Terminal nickel(ii) amide, alkoxide, and thiolate complexes containing amido diphosphine ligands of the type [N(o-C6H4PR 2)2]- (R = Ph, iPr, Cy)

Article abstract of DOI:10.1039/b719894a

A series of nickel(ii) complexes of the type [R-PNP]Ni(ER′) ([R-PNP]^- = [N(o-C₆H₄PR₂) ₂]^-; R = Ph, ⁱPr, Cy; E = NH, O, S; R′ = Ph, ^tBu) featuring unsupported, covalently bound π-donor ligands have been prepared and characterized. The metathetical reactions of [R-PNP]NiCl (R = Ph, ⁱPr, Cy) with LiNHPh, NaOPh, or NaSPh, respectively, produced the corresponding anilide [R-PNP]Ni(NHPh), phenolate [R-PNP]Ni(OPh), and thiophenolate [R-PNP]Ni(SPh) derivatives. Treatment of [Ph-PNP]NiCl with either LiNH^tBu or NaO^tBu generated tert-butyl amide [Ph-PNP]Ni(NH^tBu) and tert-butoxide [Ph-PNP]Ni(O^tBu), respectively. In contrast, attempts to prepare analogous tert-butyl amide and tert-butoxide complexes of [ⁱPr-PNP]^- or [Cy-PNP] ^- were not successful. Protonolysis studies of these nickel(ii)-heteroatom complexes revealed the basic reactivity of these π-donor ligands. The basicity follows the order NH^tBu > O ^tBu > NHPh > OPh > SPh. In addition to solution NMR spectroscopic data for all new compounds, X-ray structures of [ ⁱPr-PNP]Ni(NHPh) and [ⁱPr-PNP]Ni(OPh) are presented. The Royal Society of Chemistry 2008.

Full text of DOI:10.1039/b719894a

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Terminal nickel(II) amide, alkoxide, and thiolate complexes containing amido
diphosphine ligands of the type [N(o-C6H4PR2)2]− (R = Ph, iPr, Cy)†
Lan-Chang Liang,* Pin-Shu Chien, Pei-Ying Lee, Jia-Ming Lin and Yu-Lun Huang
Received 2nd January 2008, Accepted 9th April 2008
First published as an Advance Article on the web 8th May 2008
DOI: 10.1039/b719894a
A series of nickel(II) complexes of the type [R-PNP]Ni(ERꢀ) ([R-PNP]− = [N(o-C6H4PR2)2]−; R = Ph,
iPr, Cy; E = NH, O, S; Rꢀ = Ph, tBu) featuring unsupported, covalently bound p-donor ligands have
been prepared and characterized. The metathetical reactions of [R-PNP]NiCl (R = Ph, iPr, Cy) with
LiNHPh, NaOPh, or NaSPh, respectively, produced the corresponding anilide [R-PNP]Ni(NHPh),
phenolate [R-PNP]Ni(OPh), and thiophenolate [R-PNP]Ni(SPh) derivatives. Treatment of
[Ph-PNP]NiCl with either LiNHtBu or NaOtBu generated tert-butyl amide [Ph-PNP]Ni(NHtBu) and
tert-butoxide [Ph-PNP]Ni(OtBu), respectively. In contrast, attempts to prepare analogous tert-butyl
amide and tert-butoxide complexes of [iPr-PNP]− or [Cy-PNP]− were not successful. Protonolysis
studies of these nickel(II)–heteroatom complexes revealed the basic reactivity of these p-donor ligands.
The basicity follows the order NHtBu > OtBu > NHPh > OPh > SPh. In addition to solution NMR
spectroscopic data for all new compounds, X-ray structures of [iPr-PNP]Ni(NHPh) and
[iPr-PNP]Ni(OPh) are presented.
contribution, we aim to demonstrate the synthetic possibility of
Introduction
a series of terminal amide, alkoxide, and thiolate complexes of
t
the type [R-PNP]Ni(ERꢀ) (E = NH, O, S; Rꢀ = Ph, Bu). The
Late transition metal complexes featuring covalently bound p-
donor ligands such as amide, alkoxide, and thiolate are important
preparation, structural characterization, and reactivity toward
intermediates in a number of biological systems and catalytic
protonolysis of these nickel–heteroatom complexes are described.
processes.1–6 Compounds of this type are anticipated to be
relatively unstable and thus reactive as compared to their early
Results and discussion
transition metal counterparts and late transition metal alkyl
derivatives due to the destabilization of the metal dp electrons.6,7 As
a result, the former complexes are much less common. Much recent
attention has been paid to the preparation and reactivity studies of
these reactive species,1,8–31 from which the electronic nature of the
metal–heteroatom bonds may be better understood and thus the
subsequent reaction chemistry be possibly tailored. Notably, the
palladium catalyzed carbon–heteroatom bond forming reactions
have become a powerful tool for organic synthesis.32,33
The preparation of the terminal anilide complexes [R-
i
PNP]Ni(NHPh) (R = Ph, Pr, Cy) was achieved by metathetical
reactions of [R-PNP]NiCl37,38 with LiNHPh (Scheme 1). Upon
addition of one equiv. of LiNHPh, the green solutions of [R-
PNP]NiCl in THF or toluene rapidly turned dark blue or purple
in color, from which the desired [R-PNP]Ni(NHPh) complexes
could be generated cleanly. The solution NMR spectroscopic
data of these compounds are all consistent with C2v symmetry,
reminiscent of that found for the corresponding chloride,37,38
hydride,39 and hydrocarbyl derivatives.37,38 The C2v symmetry
observed for [R-PNP]Ni(NHPh) in solution is suggestive of facile
rotation of the terminal anilide ligand about the Ni–N bond,
as has been observed for the nickel(II) hydrocarbyl complexes
of [R-PNP]−. The p interaction of the terminal anilido nitrogen
We are currently exploring reaction chemistry of metal com-
plexes supported by o-phenylene-derived amido phosphine ligands
i
of the type [N(o-C6H4PR2)2]− ([R-PNP]−; R = Ph, Pr, Cy).34–36
It has been shown that a series of nickel(II) alkyl and hydride
complexes are thermally stable, even at elevated temperatures,
including those containing b-hydrogen atoms.37–39 The unusual sta-
bility of these nickel(II)–alkyls toward b-hydrogen elimination has
been ascribed to the rigid and robust nature of the chelating amido
diphosphine ligands employed. Remarkably, these compounds are
capable of mediating intermolecular arene C–X (X = H, halides)
bond activation.38,39 In a parallel study, we began to examine the
reaction chemistry involving a terminal p-donor ligand. In this
Department of Chemistry and Center for Nanoscience & Nanotech-
nology, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan.
