Synthesis and characterization of d0 imido complexes of vanadium. Crystal structure of [V(2,6-iPr2C6H3N)(S 2CNC4H4)3]

Article abstract of DOI:10.1039/a903507i

Interaction of [V(NR)Cl₃] compounds with 1,2-dimethoxyethane (dme) afforded [V(NR)Cl₃(dme)] (R = 2,6-ⁱPr₂C₆H₃ 1a or 1-adamantyl 1b) complexes in a nearly quantitative yield. Compounds 1 are suitable sources for the synthesis of other d⁰ imidovanadium complexes. Metathesis reactions of 1 with the sodium salt of the Klaeui's ligand, NaL_OEt (L_OEt = (H-C₅H₃)Co{P(O)(OEt)₂}₃), yielded complexes [V(NR)Cl₂(L_OEt)] (R = 2,6-ⁱPr₂C₆H₃ 2a or 1-adamantyl 2b). Treatment of 1 with several bidentate monoanionic dithio-ligands, -S₂CR′, gave the corresponding imido complexes of general formulation [V(NR)(S₂CR′)₃] (for R = 2,6-ⁱPr₂C₆H₃; R′ = NC₄H₄ 3a, NⁱPr₂ 4, OⁱPr 5a or SⁱPr 6a; for R = 1-adamantyl; R′ = NC₄H₄ 3b, OⁱPr 5b or SⁱPr 6b). The molecular structure of [V(2,6-ⁱPr₂C₆H₃N)(S ₂CNC₄H₄)₃] 3a has been determined by an X-ray study. Finally, the reaction of 1a with Na(acac), in a 1:2 molar ratio, produces complex [V(2,6-ⁱPr₂C₆H₃N)Cl(acac) ₂] 7. Copyright 1999 by the Royal Society of Chemistry.

Full text of DOI:10.1039/a903507i

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Synthesis and characterization of d0 imido complexes of vanadium.
Crystal structure of [V(2,6-iPr2C6H3N)(S2CNC4H4)3]
Francisco Montilla,a Antonio Pastor,a Angeles Monge,b Enrique Gutiérrez-Pueblab and
Agustín Galindo*a
a Departamento de Química Inorgánica, Universidad de Sevilla, Aptdo 553, 41071 Sevilla,
Spain. E-mail: galindo@cica.es
b Instituto de Ciencia de Materiales, CSIC, Campus de Cantoblanco, 28049 Madrid, Spain
Received 4th May 1999, Accepted 14th June 1999
Interaction of [V(NR)Cl3] compounds with 1,2-dimethoxyethane (dme) afforded [V(NR)Cl3(dme)] (R = 2,6-iPr2C6H3
1a or 1-adamantyl 1b) complexes in a nearly quantitative yield. Compounds 1 are suitable sources for the synthesis
of other d0 imidovanadium complexes. Metathesis reactions of 1 with the sodium salt of the Kläui’s ligand, NaLOEt
(LOEt = (η-C5H5)Co{P(O)(OEt)2}3), yielded complexes [V(NR)Cl2(LOEt)] (R = 2,6-iPr2C6H3 2a or 1-adamantyl 2b).
Treatment of 1 with several bidentate monoanionic dithio-ligands, ϪS2CRЈ, gave the corresponding imido complexes
of general formulation [V(NR)(S2CRЈ)3] (for R = 2,6-iPr2C6H3; RЈ = NC4H4 3a, NiPr2 4, OiPr 5a or SiPr 6a; for R =
1-adamantyl; RЈ = NC4H4 3b, OiPr 5b or SiPr 6b). The molecular structure of [V(2,6-iPr2C6H3N)(S2CNC4H4)3] 3a has
been determined by an X-ray study. Finally, the reaction of 1a with Na(acac), in a 1:2 molar ratio, produces complex
[V(2,6-iPr2C6H3N)Cl(acac)2] 7.
Imido ligands are widely used as stabilizing groups in high-
oxidation-state transition metal complexes.1 Their chemistry
has experienced a remarkable growth in the last years due to the
role they play in many important reactions. In particular, sev-
eral imido derivatives of vanadium have been reported as active
species in significant processes, such as C–H activation,2 poly-
merization of olefins3 and others.4 The use of imido ligands in
vanadium chemistry was initiated mainly by Preuss and co-
workers5 and Maatta and co-workers.6 More recently, a number
parent [V(NR)Cl3] compounds. Additionally, the lability of
of studies7 have been concerned with the properties of d0
dme (single broad resonances arise for the OCH3 and OCH2
groups in the 1H NMR spectra for this ligand) makes 1 suitable
imidovanadium complexes.
starting materials for the synthesis of several d0 imido com-
Following our research in this area, we have extended our
results on imido complexes of molybdenum8 to vanadium
plexes of vanadium.
