Five-coordinate nickel(II) complexes with carboxylate anions and derivatives of 1,5,9-triazacyclododec-1-ene: Structural and1H NMR spectroscopic studies

Article abstract of DOI:10.1039/b413547d

The hydroxo complexes [Ni₂(mcN₃) ₂(μ-OH)₂]₂(PF₆)₂ [mcN₃ = 2,4,4-trimethyl-1,5,9-triazacyclododec-1-ene (Me ₃-mcN₃) or 2,4,4,9-tetramethyl-1,5,9-triazacyclododec-1-ene (Me₄-mcN ₃)] react with the corresponding carboxylic acid [HA = benzoic (Hbz), salicylic (Hsal) or acetylsalicylic (Hacsal) acid] to give five-coordinate nickel(II) complexes of the type [Ni(mcN₃)(A)](PF₆). The complexes have been studied by spectroscopic methods (IR, UV-Vis and ¹H NMR). In acetone solution they exhibit isotropically shifted ¹H NMR resonances. The full assignment of these resonances has been made using one- and two-dimensional ¹H NMR techniques. The single-crystal structures of [Ni(Me₄-mcN₃)(bz)](PF ₆), [Ni(Me₄-mcN₃)(sal)](PF₆) and[Ni(Me₄-mcN₃)(acsal)](PF₆) have been established by X-ray diffraction.

Full text of DOI:10.1039/b413547d

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F U L L P A P E R
Five-coordinate nickel(II) complexes with carboxylate anions and
derivatives of 1,5,9-triazacyclododec-1-ene: structural and 1H NMR
spectroscopic studies
M. Dolores Santana,*a A. Abel Lozano,a Gabriel Garc´ıa,*a Gregorio Lo´peza and Jose´ Pe´rezb
a Departamento de Qu´ımica Inorga´nica, Universidad de Murcia, 30071, Murcia, Spain.
E-mail: dsl@um.es; Fax: (+34) 968-364148
b Departamento de Ingenier´ıa Minera, Geolo´gica y Cartogra´fica, Universidad Polite´cnica de
Cartagena, 30203, Cartagena, Spain
Received 2nd September 2004, Accepted 3rd November 2004
First published as an Advance Article on the web 22nd November 2004
The hydroxo complexes [Ni2(mcN3)2(l-OH)2]2(PF6)2 [mcN3 = 2,4,4-trimethyl-1,5,9-triazacyclododec-1-ene
(Me3-mcN3) or 2,4,4,9-tetramethyl-1,5,9-triazacyclododec-1-ene (Me4-mcN3)] react with the corresponding
carboxylic acid [HA = benzoic (Hbz), salicylic (Hsal) or acetylsalicylic (Hacsal) acid] to give five-coordinate nickel(II)
complexes of the type [Ni(mcN3)(A)](PF6). The complexes have been studied by spectroscopic methods (IR, UV-Vis
and 1H NMR). In acetone solution they exhibit isotropically shifted 1H NMR resonances. The full assignment of
these resonances has been made using one- and two-dimensional 1H NMR techniques. The single-crystal structures
of [Ni(Me4-mcN3)(bz)](PF6), [Ni(Me4-mcN3)(sal)](PF6) and[Ni(Me4-mcN3)(acsal)](PF6) have been established by
X-ray diffraction.
The condensation reaction occurs at room temperature in
Introduction
acetone with the concomitant liberation of water. This syn-
The versatile carboxylate anion can adopt a wide range of
thetic method has been previously used for the preparation of
bonding modes including monodentate, symmetric and asym-
pentacoordinate nickel(II) complexes containing N,S-donors,14
metric chelating and bidentate and monodentate bridging.1,2
oxamidate,15 hydroxamate16 and pyridonate ligands.17 Although
It is generally agreed that the carboxylate complexes of the
the hydrolysis of P–OR bonds in phosphate triesters by hydroxo
3d elements, including several examples of nickel derivatives,
complexes has been described,18 the acetyl group of the acetyl-
play an important role in biochemistry.3 Among these, salicylic
salicylic acid has not been attacked by the hydroxo ligand during
acid, its derivatives as well as some copper complexes have
the reaction time.
