hydrofuran was irradiated using a UV lamp for 1 h, resulting in
an orange solution. PNCHP (0.538 g, 0.979 mmol) in 15 mL
of tetrahydrofuran was added and the red solution stirred
for 30 min. The solution was filtered through Kieselguhr. The
solvent was removed and unchanged [Cr(CO)6] sublimed,
in vacuo. Preparative scale, thin layer chromatography,
eluting with dichloromethane–n-hexane (1:1), was used to
Complex 9, [{W(CO)5}2(PNCHP-κ2P, PЈ)]ؒ2C6H5Me. C61-
H44NO10P2W2, M = 1378.61, triclinic, a = 10.387(2), b =
12.076(2), c = 12.229 Å, α = 98.79(3), β = 100.59(3), γ =
3
¯
107.99(3)Њ, U = 1397.6(4) Å , T = 290 K, space group P1, Z = 1,
µ(Mo-Kα) = 4.23 mmϪ1
, 2754 reflections measured, 2588
unique (Rint = 0.0271) which were used in all calculations. The
2
final Rw(Fo ) = 0.0653, R(Fo) = 0.0384.
isolate
a
[Cr(CO)5(PNCHP-κ1P)]–[Cr(CO)5(PCHNP-κ1P)]
10a–10b mixture (2:1), however, these two isomers could not
be separated. In addition, the mixture could not be isolated as
an analytically pure solid since conversion into tetracarbonyl
species occurred.
X-Ray analysis. Single crystals of the complexes were grown
as described under their respective syntheses and attached to
the ends of glass fibres with cyanoacrylate glue. Data collection,
solution and refinement were performed as previously
described.34–36 Solvent molecules were located in 2, 7 and 9. In
complex 2 two molecules of toluene were found, the first of
which appeared to show little signs of disorder. However the
second was disordered over two sites with occupancy factors of
0.579 and 0.421 and the atoms of each ring were refined as a
rigid group. In 7 a half-weighted chloroform molecule was
located. The half-weighted nature results from the close
approach (C(81)–C(81Ј) 0.87 Å) of a symmetry-related chloro-
form molecule in the unit cell. Isotropic thermal motion was
assumed for C(81) of this group. In 9 the complex lies across a
centre of symmetry with the centre at the midpoint of the C–N
bond. No attempt was made to distinguish the C and N atoms
by assigning the space group as P1 and they were included in
the calculations as C. The molecule of toluene located in the
asymmetric unit showed little signs of disorder. No solvent was
located in 5.
The reaction of W(CO)6 with PNCHP to give complexes 11a
and 11b. [W(CO)6] (0.130 g, 0.367 mmol) in 30 mL of tetra-
hydrofuran was irradiated for 1 h, resulting in a yellow solution.
PNCHP (0.222 g, 0.409 mmol) in 20 mL of tetrahydrofuran
was added and the orange solution stirred for 40 min. The sol-
vent and any unchanged [W(CO)6] were removed in vacuo. The
resulting orange-red oil was dissolved in hot dichloromethane
under a stream of argon gas, then cooled to 5 ЊC. After 48 h a
mixture of [W(CO)5(PNCHP-κ1P)] 11a and [W(CO)5(PCHNP-
κ1P)] 11b (2:1) was isolated as a pale yellow solid.
[{Cr(CO)5}2(PNCHP-ꢀ2P,PЈ)] 8. [Cr(CO)6] (0.201 g, 0.913
mmol) in 25 mL of tetrahydrofuran was irradiated for 1 h,
resulting in an orange solution. PNCHP (0.250 g, 0.455 mmol)
in 15 mL of tetrahydrofuran was added and the now orange
solution stirred for 30 min. The solvent and any unchanged
[Cr(CO)6] were removed in vacuo. The resulting residue was
dissolved in toluene and filtered to remove insoluble solids. The
filtrate was allowed to stand for 48 h at 5 ЊC under argon.
[{Cr(CO)5}2(PNCHP-κ2P,PЈ)] was isolated as yellow crystals,
washed with n-pentane and dried in vacuo to yield 0.166 g
(39%), mp 160 ЊC (decomp.).
CCDC reference number 186/2053.
lographic files in .cif format.
Kinetic and equilibrium studies of complex 4
Acetone was freshly distilled over 4A molecular sieves, chlorin-
ated solvents and acetonitrile were freshly distilled over CaH2
and all were degassed with argon. Stock solutions of fac-
[Mo(CO)3(PNCHP-κ3P,N,PЈ)] 4 were prepared by dissolving
an appropriate amount of the solid complex immediately
before each experiment. Samples were transferred to a 1 cm
path-length sealed quartz cuvette placed in the constant tem-
perature ( 3%) jacket of the spectrometer. Kinetic runs as a
function of temperature (19.5–49.5 ЊC) were performed with a
HP 8452A uv-vis spectrometer at 700 nm. Absorbance readings
were taken until the reaction had progressed to equilibrium.
