Synthesis and characterisation of six Fe(II or III), Co(II) or Zr(IV) complexes containing the ligand [CH(SiMe2R)P(Ph)2NSiMe3]- (R = Me, NEt2) and of [Co{N(SiMe3)C(Ph)C(H)P(Ph)2NSiMe3}2]

Article abstract of DOI:10.1016/j.jorganchem.2008.09.020

The C,N-(trimethylsilyliminodiphenylphosphoranyl)silylmethylmetal complexes [Fe(L)₂] (3), [Co(L)₂] (4), [ZrCl₃(L)]·0.83CH₂Cl₂ (5), [Fe(L)₃] (6), [Fe(L′)₂] (7) and [Co(L′)₂] (8) have been prepared from the lithium compound Li[CH(SiMe₂R)P(Ph)₂NSiMe₃] [1a, (R = Me) {≡ Li(L)}; 1b, (R = NEt₂) {≡ Li(L′)}] and the appropriate metal chloride (or for 7, FeCl₃). From Li[N(SiMe₃)C(Ph)C(H)P(Ph)₂NSiMe₃] [≡ Li(L″)] (2), prepared in situ from Li(L) (1a) and PhCN, and CoCl₂ there was obtained bis(3-trimethylsilylimino- diphenylphosphoranyl-2-phenyl-N-trimethylsilyl-1-azaallyl-N,N′)cobalt(II) (9). These crystalline complexes 3-9 were characterised by their mass spectra, microanalyses, high spin magnetic moments (not 5) and for 5 multinuclear NMR solution spectra. The X-ray structure of 3 showed it to be a pseudotetrahedral bis(chelate), the iron atom at the spiro junction.

Full text of DOI:10.1016/j.jorganchem.2008.09.020

Journal of Organometallic Chemistry 693 (2008) 3767–3770
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Synthesis and characterisation of six Fe(II or III), Co(II) or Zr(IV) complexes
containing the ligand [CH(SiMe2R)P(Ph)2NSiMe3]ꢀ (R = Me, NEt2) and
of [Co{N(SiMe3)C(Ph)C(H)P(Ph)2NSiMe3}2]
a,b
Peter B. Hitchcock a, Michael F. Lappert a, , Zhong-Xia Wang
*
a Department of Chemistry, University of Sussex, Brighton BN1 9QJ, UK
b Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 31 July 2008
Received in revised form 5 September 2008
Accepted 10 September 2008
Available online 18 September 2008
The C,N-(trimethylsilyliminodiphenylphosphoranyl)silylmethylmetal complexes [Fe(L)2] (3), [Co(L)2] (4),
[ZrCl3(L)]ꢁ0.83CH2Cl2 (5), [Fe(L)3] (6), [Fe(L0)2] (7) and [Co(L0)2] (8) have been prepared from the lithium
compound Li[CH(SiMe2R)P(Ph)2NSiMe3] [1a, (R = Me) {ꢂ Li(L)}; 1b, (R = NEt2) {ꢂ Li(L0)}] and the appro-
priate metal chloride (or for 7, FeCl3). From Li[N(SiMe3)C(Ph)C(H)P(Ph)2NSiMe3] [ꢂ Li(L00)] (2), prepared
in situ from Li(L) (1a) and PhCN, and CoCl2 there was obtained bis(3-trimethylsilylimino- diphenylphos-
phoranyl-2-phenyl-N-trimethylsilyl-1-azaallyl-N,N0)cobalt(II) (9). These crystalline complexes 3–9 were
characterised by their mass spectra, microanalyses, high spin magnetic moments (not 5) and for 5 mul-
tinuclear NMR solution spectra. The X-ray structure of 3 showed it to be a pseudotetrahedral bis(chelate),
the iron atom at the spiro junction.
Keywords:
Late transition metals
C,N-Chelate ligands
N,N-Chelate ligands
Structures
Ó 2008 Elsevier B.V. All rights reserved.
Magnetism
1. Introduction
shown by one of us, novel Ni(II) complexes, bearing a monoanionic
P,N,P-, P,N,N-, or N,N,N-pincer ligand containing the ligand C00, were
Metal complexes containing the 1-aza-2-phospha(V)allyl ligand
A have been much studied; for a review of such s- and p-block me-
tal complexes, see Ref. [1]. Transition metal complexes are more
effective catalysts for Kumada cross-coupling reactions [11].