Interaction of compounds 1 with the sodium salt of
the monoanionic tridentate LOEt ligand [(η-C5H5)Co{P(O)-
(OEt)2}3], in a 1:1 molar ratio, affords the expected [V(NR)Cl2-
(LOEt)] (R = 2,6-iPr2C6H3 2a or 1-adamantyl 2b) compounds in
good yields, eqn. (2). Compounds 2 are orange yellowish crys-
compounds. Very recently, we have employed the complex
[V(2,6-iPr2C6H3N)Cl3(dme)] 1a to prepare [V(2,6-iPr2C6H3N)-
Cl3(P–P)] derivatives.9 The dme was used as a good stabilizing
coligand in [V(NR)Cl3] compounds; its lability in solution
leads to complexes [V(NR)Cl3(dme)] (R = 2,6-iPr2C6H3 1a or
1-adamantyl 1b) in advantageous starting materials. Here, we
report the synthesis and characterization of d0 2,6-diisopropyl-
phenyl- and 1-adamantyl-imido vanadium complexes contain-
ing monoanionic tridentate ligands, such as Kläui’s ligand,10
and monoanionic bidentate dithio-ligands, ϪS2CRЈ. While
our work was in progress, Maatta and co-workers11 reported
the synthesis of related tolylimidovanadium dithiocarbamate
[V(NC6H4Me)(S2CNRЈ2)3] complexes.
Results and discussion
The synthesis of complex [V(2,6-iPr2C6H3N)Cl3(dme)] 1a, by
addition of 1,2-dimethoxyethane (dme) to light petroleum solu-
tions of [V(2,6-iPr2C6H3N)Cl3],12 has recently been reported by
us.9 Following a similar procedure, we have prepared the analo-
gous [V(NC10H15)Cl3(dme)] 1b (C10H15 = 1-adamantyl) as a
brown greenish solid, eqn. (1). The NMR spectra of 1b are in
agreement with this formulation and compare well with the data
of 1a and [Ta(NC10H15)Cl3(dme)].13 The structure proposed is
similar to that reported for complex [V(NtBu)Cl3(dme)].14
The presence of the dme ligand enhances the stability of
complexes 1 making their manipulation easier than that for the
talline materials, readily soluble in common organic solvents,
that exhibit moderate stability to air. A Cs structure may readily
be inferred from their NMR data. For example, three separate
1
triplet signals (1:1:1 intensity ratio) are observed in the H
NMR spectrum of 2a for the methyl groups, POCH2CH3, of
the LOEt ligand. Similarly, an AX2 spin system appears in the
31P-{1H} NMR spectrum of 2 (δA = 105.3, δX = 121.9, JAX = 158
Hz, for 2a). Free rotation around the N–C bond of the
organoimido ligand takes place in solution since, for example
for 2a, only one CH resonance of the iPr groups is observed (1H
J. Chem. Soc., Dalton Trans., 1999, 2893–2896
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Table 1 Selected bond lengths (Å) and angles (Њ) for [V(2,6-iPr2-
C6H3N)(S2CNC4H4)3] 3a
and 13C-{1H} NMR spectra). Related imidovanadium com-
plexes containing hydrotris(pyrazolyl)borato ligands, namely
[V(NR)Cl2TpЈ], are known.3c,15
The interaction of compounds 1 with several dithio-ligands
of general formulation ϪS2CRЈ gives the corresponding [V(NR)-
(S2CRЈ)3] (for R = 2,6-iPr2C6H3; RЈ = NC4H4 3a, NiPr2 4, OiPr
5a or SiPr 6a; for R = 1-adamantyl; RЈ = NC4H4 3b, OiPr 5b or
SiPr 6b) eqn. (3). Complexes 3–6 are orange crystalline
V(1)–N(1)
V(1)–S(3)
V(1)–S(6)
V(1)–S(5)
S(1)–C(1)
S(5)–C(13)
S(3)–C(7)
1.689(8)
V(1)–S(1)
V(1)–S(4)
V(1)–S(2)
S(4)–C(7)
S(6)–C(13)
S(2)–C(1)
N(1)–C(19)
2.494(3)
2.500(3)
2.504(3)
1.676(11)
1.704(11)
1.675(12)
1.374(12)
2.497(3)
2.500(3)
2.564(3)
1.708(10)
1.658(12)
1.680(10)
N(1)–V(1)–S(1)
S(1)–V(1)–S(3)
S(1)–V(1)–S(4)
N(1)–V(1)–S(6)
S(3)–V(1)–S(6)
N(1)–V(1)–S(2)
S(3)–V(1)–S(2)
S(6)–V(1)–S(2)
S(1)–V(1)–S(5)
S(4)–V(1)–S(5)
S(2)–V(1)–S(5)
98.1(3)
N(1)–V(1)–S(3)
N(1)–V(1)–S(4)
S(3)–V(1)–S(4)
S(1)–V(1)–S(6)
S(4)–V(1)–S(6)
S(1)–V(1)–S(2)
S(4)–V(1)–S(2)
N(1)–V(1)–S(5)
S(3)–V(1)–S(5)
S(6)–V(1)–S(5)
92.5(3)
100.6(3)
68.46(9)
139.88(11)
138.69(10)
68.54(10)
139.76(13)
168.2(3)
85.42(10)
69.46(10)
140.37(11)
72.07(10)
98.8(3)
74.63(10)
92.7(3)
149.16(11)
74.54(10)
90.82(11)
89.41(10)
83.35(10)
materials, soluble in Et2O and other more polar solvents, and
moderately stable to air in the solid state.
