atoms have been omitted for clarity.
The RhÐN1ÐN2 bond angle of 127.6 (7)ꢀ in (I) agrees well
with the values found in six-coordinate RhIII±azide complexes
(Seok et al., 2002). Atom N3 in the azide ligand has a large
displacement ellipsoid, probably due to its terminal position.
Ê
The RhÐN bond length of 2.111 (7) A indicates an RhÐN
single bond (Davis et al., 1969; Lee & Lee, 1999). The RhÁ Á ÁFe
Ê
distance is 4.340 (2) A, which clearly rules out a direct bonding
interaction between the two metal atoms.
processes at other metal centres. Recently, an interesting Rh±
dppf chloro complex, [Cp*RhCl(dppf)]PF6, was reported
(Cp* is C5Me5), which was prepared by treating a chloro-
bridged RhIII dimer, [Cp*RhCl2]2, with dppf and NaPF6 (Ma
& Yamamoto, 1999). In order to compare structural features
and to examine the redox properties of the Rh±dppf azide
complex with respect to its chloro analogue, we have prepared
the title compound, (I), and present its structure here.
Experimental
A solution of [Cp*RhCl(dppf)]PF6 (100 mg, 0.12 mmol) and AgNO3
(62 mg, 0.36 mmol) in a mixture of dichloromethane and acetone
(1:1, 30 ml) was stirred for 3 h at room temperature, and the solvent
was removed under vacuum. The resulting solid was extracted with
Acta Cryst. (2004). C60, m189±m190
DOI: 10.1107/S0108270104004779
# 2004 International Union of Crystallography m189
Han, Won Seok