E-mail: lcliang@mail.nsysu.edu.tw; Fax: +886-7-5253908
† Electronic supplementary information (ESI) available: NMR spectra
of [Ph-PNP]Ni(NHPh), [Ph-PNP]Ni(NHtBu) and [Ph-PNP]Ni(OtBu).
CCDC reference numbers 644274 and 644275. For ESI or crystallographic
data in CIF or other electronic format see DOI: 10.1039/b719894a
Scheme 1
3320 | Dalton Trans., 2008, 3320–3327
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donor with the [R-PNP]Ni fragment is thus little or negligible
on the NMR timescale. Selected NMR data are summarized in
Table 1. The phosphorus donors of these anilide complexes are
1
observed as a singlet resonance in the 31P{ H} NMR spectra
i
at 12.9, 29.3, and 21.5 ppm for R = Ph, Pr, Cy, respectively.
These values are shifted relatively upfield as compared to those
of the corresponding chloride precursors.37,38 The 1H NMR
spectra of these anilide complexes reveal a characteristic singlet
resonance at ca. −1.2 ppm for the nitrogen-bound a-H atom.
The lack of observable coupling between the a-H atom and
the phosphorus donors in [R-PNP]Ni(NHPh) seems somewhat
unusual in view of the observation of triplet resonances for
a-H atoms of the corresponding nickel(II)–alkyl derivatives37,38
and the tert-butyl amide complex [Ph-PNP]Ni(NHtBu) (vide
infra). This phenomenon, however, is similar to that reported
for the cyclopentadienylnickel(II) amido complexes that contain a
coordinated phosphine ligand, in which no coupling was observed
for the amido hydrogen atom and the phosphorus donor.21 The o-
phenylene carbon atoms are observed as virtual triplet resonances
in the 13C{ H} NMR spectra, indicating a square-planar geometry
1
Fig.
1
Molecular structure of [iPr-PNP]Ni(NHPh) with thermal
for these molecules. The terminal anilide ligand is thus trans to the
amido nitrogen donor in the meridional [R-PNP]− ligand.
ellipsoids drawn at the 35% probability level. Selected bond
i
distances (A) and angles (◦): Ni(1)–N(2) 1.879(3), Ni(1)–N(1)
˚
Treatment of [R-PNP]NiCl (R = Ph, Pr, Cy)37,38 with one
1.911(3), Ni(1)–P(2) 2.1738(9), Ni(1)–P(1) 2.2249(10); N(2)–Ni(1)–N(1)
175.46(13), N(2)–Ni(1)–P(2) 94.08(10), N(1)–Ni(1)–P(2) 84.41(9),
N(2)–Ni(1)–P(1) 97.12(10), N(1)–Ni(1)–P(1) 84.09(9), P(2)–Ni(1)–P(1)
168.02(4), C(25)–N(2)–Ni(1) 128.5(3).
equiv. of NaOPh or NaSPh in ethereal solutions afforded the
corresponding phenolate [R-PNP]Ni(OPh) or thiophenolate [R-
PNP]Ni(SPh) complexes, respectively, in moderate to high isolated
yield. The multi-nuclear NMR spectroscopic data at room tem-
perature are all consistent with C2v symmetry for these molecules,
suggestive of little dp–pp interaction for nickel with these terminal
ligands. The 31P chemical shifts of [R-PNP]Ni(OPh) are found to
be relatively upfield as compared to those of the corresponding
[R-PNP]Ni(NHPh), whereas those of [R-PNP]Ni(SPh) are com-
paratively downfield.
Crystallographically characterized terminal amide and alkoxide
complexes of nickel(II) remain relatively rare to date.22,28–30,40–42
Crystals of [iPr-PNP]Ni(NHPh) and [iPr-PNP]Ni(OPh) suitable
for X-ray diffraction analysis were grown from a concentrated
diethyl ether solution at −35 ◦C. Fig. 1 and 2 illustrate the molec-
ular structures of [iPr-PNP]Ni(NHPh) and [iPr-PNP]Ni(OPh),
respectively. Crystallographic details are summarized in Table 2.
Table 1 Selected NMR dataa
Compound
d31P
dNH
[Ph-PNP]NiClb
18.77
12.93
8.77
Fig. 2 Molecular structure of [iPr-PNP]Ni(OPh) with thermal ellipsoids
drawn at the 35% probability level. Selected bond distances (A) and angles
[Ph-PNP]Ni(NHPh)
[Ph-PNP]Ni(OPh)
[Ph-PNP]Ni(SPh)
[Ph-PNP]Ni(NHtBu)
[Ph-PNP]Ni(OtBu)
[iPr-PNP]NiClb
−1.10
−0.70
−1.18
˚
(◦): Ni(1)–O(1) 1.863(2), Ni(1)–N(1) 1.903(3), Ni(1)–P(2) 2.1830(9),
Ni(1)–P(1) 2.2266(9); O(1)–Ni(1)–N(1) 173.01(11), O(1)–Ni(1)–P(2)
93.10(8), N(1)–Ni(1)–P(2) 84.31(9), O(1)–Ni(1)–P(1) 97.79(8),
N(1)–Ni(1)–P(1) 84.25(9), P(2)–Ni(1)–P(1) 167.83(4), C(25)–O(1)–Ni(1)
124.1(2).
23.83
12.77
−1.78
34.68
29.25
28.13
33.82
26.77
21.53
21.00
26.62
[iPr-PNP]Ni(NHPh)
[iPr-PNP]Ni(OPh)
[iPr-PNP]Ni(SPh)
[Cy-PNP]NiClb
Consistent with the solution structures determined by NMR
spectroscopy, both [iPr-PNP]Ni(NHPh) and [iPr-PNP]Ni(OPh)
are four coordinate, square planar species with the tridentate
[iPr-PNP]− ligand being in a meridional coordination mode. The
terminal anilide and phenolate ligands are trans to the diarylamido
nitrogen donor. The nickel center in [iPr-PNP]Ni(EPh) is slightly
[Cy-PNP]Ni(NHPh)
[Cy-PNP]Ni(OPh)
[Cy-PNP]Ni(SPh)
−1.26
a All spectra were recorded in C6D6 at room temperature, chemical shifts
in ppm. b Data selected from reference 38.