attracted considerable interest from structural and biological
viewpoints.4–6 Nevertheless, only two octahedral nickel salicylate
complexes have been structurally characterized and the salicylate
monoanion was coordinated through the carboxylate oxygen in
a monodentate fashion.7,8
1H NMR spectroscopy has become an excellent technique to
study the structural and magnetic properties of paramagnetic
metal ions in both model complexes and biological systems9–11
and a wealth of structural and magnetic information can be
obtained on the local environment of the paramagnetic metal
center. However, a scarcely explored issue is the determination
of the structural and magnetic properties of mononuclear and
binuclear nickel(II) ions in both biological and model systems
1
using H NMR spectroscopy.12 In this context, our group has
initiated a study aimed at the syntheses of nickel(II) complexes
with some carboxylate anions including benzoate, salicylate
or acetylsalicylate and triazamacrocycle ligands. We have used
NMR methods for the characterization in solution of these
five-coordinate mononuclear nickel(II) complexes. Relatively
few two-dimensional 1H NMR studies involving nickel(II) ions
in either model complexes or biological systems have been
reported.13
Results and discussion
Synthesis and characterization
The reaction between [Ni2(mcN3)2(l-OH)]2(PF6)2 [mcN3
=
2,4,4-trimethyl-1,5,9-triazacyclododec-1-ene (Me3-mcN3) or
2,4,4,9-tetramethyl-1,5,9-triazacyclododec-1-ene (Me4-mcN3)
and carboxylic acids [HA = benzoic (Hbz), salicylic (Hsal) or
acetylsalicylic (Hacsal) acid] leads to the formation of the car-
boxylate complexes [Ni(mcN3)(A)](PF6) 1–6 shown in Scheme 1.
Scheme 1
1 0 4
D a l t o n T r a n s . , 2 0 0 5 , 1 0 4 – 1 0 9
T h i s j o u r n a l i s
T h e R o y a l S o c i e t y o f C h e m i s t r y 2 0 0 5
©

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Complexes 1–6 are air-stable both in the solid state and in
solution. They have been characterized by partial elemental
analyses, FAB+ mass spectrometry and spectroscopic (IR, UV-
Vis and 1H NMR) methods. The IR spectra support the presence
of the carboxylate ligands, which show bands in the 1556–
1519 cm−1 region due to m(C–O), and the bands found at 1748
and 1771 cm−1 in the spectra of complexes 3 and 6 can be
=
assigned to the m(C O) vibration of the acetyl group. Complexes
1–6 also show the characteristic absorptions of the macrocyclic
ligands14: 3285–3265 cm−1 m(NH) and ≈1665 cm−1 m(C N) and
=
two bands at 840 and 560 cm−1corresponding to the PF6− anion.
The electronic spectra of 1–6 are quite similar and show two
d–d transitions in acetone solution with kmax around 640 nm
(≈90 M−1 cm−1) and 380 nm (≈200 M−1 cm−1) which could be
3
3
assigned to 3B1(F) → E(F) and 3B1(F) → A2,3E(P) transitions,
respectively. Both kmax values and molar absorptivities are con-
sistent with a pentacoordinate environment around nickel(II).19
NMR study
1
All of the complexes exhibit sharp hyperfine-shifted H NMR
signals in acetone solution in the 350–35 ppm chemical shift
range. The 1H-NMR spectra of complexes 1–6 show a resonance
line pattern observed for the mcN3 ligands that was assigned on
the basis of previous studies of nickel macrocyclic complexes.18
A representative proton NMR spectrum for complex 4 is shown
in Fig. 1. The a-methylene protons shift downfield whereas the b-
methylene protons shift upfield with regard to the diamagnetic
position.20 Moreover, the equatorial protons are expected to
experience larger contact shifts than the axial protons21 and
therefore the most downfield resonances are due to a-CHeq and
Fig. 2 1H NMR spectra (in d6-acetone solution at room temperature)
of [Ni(Me4-mcN3)(bz)](PF6) 4 (A); [Ni(Me4-mcN3)(sal)](PF6) 5 (B);
[Ni(Me4-mcN3)(acsal)](PF6) 6 (C), only the region relevant to the
assignment of phenyl resonances is shown.
