Transition metal complexes with pyrazole derivatives as ligands

Article abstract of DOI:10.1016/j.ica.2005.10.034

Degradation reactions of scorpionates were observed in the presence of transition metal salts MX₂ to give complexes of transition metal and pyrazole derivatives. Otherwise, pyrazolato complexes of transition metals and weakly coordinating anions such as nitrates have been synthesized from transition metal nitrates and 3-phenyl- and 4-phenyldiazo-pyrazole. A number of complexes with pyrazole derivatives as ligands, [Zn(3-tBupzH)₂Cl ₂], [Fe₂(3-Phpz)₆Cl₄], [Cu(pzH) ₄Br₂], [Ni(py)₂(pzH)₂Cl ₂], [Li(THF)₄][Ti₂(μ-pz)₃Cl ₄(NMe₂)₂], [Zn₂(μ-3-Phpz) ₂(3-PhpzH)₂][(NO₃)₂], [M(3-PhpzH)₄(NO₃)₂] (M = Co, Ni, Cu, Zn, Cd), [Zn(3-PhpzH)₂(NO₃)₂], [Zn(4-PhN=NpzH) ₂(NO₃)₂](H₂O), and [Cd(4-PhN=NpzH)₂(NO₃)₂(H₂O) ₂], have been crystallized and characterized by single-crystal X-ray diffraction.

Full text of DOI:10.1016/j.ica.2005.10.034

Inorganica Chimica Acta 359 (2006) 1559–1572
www.elsevier.com/locate/ica
Transition metal complexes with pyrazole derivatives as ligands
a
a
a
b
Susanne Bieller , Alireza Haghiri , Michael Bolte , Jan W. Bats ,
a
a,
*
Matthias Wagner , Hans-Wolfram Lerner
a
Institut fu¨r Anorganische Chemie, Johann Wolfgang Goethe-Universita¨t Frankfurt am Main, Marie-Curie-Straße 11, 60439 Frankfurt am Main, Germany
b
Institut fu¨r Organische Chemie, Johann Wolfgang Goethe-Universita¨t, Marie-Curie-Straße 11, 60439 Frankfurt, Germany
Received 30 September 2005; accepted 17 October 2005
Available online 7 December 2005
Abstract
Degradation reactions of scorpionates were observed in the presence of transition metal salts MX2 to give complexes of transition metal
and pyrazole derivatives. Otherwise, pyrazolato complexes of transition metals and weakly coordinating anions such as nitrates have been
synthesized from transition metal nitrates and 3-phenyl- and 4-phenyldiazo-pyrazole. A number of complexes with pyrazole derivatives as
ligands, [Zn(3-tBupzH)2Cl2], [Fe2(3-Phpz)6Cl4], [Cu(pzH)4Br2], [Ni(py)2(pzH)2Cl2], [Li(THF)4][Ti2(l-pz)3Cl4(NMe2)2], [Zn2(l-3-Phpz)2-
(3-PhpzH)2][(NO3)2], [M(3-PhpzH)4(NO3)2] (M = Co, Ni, Cu, Zn, Cd), [Zn(3-PhpzH)2(NO3)2], [Zn(4-PhN@NpzH)2(NO3)2](H2O), and
[Cd(4-PhN@NpzH)2(NO3)2(H2O)2], have been crystallized and characterized by single-crystal X-ray diffraction.
ꢀ 2005 Elsevier B.V. All rights reserved.
Keywords: Scorpionates; Pyrazole; Coordination chemistry; X-ray structure analysis
1. Introduction
complexes with pyrazole derivatives 3-R0pzH and 4-R0pzH
as ligands with the intention to reverse degradation reac-
tions of scorpionates.
Tris(1-pyrazolyl)borates (‘‘scorpionates’’) were invented
by Trofimenko [1] more than 30 years ago and today are
well established as ligands in coordination chemistry. Scor-
pionates with transition metals are now found useful in a
wide range of chemistry from modelling the active site of
metaloenzymes, through analytical chemistry and organic
synthesis to catalysis and materials science [2].
Despite their widespread use, information regarding the
degradation of these scorpionates is still rather limited
(Fig. 1). Graziani et al. [3] described that the reaction
between FeCl2 and the Tl scorpionate, Tl[tBuB(3-tBupz)3],
which led to deboronation of scorpionate anion to give
trans-FeCl2(3-tBu-pzH)4.
2. Experimental
2.1. Synthesis of [Zn(3-tBupzH)2Cl2] (1)
A solution of fluorenyl scorpionate C13H9B(3-tBupz)3-
Li Æ THF [4] (0.13 g, 0.20 mmol) in a mixture of toluene
(10 mL) and methylene chloride (5 mL) was added drop-
wise with stirring to a slurry of ZnCl2 (0.03 g, 0.20 mmol)
in methylene chloride (10 mL). After stirring for 8 h, the
white precipitate was removed by filtration and the solvent
was evaporated in vacuo. Recrystallization by slow diffu-
sion of hexane to a chloroform solution gave colorless X-
ray quality crystals.
The purpose of this paper is to give more detailed
information about the reactivity of scorpionates towards
transition metal halides. Moreover, we became interested
in synthesis and characterization of transition metal
2.2. Synthesis of [Fe2(3-PhpzH)6Cl4] (2)
*
A solution of scorpionate C13H9B(3-Phpz)3Li Æ THF [4]
Corresponding author. Tel.: +49 69 79829151; fax: +49 69 79829260.
E-mail address: lerner@chemie.uni-frankfurt.de (H.-W. Lerner).
(0.15 g, 0.21 mmol) in a mixture of toluene (10 mL) and
0020-1693/$ - see front matter ꢀ 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2005.10.034

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S. Bieller et al. / Inorganica Chimica Acta 359 (2006) 1559–1572
of hexane to a THF solution gave blue crystals suitable for
R'
X-ray crystal structure analysis.
R'
R'
N
N
N
N
2.4. Synthesis of [Ni(py)2(pzH)2Cl2] (4)
RB
R'
RB
N
N
N
N
R'
R'
-
p-C6H4(B(tBu)pz2Li)2 Æ 4THF [5] (0.53 g, 0.68 mmol) in
ethanol (10 mL) was added dropwise with stirring to a
slurry of [Ni(py)4Cl2] (0.61 g, 1.36 mmol) in ethanol
(10 mL), whereupon a green solution and a yellow precip-
itate formed. The reaction mixture was stirred for 2 h at
ambient temperature and the precipitate was removed by
filtration. The remaining green solution was evacuated to
dryness to give a turquoise solid. Colorless X-ray quality
crystals were grown by slow diffusion of hexane to a etha-
nol solution of compound 3. Yield: 0.08 g (0.19 mmol,
14%).
N
N
N
N
R'
N
N
N
N
R'
RB(4-R'pz)3
-
4-R'pzH
3-R'pzH
RB(3-R'pz)3
Fig. 1. Tris(1-pyrazolyl)borates, scorpionates.
methylene chloride (5 mL) was added dropwise with stir-
ring to a slurry of FeCl2 (0.03 g, 0.21 mmol) in methylene
chloride (10 mL). After stirring for 8 h, the white precipi-
tate was removed by filtration and the solvent was evapo-
rated in vacuo. Recrystallization by slow diffusion of
hexane to a chloroform solution gave colorless X-ray qual-
ity crystals.
2.5. Synthesis of [Li(THF)4][Ti2(l-pz)3Cl4(NMe2)2]
([Li][5])
A solution of p-C6H4(B(tBu)pz2Li)2 Æ 4THF [5] (0.73 g,
0.94 mmol) in THF (10 mL) was added at ꢀ78 ꢁC to a
2.3. Synthesis of [Cu(pzH)4Br2] (3)
p-C6H4(B(tBu)pz2Li)2 Æ 4THF [5] (0.18 g, 0.23 mmol) in
THF (10 mL) was added dropwise with stirring to a solu-
tion of CuBr2 (0.13 g, 0.46 mmol) in THF (15 mL), where-
upon a green solution formed. The solvent was removed in
vacuo, recrystallization of the green solid by slow diffusion
N
N
Mn+
RB
N
N
N
N
2
2-
N
N
N
x2
+MX2
-2 X
X
N
N
N
N
RB
N
N
N
R'
R'
B
B
N
N
R
R
N
N
-
2-
RBX(3-R'pz)2
p/m-C6H4[BX(3-R'pz)2]2
RB
N
N
R=Ph; X=pz, CH2SMe, CH2PPh2; R'=H
R=CH3C6H4; X=Me, pz; R'=H
X=Me, tBu, Ph, pz; R'=H, tBu, Ph
N
N
R=C6F5, X=Pz; R'=H
2-
R=C13H9, X=tBu, Ph; R'=H, tBu, Ph
R=Fc; X=Me, tBu, Ph, Fc, pz; R'=H, tBu, Ph
R=Cym; X=Me, Ph, pz; R'=H
X
+MX2
B
-RBX2
N
N
-pz-
R'
Fe
X
X
B
N
N
L
R'
N
L
N
X
L
M
L
2-
N
N
Fc[BX(3/4-R'pz)2]2
X=Me, Ph, pz; R'=H, tBu, Ph
Fig. 2. (1-Pyrazolyl)borates, scorpionates.
Scheme 1. Reaction of scorpionates with transition metal salts.