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Table 2 Crystallographic data for [iPr-PNP]Ni(NHPh) and [iPr-PNP]Ni(OPh)
Compound
[iPr-PNP]Ni(NHPh)
[iPr-PNP]Ni(OPh)
Formula
M
C30H42N2NiP2
551.31
C30H41NNiOP2
552.29
Crystal size/mm
0.26 × 0.21 × 0.14
0.56 × 0.45 × 0.32
D
calc/Mg m−3
1.148
1.163
Crystal system
Space group
Triclinic
¯
P1
9.4550(2)
10.7220(2)
17.7680(5)
98.2280(10)
93.5890(10)
115.4280(10)
1594.44(6)
Triclinic
¯
P1
9.41600(10)
10.7770(2)
17.6570(4)
98.8640(10)
93.5780(10)
115.7630(10)
1577.45(5)
˚
a/A
˚
b/A
˚
c/A
a/◦
b/◦
c /◦
V/A
Z
T/K
3
˚
2
2
200(2)
200(2)
˚
Radiation, k/A
Mo-Ka, 0.71073
4.07<2h<50.06
−11,11; −12,12; −21,21
19288
5606
0.0643
Mo-Ka, 0.71073
4.07<2h<50.06
−11,10; −12,12; −20,20
20003
5561
0.0766
2h range/◦
Index ranges (h; k; l)
Total no. of reflns
No. of indep. reflns
Rint
l/mm−1
0.728
0.737
No. of data/restraints/parameters
Goodness of fit
Final R indices (I > 2r(I))
5606/0/317
0.741
R1 = 0.0573, wR2 = 0.1662
R1 = 0.0707, wR2 = 0.1818
−0.885 to 0.674
5561/0/317
1.048
R1 = 0.0517, wR2 = 0.1419
R1 = 0.0607, wR2 = 0.1462
−0.765 to 0.494
R indices (all data)
Residual density/e A
−3
˚
displaced from the ideal square plane defined by the four donor
angle between Ni(1)–N(2)–C(25) and the square coordination
plane is 66.0◦, indicating that the filled p orbital of the terminal
anilido nitrogen donor avoids interaction with the frontier orbitals
of the [iPr-PNP]Ni fragment. This result is consistent with
that deduced from solution NMR study (vide supra). A similar
phenomenon is also found for the diarylamido nitrogen donor in
[iPr-PNP]− as evidenced by the dihedral angle of 32.8◦ between
C(12)–N(1)–C(13) and the square coordination plane. As a result,
the two filled p orbitals of these mutually trans nitrogen donors
are nearly orthogonal (dihedral angle of 84.7◦). The phenyl group
in the terminal anilide ligand is oriented such that it is tilted
toward P(1) and virtually parallel with the plane defined by
C(1)–C(2)–C(3) (dihedral angle 11.2◦) and that defined by C(19)–
C(20)–C(21) (dihedral angle 4.3◦) of the two pseudo-equatorial
isopropyl substituents at the phosphorus donors. The Ni–P(1)
˚
˚
atoms by 0.0720 A (E = NH) and 0.1000 A (E = O) likely
due to intramolecular steric congestion (vide infra). The two o-
phenylene rings are tilted with respect to the coordination plane
due to steric repulsion between the two CH groups ortho to the
amido nitrogen atom. The core structures of [iPr-PNP]Ni(NHPh)
and [iPr-PNP]Ni(OPh) are reminiscent of those of the previously
reported Group 10 complexes of [R-PNP]− such as [R-PNP]NiCl
and [R-PNP]NiMe.37,38
In [iPr-PNP]Ni(NHPh), the Ni–N(terminal) distance of
˚
1.879(3) A is slightly shorter than the Ni–N(chelating) distance
˚
of 1.911(3) A. This discrepancy in these nickel–anilido distances
is ascribable to the constraint of the fused five-membered
chelate rings imposed by the rigid [iPr-PNP]− ligand for the
latter. The Ni–N(terminal) distance found in [iPr-PNP]Ni(NHPh)
is comparable to other terminal anilidonickel complexes such
˚
distance of 2.2249(10) A is thus slightly longer than the Ni–P(2)
5
21
˚
˚
as (g -C5Me5)Ni(NH-p-tolyl)(PEt3) (1.903(5) A) and trans-
distance of 2.1738(9) A. These data suggest that steric effects
31
˚
Ni(NHPh)(mesityl)(PMe3)2 (1.932(3) A). The N(2)–C(25) dis-
rather than the p interaction of the terminal anilide ligand with
nickel predominate to control the molecular conformation of [iPr-
PNP]Ni(NHPh). Similar phenomena are also observed for [iPr-
PNP]Ni(OPh). Table 3 summarizes the selected dihedral angles
of [iPr-PNP]Ni(NHPh) and [iPr-PNP]Ni(OPh) for comparison.
˚
tance of 1.351(5) A is relatively short as compared to the typical N–
˚
Csp2 bond length of ca. 1.40 A, indicating partial delocalization of
the nitrogen lone pair into the phenyl ring. Accordingly, the Cortho
–
C(25)–N(2)–Ni(1) atoms are essentially coplanar. The dihedral
Table 3 Selected dihedral angles (◦) for [iPr-PNP]Ni(EPh) (E = NH, O)
Plane
Plane
E = NH
E = O
P(1)–N(1)–P(2)–E
P(1)–N(1)–P(2)–E
Ni(1)–E–C(25)
C(25)–C(26)–C(27)–C(28)–C(29)–C(30)
C(25)–C(26)–C(27)–C(28)–C(29)–C(30)
Ni(1)–E–C(25)
66.0
32.8
84.7
11.2
4.3
65.5
33.6
85.0
16.4
5.1
C(12)–N(1)–C(13)
C(12)–N(1)–C(13)
C(1)–C(2)–C(3)
C(19)–C(20)–C(21)
3322 | Dalton Trans., 2008, 3320–3327
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i
˚
employing [Ph-PNP]Ni(OtBu), [Ph-PNP]Ni(NHPh), [Ph-
PNP]Ni(OPh), or [Ph-PNP]Ni(SPh) with appropriate protic
sources were also examined. The results are summarized in
Scheme 3. No reaction, however, was found when reverse
reactions were attempted. These results demonstrate the basic
nature of the p-donor ligands in these nickel complexes. The
basicity of these p-donor ligands follows the order of NHtBu >
The Ni–O distance of 1.863(2) A in [ Pr-PNP]Ni(OPh) is slightly
shorter than the Ni–N(terminal) bond in [iPr-PNP]Ni(NHPh),
consistent with the inherent difference in covalent radii of these
˚
donor atoms. Interestingly, the Ni–N distance of 1.903(3) A in
[iPr-PNP]Ni(OPh) is identical to that in [iPr-PNP]NiCl (1.903(2)
A) but slightly shorter than those found in [iPr-PNP]Ni(NHPh)
38
˚
i
38
˚
˚
(1.911(3) A) and [ Pr-PNP]NiMe (1.945(3) A). This result is
in good agreement with the anticipated trans-influence order of
alkyl > anilide > phenolate ∼ chloride.