1
the most upfield ones to b-CHeq. The isotropically shifted H-
NMR signals observed for the methyl groups (2-Me, 4-Me(a,
b) and 9-Me-N) and phenyl groups of carboxylates can be
initially assigned by inspection of their peak areas. All the
resonances of the phenyl rings are downfield to TMS (SiMe4)
in accordance with a dominant r-delocalization pattern of spin
density consistent with the ground state of nickel(II) although
the unpaired electrons could polarize the net spin density in the
dp orbitals. A similar behaviour has been observed elsewhere.22
The spectra of complexes 4, 5 and 6 in 14–5 ppm region
are shown in Fig. 2. This portion of the spectrum exhibits a
three-spin (4), or four-spin (5, 6) system that unambiguously
assigns the corresponding protons of the aromatic rings. The
resonances observed in this region of the spectrum of 4 (Fig. 2A)
at 9.4, 8.9 and 5.6 ppm were assigned to the ortho, meta
and para protons of the phenyl ring, respectively, because the
first one is broadened by the proximity of the paramagnet.
Substitution at the ortho position breaks the ring symmetry so
that four phenyl resonances of equal intensity were observed for
5 (Fig. 2B) and 6 (Fig. 2C). However, definitive assignment of
these isotropically shifted signals comes from two-dimensional
1H NMR techniques. A magnitude COSY spectrum of 5 (Fig. 3),
recorded at 20 ◦C, clearly shows cross signals between the
resonances at 12.1, 8.6 and 6.9 ppm and also between resonances
Fig. 3 Portion of the 1H COSY spectrum of complex 5 (in d6-acetone
solution at 20 ◦C). Only the region relevant to the assignment of phenyl
resonances is shown in the top trace.
at 9.2 and 8.6 ppm. These signals can be assigned to the phenyl 3-
H (12.1), 6-H (9.2), 5-H (8.6), and 4-H (6.9) protons, respectively,
of the salicylate ligand. Therefore, on the basis of the X-ray
structure of 5 (see below) the distortion in the square pyramidal
arrangement of the nickel atom due to the small bite angle of the
chelated carboxylate moiety and the hydroxyl substituent result
in a larger magnetic anisotropy that in turn induces a larger
isotropic shift of the 3-H proton.
X-Ray diffraction study
The crystal structures of the cation of complexes 4, 5 and 6 are
shown in Figs. 4, 5 and 6. In each crystallized cation, the nickel
atom is five-coordinate, with a square pyramid arrangement
of chelating atoms. The Reedijk’s s parameter23 (s = 0 and
1 for square pyramidal and trigonal bipyramidal structures
Fig. 1 1H NMR spectrum of 4 (in d6-acetone solution at room
temperature).
D a l t o n T r a n s . , 2 0 0 5 , 1 0 4 – 1 0 9
1 0 5

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Fig. 4 ORTEP32 drawing of the cation of complex 4 (ellipsoids at 50%
probability level) with atom-labeling scheme. For clarity the hydro-
˚
gen atoms of the macrocycle are omitted. Selected bond lengths/A:
Fig. 6 ORTEP drawing of the cation of complex 6 (ellipsoids at 50%
Ni(1)–N(1) 1.988(3), Ni(1)–N(2) 2.014(3), Ni(1)–N(3) 2.044(3), Ni(1)–
O(1) 2.103(3), Ni(1)–O(2) 2.103(3). Selected bond angles/◦: N(1)–
Ni(1)–N(2) 91.36(13), N(1)–Ni(1)–N(3) 94.43(15), N(2)–Ni(1)–N(3)
101.99(15), N(1)–Ni(1)–O(1) 100.45(12), N(2)–Ni(1)–O(1) 158.39(13),
N(3)–Ni(1)–O(1) 95.13(13), N(1)–Ni(1)–O(2) 157.00(12), N(2)–Ni(1)–
O(2) 100.26(12), N(3)–Ni(1)–O(2) 102.36(14), O(1)–Ni(1)–O(2) 62.81
(10), O(1)–C(14)–O(2) 120.4(3).