Values of kobsd were obtained from linear plots of ln(A Ϫ A∞)
against time, using a minimum of 6 absorbance/time pairs. The
first-order rate constants were calculated using a linear regres-
sion method. All plots gave correlation coefficients greater than
0.9993. Activation energy was calculated from an Arrhenius
plot and activation enthalpy and entropy from an Eyring plot.
[{W(CO)5}2(PNCHP-ꢀ2P,PЈ)] 9. [W(CO)6] (0.400 g, 1.14
mmol) in 25 mL of tetrahydrofuran was irradiated for 1 h,
resulting in a yellow solution. PNCHP (0.312 g, 0.568 mmol) in
15 mL of tetrahydrofuran was added and the orange solution
stirred for 45 min. The solvent and any unchanged [W(CO)6]
were removed in vacuo. The resulting residue was dissolved in
toluene and filtered to isolate insoluble tan solids. These were
dissolved in boiling toluene, under a stream of argon gas, and
the resulting solution allowed to stand for 48 h at 5 ЊC.
[{W(CO)5}2(PNCHP-κ2P,PЈ)] was isolated as yellow diamond
shaped crystals, washed with n-pentane and dried in vacuo to
give 0.320 g (47%), mp 241–246 ЊC.
Crystallography
Crystal data. Complex 2, mer-[Mo(CO)3(PNCHP-
κ3P, N, PЈ)]ؒ2C6H5Me. C54H45MoNO3P2, M = 913.79, mono-
clinic, a = 12.490(10), b = 17.680(10), c = 20.630(10) Å,
β = 90.76(3)Њ, U = 4555(5) Å3, T = 292 K, space group P21/c,
Z = 4, µ(Mo-Kα) = 0.40 mmϪ1, 8394 reflections measured,
8000 unique (Rint = 0.0160) which were used in all calculations.
Acknowledgements
We thank the Massey University Research Fund for financial
support.
2
The final Rw(Fo ) = 0.0801, R(Fo) = 0.0416.
References
Complex 5, cis-[Cr(CO)4(PNCHP-κ2P,N)]. C41H29CrNO4-
P2, M = 713.59, monoclinic, a = 14.429(3), b = 29.433(6),
c = 17.389(3) Å, β = 108.40(3)Њ, U = 7007(2) Å3, T = 295 K,
space group P21/c, Z = 8, µ(Mo-Kα) = 0.461 mmϪ1, 6871 reflec-
tions measured, 6533 unique (Rint = 0.0359) which were used in
1 See for example, G. Franciò, R. Scopelliti, C. G. Arena, G. Bruno,
D. Drommi and F. Faraone, Organometallics, 1998, 17, 338;
R. Noyori and S. Hashiguchi, Acc. Chem. Res., 1997, 30, 97;
F. Ungváry, Coord. Chem. Rev., 1997, 167, 233; A. Carmona, A.
Corma, M. Iglesias, A. San José and F. Sánchez, J. Organomet.
Chem., 1995, 492, 11.
2 C. Bianchini, J. A. Casares, M. Peruzzini, A. Romerosa and
F. Zanobini, J. Am. Chem. Soc., 1998, 118, 4585.
3 J. Kleverlaan, F. Hartl and D. J. Stufkens, J. Organomet. Chem.,
1998, 561, 57.
2
all calculations. The final Rw(Fo ) = 0.1030, R(Fo) = 0.0363.
Complex 7, cis-[W(CO)4(PNCHP-κ2P, P Ј)]ؒ0.5CHCl3. C41.5
-
H29.5Cl1.5NO4P2W, M = 904.62, monoclinic, a = 23.476(5),
b = 18.128(4), c = 19.254(4) Å, β = 116.08(3)Њ, U = 7360(3) Å3,
space group C2/c, Z = 8, µ(Mo-Kα) = 3.38 mmϪ1, 7068 reflec-
tions measured, 3438 unique (Rint = 0.0198) which were used in
4 S. C. N. Hsu and W.-Y. Yeh, J. Chem. Soc., Dalton Trans., 1998, 125
and refs. therein.
5 A. Rodger and B. F. G. Johnson, Inorg. Chem., 1998, 27, 3062.
2
all calculations. The final Rw(Fo ) = 0.0450, R(Fo) = 0.0281.
2670
J. Chem. Soc., Dalton Trans., 2000, 2663–2671
Ainscough, Eric W.