The overall spectroscopic data for [V(NR)(S2CRЈ)3] com-
plexes are consistent with a pentagonal bipyramidal geometry.
This assumption has been confirmed with the structural charac-
terization of 3a. Seven-co-ordinate pentagonal bipyramidal
structures have been established by X-ray crystallography for
related [V(O)(S2CNEt2)3]16 and [Nb(NC6H4Me-p)(S2CNEt2)3]
1
complexes.17 The H NMR spectra indicate that these com-
plexes are fluxional at room temperature. Besides the character-
istic sharp resonances due to the organoimido ligand, broad
signals are observed for the RЈ groups of the S2CRЈ dithio-
ligands. For example, all the methyl groups of the three dithio-
carbamate S2CNiPr2 ligands of 4 produce a single pattern at
room temperature (very broad signal covering the δ 1.52–0.97
range). Similar fluxional processes have been observed for com-
pounds [M(NRЈ)(S2CNR2)3] (M = Ta or Nb).17
Variable-temperature 1H NMR studies (300 MHz) have been
carried out for complexes 4 and 5a. For 5a the spectrum
obtained at 293 K reveals two broad resonances (pseudotriplet
and doublet, 2:1 ratio) for the methyl groups of the S2COiPr
ligands. In the fast interchange limit, 343 K, a single doublet
resonance is observed for the same groups. The exchange
process responsible for the magnetic equivalence of the Me
groups, observed at 343 K, is the interconversion of the axial
and equatorial co-ordination positions of the pentagonal
bipyramidal arrangement. For both complexes the slow-
Fig. 1 Molecular structure of [V(2,6-iPr2C6H3N)(S2CNC4H4)3].
derivatives, where M is a Group 5 metal and E a multiple
bonded ligand, display high structural similarities.
exchange limit was not reached at 243 K. Similar dynamic
᎐
behaviour has recently been recognized in [Nb(RЈC᎐CRЉ)-
᎐
(S2CNR2)3] complexes18 containing a 4e-alkyne ligand, sug-
gested to be similar to the imido functionality.19
Metathesis reaction of complex 1a with Na(acac), in a 1:2
molar ratio, gives, after appropriate work-up, [V(2,6-
iPr C -
2
6
The molecular structure of [V(2,6-iPr2C6H3N)(S2CNC4H4)3]
3a has been determined by an X-ray study, Fig. 1. Selected bond
distances and angles are collected in Table 1. The structure can
be described as distorted pentagonal bipyramidal. The imido
functionality, that occupies an axial position, is linear
(175.0(7)Њ) and the V(1)–N(1) separation of 1.689(8) Å is in
agreement with a vanadium–nitrogen bond order of three. Two
dithiocarbamate ligands and the S(6) atom fit the equatorial
plane and the S(5) atom occupies the second axial site, trans to
the imide (N(1)–V(1)–S(5) bond angle of 168.2(3)Њ). The
vanadium–equatorial sulfur bond distances span the 2.494(3)–
2.504(3) Å range, whereas the V(1)–S(5) length (2.564(3) Å)
shows the expected trans influence of the imido ligand. The
H3N)Cl(acac)2] 7, eqn. (4), as a brown solid. An alternative
procedure for the synthesis of 7 is the direct interaction of 1a
with Hacac in CH2Cl2 at reflux (see Experimental section). The
structure proposed can easily be deduced from the NMR data.
For example, four carbonyl and four methyl resonances are
detected in the 13C-{1H} NMR spectrum, in agreement with the
presence of two inequivalent acac ligands.
