metal-organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
linear. The phosphine ligands are involved in CÐHÁ Á Áꢀ and
ꢀ±ꢀ interactions with contacts from the ring centres to H
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atoms of 3.5 and 3.1 A, respectively. These CÐHÁ Á Áꢀ and ꢀ±ꢀ
ISSN 0108-2701
interactions combine to form chains along the c axis and these
cis-Tetracarbonyl[(4-fluorophenyl)-
diphenylphosphine-P](piperidine-N)-
molybdenum(0)
Liam McElroy, Mark Nieuwenhuyzen* and Graham C.
Saunders
School of Chemistry, The Queens University of Belfast, Belfast BT9 5AG,
Northern Ireland
chains can be thought of as containing CÐHÁ Á Áꢀ/ꢀ±ꢀ dimers
linked via CÐHÁ Á Áꢀ interactions. These CÐHÁ Á Áꢀ/ꢀ±ꢀ
interactions between the phenyl rings of phenylphosphines are
well known and have been extensively investigated by Dance
and co-workers (Dance & Scudder, 1995, 1996a,b; Lewis &
Dance, 2000). The steric demands of the Mo coordination
sphere promote formation of an unusual intramolecular NÐ
HÁ Á Áꢀ hydrogen bond between one of the phenyl rings and the
N atom of the piperidine moiety. The ¯uoro substitutent of the
4-¯uorophenyl ring is disordered over two rings, with a
58.8 (7)% occupancy for the major position, which is involved
in an intermolecular CÐHÁ Á ÁF interaction with the piperidine
moiety (Table 2). A comparison of the MoÐP bond lengths
for (I), (II) (Cotton et al., 1982b) and the related complex (III)
(Alyea et al., 1994), which contains 4-¯uorophenyl groups,
shows that the MoÐP bond in (I) is shorter than in (II); the
Correspondence e-mail: woody.m@qub.ac.uk
Received 21 November 2000
Accepted 22 February 2001
The title molecule, [Mo{P(C6H5)2(C6H4F)}(HNC5H10)(CO)4]
or [Mo(C18H14FP)(C5H11N)(CO)4], has irregular octahedral
geometry about the Mo atom. The molecules form a
complicated hydrogen-bonded network comprising CÐ
HÁ Á ÁO, CÐHÁ Á ÁF and CÐHÁ Á Áꢀ hydrogen bonds and ꢀ±ꢀ
interactions. The CÐHÁ Á Áꢀ and ꢀ±ꢀ interactions form chains
containing CÐHÁ Á Áꢀ/ꢀ±ꢀ dimers linked via CÐHÁ Á Áꢀ inter-
actions and the chains are linked into a three-dimensional
network via CÐHÁ Á ÁO and CÐHÁ Á ÁF hydrogen bonds.
Comment
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values are 2.5670 (10) and 2.576 (2) A, respectively, and are
The molybdenum(0) complex cis-[Mo(CO)4(HNC5H10)2] is a
convenient precursor for a range of cis-[Mo(CO)4L2] (L =
phosphine, phosphite, etc) complexes. Structural studies on a
wide range of such complexes have been reported. However,
to date, the structures of only three other intermediate
piperidine±phosphine complexes, namely cis-[Mo(CO)4(HN-
C5H10)(PR3)], where R is Me2Ph, MePh2 and Ph3, have been
reported (Cotton et al., 1982a). A diffraction study of cis-
tetracarbonyl[(4-¯uorophenyl)diphenylphosphine-P](piper-
N)molybdenum(0), (I) (Fig. 1), reveals a structure similar to
that of [Mo(CO)4(HNC5H10)(PPhMe2)] [(II); Cotton et al.,
1982b], but with a signi®cantly smaller PÐMoÐN angle
[86.28 (7)ꢁ for (I) versus 90.77 (7)ꢁ for (II); see Table 1]. The
piperidine ligand of (I) exhibits the expected chair confor-
mation, and the distances and angles of this ligand are similar
to those found for (II).
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consistent with the MoÐP bond length of 2.5644 (4) A in
(III). Evidently, while the presence of an F atom in the para
position of the phenyl ring has no effect upon the PÐC
The geometry about the P atom is distorted tetrahedral and
similar to the analogous complex cis-[Mo(CO)4{P(C6H4-
F-4)3}2] [(III); Alyea et al., 1994]. The molecules of (I) are
involved in a number of CÐHÁ Á ÁO intermolcular interactions
from both the piperidine and phenyl groups, forming a three-
dimensional network (see Table 2). The ability of CÐH to act
as a hydrogen-bond donor to oxygen was established by
Taylor & Kennard (1982). They showed that CÐHÁ Á ÁO
interactions (i) are essentially electrostatic in nature, (ii) show
Figure 1
The molecular structure of (I) showing 30% probability displacement
ellipsoids. The minor disorder component is not shown for clarity.
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CÁ Á ÁO distances ranging from 3 to 4 A and (iii) are likely to be
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678 # 2001 International Union of Crystallography
Printed in Great Britain ± all rights reserved
Acta Cryst. (2001). C57, 678±679
McElroy, Liam