probability level) with atom-labeling scheme. For clarity the hydrogen
˚
atoms of the macrocycle are omitted. Selected bond lengths/A: Ni(1)–
N(1) 1.982(3), Ni(1)–N(2) 2.017(2), Ni(1)–N(3) 2.040(2), Ni(1)–O(1)
2.124(2), Ni(1)–O(2) 2.079(2). Selected bond angles/◦: N(1)–Ni(1)–
N(2) 93.32(12), N(1)–Ni(1)–N(3) 94.91(12), N(2)–Ni(1)–N(3)
103.54(10), N(1)–Ni(1)–O(1) 101.60(10), N(2)–Ni(1)–O(1) 153.50(10),
N(3)–Ni(1)–O(1) 96.93(10), N(1)–Ni(1)–O(2) 155.96(12), N(2)–Ni(1)–O
(2) 95.18(10), N(3)–Ni(1)–O(2) 104.85(12), O(1)–Ni(1)–O(2) 63.00(9),
O(1)–C(14)–O(2) 119.8(3).
the corresponding basal plane towards the apical N(3) atom for
complexes 4, 5 and 6 respectively. In all three complexes the
coordinated macrocycles exhibit chair-like conformations in the
=
two six-membered rings that do not contain the C N bond. This
is the most frequent conformation in complexes having these
macrocycles.17 The present complexes are the first pentacoordi-
nate salicylate-nickel(II) derivatives showing chelating fashion.
However, in [Cu(phen)2(sal)][sal]·H2O5 the salicylate exhibits an
asymmetric chelating mode with a tightly bonded carboxylate
oxygen and a second oxygen more weakly bonded when the
salicylate is singly deprotonated. The dideprotonated salicylate4
was found in [Cu2(phen)2(sal’)2]·2H2O (sal’ = −OC6H4CO2−);
this dimer consists of two Cu(II) atoms bridged by two salicylate
ligands via the phenoxo oxygen atom and the carboxylate
moiety is anti monodentate terminal. On the other hand, one-
dimensional copper(II) complexes having the salicylate and 4,4ꢀ-
bipyridine ligands have been reported.24 The salicylate has a
bidentate bridging or chelating coordinate mode. The Ni–O
bond distances in 4, 5 and 6 are close to each other (from
Fig. 5 ORTEP drawing of the cation of complex 5 (ellipsoids at 50%
probability level) with atom-labeling scheme. For clarity the hydrogen
˚
atoms of the macrocycle are omitted. Selected bond lengths/A: Ni(1)–
N(1) 1.972(4), Ni(1)–N(2) 2.007(4), Ni(1)–N(3) 2.029(4), Ni(1)–O(1)
2.087(3), Ni(1)–O(2) 2.099(3). Selected bond angles/◦: N(1)–Ni(1)–N(2)
93.47(14), N(1)–Ni(1)–N(3) 96.19(15), N(2), Ni(1)–N(3) 102.08(15),
N(1)–Ni(1)–O(1) 98.40(13), N(2)–Ni(1)–O(1) 155.64(15), N(3)–Ni(1)–
O(1) 97.72(15), N(1)–Ni(1)–O(2) 154.21(14), N(2)–Ni(1)–O(2) 99.12
(13), N(3)–Ni(1)–O(2) 102.99(14), O(1)–Ni(1)–O(2) 62.32(12),
O(1)–C(14)–O(2) 117.8(4).