OtBu > NHPh > OPh > SPh. Of particular note is the successful
t
deprotonation of extremely weak acids such as BuOH (pKa
=
32.2 in DMSO)43 and PhNH2 (pKa = 30.6 in DMSO).43
It has been shown that alkyl amides of Group 10 metals are
generally unstable and hardly isolable.20 Interestingly, addition of
one equiv. of LiNHtBu to a THF solution of [Ph-PNP]NiCl at
−35 ◦C led to the isolation of [Ph-PNP]Ni(NHtBu) (Scheme 2) as
a brown solid in essentially quantitative yield. Analogous to that of
other [R-PNP]− complexes of nickel(II), [Ph-PNP]Ni(NHtBu) dis-
plays solution C2v symmetry on the NMR timescale. The 31P{ H}
1
NMR spectrum exhibits a singlet resonance at 12.8 ppm, a value
that is nearly identical to that of [Ph-PNP]Ni(NHPh). In contrast
to what is observed for the anilide complexes [R-PNP]Ni(NHPh)
(vide supra), the characteristic a-H atom in [Ph-PNP]Ni(NHtBu)
is observed as a triplet resonance at −0.7 ppm with 3JHP of 8.5 Hz.
The JHP coupling constant found for [Ph-PNP]Ni(NHtBu) is
3
similar to the corresponding values of [Ph-PNP]Ni(CH2SiMe3)
(12 Hz)37 and [iPr-PNP]Ni(CH2Ph) (10 Hz).39 Attempts to
prepare [iPr-PNP]Ni(NHtBu) and [Cy-PNP]Ni(NHtBu) under
similar conditions were not successful. We tentatively ascribe this
discrepancy to the steric congestion between the bulky tert-butyl
amide and the phosphorus substituents in [iPr-PNP]− and [Cy-
PNP]− on the basis of the X-ray structure of [iPr-PNP]Ni(NHPh)
and the recent isolation of a parent amide complex of palladium
supported by a tolyl-derived amido diphosphine ligand.19
Scheme 3
Conclusions
In summary, we have prepared and characterized a series of
nickel(II) complexes featuring an unsupported, covalently bound
p-donor ligand including anilide, phenolate, thiophenolate, tert-
butyl amide, and tert-butoxide derivatives. The synthesis of
these reactive species has been facilitated by the employment
of tridentate amido diphosphine ligands of the type [R-PNP]−.
The synthetic accessibility of the nickel–heteroatom complexes
described herein is a function of the R group in [R-PNP]−.
The basic reactivity of these nickel–heteroatom complexes is
demonstrated. The basicity of the p-donor ligands follows the
order NHtBu > OtBu > NHPh > OPh > SPh. Extremely weak
acids such as tBuOH and PhNH2 may also be deprotonated.
Scheme 2
Experimental section
The metathetical reaction of [Ph-PNP]NiCl37,38 with NaOtBu
in THF at −35 ◦C produced in high yield a blue solid [Ph-
PNP]Ni(OtBu). The tert-butoxide complex also displays solution
General procedures
C
2v symmetry on the NMR timescale. In contrast to the observed
Unless otherwise specified, all experiments were performed under
nitrogen using standard Schlenk or glovebox techniques. All
solvents were reagent grade or better and purified by standard
methods. The NMR spectra were recorded on Varian Unity
or Bruker AV instruments. Chemical shifts (d) are listed as
parts per million downfield from tetramethylsilane and coupling
constants (J) in hertz. 1H NMR spectra are referenced using the
residual solvent peak at d 7.16 for C6D6. 13C NMR spectra are
referenced using the residual solvent peak at d 128.39 for C6D6.
The assignment of the carbon atoms is based on DEPT 13C NMR
spectroscopy. 31P NMR spectra are referenced externally using
85% H3PO4 at d 0. Routine coupling constants are not listed.
All NMR spectra were recorded at room temperature in specified
solvents unless otherwise noted. Elemental analysis was performed
on a Heraeus CHN-O Rapid analyzer.
similarity of [Ph-PNP]Ni(NHtBu) to [Ph-PNP]Ni(NHPh), the
31P chemical shift of −1.8 ppm found for [Ph-PNP]Ni(OtBu)
is notably different from that of [Ph-PNP]Ni(OPh). Analogous
to the tert-butyl amide counterparts, attempts to prepare [iPr-
PNP]Ni(OtBu) and [Cy-PNP]Ni(OtBu) under similar conditions
were not successful due presumably to steric reasons.
It has been shown that late transition metal–heteroatom
bonds are strongly polarized and complexes of this type may, in
some cases, be highly basic.1 Addition of one equiv. of BuOH,
PhNH2, PhOH, or PhSH, respectively, to a benzene solution
of [Ph-PNP]Ni(NHtBu) at room temperature afforded [Ph-
PNP]Ni(OtBu), [Ph-PNP]Ni(NHPh), [Ph-PNP]Ni(OPh), [Ph-
PNP]Ni(SPh) quantitatively along with liberated tBuNH2 on
the basis of NMR studies. Analogous protonolysis experiments
t
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Materials
naturally warming to room temperature with stirring, the reaction
solution gradually became blue-purple in color in 10 min. The
reaction solution was filtered through a pad of Celite to remove the
insoluble solid and evaporated to dryness under reduced pressure
to give the product as a dark purple powder; yield 120 mg (99%).
Dark purple crystals suitable for X-ray diffraction analysis were
Compounds [R-PNP]NiCl37,38 were prepared according to the
procedures reported previously. All other chemicals were obtained
from commercial vendors and used as received.
◦
1
X-Ray crystallography
grown from a concentrated diethyl ether solution at −35 C. H
NMR (C6D6, 500 MHz) d 7.75 (d, 2, Ar), 7.45 (m, 2, Ar), 7.17 (m,
6, Ar), 6.75 (t, 1, Ar), 6.70 (t, 2, Ar), 2.29 (m, 4, CHMe2), 1.53
(dd, 12, CHMe2), 1.35 (dd, 12, CHMe2), −1.18 (s, 1, NiNHPh).