∆(V–S) between the V–Seq and V–Sax is ca. 0.06 Å and compares
᎐
well with the corresponding ∆(Nb–S) in [Nb(PhC᎐CMe)-
᎐
(S2CNMe2)3]18 (ca. 0.06 Å). Larger ∆(M–S) differences and
consequently stronger trans influences can be found in com-
pounds [M(O)(S2CNEt2)3] (∆(V–S) ≈ 0.13 and ∆(Nb–S) ≈ 0.16
Å),16 [V(O)(S2COEt)3] (∆(V–S) ≈ 0.15 Å),20 [Ta(S)(S2CNEt2)3]
(∆(Ta–S) ≈ 0.14 Å),21 [Nb(S)(S2CNEt2)3] (∆(Nb–S) ≈ 0.14 Å)22
and [Nb(NC6H4Me-p)(S2CNEt2)3] (∆(Nb–S) ≈ 0.10 Å).17 All
these complexes that can be regarded as [M(E)(S2CNR2)3]
Experimental
All preparations and other operations were carried out under
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J. Chem. Soc., Dalton Trans., 1999, 2893–2896

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a dry oxygen-free nitrogen atmosphere following conventional
Schlenk techniques. Solvents were dried and degassed before
use. Microanalyses were carried out by the Microanalytical
Service of the University of Sevilla. Infrared spectra were
recorded on a Perkin-Elmer Model 883 spectrophotometer, 1H,
13C and 31P NMR spectra on Bruker AMX-300 and AMX-500
spectrometers. The 31P shifts were measured with respect to
external 85% H3PO4, 13C using the resonance of the solvent as
an internal standard but are reported with respect to SiMe4.
The light petroleum used had bp 40–60 ЊC. Complex 1a was
prepared according to the literature.9
159.2 (C ipso), 152.4 (o-C), 127.9 (p-C), 122.9 (m-C), 118.6,
117.3, 115.1, 114.6 (CH, pyrrole), 29.1 (CH(CH3)2) and 24.5
(CH(CH3)2). Found: C, 49.6; H, 4.5; N, 8.7. C27H29N4S6V
requires C, 49.7; H, 4.5; N, 8.6%.
Complex [V(NC10H15)(S2CNC4H4)3] 3b was prepared as for
3a, but using 1b (0.33 g, 0.8 mmol) and KS2CNC4H4 (0.46 g, 2.5
1
mmol) in THF (25 ml), as yellow crystals in 35% yield. H
NMR (300 MHz, CDCl3): δ 7.64 (br, 4, pyrrole), 7.56 (br, 2,
pyrrole), 6.40 (br, 4, pyrrole), 6.27 (br, 2, pyrrole), 2.01 (br, 6,
CH2, C10H15N), 1.67 (br, 3, CH, C10H15N) and 1.50 (br, 6, CH2,
C10H15N). 13C-{1H} NMR (75 MHz, CDCl3): δ 214.4 (S2C),
118.6, 117.5, 115.0, 114.2 (CH, pyrrole), 42.0 (CH2, C10H15N),
35.6 (CH2, C10H15N) and 28.8 (CH, C10H15N).
Syntheses
[V(2,6-iPr2C6H3N)(S2CNiPr2)3] 4. To a mixture of complex 1a
(0.34 g, 0.80 mmol) and KS2CNiPr2 (0.57 g, 2.6 mmol) was
added THF (20 ml). The resulting suspension was stirred at
room temperature overnight. The volatiles were removed under
reduced pressure, the residue extracted with a light petroleum–
Et2O mixture and filtered to remove KCl. The filtrate was con-
centrated and orange crystals of 4 were obtained on standing
[V(NC10H15)Cl3(dme)] 1b. A 100 ml round-bottom flask was
loaded with VOCl3 (1.6 g, 9 mmol), C10H15NCO (9 mmol) and
octane (35 ml) and the mixture warmed at reflux. After heating
for 5 h, volatiles were removed under reduced pressure. Light
petroleum (20 ml) and dme (1 ml) were added and 1b was col-
1
lected by filtration as a brown greenish solid (2.6 g, 78%). H
NMR (500 MHz, CD2Cl2): δ 3.90 (br s, 4, OCH2), 3.72 (br s, 6,
OCH3), 2.30 (br s, 6, CH2), 2.16 (br s, 3, CH) and 1.63 (br s, 6,
CH2). 13C-{1H} NMR (125 MHz, CD2Cl2): δ 73.0 (br s, OCH2),
1
the solution at room temperature (58%). H NMR (300 MHz,
toluene-d8): δ 7.08 (d, 3JHH = 7.5, 2, m-CH), 6.91 (t, 3JHH = 7.5,
64.0 (br s, OCH3), 41.7 (s, CH2), 35.6 (s, CH2) and 29.4 (s, CH).
3
1, p-CH), 4.98 (h, JHH = 6.7, 2, CH(CH3)2, Ph), 4.14 (br, 3,
2
–
Found: C, 41.3; H, 5.9; N, 3.6. C10H15Cl3NVؒ3 dme requires C,
3
CH(CH3)2, dtc), 1.63 (d, JHH = 6.7 Hz, 12, CH(CH3)2, Ph)
and 1.52–0.97 (br, 18, CH(CH3)2, dtc). 13C-{1H} NMR (75
MHz, toluene-d8): δ 207.6 (S2C ax), 205.4 (S2C eq), 158.3 (C
ipso), 151.1 (o-C), 125.4 (p-C), 122.5 (m-C), 50.3 (CH(CH3)2 ax,
dtc), 49.7 (CH(CH3)2 eq, dtc), 28.9 (CH(CH3)2, Ph), 25.4
(CH(CH3)2, Ph) and 19.9–19.7 (CH(CH3)2, dtc). Found: C,
52.1; H, 7.8; N, 7.5; S, 25.9. C33H59N4S6V requires C, 52.5; H,
7.8; N, 7.4; S, 25.5%.