R3
N
R1
scant [2]. Relevant to the present study is
a
report on
R1
Ph
R
Pri2P
P
Ph2P
N
Ph2P
N
t
Ph2P
N
PPh2
N
R2
,
obtained from
[Zr{CH(C6H4Bu -4)P(Ph)2NMes}(NMe2)3]
C
N
N
N
N
R2
R3
Zr(NMe2)4 and CH2(C6H4But-4) P(Ph)2NMes(Mes = C6H2Me3-2,4,6)
[3]. As far as we are aware, related iron and cobalt complexes have
not previously been described.
R4
R
Me3Si
Ph
R
H
C'
A
B
C
C''
The precursors used in the present study, Li(L) (1a) and Li(L0)
The bis(phosphinimino)methanido ligand B and analogues with
different substituents at phosphorus have featured widely in d-
block metal chemistry; for eleven pre-2005 citations, see Ref. [4].
Recent examples include complexes of yttrium [5], selected late
3d metals [6,7] and ruthenium [8]. The 3d metal complexes to have
been described are [M(B)X] (M = Mn, Fe or Co; R = Mes and
X = N(SiMe3)2 or OCPh3) [6a], [M(B){N(SiMe3)2}] (M = Mn, Fe or
Co, R = C6H3Pri2-2,6) [6b], [Co(B)Cl] (R = C6H3Pri2-2,6 or Mes) and
[Ni(B)Br] (R = C6H3Pri2-2,6 or Mes) [7].
(1b), were prepared by metallation of H(L) [12] or H(L0); the latter
was obtained from Li[CH2P(Ph)2NSiMe3] and SiCl(Me)2NEt2 [13].
The crystalline [Li(L)]2 and [Li(L)(OEt2)2] were X-ray-characterised
[13]. The compound Li(L00) (2), previously prepared as an oil in situ
from 1a and PhCN, was characterised as the crystalline potassium
derivative [K(L00)(tmeda)]2 [14].
SiMe3
N
SiMe3
N
A related ligand C has an iminodiphenylphosphoranyl-1-azaal-
lyl skeleton.
A lithium derivative, prepared in situ from
Ph2P
H
Ph2P
H
Ph
R1CH2P(Ph)2=NPh and successively LiNPri2 and a cyanoarene, was
used for various organic transformations [9]. An iron(II) complex
[Fe(C0)2] was obtained from [Fe{N(SiMe3)2}2] and 2 HC0 [10]. As
Ph2P
N
C
C
N
SiMe2NEt2
Me3Si
SiMe3
SiMe3
L
L'
L''
* Corresponding author. Tel.: +44 1273 678316; fax: +44 1273 677196.
E-mail address: m.f.lappert@sussex.ac.uk (M.F. Lappert).
0022-328X/$ - see front matter Ó 2008 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2008.09.020

3768
P.B. Hitchcock et al. / Journal of Organometallic Chemistry 693 (2008) 3767–3770
2. Results and discussion
2.1. Trimethylsilyliminodiphenylphosphoranyltrimethylsilylmethyl-
C,N-metal complexes 3-5
The synthesis of four crystalline metal complexes 3–6 derived
from the ligand L is summarised in Scheme 1. Thus, reaction in
the appropriate stoichiometry of FeCl2, CoCl2, ZrCl4 or FeCl3 with
Li(L) (1a) in thf furnished crystals of 3 or 4 from hexane, 5 from
dichloromethane or benzene, or 6 from pentane. No attempt was
made to optimise yields, which for 3 or 4 were excellent, of 5
was modest and of 6 was poor. The compounds were characterised
by satisfactory C, H and N microanalyses, mass spectra {parent
molecular cations for 3–5 and [Fe(L)2]+ for 6}, and for the zirco-
nium 5 multinuclear (1H, 13C, 31P) NMR solution spectra. The mag-
netic moments of the coloured compounds 3, 4 and 6 in benzene
were examined by the Evans NMR method at ambient tempera-
ture, showing that each was high-spin. The figures for leff of 5.4
Fig. 1. Molecular structure of complex 3 (50% thermal ellipsoids).