Table
2
summarizes the crystallographic data for [iPr-
PNP]Ni(NHPh) and [iPr-PNP]Ni(OPh). Data were collected
on a Bruker-Nonius Kappa CCD diffractometer with graphite
1
1
31P{ H} NMR (C6D6, 202.3 MHz) d 29.25. 31P{ H} NMR (diethyl
˚
monochromated Mo-Karadiation (k= 0.7107 A). Structures were
ether, 80.95 MHz) d 28.78. 31P{ H} NMR (CH2Cl2, 80.95 MHz) d
1
solved by direct methods and refined by full matrix least squares
procedures against F2 using the WinGX crystallographic software
package or SHELXL-97.44 All full-weight non-hydrogen atoms
were refined anisotropically. All hydrogen atoms were placed in
calculated positions. The structures of [iPr-PNP]Ni(NHPh) and
[iPr-PNP]Ni(OPh) contain disordered diethyl ether molecules. At-
tempts to obtain a suitable disorder model failed. The SQUEEZE
procedure of the Platon program45 was used to obtain a new set
of F2 (hkl) values without the contribution of solvent molecules,
leading to the presence of solvent accessible voids in both struc-
tures. The refinement reduced R1 values of [iPr-PNP]Ni(NHPh)
and [iPr-PNP]Ni(OPh) to 0.0573 and 0.0530, respectively. CCDC
reference numbers 644274 and 644275.
29.10. 13C{ H} NMR (C6D6, 125.5 MHz) d 164.02 (t, JCP = 12.3,
1
C), 160.49 (s, ipso-C6H5), 132.33 (s, CH), 131.79 (s, CH), 129.30 (s,
CH), 121.14 (t, JCP = 18.7, C), 117.46 (s, CH), 116.83 (t, JCP = 2.8,
1
CH), 116.80 (t, JCP = 5.0, CH), 110.63 (s, CH), 24.30 (t, JCP
=
10.9, CHMe2), 18.48 (t, JCP = 1.9, CHMe2), 17.68 (s, CHMe2).
Anal. calcd for C30H42N2NiP2: C, 65.34; H, 7.68; N, 5.08. Found:
C, 65.30; H, 7.66; N, 4.83%.
Synthesis of [Cy-PNP]Ni(NHPh)
n-BuLi (0.14 mL, 1.6 M in hexane, 0.22 mmol) was added to a THF
solution (1 mL) of aniline (0.02 mL, 0.22 mmol) at −35 ◦C. The
solution was stirred at room temperature for 10 min and added to
a pre-chilled green solution of [Cy-PNP]NiCl (144 mg, 0.22 mmol)
in THF (2 mL) at −35 ◦C. The reaction solution was stirred at
room temperature to become reddish purple in color in 10 min and
then blue-purple after 6 h. All volatiles were removed in vacuo. The
solid residue was triturated with pentane (2 mL) and dissolved in
diethyl ether (4 mL). The ether solution was filtered through a
pad of Celite and evaporated to dryness under reduced pressure
to afford the product as a dark purple solid; yield 63 mg (41%).
1H NMR (C6D6, 500 MHz) d 7.56 (d, 2, Ar), 7.20 (t, 2, Ar), 7.03
(m, 2, Ar), 6.99 (d, 2, Ar), 6.92 (t, 2, Ar), 6.48 (t, 1, Ar), 6.45 (t, 2,
Ar), 2.43 (d, 4, Cy), 2.07 (m, 4, Cy), 1.80 (m, 8, Cy), 1.61 (m, 12,
Cy), 1.50 (d, 4, Cy), 1.18 (q, 4, Cy), 1.03 (m, 8, Cy), −1.26 (s, 1,
Synthesis of [Ph-PNP]Ni(NHPh)
n-BuLi (0.14 mL, 1.6 M in hexane, 0.220 mmol) was added to
a solution of aniline (0.02 mL, Lancaster, 0.220 mmol) in THF
(2 mL) at −35 ◦C. After being stirred at room temperature for
1 h, the solution was cooled to −35 ◦C again and then added to a
solution of [Ph-PNP]NiCl (138 mg, 0.220 mmol) in THF (8 mL)
at −35 ◦C. The reaction mixture was naturally warmed and stirred
at room temperature for 30 min to give a greenish blue solution.
All volatiles were removed in vacuo. The resulting residue was then
triturated with pentane (1 mL × 3) and the product was extracted
with benzene (8 mL). The benzene solution was passed through a
pad of Celite and evaporated to dryness, affording the product as
a dark greenish blue solid; yield 53.5 mg (98.5%). 1H NMR (C6D6,
500 MHz) d 7.73 (m, 7, Ar), 7.66 (dt, 2, Ar), 7.06 (dt, 2, Ar), 7.01
(m, 5, Ar), 6.95 (m, 8, Ar), 6.89 (t, 2, Ar), 6.66 (m, 4, Ar), 6.40 (t, 2,
1
1
NiNH). 31P{ H} NMR (THF, 121.4 MHz) d 21.57. 31P{ H} NMR
(C6D6, 202.3 MHz) d 21.53.13C{ H} NMR (C6D6, 125.7 MHz) d
1
164.23 (t, JCP = 12.82, C), 160.15 (s, C), 132.44 (s, CH), 131.69 (s,
CH), 129.34 (s, CH), 121.56 (t, JCP = 18.35, C), 117.65 (s, CH),
116.86 (s, CH), 116.82 (t, JCP = 2.03, CH), 110.63 (s, CH), 33.92 (t,
Ar), 6.29 (t, 1, Ar), −1.10 (s, 1, NH). 31P{ H} NMR (C6D6, 202.3
1
MHz) d 12.93. 31P{ H} NMR (THF, 80.95 MHz) d 12.82. 13C{ H}
NMR (C6D6, 125.7 MHz) d 163.25 (t, JCP = 14.5 Hz, C), 158.71
(s, NCipso), 134.82 (s, CH), 133.88 (t, JCP = 6.3 Hz, CH), 132.29 (s,
1
1
1JCP = 10.56, PCH), 28.63 (s, CH2), 27.93 (s, CH2), 27.86 (t, JCP
=
6.41, CH2), 27.49 (t, JCP = 5.03, CH2), 26.68 (s, CH2). Anal. calcd
for C42H58N2NiP2: C, 70.89; H, 8.22; N, 3.94. Found: C, 71.06; H,
8.24; N, 3.55%.