˚
2.079 to 2.124 A); the carboxylate ligands are bonded in a
symmetric (or almost) chelating mode with |DO| = {[Ni–O(2)] −
˚
[Ni–O(1)]}values of 0.000, 0.012 and 0.045 A for 4, 5 and 6,
respectively. In 5, the O(2) atom is involved in hydrogen bonding
to the hydroxyl H(3) and the contact with nickel is longer. In 6
there is also intermolecular hydrogen bonding between H(23) of
the water molecule and the carboxylate O(2) atom, contributing
to lengthening of the O(2) to Ni contact distance. The hydrogen
bonds of complexes 5 and 6 are summarised in Table 1 (see Figs. 7
and 8). These bond distances are comparable to those reported
for other crystallographically characterized nickel-carboxylate
complexes with a distorted square pyramidal25 or octahedral24–27
respectively) shows values of 0.023, 0.024 and 0.041 for com-
plexes 4, 5 and 6 respectively. The three nitrogen atoms of the N3-
macrocycle hold the apical position and two adjacent basal ones,
whereas the other two basal positions correspond to the O,Oꢀ-
carboxylate group. The basal plane is formed by N(1), N(2),
O(1) and O(2), with a r.m.s. deviation of fitted atoms of 0.0168,
˚
0.0101 and 0.0147 A, for complexes 4, 5 and 6, respectively.
˚
The Ni atom is 0.3012(16), 0.3426(19) and 0.3498(15) A above
Table 1 Structural parameters for H-bonds in complexes 5 and 6
∠(D–H · · · A)/◦
d(D · · · A)/A
A
˚
˚
˚
Complex
D–H
d(D–H)/A
d(H · · · A)/A
5
6
O(3)–H(3)
N(2)–H(2)
O(5)–H(23)
O(5)–H(24)
N(2)–H(2)
0.840
0.930
0.974
0.941
0.930
1.835
2.174
1.992
2.175
2.233
142.44
167.46
169.37
137.55
152.21
2.553
3.088
2.954
2.939
3.086
O(2)
F(6)
O(2)
F(6)
F(6)
1 0 6
D a l t o n T r a n s . , 2 0 0 5 , 1 0 4 – 1 0 9

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operating in the FAB+ mode. Infrared spectra were recorded on
a Perkin-Elmer 16F PC FT-IR spectrophotometer using Nujol
mulls between polyethylene sheets. The UV/Vis spectra (in
acetone) were recorded on a UNICAM 520 spectrophotometer
equipped with matched quartz cells in the 300–800 nm range.
The 1H NMR spectra were recorded on a Bruker model AC 200E
or a Bruker AV-400 spectrometer. Chemical shifts (in ppm) are
reported with respect to the residual solvent signal and the line
1
widths given below (Dm1/2) are in Hz. The H COSY spectrum
was obtained at 20 ◦C for 3 with 512 data points in the F1
dimension and 1024 data points in the F2 dimension with a
delay time of 150 ms. An unshifted sine-bell-squared weighting
function was applied prior to Fourier transformation followed
by baseline correction in both dimensions and symmetrization.
Synthesis
[Ni(mcN3)(A)](PF6) (mcN3 = Me3-mcN3, A = sal (2), acsal
(3); mcN3 = Me4-mcN3, A = sal (5), acsal (6)). These com-
plexes were prepared by reaction of [Ni2(mcN3)2(l-OH)2](PF6)2
(0.12 mmol) with the corresponding carboxylic acid (0.24 mmol)
in acetone (25 mL). After stirring for 30 min the solution
was concentrated under reduced pressure and the addition of
diethyl ether caused the precipitation of a green solid, which was
collected by filtration, washed with diethyl ether and air-dried.
[Ni(Me3-mcN3)(sal)](PF6) 2. Yield 122 mg, 95%. Elemen-
tal anal. Calc. for C19H30F6N3NiO3P: C 41.33, H 5.48, N 7.61.
Found: C 40.89, H 5.65, N 7.84%. Mass spectrum (FAB+): m/z
Fig. 7 Hydrogen bonding in compound 5. ORTEP drawing (ellipsoids
at 50% probability level) with atom-labeling scheme. For clarity the
hydrogen atoms of the macrocycle are omitted.
geometry. The bite angle of the carboxylate anion shows a value
of 62.81(10), 62.32(12) and 63.00(9)◦ for complexes 4, 5 and 6,
respectively. The angle between the phenyl ring and the nickel-
bonded carboxylate group are 1.14 and 0.98◦ in complexes 4 and
5, respectively. In complex 6 the angle arises to 37.05◦. This high
value could be due to the steric hindrance of the acetyl group
and carboxylate O(1) atom.