(4) to 6.3 lB (3) were considerably higher than for spin-only (lS
)
values (e.g., 4.9 for Fe2+ and 3.9lB for Co2+), lower than lJ (e.g.,
6.7 for Fe2+ and 6.6lB for Co2+), bur larger than lS+L (e.g., 5.5 for
Fe2+ and 5.2lB for Co2+). The result for leff of 3 may be compared
with those for [Fe{(N(C6H3Pri2-2,6)C(Me))2CH}{N(SiMe3)2}] [15],
[Fe(B){N(SiMe3)2}] (R in B = SiMe3) [6a] and [Fe{(N(Si-
Table 1
Selected bond distances (Å) and angles (°) for 3
Fe–N1
Fe–N2
Fe–C1
Fe–C20
N1–P1
N2–P2
C1–P1
C20–P2
2.099(3)
2.062(3)
2.166(4)
2.205(4)
1.619(4)
1.609(3)
1.693(4)
1.733(4)
N1–Si1
N2–Si3
C1–Si2
C20–Si4
P1–C2
P2–C21
P1–C8
P2–C27
1.739(4)
1.719(3)
1.804(4)
1.835(4)
1.818(5)
1.822(4)
1.819(5)
1.809(4)
Me3)C(Ph))2CH}2] [16] of 4.94
and those of 4 with the 4.9lB for [Co(B){N(SiMe3)2}] (R in
B = SiMe3) [6a]. The leff for 6 is close to the lS for Fe3+ of 5.9lB
lB, 5.25lB and 5.06lB, respectively;
.
We are unable to account for the high value of leff for 3; it would
have been useful to obtain variable temperature data on the solid
sample of this compound using a SQUID magnetometer.
N1–P1–C1
N2–P2–C20
P1–C1–Fe
P2–C20–Fe
P1–N1–Fe
P2–N2–Fe
C1–Fe–N1
C20–Fe–N2
C1–Fe–C20
N1–Fe–N2
104.9(2)
N1–P1–C8
N2–P2–C27
N1–P1–C2
N2–P2–C21
C1–P1–C8
C20–P2–C27
C1–P1–C2
C20–P2–C21
C1–Fe–N2
C20–Fe–N1
113.2(2)
111.33(19)
111.5(2)
111.25(18)
109.9(2)
111.79(19)
115.0(2)
113.8(2)
120.76(16)
136.27(16)
105.12(18)
86.46(19)
84.90(16)
90.67(16)
92.96(16)
76.05(15)
76.88(14)
123.97(16)
129.88(15)
The molecular structure of the crystalline Fe(II) compound 3 is
shown in an ORTEP representation in Fig. 1. Selected bond lengths
and angles are listed in Table 1. The FeC20P2N2 ring deviates only
very slightly from planarity, but the FeC1P1N1 ring somewhat
more so; the dihedral angle between them is 88.74(14)°. The aver-
age Fe–N bond length of 2.08 Å is longer than values for related
molecules; e.g., 1.916(4) in [Fe{CH(SiMe3)C(But)NSiMe3}2] (D)
[17]. The mean Fe–C distance of 2.185 Å is unexceptional; cf.,
2.105(5) in D [17]. The average P–N (1.615 Å), endocyclic P–C
(1.71 Å) bond lengths and the average endocyclic N–P–C angle
(105°) in 3 may be compared with the corresponding data for
iron(III) chloride was, however, surprising. Thus, [Fe(L0)2] (7) was
isolated by treating FeCl3 with 3 Li(L0) in thf, using similar reaction
conditions to those which had been successfully employed for the
synthesis of [Fe(L0)3], vide infra. The first formed intermediate in
both reactions is likely to have been E (R = Me or NEt2). The
diethylamino substituent is believed for stereoelectronic reasons
to have made the corresponding species E (R = NEt2) kinetically la-
bile, homolysis furnishing FeCl2 [and therefrom 7, with 2 Li(L0), by
analogy with the synthesis of 8 from CoCl2; the reaction FeCl2 + 2
Li(L0) was not studied separately] and the appropriate carbon-cen-
tred radical which may have been converted to the dimer F.
Although no attempt was made to isolate F, it is noted that a close
analogue [Me3SiN=P(Ph)2CH2-]2 has long been known [18a] and is
readily deprotonated [18b].
[Zr{CH(C6H4But-4)P(Ph)2NC6H2Me3-2,4,6}(NMe2)3]
of
1.613(3) Å,
1.735(3) Å and 99.27(14)°, respectively, [3].