CH), 131.35 (t, JCP = 22.2 Hz, C), 130.67 (s, CH), 129.23 (t, JCP
=
4.6 Hz, CH), 128.71 (s, CH), 123.71 (t, JCP = 22.7 Hz, C), 119.52
(s, CH), 118.05 (t, JCP = 3.1 Hz, CH), 117.58 (t, JCP = 5.0 Hz,
CH), 112.23 (s, CH). Anal. calcd for C42H34N2NiP2: C, 73.37; H,
4.99; N, 4.08. Found: C, 73.24; H, 4.69; N, 4.27%.
Synthesis of NaOPh
Sodium hydride (270 mg, Aldrich, 60% in mineral oil, 6.76 mmol,
1.2 equiv.) was suspended in THF (12 mL) under nitrogen and
cooled to 0 ◦C in an ice bath. Phenol (0.5 mL, Lancaster,
5.63 mmol) was added via a syringe. After being stirred at 0 ◦C for
1 h, the reaction mixture was passed through a pad of Celite and
evaporated to dryness under reduced pressure. The off-white solid
thus obtained was washed with pentane (4 mL × 3) to remove the
mineral oil and dried in vacuo to afford NaOPh as an off-white
solid; yield 640 mg (97.9%).
Synthesis of [iPr-PNP]Ni(NHPh)
Lithium anilide was prepared in situ upon addition of n-BuLi
(0.14 mL, 0.22 mmol) to a soluti◦on of aniline (0.02mL, 0.22 mmol)
in diethyl ether (1 mL) at −35 C with stirring for 10 min. Solid
[iPr-PNP]NiCl (109 mg, 0.22 mmol) was dissolved in toluene
(2 mL) and cooled to −35 ◦C. To the green toluene solution
was added dropwise the diethyl ether solution of LiNHPh. Upon
3324 | Dalton Trans., 2008, 3320–3327
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Synthesis of [Ph-PNP]Ni(OPh)
(C6D6, 500 MHz) d 7.54 (d, 2, Ar), 7.50 (d, 2, Ar), 7.28 (t, 2, Ar),
7.03 (m, 2, Ar), 6.9 (t, 2, Ar), 6.68 (t, 1, Ar), 6.44 (t, 2, Ar), 2.50
(m, 4, PCH), 2.05 (m, 4, Cy), 1.95 (q, 4, Cy), 1.82 (m, 4, Cy),
1.60 (m, 12, Cy), 1.48 (m, 4, Cy), 1.20 (q, 4, Cy), 1.03 (q, 8, Cy).
A colorless solution of NaOPh (18.42 mg, 0.159 mmol) in THF
(2 mL) was added to a green solution of [Ph-PNP]NiCl (100 mg,
0.159 mmol) in THF (6 mL) at −35 ◦C. Upon addition of NaOPh,
the reaction solution became red in color immediately. After
being stirred at room temperature for 30 min, the solution was
evaporated to dryness under reduced pressure. The solid residue
was then triturated with pentane (1 mL × 3) and extracted with
benzene (6 mL). The benzene solution was filtered through a pad
of Celite and the solvent was removed in vacuo, affording the
1
1
31P{ H} NMR (THF, 80.9 MHz) d 20.92. 31P{ H} NMR (C6D6,
1
202.3 MHz) d 21.00. 13C{ H} NMR (C6D6, 125.7 MHz) d 168.95
(s, C), 164.18 (t, JCP = 12.82, C), 132.56 (s, CH), 131.59 (s, CH),
129.26 (s, CH), 121.65 (s, CH), 120.98 (t, JCP = 19.23, C), 117.40 (t,
JCP = 4.53, CH), 117.11 (t, JCP = 2.77, CH), 114.09 (s, CH), 33.34
1
(t, JCP = 11.06, PCH), 28.41 (s, CH2), 27.76 (m, CH2), 27.47 (t,
JCP = 4.53, CH2), 26.61 (s, CH2). Anal. calcd for C42H57NNiOP2:
1
product as a purple solid; yield 100 mg (92%). H NMR (C6D6,
500 MHz) d 7.80 (m, 7, Ar), 7.57 (dt, 2, Ar), 7.10 (m, 2, Ar),
C, 70.80; H, 8.06; N, 1.97. Found: C, 70.56; H, 8.48; N, 1.86%.
6.95–7.05 (m, 15, Ar), 6.84 (t, 2, Ar), 6.75 (t, 2, Ar), 6.42 (t, 1,
Synthesis of NaSPh
1
Ar), 6.38 (m, 2, Ar). 31P{ H} NMR (C6D6, 202.3 MHz) d 8.77.
1
1
31P{ H} NMR (toluene, 80.9 MHz) d 8.65. 31P{ H} NMR (THF,
Sodium hydride (195.7 mg, Aldrich, 60% in mineral oil,
4.892 mmol) was suspended in THF (7 mL) under nitrogen and
cooled to 0 ◦C in an ice bath. Thiophenol (0.5 mL, 4.892 mmol) was
added via a syringe. After being stirred at 0 ◦C for 1 h, the reaction
mixture was evaporated to dryness under reduced pressure. The
solid thus obtained was washed with diethyl ether (4 mL × 3) and
dried in vacuo, affording NaSPh as an off-white solid; yield 530 mg
(82%).
80.9 MHz) d 8.61. 13C{ H} NMR (C6D6, 125.7 MHz) d 167.73
1
(s, OCipso), 163.30 (t, JCP = 14.1 Hz, C), 134.69 (s, CH), 134.21
(t, JCP = 6.3 Hz, CH), 132.31 (s, CH), 130.86 (t, JCP = 22.2 Hz,
C), 130.78 (s, CH), 129.19 (t, JCP = 5.0 Hz, CH), 128.79 (s, CH),
123.16 (t, JCP = 24.1 Hz, C), 122.44 (s, CH), 118.30 (t, JCP
=
3.2 Hz, CH), 118.04 (t, JCP = 5.5 Hz, CH), 114.58 (s, CH). Anal.
calcd for C42H33NNiOP2: C, 73.28; H, 4.83; N, 2.03. Found: C,
73.32; H, 4.90; N, 1.99%.
Synthesis of [Ph-PNP]Ni(SPh)
Synthesis of [iPr-PNP]Ni(OPh)
A colorless solution of NaSPh (21 mg, 0.159 mmol) in THF
(6 mL) was added to a green solution of [Ph-PNP]NiCl (100 mg,
0.159 mmol) in THF (6 mL) at −35 ◦C. Upon addition, the
reaction solution became red in color then turned green in ca.
