Fig. 2 Molecular structure of 7. Selected bond lengths (Å) and angles
Fig. 1 Molecular structure of 4. Selected bond lengths (Å) and angles
(Њ): Ir(1)–C(12) 1.867(13), Ir(1)–C(1) 1.918(14), Ir(1)–P(2) 2.342(3),
Ir(1)–P(3) 2.386(3), Ir(1)–P(1) 2.442(3), P(1)–C(1) 1.753(13), O(1)–
C(12) 1.176(15); C(12)–Ir(1)–C(1) 104.4(5), C(12)–Ir(1)–P(2) 93.7(4),
C(1)–Ir(1)–P(2) 127.5(4), C(12)–Ir(1)–P(3) 92.7(4), C(1)–Ir(1)–P(3)
128.2(4), P(2)–Ir(1)–P(3) 98.93(12), C(12)–Ir(1)–P(1) 149.1(4),
C(1)–Ir(1)–P(1) 45.5(4), P(2)–Ir(1)–P(1) 110.33(11), P(3)–Ir(1)–P(1)
102.11(11), C(1)–P(1)–Ir(1) 51.3(4), P(1)–C(1)–Ir(1) 83.3(6).
(Њ): Ir(1)–C(13) 1.889(7), Ir(1)–C(1) 2.018(7), Ir(1)–C(2) 2.209(7),
Ir(1)–P(2) 2.3481(19), Ir(1)–P(1) 2.3769(19), Ir(1)–P(1)Ј 2.4550(17),
P(1)–C(2) 1.800(8), O(1)–C(1) 1.213(8), C(1)–C(2) 1.433(11); C(1)–
C(2)–P(1) 104.0(5), O(1)–C(1)–C(2) 139.7(8), C(2)–P(1)–C(7) 109.1(3),
C(2)–P(1)–Ir(1)Ј 122.1(2), Ir(1)–C(1)–O(1) 142.7(7), Ir(1)–P(1)–C(7)
116.9(2). Symmetry operation: Ј = Ϫx, Ϫy ϩ 1, Ϫz.
Notes and references
† Selected data for 4: (yield 51%); mp 170–174 ЊC (dec.). 1H NMR
(400 MHz, C6D6, 300 K): δ 0.72–2.11 (m, 11H, Cy), 1.77 (s, 9H, But),
6.73–7.77 (m, 30H, ArH); 13C NMR (101.6 MHz, C6D6, 300 K): δ 27.9
ligand and formation of 6. This was confirmed by the 31P{1H}
NMR spectrum of this complex in which the signal correspond-
ing to the phosphido centre (Ϫ152.3 ppm) has shifted only
slightly down field from that in 4 but is now only coupled to one
PPh3 ligand (2JPP = 79 Hz). In addition, the IR spectrum of 6
shows two strong CO stretching absorptions (1977, 1949 cmϪ1).
Compound 6 is thermally stable in the solid state but in
toluene or ethereal solutions decomposes over several hours to
give many phosphorus containing products. We managed to
isolate one of these, 7, in very low yield (< 1%) but unfort-
unately were not able to obtain any data on this compound
other than its X-ray crystal structure (Fig. 2). This is worthy of
inclusion here as it demonstrates the ability of the phosphido-
carbene ligand in 6 to undergo a facile intramolecular C–C
bond forming reaction with one of its carbonyl ligands. This
has given rise to a complex in which the oxo-η3-phosphaallylic
ligand adopts an anti-configuration, thus allowing its P-lone
pair to intermolecularly donate to an Ir centre to give the
observed 18eϪ dimeric structure for 7. There is only one other
crystallographically characterised example of an oxo-phospha-
2
(m, CCH3), 31.5 (m, CH), 33.6 (d, CH2, JPC = 18 Hz), 34.2 (d, CH2,
3JPC = 11 Hz), 36.4 (s, CH2), 50.9 (m, CCH3), 134.0 (d, m-ArC, 3JPC = 10
2
Hz), 134.5 (d, o-ArC, JPP = 13 Hz), 135.0 (s, p-ArC), 137.3 (m, ipso-
2
ArC), 187.6 (dd, CO, JPC = 17 and 5 Hz), 331.5 (m, Ir᎐C); 31P{1H}
᎐
2
NMR (121.7 MHz, C6D6) δ Ϫ157.2 (dd, Ir᎐CP, JPP = 22 and 66 Hz),
᎐
2
2
2.2 (dd, PPh3, JPP = 22 and 66 Hz), 16.0 (v. tr., PPh3, JPP = 22 and
22 Hz); MS APCI: m/z (%) 929 (MHϩ, 15), 263 (PPh3Hϩ, 100); IR
(Nujol) ν/cmϪ1: 1954(s) CO; Found: C, 46.67; H, 7.11; C48H50OP3Ir
requires: C, 47.0; H, 7.10%.