41.5; H, 5.9; N, 3.8%.
[V(2,6-iPr2C6H3N)Cl2(LOEt)] 2a. A reaction flask was charged
with complex 1a (0.40 g, 0.95 mmol) and NaLOEt (0.53 g, 0.95
mmol), THF (30 ml) was added and the resulting solution
stirred at ambient temperature for 7 h. Volatiles were then
removed, the residue was extracted with Et2O (20 ml) and fil-
tered to separate NaCl. Concentration of the solution and cool-
ing to Ϫ20 ЊC afforded orange crystals of compound 2a (75%).
31P-{1H} NMR (C6D6): AX2 spin system, δ 121.9 (d, JAX = 158
Hz), 105.3 (t). 1H NMR (500 MHz, C6D6): δ 6.95 (d,
[V(2,6-iPr2C6H3N)(S2COiPr)3] 5a. Prepared as for complex
4, using 1a (0.34 g, 0.80 mmol) and KS2COiPr (0.57 g, 2.6
1
mmol) in THF (20 ml), as orange crystals in 67% yield. H
3
3JHH = 7.5, 2, m-CH), 6.63 (t, JHH = 7.5, 1, p-CH), 5.46 (h,
NMR (300 MHz, toluene-d8, 298 K): δ 6.86–6.74 (m, 3, m-
and p-CH), 5.32–5.21 (m, 3, CH(CH3)2, carbonate), 4.56 (h,
3JHH = 6.8, 2, CH(CH3)2, Ph), 1.35 (d, 3JHH = 6.8, 12, CH(CH3)2,
3JHH = 6.7, 2, CH(CH3)2), 4.83 (s, 5, CH, Cp), 4.53–3.98 (m, 12,
3
CH2), 1.53 (d, JHH = 6.7, 12, CH(CH3)2), 1.30, 1.19, 0.97 (t,
3JHH = 7 Hz, 6, CH3). 13C-{1H} NMR (125 MHz, C6D6): δ 159.4
(C ipso), 154.2 (o-C), 129.1 (p-C), 122.1 (m-C), 88.9 (Cp), 62.9–
60.9 (CH2), 27.6 (CH(CH3)2), 25.6 (CH(CH3)2) and 16.6–16.1
(CH3). Found: C, 42.0; H, 6.4; N, 1.7. C29H52Cl2CoNO9P3V
requires C, 41.8; H, 6.3; N, 1.7%.
3
Ph), 1.00 (d, JHH = 6.2 Hz, 6, CH(CH3)2 ax, carbonate) and
1
0.93 (m, 12, CH(CH3)2 eq, carbonate). H NMR (300 MHz,
toluene-d8, 343 K): δ 5.31 (h, 3JHH = 6.2, 3, CH(CH3)2, carbon-
3
ate), 0.92 (s, JHH = 7.2 Hz, CH(CH3)2, carbonate). 13C-{1H}
NMR (75 MHz, C6D6, 298 K): δ 228.3 (S2C ax), 227.5 (S2C eq),
159.5 (C ipso), 152.6 (o-C), 123.4 (m-C), 77.2 (CH(CH3)2 ax,
carbonate), 76.8 (CH(CH3)2 eq, carbonate), 29.7 (CH(CH3)2
Ph), 25.4 (CH(CH3)2 Ph) and 21.4–20.1 (CH(CH3)2, carbonate).
Found: C, 45.7; H, 5.9; N, 2.3. C24H38NO3S6V requires C, 45.6;
H, 6.0; N, 2.2%.
Following a similar synthetic procedure, starting from com-
plex 1b (0.21 g, 0.5 mmol) and NaLOEt (0.5 mmol), was prepared
[V(NC10H15)Cl2(LOEt)] 2b (65% yield). 31P-{1H} NMR (C6D6):
AX2 spin system, δ 122.9 (d, JAX = 152 Hz), 104.2 (t). 1H NMR
(300 MHz, C6D6): δ 4.86 (s, 5, CH, Cp), 4.31–4.17 (br m, 12,
CH2, LOEt), 2.42 (br s, 6, CH2, C10H15N), 1.83 (br s, 3, CH,
C10H15N), 1.36 (br s, 3, CH2, C10H15N), 1.29 (br s, 3, CH2,
C10H15N) and 1.2 (br m, 18, CH3, LOEt). 13C-{1H} NMR (75
MHz, C6D6): δ 88.9 (Cp), 84.4 (C, C10H15N), 62.7 (2 CH2, LOEt),
61.8 (CH2, LOEt), 61.7 (CH2, LOEt), 60.8 (2 CH2, LOEt), 41.8 (3
CH2, C10H15N), 35.6 (3 CH2, C10H15N), 28.9 (3 CH, C10H15N)
and 16.5 (6 CH3, LOEt). Found: C, 41.3; H, 6.5; N, 1.7. C27H50-
Cl2CoNO9P3Vؒ0.5Et2O requires C, 41.3; H, 6.5; N, 1.7%.