+
−1
=
406 [M] . IR (Nujol, cm ): 3285, 3265 m(N–H), 1660 m(C N),
1556 m(CO). 1H NMR ((CD3)2CO): d 329.8 (Ha, 2H, Dm1/2 1707),
235.6 (Ha, Dm1/2 2679), 217.1 (Ha, Dm1/2 3239), 103.0 (Ha, Dm1/2
836), 91.1 (Ha, Dm1/2 839), 53.5 (4-Me, 3H, Dm1/2 1171), 39.5 (Ha,
Dm1/2 1080), 35.2 (Ha, Dm1/2 649), 16.0 (4-Me, 3H, Dm1/2 218), 11.8
(3-H, Dm1/2 21), 8.5 (5-H + 6-H, 2H, Dm1/2 26), 7.2 (4-H, Dm1/2
17), −11.8 (Hb, 2H, Dm1/2 472), −12.8 (Hb, Dm1/2 935), −17.0 (2-
Me, 3H, Dm1/2 144), −24.0 (Hb, Dm1/2 280), −28.4 (Hb, Dm1/2 321),
−30.8 (Hb, Dm1/2 536).
[Ni(Me3-mcN3)(acsal)](PF6) 3. Yield 107 mg, 78%. Ele-
mental anal. Calc. for C21H32F6N3NiO4P: C 42.45, H 5.43,
N 7.07. Found: C 42.29, H 5.75, N 7.24%. Mass spec-
trum (FAB+): m/z 448 [M]+, 406 [Ni(Me3-mcN3)(sal)]+, 328
[Ni(Me3-mcN3)(ac)]+. IR (Nujol, cm−1): 3284, 3263 m(N–H),
1
=
=
1748m(C O), 1665 m(C N), 1524 m(CO). H NMR ((CD3)2CO):
d 328.7 (Ha, 2H), 227.0 (Ha, Dm1/2 5829), 218.6 (Ha, Dm1/2 3744),
103.6 (Ha, Dm1/2 1181), 90.5 (Ha, Dm1/2 1391), 52.8 (4-Me, 3H,
Dm1/2 1528), 39.4 (Ha, Dm1/2 1214), 35.0 (Ha, Dm1/2 817), 15.9 (4-
Me, 3H, Dm1/2 315), 10.3 (3-H, Dm1/2 22), 9.2 (5-H, Dm1/2 28), 8.8
(6-H, Dm1/2 166), 5.9 (4-H, Dm1/2 82), 3.4 (-OCOCH3, 3H, Dm1/2
18), −11.8 (Hb, 2H, Dm1/2 409), −13.4 (Hb, Dm1/2 812), −16.9 (2-
Me, 3H, Dm1/2 206), −23.8 (Hb, Dm1/2 320), −28.3 (Hb, Dm1/2 371),
−30.3 (Hb, Dm1/2 907).
Fig. 8 Hydrogen bonding in compound 6. ORTEP drawing (ellipsoids
at 50% probability level) with atom-labeling scheme. For clarity the
hydrogen atoms of the macrocycle are omitted.
[Ni(Me4-mcN3)(sal)](PF6) 5. Yield 107 mg, 84%. Elemen-
tal anal. Calc. for C20H32F6N3NiO3P: C 42.43, H 5.70, N 7.42.
Found: C 42.26, H 5.67, N 7.43%. Mass spectrum (FAB+): m/z
420 [M] . IR (Nujol, cm ): 3271 m(N–H), 1668 m(C N), 1544
m(CO). H NMR ((CD3)2CO): d 365.1 (Ha), 317.0 (Ha, Dm1/2
+
−1
=
Experimental
1
Materials
1804), 288.1 (Ha, Dm1/2 2457), 245.3 (Ha, 2H, Dm1/2 3038), 137.7
(9-Me, 3H, Dm1/2 782), 101.1 (Ha, Dm1/2 694), 65.5 (4-Me, 3H,
Dm1/2 1328), 49.2 (Ha, 2H, Dm1/2 2833), 19.9 (4-Me, 3H, Dm1/2
162), 12.1 (3-H, Dm1/2 20), 9.2 (6-H, Dm1/2 76), 8.6 (5-H, Dm1/2 18),
6.9 (4-H, Dm1/2 18), −9.6 (Hb, 2H, Dm1/2 266), −13.4 (Hb, Dm1/2
170), −16.6 (2-Me, 3H, Dm1/2 77), −25.1 (Hb, Dm1/2 149), −32.7
(Hb, 2H, Dm1/2 215).