2.2. Trimethylsilyliminodiphenylphosphoranyldiethylaminodimethyl-
silylmethyl-C,N-metal complexes 7 and 8
The preparation in high yield of the crystalline metal com-
pounds 7 and 8 derived from the lithium salt 1b is outlined in
Scheme 2. The outcome for 8 was unexceptional, in that it was ob-
tained from cobalt(II) chloride and 2 Li(L0). The formation of 7 from
Scheme 1.
Scheme 2.

P.B. Hitchcock et al. / Journal of Organometallic Chemistry 693 (2008) 3767–3770
3769
spec instrument. The magnetic momentswere determinedby Evans’
method on dilute standard solutions in C6H6/C6D6 at ambient tem-
perature, with C6H6 in a sealed capillary as external standard. The
compounds Li[CH(SiMe2R) P(Ph)2NSiMe3] [R = Me (1a), NEt2 (1b)]
were prepared as previously described [13]. The metal chlorides
(FeCl2, FeCl3, CoCl2, ZrCl4) were commercial samples (Aldrich) and
were rigorously dried before use.
SiMe3
N
Me3Si
SiMe3
Ph
Ph
N
P
N
P
Ph
Ph
Ph
Ph
P
C
H
Cl
Cl
CH
Si
CH
Si
Fe
Si
Et2N
NEt2
[Fe{CH(SiMe )P(Ph) NSiMe } ]
R
3.2. Preparation of
(3)
3 2
Me
3
2
Me
Me
Me
Me
Me
Iron(II) chloride (0.18 g, 1.42 mmol) was added to a stirred solu-
tion of the lithium compound Li(L) (1a) (1.04 g, 2.85 mmol) in thf
(30 cm3) at –78 °C. The mixture was allowed to warm to room tem-
perature and was stirred for ca. 12 h. Volatiles were removed in va-
cuo and the residue was extracted with hexane. The filtered extract
was concentrated to ca. 3 cm3, which after ca. 12 h at room tem-
perature yielded yellow crystals of 3a (0.88 g, 82%), mp. 209 C (de-
comp.), leff 6.4lB (C38H58FeN2P2Si4 requires C, 59.0; H, 7.56; N,
3.62. Found: C, 58.5; H, 7.49; N, 3.53%). X-ray quality crystals of
3 were obtained from hexane.
E
F
The coloured paramagnetic compounds 7 and 8 showed parent
ions in their EI-mass spectra, but the C, H, N microanalyses were
satisfactory only for 7. The magnetic moments indicated that both
7 and 8 are high spin, with the leff values, as for 3 and 4, signifi-
cantly greater than due solely to spin-only.
2.3. The bis[3-trimethylsilyliminodiphenylphosphoranyl-2-phenyl-1-
trimethylsilylazaallyl]cobalt(II) complex 9
[Co{CH(SiMe )P(Ph) NSiMe } ]
3.3. Preparation of
(4)
3 2
3
2
The blue complex 4 (0.37 g, 69%), mp. 245–248 °C, leff 5.4lB
(C38H58CoN2P2Si4 requires C, 58.8; H, 7.53; N, 3.61. Found: C, 58.5;
H, 7.51; N, 3.54%) was obtained, using a similar procedure to that
for 3, from 1a (0.50 g, 1.37 mmol) and CoCl2 (0.09 g, 0.69 mmol).
Compound 9 was prepared as shown in Scheme 3. Thus, treat-
ment of cobalt(II) chloride with 2 Li(L00) (2), prepared in situ from
equivalent portions of Li(L) (1a) and benzonitrile in thf, and crys-
tallisation from hexane afforded in good yield blue crystals of 9.
The rate of this reaction was slower than those for the cobalt(II)
complexes 4 or 8. If the reaction time was insufficiently long, green
crystals of a presumed monosubstituted cobalt complex were
formed. [Attempts to prepare an iron(II) analogue of 9 from FeCl2
and 2 Li(L00) were unsuccessful; unidentified mixtures of products
were obtained.]