[V(NC10H15)(S2COiPr)3] 5b. Prepared as for complex 4, using
1b (0.24 g, 0.6 mmol) and KS2COiPr (0.31 g, 1.8 mmol) in THF
1
(30 ml), as orange crystals in 60% yield. H NMR (300 MHz,
toluene-d8, 298 K): δ 5.38 (h, 3JHH = 6.1, 2, CH(CH3)2), 5.27 (h,
3JHH = 6.1 Hz, 1, CH(CH3)2), 2.08 (br, 6, CH2, C10H15N), 1.72
(br, 3, CH, C10H15N), 1.29 (br, 6, CH2, C10H15N) and 1.02 (br,
18, CH(CH3)2). 13C-{1H} NMR (75 MHz, toluene-d8, 298 K):
δ 227.7 (S2C), 227.1 (S2C), 81.0 (C, C10H15N), 76.6 (CH(CH3)2),
76.0 (CH(CH3)2), 42.4 (CH2, C10H15N), 36.0 (CH2, C10H15N),
29.4 (CH, C10H15N) and 21.5 (CH(CH3)2). Found: C, 45.1; H,
5.9; N, 2.3. C22H36NO3S6V requires C, 43.6; H, 5.9; N, 2.3%.
[V(2,6-iPr2C6H3N)(S2CNC4H4)3] 3a. To a solution of com-
plex 1a (0.21 g, 0.5 mmol) in THF (20 ml), KS2CNC4H4 (0.23 g,
1.4 mmol) in THF (10 ml) was added. The orange mixture was
stirred at room temperature overnight. Volatiles were removed
and the residue was extracted with 1:1 light petroleum–Et2O.
After cooling at Ϫ20 ЊC, orange crystals of 3a were obtained
(46%). 1H NMR (300 MHz, C6D6): δ 7.59 (pseudo t, 3JHH = 2.3,
[V(2,6-iPr2C6H3N)(S2CSiPr)3] 6a. Prepared as for complex 4,
using 1a (0.34 g, 0.80 mmol) and NaS2CSiPr (0.57 g, 2.6 mmol)
in THF (25 ml), as orange crystals in 45% yield. 1H NMR (500
3
3
2, pyrrole), 7.44 (pseudo t, JHH = 2.3, 4, pyrrole), 6.83 (m, 3,
MHz, toluene-d8): δ 6.83 (d, JHH = 8, 2, m-CH), 6.76 (t,
3
3
m- and p-CH), 5.93 (pseudo t, JHH = 2.3, 2, pyrrole), 5.89
3JHH = 8, 1, p-CH), 4.49 (h, JHH = 7, 2, CH(CH3)2, Ph), 3.83
3
3
3
3
(pseudo t, JHH = 2.3, 4, pyrrole), 4.58 (h, JHH = 6.7, 2,
(h, JHH = 7, 3, CH(CH3)2, carbonate), 1.35 (d, JHH = 7, 12,
3
3
CH(CH3)2) and 1.32 (d, JHH = 6.7 Hz, 12, CH(CH3)2). 13C-
CH(CH3)2, Ph), 1.04 (d, JHH = 7, 6, CH(CH3)2 ax, carbonate)
{1H} NMR (75 MHz, C6D6): δ 214.5 (S2C ax), 214.2 (S2C eq),
and 0.95 (d, 3JHH = 7 Hz, 12, CH(CH3)2 eq, carbonate). 13C-{1H}
J. Chem. Soc., Dalton Trans., 1999, 2893–2896
2895

View Article Online
Table 2 Crystallographic data for complex 3a
CCDC reference number 186/1515.
See http://www.rsc.org/suppdata/dt/1999/2893/ for crystallo-
graphic files in .cif format.
Formula
M
C27H29N4S6V
652.84
Crystal system
Space group
a/Å
b/Å
Monoclinic
C2/c
Acknowledgements
We are grateful for financial support from Dirección General de
Ensen`anza Superior e Investigación Científica (PB97-740) and
Junta de Andalucía.
25.913(3)
10.0434(12)
27.989(3)
106.690(2)
6977(2)
8
1.243
0.665
148(2)
0.71073
4005
c/Å
β/Њ
U/Å3
Z
References
Dc/g cmϪ3
µ(Mo-Kα)/cmϪ1
1 D. E. Wigley, Prog. Inorg. Chem., 1994, 42, 239; W. A. Nugent and
J. M. Mayer, Metal–Ligand Multiple Bonds, Wiley Interscience,
New York, 1988.