The chemicals were purchased from Aldrich and were used
without further purification. Solvents were dried and distilled
by general methods before use. The complexes [Ni2(mcN3)2(l-
OH)2](PF6)2 (mcN3 = 2,4,4-trimethyl-1,5,9-triazacyclododec-1-
ene (Me3-mcN3) or 2,4,4,9-tetramethyl-1,5,9-triazacyclododec-
1-ene (Me4-mcN3) were prepared by previously described
procedures.28,29
[Ni(Me4-mcN3)(acsal)](PF6)·H2O 6. Yield 97 mg, 71%.
Elemental anal. Calc. for C22H36F6N3NiO5P: C 42.20, H 5.79, N
6.71. Found: C 42.55, H 5.91, N 6.73%. Mass spectrum (FAB+):
m/z 462 [M]+, 342 [Ni(Me4-mcN3)(ac)]+. IR (Nujol, cm−1): 3276
Physical measurements
m(N–H), 1771m(C O), 1660 m(C N), 1525 m(CO). 1H NMR
((CD3)2CO): d 352.3 (Ha), 309.3 (Ha, Dm1/2 2656), 287.5 (Ha,
Dm1/2 2533), 244.7 (Ha, Dm1/2 2937), 234.1 (Ha, Dm1/2 1389), 133.0
=
=
C, H and N analyses were carried out with a Carlo Erba
model EA 1108 microanalyzer. Fast atom bombardment (FAB)
mass spectra were run on a Fisons VG Autospec spectrometer
D a l t o n T r a n s . , 2 0 0 5 , 1 0 4 – 1 0 9
1 0 7

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Table 2 Crystallographic data for complexes 4, 5 and 6
4
5
6
Formula
M
C20H32F6N3NiO2P
550.17
Monoclinic
P21/c
4
8.2367(6)
15.3163(12)
18.7672(14)
90
91.2290(10)
90
2367.0(3)
100(2)
0.71073
0.957
C20H32F6N3NiO3P
566.17
Orthorhombic
P21cn
4
8.3340(11)
15.805(2)
18.376(2)
90
90
90
2420.5(5)
100(2)
0.71073
0.941
C22H34F6N3NiO4P·H2O
626.22
Crystal system
Space group
Z
Monoclinic
P21
2
8.2175(4)
15.2313(8)
10.7289(5)
90
98.8200(10)
90
1326.98(11)
100(2)
0.71073
0.872
˚
a/A
˚
b/A
˚
c/A
a/◦
b/◦
c /◦
3
˚
V/A
T/K
˚
k/A
l/mm−1
Reflections collected
Independent reflections
Goodness-of-fit on F2
Final R indices [I>2r(I)]a,b
R indices (all data)a,b
27013
14681
15098
5464 (Rint = 0.0265)
4784 (Rint = 0.0305)
5943 (Rint = 0.0181)
1.083
1.155
1.057
R1 = 0.0703, wR2 = 0.1743
R1 = 0.0733, wR2 = 0.1766
1.440, −0.895
R1 = 0.0531, wR2 = 0.1253
R1 = 0.0563, wR2 = 0.1270
0.890, −0.548
R1 = 0.0405, wR2 = 0.1125
R1 = 0.0411, wR2 = 0.1129
1.519, −0. 614
−3
˚
Max, min Dq/e A
2
1/2
2
a R1 = R ꢁFo| − |Fcꢁ/R|Fo| for reflections with I > 2r I. b wR2 = {R[w(Fo − Fc2)2]/R[w(Fo2)2]} for all reflections; w −1 = r2(F ) + (aP)2 + bP, in
2
which P = (2Fc + Fo2)/3 and a and b are constants set by the program.