S. Bieller et al. / Inorganica Chimica Acta 359 (2006) 1559–1572
1561
solution of Ti(NMe2)2Cl2 (0.39 mg, 1.87 mmol) in THF
(10 mL). After 1 h, stirring was continued at ambient
temperature for 3 h, the solvent was reduced in vacuo
to 5 mL and the solution was layered with pentane
(15 mL) to form crystals of [Li][5] suitable for X-ray
determination.
was layered with pentane (10 mL) to form crystals of
[6][(NO3)2] suitable for X-ray determination.
2.7. Syntheses of [M(3-PhpzH)4(NO3)2] (M = Co, Ni,
Cu, Zn, Cd) 7(Co), 7(Ni), 7(Cu), 7(Zn), and 7(Cd)
One equivalent of a transition metal nitrate as hydrate
2.6. Synthesis of [Zn2(l-3-Phpz)2(3-PhpzH)2][(NO3)2]
([6][(NO3)2])
[Co(NO3)2 Æ 6H2O (0.14 mmol); Ni(NO3)2 Æ 6H2O (0.14 mmol);
Cu(NO3)2 Æ 3H2O
(0.14 mmol);
Zn(NO3)2 Æ
6H2O
(0.07 mmol) and Cd(NO3)2 Æ 6H2O (0.14 mmol)] and 4
equivalents of 3-phenylpyrazole [7] were combined in etha-
nol (10 mL) under ambient conditions, forming a clear
solution. Slow evaporation of the solvent led to deposition
of X-ray quality crystals of pink 7(Co), blue 7(Ni), green
7(Cu), colorless 7(Zn), and colorless 7(Cd).
A solution of Zn(NO3)2 Æ 6H2O (0.36 g, 0.14 mmol) in
THF (10 mL) was added at ambient temperature to a solu-
tion of [FcB(3-Phpz3)3][Li(THF)] [6] (0.704 g, 1 mmol) in
THF (50 mL). After 8 h of stirring at ambient temperature,
the solvent was reduced in vacuo to 10 mL and the solution
Ph
Ph
tBu
HN
HN
HN
N
N
-
Ph
N
Fe
N
N
Fe
N
HN
N
Cl
Cl
Cl
Cl
N
N
Cl
Cl
Me2N
Zn
Cl
Cl
Ti
Ti
HN
N
N
Cl
Cl
N
NH
tBu
NMe2
N
N
1
2
Ph
HN
HN
Ph
[5]-
Ph
i
i
R'
R'
ii
N
N
N
iv
R'
RB
X
N
N
N
ii
N
RB
X
iii
N
R'
Br
N
N
NH
HN
N
N
Cu
Br
N
N
N
2+
Ph
Ph
Cl
NH
HN
Ph
Zn
Ph
Ph
Ni
N
N
N
N
N
N
N
Cl
N
N
4
N
N
3
Zn
Ph
N
N
N
N
Scheme 2. Deboronation of scorpionates with bulky substituents; i:
+ZnCl2/+H+/ꢀRBBr2/ꢀCu2+/ꢀ3-tBupzH,
X = 3-tBupz/R = C13H9/
[6]2+
R0 = tBu; ii: +FeCl2/+H+/ꢀRXBCl/ꢀFe2+/ꢀ3-PhpzH, X = 3-Phpz/
R = C13H9/R0 = Ph; iii: +CuBr2/+H+/ꢀRXBBr/ꢀCu2+/ꢀpzH, X =
Scheme 3. Syntheses of the dinuclear complexes Li[5] and [6](NO3)2; i:
+TiCl2(NMe2)2/ꢀRXBNMe2/ꢀpz X = C6H4/R = tBu/R0 = H; and ii:
+Zn(NO3)2/+H+/ꢀRXB(3-Phpz), X = 3-Phpz/R = Fc/R0 = Ph.
C6H4/R = tBu/R0 = H; and iv: +Ni(py)2Cl2/+H+/ꢀRXBBr/ꢀNi2+
ꢀpzH, R = tBu/X = C6H4/R = tBu/R0 = H.
/