T/K
λ(Mo-Kα)/Å
Unique reflections, I ≥ 2σ(I)
R
2 J. de With and A. D. Horton, Angew. Chem., Int. Ed. Engl., 1993, 32,
903; J. de With, A. D. Horton and A. G. Orpen, Organometallics,
1993, 12, 1493; T. R. Cundari, Organometallics, 1994, 13, 2987.
3 (a) M. C. W. Chan, K. C. Chew, C. I. Dalby, V. C. Gibson,
A. Kohlmann, I. R. Little and W. Reed, Chem. Commun., 1998,
1673; (b) M. C. W. Chan, J. M. Cole, V. C. Gibson and J. A. K.
Howard, Chem. Commun., 1997, 2345; (c) S. Scheuer, J. Fischer and
J. Kress, Organometallics, 1995, 14, 2627.
0.0782
0.2087
RЈ
NMR (75 MHz, toluene-d8): δ 244.4 (S2C eq), 241.4 (S2C ax),
159.4 (C ipso), 152.6 (o-C), 122.9 (m-C), 41.4 (CH(CH3)2 ax,
carbonate), 39.7 (CH(CH3)2 eq, carbonate), 29.6 (CH(CH3)2,
Ph), 24.8 (CH(CH3)2, Ph), 22.1 (CH(CH3)2 ax, carbonate) and
21.9 (CH(CH3)2 eq, carbonate). Found: C, 42.3; H, 5.9; N, 2.0.
C24H38NS9V requires C, 42.4; H, 5.6; N, 2.1%.
4 F. Tabellion, A. Nachbauer, S. Leininger, C. Peters, F. Preuss and
M. Regitz, Angew. Chem., Int. Ed., 1998, 37, 1233.
5 See, for example, F. Preuss and W. Towae, Z. Naturforsch., Teil B,
1981, 36, 1130; F. Preuss, H. Noichl and J. Kaub, Z. Naturforsch.,
Teil B, 1987, 41, 1085; F. Preuss, H. Becker and H.-J. Häusler,
Z. Naturforsch., Teil B, 1987, 42, 881; F. Preuss, H. Becker, J. Kaub
and W. S. Sheldrick, Z. Naturforsch., Teil B, 1988, 43, 1195;
F. Preuss, T. Wieland, J. Perner and G. Heckmann, Z. Naturforsch.,
Teil B, 1992, 47, 1355; F. Preuss, T. Wieland and B. Günther,
Z. Anorg. Allg. Chem., 1992, 609, 45.
[V(NC10H15)(S2CSiPr)3] 6b. Prepared as for complex 4, using
1b (0.21 g, 0.50 mmol) and NaS2CSiPr (0.26 g, 1.5 mmol) in
THF (40 ml), as orange crystals in 30% yield. H NMR (300
MHz, C6D6): δ 3.93 (br, 3, CH(CH3)2), 2.15 (br, 6, CH2,
C10H15N), 1.70 (br, 3, CH, C10H15N), 1.28 (br, 6, CH2, C10H15N)
and 1.02 (br, 18, CH(CH3)2). 13C-{1H} NMR (75 MHz, C6D6):
δ 244.3 (S2C), 241.4 (S2C), 81.0 (C, C10H15N), 42.2 (CH2,
C10H15N), 41.4 (CH(CH3)2), 39.4 (CH(CH3)2), 35.5 (CH2,
C10H15N), 29.0 (CH, C10H15N), 22.3 (CH(CH3)2) and 21.6
(CH(CH3)2). Found: C, 40.8; H, 5.6; N, 2.2. C22H36NS9V
requires C, 40.4; H, 5.5; N, 2.1%.
1
6 D. D. Devore, J. D. Lichtenhan, F. Takusagawa and E. A. Maatta,
J. Am. Chem. Soc., 1987, 109, 7408.
7 See, for example, V. J. Murphy and H. Turner, Organometallics, 1997,
16, 2495; P. T. Witte, A. Meetsma, B. Hessen and P. H. M.
Budzelaar, J. Am. Chem. Soc., 1997, 119, 10561; H. Schumann,
Inorg. Chem., 1996, 35, 1808; P. L. Hill, G. P. A. Yap, A. L. Reingold
and E. A. Maatta, J. Chem. Soc., Chem. Commun., 1995, 737; C. C.
Cummins, R. R. Schrock and W. M. Davis, Inorg. Chem., 1994, 33,
1448.
[V(2,6-iPr2C6H3N)Cl(acac)2] 7. To a mixture of complex 1a
(0.24 g, 0.57 mmol) and Na(acac) (0.14 g, 1.15 mmol) was
added THF (25 ml). The resulting suspension was stirred at
room temperature overnight. The volatiles were removed under
reduced pressure and the red residue extracted with light petrol-
eum and filtered to remove NaCl. The filtrate was concentrated
and cooled to Ϫ20 ЊC. Crystals of 7 were obtained in 54% yield.