10 min. After being stirred at room temperature for 30 min, the
solution was evaporated to dryness under reduced pressure. The
residue thus obtained was triturated with pentane (1 mL × 3) and
extracted with benzene (6 mL). The green benzene solution was
filtered through a pad of Celite and the solvent was removed in
vacuo. The resulting solid was triturated with pentane (1 mL ×
3), affording the product as a brownish green powder; yield 60 mg
Diethyl ether (3 mL) was added to a solid mixture of [iPr-
PNP]NiCl (60 mg, 0.12 mmol) and NaOPh (14 mg, 0.12 mmol)
at room temperature. The reaction mixture was stirred at room
temperature for 12 h and filtered through a pad of Celite, which
was further washed with diethyl ether until the washings were
colorless. The diethyl ether solution was evaporated to dryness
under reduced pressure and triturated with pentane (2 mL × 2) to
afford the product as a dark brown solid; yield 43 mg (65%). Dark
brown crystals suitable for X-ray diffraction analysis were grown
◦
1
from a concentrated diethyl ether solution at −35 C. H NMR
(C6D6, 500 MHz) d 7.45 (d, 2, Ar), 7.41 (d, 2, Ar), 7.23 (t, 2, Ar),
6.89 (m, 2, Ar), 6.85 (t, 2, Ar), 6.66 (t, 1, Ar), 6.41 (t, 2, Ar), 2.02 (m,
1
(54%). H NMR (C6D6, 500 MHz) d 7.82 (m, 7, Ar), 7.66 (m, 2,
Ar), 7.38 (m, 2, Ar), 6.95 (m, 14, Ar), 6.88 (t, 3, Ar), 6.59 (t, 1,
1
4, CHMe2), 1.30 (dd, 12, CHMe2), 1.14 (dd, 12, CHMe2). 31P{ H}
1
Ar), 6.42 (t, 2, Ar), 6.37 (t, 2, Ar). 31P{ H} NMR (C6D6, 202.3
1
NMR (diethyl ether, 80.9 MHz) d 28.02. 31P{ H} NMR (C6D6,
1
1
MHz) d 23.83. 31P{ H} NMR (THF, 80.9 MHz) d 23.69. 13C { H}
NMR (C6D6, 125.7 MHz) d 162.66 (t, JCP = 13.8 Hz, C), 144.11
(t, JCP = 6.6 Hz, SC), 134.93 (s, CH), 134.82 (s, CH), 132.40 (S,
1
202.3 MHz) d 28.13. 13C{ H} NMR (C6D6, 125.7 MHz) d 169.19
(s, C), 163.98 (t, JCP = 12.44, C), 132.40 (s, CH), 131.70 (s, CH),
129.25 (s, CH), 121.40 (s, CH), 120.65 (t, JCP = 19.23, C), 117.40
(t, JCP = 4.65, CH), 117.11 (t, JCP = 2.76, CH), 114.13 (s, CH),
23.90 (t, JCP = 11.06, CHMe2), 18.35 (t, JCP = 2.39, CHMe2), 17.60
(s, CHMe2). Anal. calcd for C30H41NNiOP2: C, 65.22; H, 7.49; N,
2.54. Found: C, 65.14; H, 7.50; N, 2.47%.
CH), 130.69 (S, CH), 130.65 (t, JCP = 23.8 Hz, C), 129.04 (t, JCP
=
5.0 Hz, CH), 127.77 (S, CH), 125.29 (t, JCP = 22.9 Hz, C), 123.39
(S, CH), 118.11 (t, JCP = 3.4 Hz, CH), 117.21 (t, JCP = 5.2 Hz,
CH). Anal. calcd for C42H33NNiP2S: C, 71.61; H, 4.72; N, 1.99.
Found: C, 71.76; H, 4.80; N, 1.83%.
Synthesis of [Cy-PNP]Ni(OPh)
Synthesis of [iPr-PNP]Ni(SPh)
A solid mixture of [Cy-PNP]NiCl (50 mg, 0.08 mmol) and
NaOPh (9 mg, 0.08 mmol) was dissolved in THF (3 mL) at
room temperature. The reaction solution was stirred at room
temperature for 15 h and the brownish red solution was evaporated
to dryness under reduced pressure. The solid residue was triturated
with pentane (2 mL) and diethyl ether (5 mL) was added. The ether
solution was filtered through a pad of Celite and evaporated to
dryness to give a brownish red solid, which was triturated with
pentane (2 mL) and dried in vacuo; yield 43 mg (80%). 1H NMR
Diethyl ether (3 mL) was added to a solid mixture of [iPr-
PNP]NiCl (60 mg, 0.12 mmol) and NaSPh (16 mg, 0.12 mmol)
at room temperature. The reaction mixture was stirred at room
temperature for 12 h and filtered through a pad of Celite, which
was further washed with diethyl ether until the washings were
colorless. The diethyl ether solution was evaporated to dryness
under reduced pressure and triturated with pentane (2 mL × 2)
to afford the product as a brownish red solid; yield 54 mg (79%).
1H NMR (C6D6, 500 MHz) d 8.02 (d, 2, Ar), 7.58 (d, 2, Ar), 7.01
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(t, 2, Ar), 6.95 (m, 4, Ar), 6.88 (t, 1, Ar), 6.45 (t, 2, Ar), 2.10 (m,
(s, NCMe3), 35.82 (s, NC(CH3)3). Anal. calcd for C40H38N2NiP2:
C, 71.97; H, 5.74; N, 4.20. Found: C, 71.63; H, 5.42; N, 4.11%.
1
4, CHMe2), 1.37 (dd, 12, CHMe2), 1.13 (dd, 12 CHMe2). 31P{ H}
1
NMR (diethyl ether, 80.9 MHz) d 33.16. 31P{ H} NMR (C6D6,
1
202.3 MHz) d 33.82. 13C{ H} NMR (C6D6, 125.7 MHz) d 163.82
Synthesis of [Ph-PNP]Ni(OtBu)