(9-Me, 3H, Dm1/2 824), 99.3 (Ha, Dm1/2 714), 65.4 (4-Me, 3H, Dm1/2
1412), 46.7 (Ha, 2H, Dm1/2 2252), 20.1 (4-Me, 3H, Dm1/2 129), 10.6
(3-H, Dm1/2 17), 9.2 (5-H+6-H, 2H, Dm1/2 26), 5.9 (4-H, Dm1/2 17),
3.5 (-OCOCH3, 3H, Dm1/2 62), −9.6 (Hb, 2H, Dm1/2 293), −13.3
(Hb, Dm1/2 155), −16.2 (2-Me, 3H, Dm1/2 65), −24.9 (Hb, Dm1/2
129), −31.8 (Hb, Dm1/2 238), −32.6 (Hb, Dm1/2 197).
[Ni(Me3-mcN3)(bz)](PF6) (mcN3 = Me3-mcN3 (1), Me4-mcN3
(4)). To a solution of [Ni2(mcN3)2((-OH)2](PF6)2 (0.12 mmol)
in acetone (25 mL) benzoic acid (0.24 mmol) was added. The
mixture was stirred at room temperature for 1 h. The solvent was
completely evaporated under reduced pressure and the residue
was extracted with diethyl ether. The solid which formed was
collected by filtration and air-dried.
glass fibre for photographic examination and data collection.
Diffraction data were measured on a Bruker SMART APEX
˚
using Mo-Ka radiation (k = 0.71073 A). Crystallographic data
for 4, 5 and 6 are summarised in Table 2. SADABS30 method of
correcting absorption was applied in all cases. The WINGX31
program package was used to solve and refine the structure
by direct methods. All non-hydrogen atoms were refined with
anisotropic displacements parameters. Hydrogen atoms were
included using a riding model. For complex 6, the hydrogen
atoms of the water molecule were assigned from electron density
signals at suitable bond-lengths.
CCDC reference numbers 249396–249398.
See http://www.rsc.org/suppdata/dt/b4/b413547d/ for cry-
stallographic data in CIF or other electronic format.
[Ni(Me3-mcN3)(bz)](PF6) 1. Yield 71 mg, 57%. Elemental
anal. Calc. for C19H30F6N3NiO2P: C 42.57, H 5.64, N 7.84.
Found: C 42.39, H 5.83, N 7.73%. Mass spectrum (FAB+): m/z
Acknowledgements
+
−1
=
390 [M] . IR (Nujol, cm ): 3285, 3265 m(N–H), 1660 m(C N),
1556 m(CO). 1H NMR ((CD3)2CO): d 339.9 (Ha, 2H), 232.9 (Ha,
Dm1/2 2506), 231.3 (Ha, Dm1/2 1782), 214.9 (Ha, Dm1/2 4433), 104.4
(Ha, Dm1/2 750), 56.1 (4-Me, 3H, Dm1/2 1713), 49.7 (Ha), 49.4 (Ha),
18.1 (4-Me, 3H, Dm1/2 192), 9.0 (Ho, 2H), 8.8 (Hm, 2H, Dm1/2 35),
5.8 (Hp, Dm1/2 24), −11.2 (Hb, Dm1/2 327), −12.2 (Hb, 2H, Dm1/2
484), −15.5 (2-Me, 3H, Dm1/2 137), −24.8 (Hb, Dm1/2 232), −29.7
(Hb, 2H, Dm1/2 429).
We thank the Fundacio´n Se´neca, CARM (Project PI-
32/00800/FS/01) for financial support and the Direccio´n Gen-
eral de Investigacio´n del Ministerio de Ciencia y Tecnolog´ıa for
partial financial support (Project BQU2001-0979-C02). A. A. L.
thanks Fundacio´n Seneca for a grant.
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1 0 8
D a l t o n T r a n s . , 2 0 0 5 , 1 0 4 – 1 0 9

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D a l t o n T r a n s . , 2 0 0 5 , 1 0 4 – 1 0 9
1 0 9