3.4. Preparation of [ZrCl3{CH(SiMe3)P(Ph)2NSiMe3}] (5)
Zirconium(IV) chloride (0.72 g, 3.09 mmol) was added to a stir-
red solution of 1a (1.12 g, 3.07 mmol) in toluene (30 cm3) at
–50 °C. The mixture was brought to room temperature and stirred
for ca. 20 h. Volatiles were removed in vacuo and the residue was
extracted with dichloromethane. The filtered extract was concen-
trated to ca. 2 cm3, which after 12 h furnished the colourless crys-
talline complex 5 as the 0.83 CH2Cl2 adduct (0.91 g, 47%), which
upon being washed with benzene gave the crystalline complex as
Characterisation of 9 was by C, H, N microanalysis, the mass
spectrum showing the molecular cation and appropriate frag-
ments, and the magnetic moment. The value for leff was similar
to those found for 4 and 8, being significantly greater than lS
.
5
as
the
0.57
C6H6
adduct,
mp.
240–245 °C
3. Experimental
(C19H29Cl3NPSi2Zrꢁ0.57C6H6 requires C, 44.8; H, 5.44; N, 2.33.
Found: C, 45.0; H, 5.34; N, 2.20%). 1H NMR (CDCl3): d –0.14 [s,
9H, CHSi(CH3)3], 0.20 [s, 9H, NSi(CH3)3], 1.64 [d, 1 H, 2J (1Hꢀ31P)
14.1 Hz, CH], 7.42 (s, 3.4H, C6H6), 7.56–7.62 (m, 6H, Ph), 7.79–
7.92 (m, 4H, Ph); 13C{1H} NMR (C5D5N): d 3.04 [d, 3J (13Cꢀ31P)
4.5 Hz, Si(CH3)3], 3.90 [d, 3J (13Cꢀ31P) 3.1 Hz, Si(CH3)3], 33.4 [d, 1J
3.1. General details
Syntheses were carried out under an atmosphere of argon or in a
vacuum, using Schlenk apparatus and vacuum line techniques. The
solvents used were reagent grade or better and were freshly distilled
under dry nitrogen gas and freeze/thaw degassed prior to use. The
drying agents employed were sodium benzophenone (C6H6, C6D6,
C6H5Me, Et2O, thf), sodium-potassium alloy (C5H12, C6H14), or phos-
phorus(V) oxide (CH2Cl2). The solvents for NMR spectroscopy
(CDCl3, C5D5N) were stored over molecular sieves (A4). Elemental
analyses were obtained by Medac Ltd., Brunel University. Melting
points were measured in sealed capillaries. The 1H-, 13C{1H}- and
31P{1H}- NMR spectra were recorded using a Bruker WM-360 instru-
mentandwere referencedinternally(1H, 13C) toresidual solventres-
onances, orexternally(31P, with85%aq. H3PO4 as standard). Electron
impact mass spectra were taken from solid samples, with a VG Auto-
(
(
13Cꢀ31P) 39.3 Hz, CH], 129.1 [d, J (13Cꢀ31P) 5.0 Hz], 129.2 [d, J
13Cꢀ31P) 5.0], 131.4 [d, J (13Cꢀ31P) 11.1 Hz], 132.4 [d, J (13Cꢀ31P)
11.3 Hz], 133.0 (Ph); 31P{1H} NMR (CDCl3): d 25.3.
[Fe{CH(SiMe )P(Ph) NSiMe } ]
3.5. Preparation of
(6)
3 3
3
2
Iron(III) chloride (0.13 g, 0.80 mmol) was added to a stirred
solution of Li(L) (1a) (0.91 g, 2.49 mmol) in thf (30 cm3) at
–78 °C. The mixture was brought to room temperature and stirred
for ca. 12 h. Volatiles were removed in vacuo and the residue was
extracted with pentane. The filtered extract was concentrated in
vacuo to ca. 2 cm3, yielding after 12 h at room temperature yel-
low–brown crystals of 6 (0.24 g, 25%), mp. 131–133 °C, leff 6.1lB
(C57H87FeN3P3Si6 requires C, 60.5; H, 7.55; N, 3.71. Found: C,
59.4; H, 7.50; N, 3.64%).
[Fe{CH(SiMe NEt )P(Ph) NSiMe } ]
3.6. Preparation of
(7)
3 2
2
2
2
Iron(III) chloride (0.22 g, 1.36 mmol) was added to a stirred
solution of Li(L0) (1b) (1.7 g, 4.03 mmol) in thf (30 cm3) at –78 °C.
The mixture was allowed to warm to room temperature and was
Scheme 3.