1562
S. Bieller et al. / Inorganica Chimica Acta 359 (2006) 1559–1572
2.8. Synthesis of [Zn(3-PhpzH)2(NO3)2] (8)
Ph
N
N
Zn(NO3)2 Æ 6H2O (0.04 g, 0.14 mmol) and 3-phenylpy-
razole (0.04 g, 0.28 mmol) were combined in ethanol
(10 mL) under ambient conditions, forming a clear color-
less solution. Slow evaporation of the solvent led to depo-
sition of colorless plates of 8.
+
M(NO3)2
2.9. Synthesis of [Zn(4-PhN@NpzH)2(NO3)2(H2O)] (9)
ONO2
Zn(NO3)2 Æ 6H2O (0.04 g, 0.14 mmol) and 4-phenyldiaz-
opyrazole [8] (0.05 g, 0.27 mmol) were combined in ethanol
(10 mL) under ambient conditions, forming a clear red
solution. Slow evaporation of the solvent led to deposition
of red plates of product 9.
Ph
Ph
Ph
Ph
N
NH
NH
HN
HN
N
N
M
N
2.10. Synthesis of [Cd(4-PhN@NpzH)2(NO3)2(H2O)2]
(10)
ONO2
6(M)
Cd(NO3)2 Æ 4H2O (0.04 g, 0.14 mmol) and 4-phenyldiaz-
opyrazole (0.048 g, 0.28 mmol) were combined in wet etha-
nol (10 mL) under ambient conditions, forming a clear red
solution. Slow evaporation of the solvent led to deposition
of red plates of product 10.
Scheme 4. Synthesis of pyrazolato complexes 7(Co), 7(Ni), 7(Cu), 7(Zn),
and 7(Cd).
2.11. Crystal structure determination
Data collection. STOE IPDS II two-circle diffractometer
[1, 2, 3, 4, [Li][5], [6][(NO3)2], 7(Co), 7(Ni), 7 (Cu), 7(Zn),
7(Cd),8, and 9], Siemens-SMART-CCD three-circle diffrac-
tometer [10], graphite monochromated Mo Ka radiation
ONO2
Ph
H2O
N
HN
N
N
˚
(k = 0.71073 A), T = 173(2) K. Empirical absorption cor-
M
N
N=N-Ph
N
Zn
rections were performed using SADABS [9] [10] or the MULABS
[10] option [1, 2, 3, 4, [Li][5], [6][(NO3)2], 7 (Co), 7(Ni),
7(Cu), 7(Zn), 7(Cd), 8, and 9] in PLATON [11]. The structures
were solved by direct methods using the program SHELXS
[12] and refined against F2 with full-matrix least-squares
techniques using the program SHELXL-97 [13]. All non-
hydrogen atoms were refined with anisotropic displacement
parameters. Hydrogen atoms were located by difference
Fourier synthesis and refined using a riding model.
ONO2
ONO2
H
HN
HN
Ph-N=N
ONO2
ONO2
Ph
8
9
N=N-Ph
N
NH
H2O
N
M
3. Results and discussion
OH2
HN
Ph-N=N
3.1. Deboronation of scorpionates
ONO2
10
Recently, we have synthesized different types of homo-
and heteroscorpionates [4,5,14–21]. As shown in Fig. 2,
Scheme 5. Pyrazolato complexes 8, 9, and 10.
Table 1
Selected bond lengths and angles of 7(Co), 7(Ni), 7(Cu), 7(Zn), and 7(Cd)
Compound 7(Co) 7(Ni)
2.1127(12) 2.0810(10)
2.1068(10)
138.68(9)
7(Cu)
2.0174(18)
7(Zn)
2.1231(10)
2.1688(9)
143.08(8)
7(Cd)
2.3258(16)
˚
M–N av. (A)
M–O (A)
˚
2.1637(11)
143.11(10)
2.3417(15)
2.3842(12)
M–O(1)–N(1) (ꢁ)
147.66(14)
126.22(11)

Table 2
Crystallographic data of 1, 2, 3, 4, [Li][5], [6][(NO3)2], 7(Co), 7(Ni), 7(Cu), 7(Zn), 7 (Cd), 8, 9, and 10
Compound
1
2
3
4
[Li][5]
[6][(NO3)2]
7(Co)
Formula
Formula weight
Color
Crystal size (mm)
T (K)
C
384.64
colorless
0.25 · 0.15 · 0.11
100(2)
14H24C12N4Zn
C54H48C14Fe2N12
1118.54
colorless
0.22 · 0.21 · 0.19
173(2)
C12H16Br2CuN8
495.69
blue
0.24 · 0.18 · 0.09
173(2)
0.71073
C16H18C12N6Ni
423.97
colorless
0.25 · 0.23 · 0.05
173(2)
C29H53C14LiN8O4Ti2
822.33
colorless
0.25 · 0.24 · 0.12
173(2)
C54H46N14O6Zn2
1117.79
colorless
0. 26 · 0.18 · 0.14
100(2)
C36H32CoN10O6
759.65
pink
0.38 · 0.26 · 0.12
100(2)
0.71073
˚
Radiation (A)
0.71073
0.71073
0.71073
0.71073
0.71073
Crystal system
Space group
triclinic
monoclinic
P21/n
11.8555(18)
17.781(2)
12.8403(17)
90
102.073(11)
90
2646.9(6)
2
monoclinic
C2/c
14.2274(16)
9.3074(10)
14.4078(18)
90
118.176(8)
90
1681.8(3)
4
monoclinic
P21/n
7.6754(6)
16.0945(8)
15.5772(11)
90
92.553(6)
90
1922.4(2)
4
monoclinic
P21/n
11.8715(8)
23.145(2)
14.9585(10)
90
95.741(5)
90
4089.5(5)
4
monoclinic
C2/c
24.657(2)
13.6400(10)
16.4960(10)
90
113.024(6)
90
5106.0(6)
4
triclinic
ꢀ
ꢀ
P1
P1
˚
a (A)
9.541(3)
9.719(3)
10.948(3)
85.46(2)
89.82(2)
67.50(2)
934.6(5)
2
7.7915(8)
9.8735(10)
12.5155(14)
71.718(8)
76.695(8)
75.676(8)
873.53(16)
1
˚
b (A)
˚
c (A)
a (ꢁ)
b (ꢁ)
c (ꢁ)
3
˚
V (A )
Z
Dcalc (g cmꢀ3
F(000)
)
1.367
400
1.599
1.403
1152
0.799
1.958
972
6.061
1.465
872
1.298
1.336
1720
0.693
1.454
2304
1.006
1.444
393
0.553
l (mmꢀ1
)
Minimum/maximum h (ꢁ)
0.6907/0.8438
3340
3340
3340/0/191
1.096
0.8438/0.8630
11003
4874
4874/0/337
1.056
0.3240/0.6115
1548
1548
1548/0/107
1.058
0.7373/0.9379
22608
3600
3600/0/234
1.054
0.8458/0.9214
21661
7835
7835/0/437
1.019
0.7800/0.8720
31041
4908
4908/0/351
0.928
0.8172/0.9366
12279
4021
4021/0/241
1.076
Number of reflections collected
Number of independent reflections (Rint
Number of data/restraints/parameters
Goodness-of-fit on F2
)
R1, wR2 [I > 2r(I)]
R1, wR2 (all data)
Largest difference in peak and hole (e A
0.0683, 0.1857
0.1132, 0.2279
0.951 and ꢀ0.864
0.0652, 0.1531
0.0979, 0.1674
0.856 and ꢀ0.874
0.0382, 0.1020
0.0422, 0.1050
0.814 and ꢀ1.075
0.0308, 0.0638
0.0398, 0.0666
0.216 and ꢀ0.359
0.0572, 0.1236
0.0931, 0.1379
0.854 and ꢀ0.406
0.0453, 0.0917
0.0815, 0.1021
0.357 and ꢀ0.887
0.0387, 0.1039
0.0401, 0.1051
0.534 and ꢀ1.241
ꢀ3
˚
)
Compound
7(Ni)
7(Cu)
7(Zn)
7(Cd)
8
9
10
Formula
Formula weight
Color
C
759.43
blue
36H32N10NiO6
C36H32CuN10O6
764.26
green
C36H32N10O6Zn
766.09
colorless
C36H32CdN10O6
813.12
colorless
C18H16N6O6Zn
477.74
colorless
C18H18N10O7Zn
551.79
red
C18H20CdN10O8
616.84
red
Crystal size (mm)
T (K)
Radiation (A)
Crystal system
Space group
0.38 · 0.32 · 0.28
100(2)
0.71073
triclinic
0.28 · 0.22 · 0.11
100(2)
0.71073
0.46 · 0.38 · 0.32
100(2)
0.71073
0.27 · 0.14 · 0.08
100(2)
0.71073
0.31 · 0.18 · 0.07
100(2)
0.71073
0.35 · 0.15 · 0.14
100(2)
0.71073
monoclinic
C2/c
25.689(2)
10.3260(7)
8.5928(8)
90
104.651(7)
90
0.16 · 0.08 · 0.06
147(2)
0.71073
monoclinic
P21/c
14.078(3)
8.3015(12)
10.130(3)
90
93.646(15)
90
˚
triclinic
triclinic
triclinic
triclinic
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
P1
P1
P1
P1
P1
˚
a (A)
7.7143(12)
9.8592(16)
12.425(2)
72.792(13)
77.420(13)
76.024(13)
865.0(2)
1
7.9618(11)
9.8234(15)
12.3207(19)
71.836(12)
76.526(11)
74.898(11)
871.8(2)
1
7.7944(6)
9.8693(8)
12.5030(10)
71.962(6)
76.707(6)
75.642(6)
873.63(12)
1
7.9531(5)
9.8226(7)
23.8269(17)
82.792(6)
80.535(6)
80.535(6)
1766.9(2)
2
7.8214(10)
15.6360(19)
15.904(2)
86.370(10)
89.577(11)
85.641(10)
1935.5(4)
4
˚
b (A)
˚
c (A)
a (ꢁ)
b (ꢁ)
c (ꢁ)
3
˚
V (A )
2205.3(3)
4
1.662
1181.5(4)
2
1.734
Z
Dcalc (g cmꢀ3
F(000)
)
1.458
394
1.456
395
1.456
396
1.528
828
1.640
976
1128
620
(continued on next page)