(t, JCP = 12.32, C), 148.14 (t, JCP = 3.77, C), 133.64 (s, CH), 132.39
(s, CH), 131.83 (s, CH), 128.02 (s, CH), 122.46 (s, CH), 122.09 (t,
JCP = 18.35, C), 117.05 (t, JCP = 3.27, CH), 116.74 (t, JCP = 4.65,
CH), 24.87 (t, JCP = 11.94, CHMe2), 18.82 (s, CHMe2), 17.90 (s,
CHMe2). Anal. calcd for C30H41NNiP2S: C, 63.39; H, 7.28; N,
2.47. Found: C, 63.18; H, 7.29; N, 2.43%.
A colorless solution of NaOtBu (7.6 mg, 0.079 mmol) in THF
(2 mL) was added dropwise to a green solution of [Ph-PNP]NiCl
(50 mg, 0.079 mmol) in THF (4 mL) at −35 ◦C. Upon addition,
the solution became deep blue in color. After being stirred at room
temperature for 30 min, the reaction solution was evaporated to
dryness under reduced pressure. The residue was triturated with
pentane (1 mL × 3) and the product was extracted with diethyl
ether (6 mL). The ether solution was passed through a pad of
Celite and evaporated to dryness to afford the product as a deep
blue solid; yield 40 mg (75%). 1H NMR (C6D6, 500 MHz) d 8.07
(m, 8, Ar), 7.48 (dt, 2, Ar), 7.07 (m, 14, Ar), 6.78 (t, 2, Ar), 6.34
Synthesis of [Cy-PNP]Ni(SPh)
THF (3 mL) was added to a solid mixture of [Cy-PNP]NiCl
(80 mg, 0.12 mmol) and NaSPh (16 mg, 0.12 mmol) at room
temperature. The reaction solution was stirred at room tempera-
ture for 15 h to become reddish purple in color. All volatiles were
removed in vacuo. The solid residue was triturated with pentane
(2 mL) and dissolved in diethyl ether (5 mL). The ether solution
was filtered through a pad of Celite and evaporated to dryness
under reduced pressure to afford the product as a reddish purple
solid; yield 85 mg (96%). 1H NMR (C6D6, 500 MHz) d 8.03 (d, 2,
Ar), 7.68 (d, 2, Ar), 7.13 (m, 2, Ar), 7.03 (t, 2, Ar), 6.96 (t, 2, Ar),
6.90 (t, 1, Ar), 6.49 (t, 2, Ar), 2.41 (d, 4, Cy), 2.12 (m, 4, Cy), 1.87
(m, 8, Cy), 1.78 (m, 4, Cy), 1.61 (m, 8, Cy), 1.48 (m, 4, Cy), 1.17
1
(t, 2, Ar), 0.97 (s, 9, CH3). 31P{ H} NMR (C6D6, 202.3 MHz) d
1
1
−1.78. 31P{ H} NMR (THF, 80.9 MHz) d −1.86. 31P{ H} NMR
(toluene, 80.9 MHz) d −1.77. 13C{ H} NMR (C6D6, 125.7 MHz)
1
d 163.02 (t, JCP = 14.1 Hz, C), 134.77 (t, JCP = 5.9 Hz, CH), 134.47
(s, CH), 132.04 (t, JCP = 20.9 Hz, C), 131.83 (s, CH), 130.62 (s,
CH), 129.10 (t, JCP = 4.5 Hz, CH), 125.32 (t, JCP = 22.7 Hz, C),
117.88 (t, JCP = 4.5 Hz, CH), 117.86 (t, JCP = 2.8 Hz, CH), 68.60 (s,
OCMe3), 35.43 (s, CH3). Anal. calcd for C40H37NNiOP2: C, 71.86;
H, 5.58; N, 2.10. Found: C, 71.42; H, 5.36; N, 1.63%. Multiple
attempts to obtain satisfactory analysis data were not successful.
The NMR spectra of this compound are supplied as ESI.†
1
(q, 4, Cy), 1.05 (m, 8, Cy). 31P{ H} NMR (THF, 121.4 MHz) d
1
1
27.20. 31P{ H} NMR (C6D6, 202.3 MHz) d 26.62. 13C{ H} NMR
(C6D6, 125.7 MHz) d 164.13 (t, JCP = 12.82, C), 147.92 (t, JCP
=
3.65, ipso-SPh), 133.97 (s, CH), 132.63 (s, CH), 131.66 (s, CH),
Acknowledgements
128.17 (s, CH), 122.55 (s, CH), 122.35 (t, JCP = 18.35, C), 117.09
1
We thank the National Science Council of Taiwan for financial
support (NSC 96–2628-M-110–007-MY3) of this work, Mr Ting-
Shen Kuo (National Taiwan Normal University) for solving the X-
ray structures, Prof. Hon Man Lee (National Changhua University
of Education) for assistance on the SQUEEZE procedure, and the
National Center for High-performance Computing (NCHC) for
computer time and facilities. Comments and suggestions from the
reviewer on crystallographic data are highly appreciated.
(t, JCP = 2.77, CH), 116.80 (t, JCP = 4.65, CH), 34.56 (t, JCP
=
11.94, PCH), 29.10 (s, CH2), 28.32 (s, CH2), 27.78 (t, JCP = 5.53,
CH2), 27.70 (t, JCP = 5.41, CH2), 26.79 (s, CH2). Anal. calcd for
C42H57NNiP2S: C, 69.24; H, 7.89; N, 1.92. Found: C, 69.34; H,
8.03; N, 1.91%.
Synthesis of [Ph-PNP]Ni(NHtBu)
A solution of t-butyl amine (0.02 mL, Acros, 0.189 mmol) in
THF (2 mL) was cooled to −35 ◦C and n-butyllithium (0.12 mL,
1.6 M hexane solution, 0.189 mmol) was added dropwise. After
being stirred at room temperature for 1 h, the solution was cooled
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◦
to −35 C again and added dropwise to a cold solution of [Ph-
PNP]NiCl (119 mg, 0.189 mmol) in THF (8 mL) at −35 ◦C. Upon
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dryness in vacuo to afford the product as a brown solid; yield
1
122.5 mg (98%). H NMR (500 MHz, C6D6) d 8.08 (m, 8, Ar),
7.40 (m, 2, Ar), 7.06 (m, 14, Ar), 6.79 (t, 2, Ar), 6.35 (t, 2, Ar),
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1
(C6D6, 202.3 MHz) d 12.76. 31P{ H} NMR (THF, 80.9 MHz) d
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1
12.49. 13C{ H} NMR (C6D6, 125.7 MHz) d 162.10 (t, JCP = 13.1,
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C), 134.75 (t, JCP = 6.4, CH), 133.89 (s, CH), 132.99 (t, JCP
=
20.0, C), 131.79 (s, CH), 130.57 (s, CH), 129.09 (t, JCP = 5.0, CH),
128.91 (s, CH), 127.04 (t, JCP = 23.6, C), 117.27 (s, CH), 53.12
3326 | Dalton Trans., 2008, 3320–3327
This journal is
The Royal Society of Chemistry 2008
©

View Article Online
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