3770
P.B. Hitchcock et al. / Journal of Organometallic Chemistry 693 (2008) 3767–3770
Table 2
Mass spectral data (EI, 70 eV) on 3–9a
Compound
m/e (relative intensity, %), and assignment
[Fe(L)2] (3)
Co(L)2] (4)
772(100), [M]+; 699(17), [M-SiMe3]+; 487(16), [Fe(L)SiMe3]+; 413(88), [Fe(L)ꢀ1]+
775(22), [M]+; 760(2), [M–Me]+; 702(2), [M–SiMe3]+; 675(8), [M–CHSiMe3–Me+1]+
555(4), [M]+; 540(31), [M–Me]+; 518(14), [M–Cl]+; 464(54), [M–Ph–Me+1]+
[ZrCl3(L)] (5)
[Fe(L)3] (6)
[Fe(L0)2] (7)
[Co(L0)2] (8)
[Co(L00)2] (9)
772(15), [M–L]+; 442(21), [M–L–2Ph–2SiMe3–2Me]+; 428(50), [M–L–2Ph–SiMe3–NSiMe3–2Me]+; 344(42), [HL–Me]+
886(34), [M]+; 814(12), [M–NEt2]+; 470(85), [FeL0–1]+; 401(61), [HL0–Me]+
889(6), [M]+; 818(3), [M–NEt2+1]+; 690(3), [M–2Ph–3Me]+; 616(7), [M–2SiMe2NEt2–CH]+
981(19), [M]+; 967(43), [M–Me+1]+; 879(19), [M–NSiMe3–Me]+; 792(18), [M–2NSiMe3–Me]+
[M]+ represents the parent molecular ion; only the four hightest m/e peaks are listed.
a
Table 3
(k = 0.71069 Å). Crystals were mounted under an inert atmosphere
into a capillary which was then sealed. All non-hydrogen atoms
were anisotropic; H’s were included in riding mode with
Uiso(H) = 1.2 Ueq(C) or 1.5 Ueq(C) for methyl groups. The structure
was refined on all F2 using SHELXL-97 [19]. Further details are in
Table 3.
Selected crystallographic data for 3
Formula
M
Crystal system
Space group
a (Å)
C38H58FeN2P2Si4
773.01
Monoclinic
P21/c (No. 14)
12.935(2)
18.013(9)
19.781(5)
106.28(2)
4424(3)
4
0.55
7775, 0.019
5083
b (Å)
c (Å)
Acknowledgements
b (°)
V (Å3)
Z
We thank the Chinese Government and the British Council for
financial support for Z.-X.W., and Dr. A.V. Protchenko for useful
discussion.
Absorption coefficient (mmꢀ1
)
Unique reflections, Rint
Reflections with I > 2
r
(I) R1, wR2
Final R indices [I > 2
R indices (all data)
r(I)]
0.060, 0.138
0.103, 0.162
Appendix A. Supplementary material
CCDC 696887 contains the supplementary crystallographic data
for complex 3. These data can be obtained free of charge from The
Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/
data_request/cif.
then stirred for ca. 12 h. Volatiles were removed from the red-
brown solution in vacuo. The residue was extracted with pentane.
The filtered extract was concentrated in vacuo to ca. 2 cm3, which
after 12 h at room temperature yielded yellow crystals of 7
(0.94 g, 79%), mp. 151–153 °C,
C, 59.6; H, 8.18; N, 6.31. Found: C, 58.7; H, 8.20; N, 6.21%).
leff 6.0lB (C44H72FeN4P2Si4 requires
References
[1] K. Izod, Coord. Chem. Rev. 227 (2002) 153.
[Co{CH(SiMe2NEt2)P(Ph)2NSiMe3}2]
3.7. Preparation of
(8)
[2] C. Freund, N. Barros, H. Gornitzka, B. Martin-Vaca, L. Maron, D. Bourissou,
Organometallics 25 (2006) 4927. and references therein.
[3] M. Said, M. Thornton-Pett, M. Bochmann, J. Chem. Soc., Dalton Trans. (2001)
2844.
[4] S.A. Ahmed, M.S. Hill, P.B. Hitchcock, Organometallics 25 (2006) 394. and
references therein.