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S. Bieller et al. / Inorganica Chimica Acta 359 (2006) 1559–1572
simple scorpionates have been prepared on the one hand,
bitopic benzene- and ferrocene-based scorpionates have
been established on the other hand.
In some reactions of the alkali metal or thallium scorpi-
onates with metal salts MX2, the formation of the corre-
sponding transition metal–pyrazolato complexes has been
observed. Obviously, in these cases deboronation was
preferable to metathesis (see Scheme 1).
An important factor influencing the stability of scorpio-
nates appears to be the degree of steric crowding around
the boron center. The results of earlier studies [3] and inves-
tigations in our group show that scorpionates RBð3-R0pzÞ
ꢀ
3
and RBð3-R0pzÞ decompose in the presence of transition
ꢀ
3
metal salts much more easily when R and R0 are bulky. We
found that treatment of fluorenyl scorpionate [C13H9B-
(3-tBupz)3Li(THF)] [4] with ZnCl2 or of [C13H9B-
(3-Phpz)3Li(THF)] [4] with FeCl2 led to the formation of
the coordination compounds 1 and 2 as shown in Scheme
2.
Moreover, we observed that the ditopic scorpionate [p-
C6H4(BtBupz2)2][Li(THF)4]2 [5] with the bulky tBu substi-
tuent on the boron center reacts with CuBr2 or with
Ni(py)2Cl2 to produce the corresponding pyrazolato com-
plexes as depicted in Scheme 2.
Another reason for the deboronation of these scorpio-
nates may be the difference in Lewis acidity of the metal
center in MX2 on the one side and of the boron center in
the corresponding borane of pyrazolyl borate on the other
side. Obviously, the stronger Lewis acid reacts with the
pyrazolide anion.
Our studies show that the reaction of scorpionate [p-
C6H4(BtBupz2)2][Li(THF)4]2 [5] with Ti(NMe2)2Cl2 led to
the formation of dinuclear anion [5]ꢀ. As shown in Scheme
3,
a similar reaction was observed when [FcB(3-
phpz)3][Li(THF)] [6] was treated with Zn(NO3)2. Single
crystals of the cationic dinuclear pyrazolato Zn complex
were obtained from THF, whereas X-ray quality crystals
of the anionic dinuclear pyrazolato Ti complex were grown
from hexane at ambient temperature.
It is interesting to note that degradation reactions of
scorpionates were preferred in the presence of nucleophilic
halides. In our aim to reverse deboronation reactions of
scorpionates, we decided to synthesize pyrazolato com-
plexes with weakly coordinating anions such as nitrates.
3.2. Syntheses of pyrazolato transition metal nitrates
Pyrazolato complexes 7(Co), 7(Ni), 7(Cu), 7(Zn), and
7(Cd) are easily accessible from the reaction of one equiv-
alent of M(NO3)2 (M = Co, Ni, Cu, Zn, Cd) and four
equivalents of 3-phenylpyrazole in ethanol (Scheme 4).
The syntheses of tetra-coordinate Zn compound 8 were
conveniently achieved by the reaction of one equivalent
Zn(NO3)2 with two equivalents of 3-phenylpyrazole [7].
Complexes [Zn(4-PhN@NpzH)2(NO3)2(H2O)] (9) and
[Cd(4-PhN@NpzH)2(NO3)2(H2O)2] (10) were synthesized
by a similar route as shown for 3-phenylpyrazolato

S. Bieller et al. / Inorganica Chimica Acta 359 (2006) 1559–1572
1565
˚
Fig. 3. Molecular structure of compound 1; thermal ellipsoids shown at the 50% probability level. Selected bond lengths (A) and angles (ꢁ): Zn(1)–N(11)
2.029(9), Zn(1)–N(1) 2.040(8), Zn(1)–Cl(2) 2.232(3), Zn(1)–Cl(1) 2.305(3), N(1)–C(1) 1.347(12), N(1)–N(2) 1.383(12), N(2)–C(3) 1.368(12), C(1)–C(2)
1.385(16), C(2)–C(3) 1.399(14), C(3)–C(4) 1.537(15), N(11)–C(11) 1.354(13), N(11)–N(12) 1.379(13), N(12)–C(13) 1.370(13), C(11)–C(12) 1.404(14), C(12)–
C(13) 1.419(16), C(13)–C(14) 1.498(16); N(11)–Zn(1)–N(1) 117.8(4), N(11)–Zn(1)–Cl(2) 105.5(3), N(1)–Zn(1)–Cl(2) 106.7(2), N(11)–Zn(1)–Cl(1) 106.8(2),
N(1)–Zn(1)–Cl(1) 105.6(3), Cl(2)–Zn(1)–Cl(1) 114.74(12), C(1)–N(1)–N(2) 105.6(8), C(1)–N(1)–Zn(1) 124.9(8), N(2)–N(1)–Zn(1) 128.3(6).
˚
Fig. 4. Molecular structure of compound 2; thermal ellipsoids shown at the 50% probability level. Selected bond lengths (A) and angles (ꢁ): Fe(1)–N(31)
2.159(4), Fe(1)–N(21) 2.163(4), Fe(1)–N(11) 2.197, Fe(1)–Cl(1) 2.5131(13), Fe(1)–Cl(2)#1 2.5225(11), Fe(1)–Cl(2) 2.5641(13), Cl(2)–Fe(1)#1 2.5225(11),
N(11)–C(15) 1.334(6), N(11)–N(12) 1.359(5), N(12)–C(13) 1.357(6), C(13)–C(14) 1.384(7), C(13)–C(41) 1.475(6), C(14)–C(15) 1.406(6), N(21)–C(25)
1.329(7), N(21)–N(22) 1.365(5), N(22)–C(23) 1.351(6), C(23)–C(24) 1.393(8), C(23)–C(51) 1.473(7), C(24)–C(25) 1.414(8), N(31)–C(35) 1.328(7), N(31)–
N(32) 1.372(5), N(32)–C(33) 1.362(6), C(33)–C(34) 1.375(7), C(33)–C(61) 1.470(7), C(34)–C(35) 1.409(7), C(41)–C(42) 1.397(7), C(41)–C(46) 1.407(6),
C(42)–C(43) 1.395(7), C(43)–C(44) 1.395(7), C(44)–C(45) 1.386(8), C(45)–C(46) 1.393(7), C(51)–C(56) 1.397(7), C(51)–C(52) 1.401(7), C(52)–C(53)
1.406(7), C(53)–C(54) 1.386(8), C(54)–C(55) 1.392(9), C(55)–C(56) 1.397(8), C(61)–C(66) 1.402(7), C(61)–C(62) 1.406(8), C(62)–C(63) 1.393(8), C(63)–
C(64) 1.381(8), C(64)–C(65) 1.394(9), C(65)–C(66) 1.387(8); N(31)–Fe(1)–N(21) 177.07(14), N(31)–Fe(1)–N(11) 88.72(14), N(21)–Fe(1)–N(11) 88.41(14),
N(31)–Fe(1)–Cl(1) 88.46(11), N(21)–Fe(1)–Cl(1) 90.90(11), N(11)–Fe(1)–Cl(1) 88.75(11), N(31)–Fe(1)–Cl(2)#1 90.52(10), N(21)–Fe(1)–Cl(2)#1 92.39(10),
N(11)–Fe(1)–Cl(2)#1 175.71(11), Cl(1)–Fe(1)–Cl(2)#1 95.45(4), N(31)–Fe(1)–Cl(2) 91.87(11), N(21)–Fe(1)–Cl(2) 88.65(11), N(11)–Fe(1)–Cl(2) 88.79(11),
Cl(1)–Fe(1)–Cl(2) 177.51(4), Cl(2)#1–Fe(1)–Cl(2) 87.02(4), Fe(1)#1–Cl(2)–Fe(1) 92.98(4). Symmetry transformations used to generate equivalent atoms:
#1: ꢀx + 1, ꢀy + 1, ꢀz + 1.