For 6: (yield 100%); mp 170–172 ЊC (dec.). 1H NMR (400 MHz,
C6D6, 300 K): δ 0.67–2.21 (m, 11H, Cy), 1.48 (s, 9H, But), 6.67–7.57 (m,
15H, ArH); 31P{1H} NMR (121.7 MHz, C6D6) δ Ϫ152.3 (d, Ir᎐CP,
᎐
2JPP = 79 Hz), 10.2 (d, PPh3, JPP = 79 Hz); MS APCI: m/z (%) 666
2
(M Ϫ COϩ, 22), 262 (PPh3ϩ, 100); IR (Nujol) ν/cmϪ1: 1977(s), 1949(s).
‡ Crystal data for 4: C48H50OP3Ir, M = 927.99, orthorhombic, space
group P212121, a = 10.552(2), b = 12.359(3), c = 32.250(7) Å, V =
4205.8(15) Å3, Z = 4, Dc = 1.466 g cmϪ3, F(000) = 1872, µ(Mo-Kα) =
3.32 mmϪ1, 150(2) K, 7325 unique reflections [R(int) = 0.0949], R (on
F) = 0.0650, wR (on F 2) = 0.1401 (I > 2σI).
For 7: C31H35O2P2Ir, M = 693.73, monoclinic, space group P21/n,
a = 11.381(2), b = 14.501(3), c = 16.922(3) Å, β = 94.83(3)Њ, V =
2782.8(10) Å3, Z = 4, Dc = 1.656 g cmϪ3, F(000) = 1376, µ(Mo-Kα) =
4.93 mmϪ1, 150(2) K, 6327 unique reflections [R(int) = 0.0818], R (on
F) = 0.0476, wR (on F 2) = 0.1033 (I > 2σI). CCDC reference numbers
for crystallographic data in CIF or other electronic format.
allylic complex, [Cp*Fe(CO){η3-O᎐CC(H)P[C(H)(SiMe ) ]}] 8,
᎐
3
2
which was isolated as both its syn- and anti-isomers.11 In 7, the
phosphaallylic ligand appears to be largely delocalised (as is the
case in 8) with both the P(1)–C(2) [1.800(8) Å] and C(1)–C(2)
[1.433(11) Å] bond lengths lying between the norms for double
and single bonded interactions.10 The bond lengths from this
ligand to Ir(1) confirm its η3-mode of attachment and the
C(1)–O(1) bond length [1.213(8) Å] is strongly suggestive of
a localised double bond.
1 D. E. Hibbs, C. Jones and A. F. Richards, J. Chem. Soc., Dalton
Trans., 1999, 3531.
2 C. Jones and A. F. Richards, J. Chem. Soc., Dalton Trans., 2000, 3233.
3 C. Jones and A. F. Richards, J. Organomet. Chem., 2001, 629, 109.
4 C. Jones, J. A. Platts and A. F. Richards, Chem. Commun., 2001, 663.
5 C. Jones, A. F. Richards, S. Fritzsche and E. Hey-Hawkins,
Organometallics, 2002, 21, 438.
6 N. H. T. Huy, J. Fischer and F. Mathey, Organometallics, 1988, 7, 240.
7 L. Weber, G. Dembeck, H. G. Stammler, B. Neumann,
M. Schmidtmann and A. Müller, Organometallics, 1998, 17, 5254.
8 V. C. Gibson, T. P. Kee, S. T. Carter, R. D. Sanner and W. Clegg,
J. Organomet. Chem., 1991, 418, 197.
In conclusion, we have developed a facile synthetic route to
the first example of an iridaphosphirene complex, 4, which,
based upon preliminary results, should prove to have a rich
chemistry. We are currently looking at the reactions of 4 with a
range or 2eϪ donors and other reagents, e.g. nitriles, isonitriles,
carbenes, MeI etc. The results of our endeavours in this area
will be reported in a forthcoming full paper.
9 S. S. Al-Juaid, D. Carmichael, P. B. Hitchcock, A. Marinetti,
F. Mathey and J. F. Nixon, J. Chem. Soc., Dalton Trans., 1991, 905.
10 Value determined from a search of the Cambridge Structural
Database.
Acknowledgements
We gratefully acknowledge financial support from the EPSRC
(studentships for A. F. R. and M. B.).
11 L. Weber, E. Lücke and R. Boese, Chem. Ber., 1990, 123, 23.
J. Chem. Soc., Dalton Trans., 2002, 2800–2801
2801