Alternatively, to a solution of complex 1a (0.35 g, 0.83 mmol)
in CH2Cl2 (25 ml) was added an excess of Hacac (0.3 ml) and
the mixture stirred overnight at reflux. The resulting solution
was taken to dryness and worked up as stated before. 1H NMR
8 A. Galindo, F. Montilla, A. Pastor, E. Carmona, E. Gutiérrez-
Puebla, A. Monge and C. Ruiz, Inorg. Chem., 1997, 36, 2379;
F. Montilla, A. Galindo, E. Carmona, E. Gutiérrez-Puebla and
A. Monge, J. Chem. Soc., Dalton Trans., 1998, 1299.
9 F. Montilla, A. Pastor, A. Galindo, E. Gutiérrez-Puebla, A. Monge,
J. F. Sanz, N. Cruz Hernández and D. del Río, Inorg. Chem., 1999,
in press.
10 W. Kläui, Angew. Chem., Int. Ed. Engl., 1990, 29, 627.
11 D. E. Wheeler, J.-F. Wu and E. A. Maatta, Polyhedron, 1998, 17, 969.
12 J.-K. F. Buijink, A. Meetsma, J. H. Teuben, H. Kooijman and
A. L. Spek, J. Organomet. Chem., 1995, 497, 161.
13 A. V. Korolev, A. L. Rheingold and D. S. Williams, Inorg. Chem.,
1997, 36, 2647.
14 F. Preuss, G. Hornung, W. Frank, G. Reib and S. Müller-Becker,
Z. Anorg. Allg. Chem., 1995, 621, 1663.
15 J. Sundermeyer, J. Putterlik, M. Foth, J. S. Field and N. Ramesar,
Chem. Ber., 1994, 127, 1201.
16 J. C. Dewan, D. L. Kepert, C. L. Raston, D. Taylor, A. H. White and
E. N. Maslen, J. Chem. Soc., Dalton Trans., 1973, 2082.
17 L. S. Tan, G. V. Goeden and B. L. Haymore, Inorg. Chem., 1983, 22,
1744.
18 J. Fernández-Baeza, F. A. Jalón, A. Otero, M. E. Rodrigo-Blanco
and M. Etienne, J. Chem. Soc., Dalton Trans., 1998, 769.
19 See, for example, A. J. Nielson, P. D. W. Boyd, G. R. Clark,
P. A. Hunt, M. B. Hursthouse, J. B. Metson, C. E. F. Rickard and
P. A. Schwerdtfeger, J. Chem. Soc., Dalton Trans., 1995, 1153
and refs. therein.
20 Von G. Gattow, G. Kiel and H. Sayin, Z. Anorg. Allg. Chem., 1983,
498, 85.
21 E. J. Peterson, R. B. von Dreele and T. M. Brown, Inorg. Chem.,
1978, 17, 1410.
3
(300 MHz, Cl3CD): δ 6.98 (d, JHH = 7.6, 2, m-CH), 6.84 (t,
3JHH = 7.6, 1, p-CH), 5.63, 5.52 (s, 1, CH, acac), 4.38 (h,
3JHH = 6.6, 2, CH(CH3)2), 2.24, 2.12, 2.10, 1.93 (s, 3, CH3, acac),
1.27, 1.29 (d, 3JHH = 6.8 Hz, 6, CH(CH3)2). 13C-{1H} NMR (75
MHz, Cl3CD): δ 194.6, 190.1, 189.9, 181.4 (CO, acac), 160.1 (C
ipso), 153.3 (o-C), 129.7 (p-C), 122.1 (m-C), 102.1, 100.4 (CH,
acac), 28.0 (CH3, acac), 27.6 (CH(CH3)2), 26.1, 25.6, 24.65
(CH3, acac), 24.6, 24.2 (CH(CH3)2). Found: C, 58.3; H, 6.9; N,
3.4. C22H31ClNO4V requires C, 57.5; H, 6.8; N, 3.1%.
Crystallography
A summary of the fundamental crystal and refinement data is
given in Table 2. A crystal was mounted on a Brucker-Siemens
Smart CCD detector diffractometer equipped with a low
temperature device. Full matrix least-squares refinement was
carried out on F2 for all reflections. Weighted R factor (RЈ)
based on F2, conventional R on F. Most of the calculations
were carried out with SMART23 software for data collection
and reduction and SHELXTL23 for structure solution and
refinements.
22 M. G. B. Drew, D. A. Rice and D. M. Williams, J. Chem. Soc.,
Dalton Trans., 1985, 1821.
23 SHELXTL, Siemens Energy
&
Automation Inc., Analytical
Instrumentation, Madison, WI, 1996.
Paper 9/03507I
© Copyright 1999 by the Royal Society of Chemistry
2896
J. Chem. Soc., Dalton Trans., 1999, 2893–2896