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S. Bieller et al. / Inorganica Chimica Acta 359 (2006) 1559–1572
transition metal complexes from 4-phenyldiazopyrazole
[8] and M(NO3)2 (M = Zn, Cd) in ethanol at room tem-
perature (Scheme 5).
plexes, [5]ꢀ and [6]2+, pyrazolide anions 3-R0pzꢀ (R0 = H,
Ph) act as bridging ligands.
ꢀ
Complex 1 crystallizes in the triclinic space group P1
Therefore, it can be concluded that complexes 7(Co),
7(Ni), 7(Cu), 7(Zn), 7(Cd), 8, 9, and 10 possess a syn-
thetic potential for the preparation of scorpionates.
However, up to now our efforts to reverse the degrada-
tion reactions have not yet succeeded. So at 80 ꢁC in
the presence of Lewis bases such as NEt3, reactions of
aryldiaminioboranes and pyrazolato transition metal
nitrates led to a cleavage of the C–B bond of aryldiami-
noboranes [22].
(Fig. 3). The Zn center in 1 is coordinated by two Cl atoms
and two 3-tBu-pyrazole molecules in a tetrahedral fashion.
The coordination geometry of the Fe atoms in 2 (mono-
clinic space group P21/n) is octahedral. The molecules form
centrosymmetric dimers connected by two symmetry-
˚
related long axial Fe–Cl contacts of 2.5438(13) A (Fig. 4).
˚
The Feꢁ ꢁ ꢁFe distance within the dimer is 3.689 A. In the
solid-state structure of dimeric 2, two pyrazole molecules
act as equatorial ligands and four pyrazole groups as axial
ligands.
3.3. X-ray crystallographic structures
Fig. 5 shows the molecular structure of 3 (monoclinic
space group C2/c). The Cu center in 3 is coordinated by
four pyrazole groups and two bromide ions. The four pyr-
azole molecules in 3 are equatorially coordinated, the two
bromide ions act as axial ligands. The Cu–Br bonds of
The molecular structures of complexes 1, 2, 3, 4, [Li][5],
[6][(NO3)2], 7(Co), 7(Ni), 7(Cu), 7(Zn), 7(Cd), 8, 9, and 10
are shown in Figs. 3–14. Selected bond lengths and angles
are listed in the corresponding figure captions and Table 1,
details of the crystal structure analyses are summarized in
Table 2.
In complexes 1, 2, 3, 4, 7(Co), 7(Ni), 7(Cu), 7(Zn), 7(Cd),
8, 9, and 10, pyrazole derivatives 3-R0pzH (R0 = H, tBu,
Ph) and 4-R0pzH (R0 = H, PhN@N) act as monodentate
ligands, whereas in dinuclear anionic and cationic com-
˚
2.9976(5) A are significantly longer than the Cu–Br bonds
in the solid-state structure of CuBr2.
As depicted in Fig. 6, the crystal structure of 4 (mono-
clinic space group P21/n) shows that all ligands in 3 are
in a trans position. The average Ni–Cl distance in 3 of
˚
2.4529(5) A represents a characteristic value for Ni–Cl
bonds.
˚
Fig. 5. Molecular structure of compound 3; thermal ellipsoids shown at the 50% probability level. Selected bond lengths (A) and angles (ꢁ): Cu(1)–N(1)
2.013(3), Cu(1)–N(1)#1 2.013(3), Cu(1)–N(11) 2.025(3), Cu(1)–N(11)#1 2.025(3), Cu(1)–Br(1)#1 2.9976(5), Cu(1)–Br(1) 2.9976(5), N(1)–C(5) 1.337(6),
N(1)–N(2) 1.340(5), N(2)–C(3) 1.351(6), C(3)–C(4) 1.369(7), C(4)–C(5) 1.382(7), N(11)–C(15) 1.346(6), N(11)–N(12) 1.352(5), N(12)–C(13) 1.345(6),
C(13)–C(14) 1.363(8), C(14)–C(15) 1.391(7); N(1)–Cu(1)–N(1)#1 179.998(1), N(1)–Cu(1)–N(11) 89.77(14), N(1)#1–Cu(1)–N(11) 90.22(14), N(1)–Cu(1)–
N(11)#1 90.22(14), N(1)#1–Cu(1)–N(11)#1 89.78(14), N(11)–Cu(1)–N(11)#1 180.0(3), N(1)–Cu(1)–Br(1)#1 91.44(10), N(1)#1–Cu(1)–Br(1)#1 88.56(10),
N(11)–Cu(1)–Br(1)#1 88.66(10), N(11)#1–Cu(1)–Br(1)#1 91.34(10), N(1)–Cu(1)–Br(1) 88.56(10), N(1)#1–Cu(1)–Br(1) 91.44(10), N(11)–Cu(1)–Br(1)
91.34(10), N(11)#1–Cu(1)–Br(1) 88.66(10), Br(1)#1–Cu(1)–Br(1) 180.0 Symmetry transformations used to generate equivalent atoms: #1: ꢀx + 3/2,
ꢀy + 3/2, ꢀz + 1.

