Syntheses
[V(NS3)(NMeNH2)], 1. Methylhydrazine (4 ml, excess) was
added to [V(NS3)O] (1.31 g, 5 mmol). A vigorous reaction took
place resulting in a red solution; this was filtered and ether
(96 ml) added to the filtrate which was kept at Ϫ20 ЊC over-
night. Red crystals suitable for X-ray studies (1.32 g, 90%) were
filtered off. Found: C, 28.9; H, 5.8; N, 15.8. C7H17N3S3V
requires C, 29.0; H, 5.9; N, 14.5%. µeff = 1.81 µB (S = 1/2).
IR 3337, 3154 cmϪ1 [ν(NH)].
[V(NS3)(NNC5H10)], 2. N-Aminopiperidine (5 ml, excess)
was added to [V(NS)3)O] (0.52 g, 2 mmol). The mixture was
heated to 140 ЊC when a vigorous reaction took place resulting
in a red solution; this was cooled overnight giving orange crys-
tals (0.53 g, 78%). Found: C, 38.7; H, 6.4; N, 12.3. C11H22N3S3V
1
requires C, 38.5; H, 6.5; N, 12.2%. H NMR (CD2Cl2): δ 1.58
(m, 2H, CH2), 1.84 (m, 4H, CH2), 3.39 (m, 6H, NCH2CH2S),
3.45 (m, 6H, NCH2CH2S), 3.85 (m, 4H, CH2). 51V NMR
(CD2Cl2): δ 401, fwhm = 820 Hz. X-Ray quality crystals were
obtained by recrystallisation from CH2Cl2.
[V(NS3)(NNCPh2)], 3. Benzophenone hydrazone (0.98 g,
5 mmol) was added to [V(NS)3)O] (0.13 g, 0.5 mmol) in diglyme
(10 ml). The mixture was taken to reflux temperature (162 ЊC)
for 30 minutes, during which time the colour changed from
purple to orange. The solution was allowed to cool overnight
and was filtered from a small black precipitate, then the volume
of filtrate was reduced in vacuo at 60 ЊC to 4 ml when red
crystals (0.10 g, 45%) deposited. Found: C, 52.5; H, 5.0; N, 9.6.
C19H22N3S3V requires C, 51.9; H, 5.0; N, 9.6%. 1H NMR
(CD2Cl2): δ 3.46 (m, 6H, NCH2CH2S), 3.61 (m, 6H, NCH2-
CH2S), 7.50 (m, 6H, Ph), 7.80 (m, 4H, Ph). 51V NMR (CD2Cl2):
δ 437, fwhm = 1060 Hz. X-Ray quality crystals were obtained
by recrystallisation from acetonitrile.
Fig. 3 View of a molecule of [V(NS3)(NNCPh2)], 3.
In contrast to the reaction with benzophenone hydrazone,
treatment of [V(NS3)O] with salicylaldehyde hydrazone at
160 ЊC resulted in displacement of the NS3 ligand to give tris-
(salicylaldehyde hydrazonato)vanadium() which has been
prepared from [VCl3(thf )3] by treatment with salicylaldehyde
and hydrazine.10
Benzoic hydrazide PhCONHNH2 reacted with [V(NS3)O] at
140 ЊC giving a yellow solution and a green precipitate of
{V(NS3)}n i.e. there was reduction and no V–N bond form-
ation. The same product was observed when [V(NS3)O] was
treated with either hydroxyethylhydrazine or pentafluoro-
phenylhydrazine, under comparable conditions.
[V(NS3)O] did not react with two other compounds contain-
ing the NNH2 group, 4-amino-1,2,4-triazole and N-amino-
phthalimide, at 160 ЊC. Attempts to heat solutions or
suspensions of [V(NS3)O] (with or without other reactants) at
temperatures higher than 160 ЊC [by using benzonitrile (bp 170
ЊC) or ethylene glycol (bp 192 ЊC) at reflux temperatures]
resulted in rapid decomposition to give insoluble materials
including {V(NS3)}n. The vanadium() compound [V(NS3)-
(NSiMe3)],5 which is more soluble in ethers or in MeCN than is
[V(NS3)O], was also treated with some of the above compounds
containing NNH2 groups in an attempt to form V–N–N bonds
at lower temperatures, but in every case the product formed was
[V(NS3)(NH)]5 by abstraction of one of the active hydrogens
from the NNH2 group.
Thus it is possible to make some compounds containing
V–N–N systems using [V(NS3)O] and substituted hydrazines
or hydrazones as starting materials, but reactions targeted to
obtain V–N–N bonds must compete with reduction of the
vanadium() oxide to vanadium() which results in formation
of the polymeric {V(NS3)}n or in complete displacement of the
NS3 ligand.
Crystal structure analyses
The crystal structure analysis of [V(NS3)(NNC5H10)]ؒ0.5CD2-
Cl2, 2ؒ0.5CD2Cl2, is described here. The two other analyses
followed very similar procedures and crystal data for the three
structures are listed in Table 2.
Crystals of 2 are deep red, striated plates. One, ca. 0.10 ×
0.43 × 0.55 mm, was mounted, in air, on a glass fibre. After
preliminary photographic examination, this was transferred to
an Enraf-Nonius CAD4 diffractometer (with monochromated
radiation) for determination of accurate cell parameters (from
the settings of 25 reflections, θ = 10–11Њ, each centred in four
orientations) and for measurement of diffraction intensities
(3835 unique reflections to θmax = 27Њ; 2778 were ‘observed’ with
I > 2σI).
During processing, corrections were applied for Lorentz-
polarisation effects, absorption (by semi-empirical ψ-scan
methods) and to eliminate negative net intensities (by Bayesian
statistical methods). No deterioration correction was necessary.
The structure was determined by the direct methods routines
in the SHELXS program11 and refined by full-matrix least-
squares methods, on F 2 in SHELXL.12 The vanadium complex
was well-resolved and showed disorder in the NS3 ligand with
the major/minor component ratio of 0.695(5) : 0.305. Hydrogen
atoms were included, on both components and on the piper-
idine ring, in idealised positions. The non-hydrogen atoms
(except those of the minor component) were refined with aniso-
tropic thermal parameters and the H-atom Uiso values were set
to ride on the Ueq or Uiso values of the parent carbon atoms.
There is also a solvent (CD2Cl2) molecule, disordered over
several orientations about a centre of symmetry; these part-
atoms (with a range of site occupancies) were refined iso-
tropically, and no hydrogen/deuterium atoms were included.
At the conclusion of the refinement, wR2 = 0.116 and R1 =
Experimental
All operations were carried out under a dry dinitrogen atmos-
phere, using standard Schlenk techniques. Solvents were dis-
tilled under dinitrogen from the appropriate drying agents prior
to use. Preparations of the ligand NS3H3 and of [V(NS3)O], as
well as spectroscopic and magnetic measurements, were made
as described previously.5
2
0.05612 for all 3835 reflections weighted w = [σ2(Fo ) ϩ
J. Chem. Soc., Dalton Trans., 2002, 2811–2814
2813
Davies, Sian C.