Using a similar procedure to that described for 7, treatment of
cobalt(II) chloride (0.15 g, 1.15 mmol) with 1b (1.0 g, 2.37 mmol)
afforded deep blue crystals of 8 (0.84 g, 80%), mp. 146–149 °C, leff
lB (C44H72CoN4P2Si4 requires C, 59.4; H, 8.15; N, 6.29. Found: C,
61.2; H, 8.55; N, 5.56%).
[5] (a) T.K. Panda, A. Zulys, M.T. Gamer, P.W. Roesky, Organometallics 24 (2005)
2197;
5.9
(b) M. Rastätter, A. Zulys, P.W. Roesky, Chem. Eur. J. 13 (2007) 3606;
(c) M.T. Gamer, P.W. Roesky, I. Palard, M. Le Hellaye, S.M. Guillaume,
Organometallics 26 (2007) 651.
[Co{N(SiMe )C(Ph)C(H)P(Ph) NSiMe } ]
3.8. Preparation of
(9)
3 2
3
2
[6] (a) D.J. Evans, M.S. Hill, P.B. Hitchcock, Dalton Trans. (2003) 570;
(b) M.S. Hill, P.B. Hitchcock, J. Organomet. Chem. 689 (2004) 3163.
[7] S. Al-Benna, M.J. Sarsfield, M. Thornton-Pett, D.L. Ormsby, P.J. Maddox, P. Brès,
M. Bochmann, J. Chem. Soc., Dalton Trans. (2000) 4247.
[8] C. Bibal, M. Pink, Y.D. Smurnyy, J. Tomaszewski, K.G. Caulton, J. Am. Chem. Soc.
126 (2004) 2312.
Cobalt(II) chloride (0.11 g, 0.85 mmol) was added to a solution
of Li(L), prepared from the reaction of the lithium salt 1a (0.65 g,
1.78 mmol) and benzonitrile (0.18 cm3, 1.77 mmol) in thf
(30 cm3), at –78 °C. The stirred mixture was set aside for ca. 12 h,
whereafter the volatiles were removed in vacuo. The residue was
extracted with hexane. The filtered extract was concentrated to
ca. 2 cm3; which, after 12 h at room temperature, yielded dark blue
(0.51 g, 61%), mp. 150–154 °C, leff 5.8lB
(C52H68CoN4P2Si4 requires C, 63.6; H, 6.98; N, 5.70. Found: C,
62.4; H, 7.28; N, 5.43%).
[9] J. Barluenga, F. López, F. Palacios, J. Chem. Res. S 211 (1985) 2541. M (1985)
2541.
[10] A. Murso, D. Stalke, Eur. J. Inorg. Chem. (2004) 4272.
[11] Z.-X. Wang, L. Wang, Chem. Commun. (2007) 2423.
[12] K. Itoh, M. Okamura, Y. Ishii, J. Organomet. Chem. 65 (1974) 327.
[13] P.B. Hitchcock, M.F. Lappert, P.G.H. Uiterweerd, Z.-X. Wang, J. Chem. Soc.,
Dalton Trans. (1999) 3413.
[14] P.B. Hitchcock, M.F. Lappert, Z.-X. Wang, J. Chem. Soc., Dalton Trans. (1997)
1953.
[15] A. Panda, M. Spender, R.J. Wright, M.M. Olmstead, P. Klavins, P.P. Power, Inorg.
Chem. 41 (2002) 3909.
crystals of
9
3.9. Mass spectra of 3–9
[16] P.B. Hitchcock, M.F. Lappert, R. Sablong, J.R. Severn, J. Organomet. Chem. 693
(2009). manuscript in preparation.
[17] A.G. Avent, P.B. Hitchcock, M.F. Lappert, R. Sablong, J.R. Severn,
Organometallics 23 (2004) 2591.
[18] (a) R. Appel, I. Ruppert, Z. Anorg, Allg. Chem. 406 (1974) 131;
(b) M.J. Sarsfield, M. Said, L.A. Gerrard, M. Thornton-Pett, M. Bochmann, J.
Chem. Soc., Dalton Trans. (2001) 822.
The four highest m/e peaks of the EI mass spectra for each of
compounds 3–9, with assignments, are listed in Table 2.
3.10. X-ray crystallographic study
[19] G.M. Sheldrick, SHELXL-97
, Program for the Crystal Structure Refinement,
Universität Göttingen, 1997.
Diffraction data were collected at 293(2) K on an Enraf–Nonius
CAD4 diffractometer using monochromated Mo
Ka radiation