S. Bieller et al. / Inorganica Chimica Acta 359 (2006) 1559–1572
1567
The structure of dinuclear anion [5]ꢀ (monoclinic space
group P21/n) is displayed in Fig. 7. The Ti centers in Li[5]
are coordinated by three bridging pyrazolide ligands, two
dimethylamido groups and four Cl atoms, forming a
slightly distorted octahedron. The coordination geometry
of the Ti atoms in the dinuclear anion [5]ꢀ is octahedral.
cules, forming a slightly distorted tetrahedron. It is inter-
esting to note that the two moieties of the dinuclear
cation in [6][ꢀ(NO3)2] are also linked by hydrogen bridges
via two NO3 anions.
Compounds 7(Co), 7(Ni), 7(Cu), 7(Zn), and 7(Cd) are
isostructural pyrazolato complexes. These compounds
˚
˚
ꢀ
The Ti–N(1) [1.905(3) A] and Ti–N(2) [1.906(4) A] dis-
tances are short Ti–N single bonds. The Ti–Cl bonds of
crystallize in the triclinic space group P1 (Figs. 10 and
11). The unit cell dimensions of pyrazolato complexes
7(Co), 7(Ni), 7(Cu), and 7(Zn) are quite similar whereas
those of 7(Cd) differ somewhat. The metal atoms in
7(Co), 7(Ni), 7(Cu), 7(Zn), and 7(Cd) have octahedral coor-
dination geometries. The metal centers are coordꢀinated by
four 3-phenylꢀpyrazole molecules and two NO3 anions.
The two NO3 anions are in a trans position. In contrast
to 7(Ni), the ligand sphere of the Cu center in the solid-
state structure of 7(Cu) is thus considerably affected by a
Jahn–Teller distortion. As shown in Table 1, complexes
7(Co), 7(Ni), 7(Cu), 7(Zn), and 7(Cd) feature metal nitro-
˚
2.3445(12) A are comparable in length to the Ti–Cl bonds
in titanium chloride derivatives. Fig. 8 illustrates the crystal
packing of Li[5].
The dinuclear Zn complex [6][(NO3)2], shown in Fig. 9,
crystallizes in the monoclinic C2/c space group. The Zn
atoms in [6][(NO3)2] are coordinated by two bridging 3-
phenylpyrazolide ligands and two 3-phenylpyrazole mole-
˚
gen distances with bond lengths between 2.0174(18) A
˚
[7(Cu)] and 2.3258(16) A [7(Cd)] and metal oxygen dis-
˚
tances with bond lengths between 2.1068(10) A [7(Ni)]
˚
and 2.3842(12) A [7(Cd)].
ꢀ
Complex 8 crystallizes in the triclinic space group P1
(Fig. 12). Zinc complex 8 shown in Fig. 12 (selected bond
lengths and angles in the figure caption) crystallizes with
two molecules in the asymmetric unit. The zinc ion in 8
is coordinated in a tetrahedral fashion by two 3-phenylpy-
˚
razole molecules [molecule A: Zn–N = 1.988(11) A (av);
˚
moleꢀcule B: Zn–N = 1.991(11) A (av)] and further by two
˚
NO3 anions [molecule A: Zn–O = 2.048(9) A (av); mole-
˚
cule B: Zn–O = 2.029(9) A (av)].
In the solid state, 9 (monoclinic space group C2/c) fea-
tures a trigonal-pyramidally coordinated zinc center
(Fig. 13). The Zn–O(1W) and Zn–N(1) bonds are equato-
˚
rial and have Zn–O bond lengths of 1.9722(13) A and
˚
Zn–N bond lengths of 2.0170(10) A, while the Zn–O(1)
˚
bond of 2.1935(9) A represents an axial bond (Fig. 14).
The solid-state structure of 10 shows that the Cd atom
lies on a crystallographic inversion center. The Cd atom
has octahedral coordination geometry. It is coordinated
by two pyrazole groups, two nitrate groups and two water
molecules. The azo group in 10 has a trans conformation.
The angle between the plane of the pyrazole group and
the plane of the azo group is 12.4ꢁ. The angle between
the plane of the azo group and the plane of the phenyl
ring is 17.5ꢁ. The shortest intramolecular contact dis-
tances are N(3)ꢁ ꢁ ꢁH(5) 2.46 A and O(3)ꢁ ꢁ ꢁH(4B) 2.47 A.
The crystal packing shows intermolecular hydrogen bond-
ing between the water molecules, pyrazole groups and
nitrate anions. The crystal packing also features a weak
intermolecular C–Hꢁ ꢁ ꢁN interaction and intermolecular
pꢁ ꢁ ꢁp interactions.
Fig. 6. Molecular structure of compound 4; thermal ellipsoids shown at
˚
the 50% probability level. Selected bond lengths (A), atom–atom distances
˚
(A) and angles (ꢁ): Ni(1)–N(21) 2.0928(18), Ni(1)–N(31) 2.1095(18), Ni(1)–
N(1) 2.1361(18), Ni(1)–N(11) 2.1793(18), Ni(1)–Cl(1) 2.4400(5), Ni(1)–
Cl(2) 2.4658(5), N(1)–C(6) 1.345(3), N(1)–C(2) 1.346(3), C(2)–C(3)
1.390(3), C(3)–C(4) 1.384(4), C(4)–C(5) 1.381(4), C(5)–C(6) 1.389(3),
N(11)–C(12) 1.337(3), N(11)–C(16) 1.342(3), C(12)–C(13) 1.394(4), C(13)–
C(14) 1.377(5), C(14)–C(15) 1.367(5), C(15)–C(16) 1.388(4), N(21)–C(25)
1.343(3), N(21)–N(22) 1.350(3), N(22)–C(23) 1.344(3), C(23)–C(24)
1.380(3), C(24)–C(25) 1.398(3), N(31)–C(35) 1.338(3), N(31)–N(32)
1.357(2), N(32)–C(33) 1.344(3), C(33)–C(34) 1.379(3), C(34)–C(35)
1.402(3); N(21)–Ni(1)–N(31) 178.35(7), N(21)–Ni(1)–N(1) 89.04(7),
N(31)–Ni(1)–N(1) 90.26(7), N(21)–Ni(1)–N(11) 90.84(7), N(31)–Ni(1)–
N(11) 89.90(7), N(1)–Ni(1)–N(11) 178.40(7), N(21)–Ni(1)–Cl(1) 90.83(5),
N(31)–Ni(1)–Cl(1) 90.66(5), N(1)–Ni(1)–Cl(1) 89.20(5), N(11)–Ni(1)–Cl(1)
89.20(5), N(21)–Ni(1)–Cl(2) 89.62(5), N(31)–Ni(1)–Cl(2) 88.88(5), N(1)–
Ni(1)–Cl(2) 89.88(5), N(11)–Ni(1)–Cl(2) 91.72(5), Cl(1)–Ni(1)–Cl(2)
178.97(2).
˚
˚
4. Supplementary data
Crystallographic data (excluding structure factors) for
the structures reported in this paper have been deposited

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S. Bieller et al. / Inorganica Chimica Acta 359 (2006) 1559–1572
˚
Fig. 7. Structure of the anion [5]; thermal ellipsoids shown at the 50% probability level. Selected bond lengths (A) and angles (ꢁ): Ti(1)–N(1) 1.905(3),
Ti(1)–N(31) 2.150(3), Ti(1)–N(11) 2.155(3), Ti(1)–N(21) 2.185(3), Ti(1)–Cl(11) 2.3427(12), Ti(1)–Cl(12) 2.3463(11), N(1)–C(11) 1.460(6), N(1)–C(12)
1.461(6), Ti(2)–N(2) 1.906(4), Ti(2)–N(12) 2.154(3), Ti(2)–N(32) 2.157(3), Ti(2)–N(22) 2.196(3), Ti(2)–Cl(21) 2.3496(11), Ti(2), Cl(22) 2.3525(12), N(2)–
C(21) 1.469(5), N(2)–C(22) 1.470(6), N(11)–N(12) 1.365(4), N(11)–C(15) 1.367(5), N(12)–C(13) 1.351(5), C(13)–C(14) 1.378(6), C(14)–C(15) 1.377(6),
N(21)–C(25) 1.352(5), N(21)–N(22) 1.368(4), N(22)–C(23) 1.350(5), C(23)–C(24) 1.384(7), C(24)–C(25) 1.379(6), N(31)–C(35) 1.356(5), N(31)–N(32)
1.366(4), N(32)–C(33) 1.364(5), C(33)–C(34) 1.371(6), C(34)–C(35) 1.380(6); N(1)–Ti(1)–N(31) 88.69(13), N(1)–Ti(1)–N(11) 88.46(14), N(31)–Ti(1)–N(11)
86.32(12), N(1)–Ti(1)–N(21) 168.56(14), N(31)–Ti(1)–N(21) 83.21(11), N(11)–Ti(1)–N(21) 82.99(12), N(1)–Ti(1)–Cl(11) 96.29(11), N(31)–Ti(1)–Cl(11)
173.30(9), N(11)–Ti(1)–Cl(11) 89.33(9), N(21)–Ti(1)–Cl(11) 91.21(9), N(1)–Ti(1)–Cl(12) 98.29(11), N(31)–Ti(1)–Cl(12) 90.72(8), N(11)–Ti(1)–Cl(12)
172.57(9), N(21)–Ti(1)–Cl(12) 89.91(8), Cl(11)–Ti(1)–Cl(12) 92.99(4), C(11), N(1)–C(12) 111.0(4), C(11)–N(1)–Ti(1) 120.8(3), C(12)–N(1)–Ti(1) 128.1(3),
N(2)–Ti(2)–N(12) 88.15(13), N(2)–Ti(2)–N(32) 86.97(13), N(12)–Ti(2)–N(32) 86.44(12), N(2)–Ti(2)–N(22) 166.39(14), N(12)–Ti(2)–N(22) 82.82(12),
N(32)–Ti(2)–N(22) 82.34(12), N(2)–Ti(2)–Cl(21) 96.86(11), N(12)–Ti(2)–Cl(21) 173.87(9), N(32)–Ti(2)–Cl(21) 90.29(8), N(22)–Ti(2)–Cl(21) 91.61(9),
N(2)–Ti(2)–Cl(22) 98.43(11), N(12)–Ti(2)–Cl(22) 90.49(9), N(32), Ti(2)–Cl(22) 173.71(9), N(22)–Ti(2)–Cl(22) 91.84(9), Cl(21)–Ti(2)–Cl(22) 92.26(5),
C(21)–N(2)–Ti(2) 120.6(3), C(22)–N(2)–Ti(2) 127.9(3), C(25)–N(21)–Ti(1) 123.7(3), N(22)–N(21)–Ti(1) 128.6(2), C(23)–N(22)–Ti(2) 123.7(3), N(21)–
N(22)–Ti(2) 128.9(2), C(35)–N(31)–Ti(1) 122.4(3), N(32)–N(31)–Ti(1) 129.6(2), C(33)–N(32)–Ti(2) 123.4(3), N(31)–N(32)–Ti(2) 129.5(2).
Fig. 8. Crystal packing diagram of compound [Li][5]; thermal ellipsoids shown at the 50% probability level.

S. Bieller et al. / Inorganica Chimica Acta 359 (2006) 1559–1572
1569
˚
Fig. 9. Molecular structure of compound [6][(NO3)2]; thermal ellipsoids shown at the 50% probability level. Selected bond lengths (A) and angles (ꢁ):
Zn(1)–N(12)#1 1.974(3), Zn(1)–N(11) 1.987(3), Zn(1)–N(21) 2.058(3), Zn(1)–N(31) 2.058(3), N(11)–C(15) 1.346(4), N(11)–N(12) 1.390(4), N(12)–C(13)
1.369(4), N(12)–Zn(1)#1 1.975(3), C(13)–C(14) 1.391(5), C(13)–C(131) 1.482(4), C(14)–C(15) 1.393(5), N(21)–C(25) 1.348(4), N(21)–N(22) 1.372(4),
N(22)–C(23) 1.362(4), N(22)–H(22) 1.01(6), C(23)–C(24) 1.397(5), C(23)–C(231) 1.476(5), C(24)–C(25) 1.396(5), N(31)–C(35) 1.357(4), N(31)–N(32)
1.364(4), N(32)–C(33) 1.347(4), N(32)–H(32) 0.86(4), C(33)–C(34) 1.391(5), C(33)–C(331) 1.479(5), C(34)–C(35) 1.395(5), C(131)–C(132) 1.399(5), C(131)–
C(136) 1.405(5), C(132)–C(133) 1.399(5), C(133)–C(134) 1.392(6), C(134)–C(135) 1.391(6), C(135)–C(136) 1.398(5), C(231)–C(232) 1.386(6), C(231)–
C(236) 1.397(5), C(232)–C(233) 1.384(6), N(1)–O(2) 1.255(4), N(1)–O(3) 1.263(4), N(1)–O(1) 1.269(4); N(12)#1–Zn(1)–N(11) 113.84(11), N(12)#1–Zn(1)–
N(21) 125.61(12), N(11)–Zn(1)–N(21) 102.89(11), N(12)#1–Zn(1)–N(31) 107.16(11), N(11)–Zn(1)–N(31) 111.47(12), N(21)–Zn(1)–N(31) 94.06(11), C(15)–
N(11)–N(12) 107.8(2), C(15)–N(11)–Zn(1) 124.1(2), N(12)–N(11)–Zn(1) 127.8(2), C(13)–N(12)–N(11) 107.5(3), C(13)–N(12)–Zn(1)#1 132.7(2), N(11)–
N(12)–Zn(1)#1 118.18(19). Symmetry transformations used to generate equivalent atoms: #1: ꢀx + 1/2, ꢀy + 3/2, ꢀz + 1.
Fig. 10. Molecular structure of compound 7(Co); thermal ellipsoids shown at the 50% probability level. 7(Co), 7(Ni), 7(Cu), and 7(Zn) are isostructural.

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Fig. 11. Molecular structure of compound 7(Cd); thermal ellipsoids shown at the 50% probability level.
˚
˚
Fig. 12. Molecular structure of compound 8; thermal ellipsoids shown at the 50% probability level. Selected bond lengths (A), atom–atom distances (A) and
angles (ꢁ): Zn(1)–N(11) 1.983(11), Zn(1)–N(21) 1.992(11), Zn(1)–O(21) 2.033(9), Zn(1)–O(11) 2.062(9), Zn(1)–O(33)#1 2.534(8), Zn(2)–N(41) 1.966(11),
Zn(2)–O(31) 2.003(9), Zn(2)–N(31) 2.012(11), Zn(2)–O(41) 2.055(9), Zn(2)–O(22) 2.527(9), N(1)–O(13) 1.238(14), N(1)–O(12) 1.252(14), N(1)–O(11)
1.304(14), N(2)–O(23) 1.242(14), N(2)–O(21) 1.247(14), N(2)–O(22) 1.248(13), N(3)–O(32) 1.218(14), N(3)–O(33) 1.241(13), N(3)–O(31) 1.299(14), N(4)–
O(42) 1.213(14), N(4)–O(43) 1.244(13), N(4)–O(41) 1.268(14), N(11)–C(13) 1.351(16), N(11)–N(12) 1.376(15), N(12)–C(11) 1.354(16), C(11)–C(12)
1.388(17), C(11)–C(14) 1.480(18), C(12)–C(13) 1.367(18); N(11)–Zn(1)–N(21) 115.8(4), N(11)–Zn(1)–O(21) 124.7(4), N(21)–Zn(1)–O(21) 114.7(4), N(11)–
Zn(1)–O(11) 89.1(4), N(21)–Zn(1)–O(11) 107.1(4), O(21)–Zn(1)–O(11) 96.6(4), N(11)–Zn(1)–O(33)#1 86.8(4), N(21)–Zn(1)–O(33)#1 79.5(4), O(21)–Zn(1)–
O(33)#1 81.4(3), O(11)–Zn(1)–O(33)#1 173.3(4), N(41)–Zn(2)–O(31) 135.0(4), N(41)–Zn(2)–N(31) 114.9(4), O(31)–Zn(2)–N(31) 104.8(4), N(41)–Zn(2)–
O(41) 103.0(4), O(31)–Zn(2)–O(41) 97.2(4), N(31)–Zn(2)–O(41) 89.8(4), N(41)–Zn(2)–O(22) 78.1(4), O(31)–Zn(2)–O(22) 82.7(3), N(31)–Zn(2)–O(22)
88.7(4), O(41)–Zn(2)–O(22) 178.5(3), O(13)–N(1)–O(12) 124.1(11), O(13)–N(1)–O(11) 120.8(10), O(12)–N(1)–O(11) 115.1(10), N(1)–O(11)–Zn(1) 118.6(7),
O(23)–N(2)–O(21) 120.1(10), O(23)–N(2)–O(22) 120.2(11), O(21)–N(2)–O(22) 119.7(11), N(2)–O(21)–Zn(1) 111.7(7), N(2)–O(22)–Zn(2) 144.1(8), O(32)–
N(3)–O(33) 123.6(11), O(32)–N(3)–O(31) 118.8(11), O(33)–N(3)–O(31) 117.6(10), N(3)–O(31)–Zn(2) 112.4(7), O(42)–N(4)–O(43) 123.5(11), O(42)–N(4)–
O(41) 119.4(10), O(43)–N(4)–O(41) 117.1(10), N(4)–O(41)–Zn(2) 119.0(8). Symmetry transformations used to generate equivalent atoms: #1: x ꢀ 1, y, z.

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Fig. 13. Molecular structure of compound 9; thermal ellipsoids shown at the 50% probability level. Selected bond lengths (A), atom–atom distances (A)
and angles (ꢁ): Zn(1)–O(1W) 1.9722(13), Zn(1)–N(1) 2.0170(10), Zn(1)–N(1)#1 2.0170(10), Zn(1)–O(1)#1 2.1935(9), Zn(1)–O(1) 2.1935(9), N(1)–C(3)
1.3390(14), N(1)–N(2) 1.3558(14), N(2)–C(1) 1.3348(15), C(1)–C(2) 1.3833(17), C(2)–C(3) 1.4047(16), C(2)–N(3) 1.4090(14), N(3)–N(4) 1.2584(15),
N(4)–C(11) 1.4334(15), C(11)–C(12) 1.3929(18), C(11)–C(16) 1.3962(17), C(12)–C(13) 1.3932(17), C(13)–C(14) 1.387(2), C(14)–C(15) 1.3936(19), C(15)–
C(16) 1.3899(16), N(5)–O(3) 1.2322(13), N(5)–O(2) 1.2442(13), N(5)–O(1) 1.2967(13); O(1W)–Zn(1)–N(1) 119.64(3), O(1W)–Zn(1)–N(1)#1 119.64(3),
N(1)–Zn(1)–N(1)#1 120.72(6), O(1W)–Zn(1)–O(1)#1 81.53(2), N(1)–Zn(1)–O(1)#1 98.51(4), N(1)#1–Zn(1)–O(1)#1 89.87(4), O(1W)–Zn(1)–O(1)
81.53(2), N(1)–Zn(1)–O(1) 89.87(4), N(1)#1–Zn(1)–O(1) 98.51(4), O(1)#1–Zn(1)–O(1) 163.06(4), C(3)–N(1)–N(2) 105.89(9), C(3)–N(1)–Zn(1) 130.16(8),
N(2)–N(1)–Zn(1) 122.41(7), C(1)–N(2)–N(1) 111.86(10), C(1)–N(2)–H(2) 128.0(12), N(1)–N(2)–H(2) 120.2(12), O(3)–N(5)–O(2) 122.55(10), O(3)–N(5)–
O(1) 118.91(10), O(2)–N(5)–O(1) 118.53(9), N(5)–O(1)–Zn(1) 114.37(7). Symmetry transformations used to generate equivalent atoms: #1: ꢀx + 1, y,
ꢀz + 3/2.
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Fig. 14. Molecular structure of compound 10; thermal ellipsoids shown at the 50% probability level. Selected bond lengths (A), atom–atom distances (A),
angles (ꢁ) and torsion angles (ꢁ): Cd–N(1) 2.256(3), Cd–N(1)#1 2.256(3), Cd–O(4)#1 2.336(2), Cd–O(4) 2.336(2), Cd–O(1) 2.411(2), Cd–O(1)#1 2.411(2),
O(2)–N(5) 1.239(3), O(1)–N(5) 1.273(3), N(3)–N(4) 1.249(3), N(3)–C(2) 1.406(4), O(3)–N(5) 1.243(3), N(2)–C(1) 1.334(4), N(2)–N(1) 1.358(3), N(4)–C(4)
1.444(4), C(3)–N(1) 1.327(4), C(3)–C(2) 1.409(4), C(2)–C(1) 1.370(4), C(4)–C(5) 1.366(5), C(4)–C(9) 1.374(5), C(9)–C(8) 1.388(4), C(7)–C(6) 1.369(5),
C(7)–C(8) 1.379(5), C(6)–C(5) 1.382(5); N(1)–Cd–N(1)#1 180.0, N(1)–Cd–O(4)#1 92.19(9), N(1)#1–Cd–O(4)#1 87.81(9), N(1)–Cd–O(4) 87.81(9),
N(1)#1–Cd–O(4) 92.19(9), O(4)#1–Cd–O(4) 180.0, N(1)–Cd–O(1) 85.68(9), N(1)#1–Cd–O(1) 94.32(9), O(4)#1–Cd–O(1) 74.11(10), O(4)–Cd–O(1)
105.89(10), N(1)–Cd–O(1)#1 94.32(9), N(1)#1–Cd–O(1)#1 85.68(9), O(4)#1–Cd–O(1)#1 105.89(10), O(4)–Cd–O(1)#1 74.11(10), O(1)–Cd–O(1)#1 180.0,
N(5)–O(1)–Cd 109.90(18), N(4)–N(3)–C(2) 114.4(3), O(2)–N(5)–O(3) 121.8(3), O(2)–N(5)–O(1) 119.5(3), O(3)–N(5)–O(1) 118.8(3), C(1)–N(2)–N(1)
111.7(3), N(3)–N(4)–C(4) 112.6(3), N(1)–C(3)–C(2) 110.6(3), C(3)–N(1)–N(2) 105.3(2), C(3)–N(1)–Cd 130.7(2), N(2)–N(1)–Cd 123.93(19). Symmetry
transformations used to generate equivalent atoms: #1: ꢀx + 1, ꢀy, ꢀz.
with the Cambridge Crystallographic Data Centre as
supplementary publication Nos. CCDC 282886 [1], CCDC
282889 [2], CCDC 282888 [3], CCDC 282887 [4], CCDC
282890 [Li][5], CCDC 283070 [6][(NO3)2], CCDC 282881
[7(Co)], CCDC 282880 [7(Ni)], CCDC 282882 [7(Cu)],
CCDC 282883 [7(Zn)], CCDC 282885 [7(Cd)], CCDC
282879 [8], CCDC 282884 [9], and CCDC 283003 [10]. Cop-
ies of the data can be obtained free of charge on application
to CCDC, 12 Union Road, Cambridge CB2 1EZ, UK (fax:
+44 1223 336 033; e-mail: deposit@ccdc.cam.ac.uk).
Acknowledgements
We are grateful to the University of Frankfurt for finan-
cial funding. M.W. is grateful to the ‘‘Deutsche Fors-
chungsgemeinschaft’’ (DFG) for financial support.

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