Syntheses and structures of the cobalt, nickel, and zinc complexes with 1,4-diaza-1,3-butadiene ligands

Article abstract of DOI:10.1134/S1070328413010089

Several cobalt(II), nickel(II), and zinc(II) complexes with a series of ligands of the 1,4-diaza-1,3-butadiene type bearing aryl (2,6-di-iso- propylphenyl, mesityl) and alkyl (tert-butyl, iso-propyl) substituents at the nitrogen atoms are synthesized. The obtained complexes are characterized by X-ray structure analysis, IR spectroscopy, and elemental analysis.

Full text of DOI:10.1134/S1070328413010089

ISSN 1070ꢀ3284, Russian Journal of Coordination Chemistry, 2013, Vol. 39, No. 1, pp. 11–22. © Pleiades Publishing, Ltd., 2013.
Original Russian Text © P.A. Petrov, T.S. Sukhikh, D.A. Piryazev, A.V. Virovets, S.N. Konchenko, 2013, published in Koordinatsionnaya Khimiya, 2013, Vol. 39, No. 1, pp. 14–25.
Syntheses and Structures of the Cobalt, Nickel, and Zinc Complexes
with 1,4ꢀDiazaꢀ1,3ꢀButadiene Ligands
P. A. Petrov, T. S. Sukhikh, D. A. Piryazev, A. V. Virovets, and S. N. Konchenko*
Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences,
pr. akademika Lavrent’eva 3, Novosibirsk, 630090 Russia
*eꢀmail: konch@niic.nsc.ru
Received January 11, 2012
Abstract—Several cobalt(II), nickel(II), and zinc(II) complexes with a series of ligands of the 1,4ꢀdiazaꢀ1,3ꢀ
butadiene type bearing aryl (2,6ꢀdiꢀisoꢀpropylphenyl, mesityl) and alkyl (tertꢀbutyl, isoꢀpropyl) substituents
at the nitrogen atoms are synthesized. The obtained complexes are characterized by Xꢀray structure analysis,
IR spectroscopy, and elemental analysis.
DOI: 10.1134/S1070328413010089
Interest in transition metal complexes with diimine Xꢀray structure analysis of the same type complexes
ligands has substantially increased after the discovery
by M. Brookhart and coauthors of the catalytic activity
of the Ni(II) and Pd(II) complexes with substituted
1,4ꢀdiazaꢀ1,3ꢀbutadienes (DAB) and their analogs,
acetanaphtheneꢀ1,2ꢀdiimines (BIAN), in the polyꢀ
[
M(R1DABR2)X2] of different transition metals with
the same ligand environment are urgent problems. It is
important to determine the structures of these comꢀ
plexes for understanding tendencies in changing their
catalytic properties.
merization of ꢀolefins [1]. Due to the possibility of
α
This work is devoted to the development of methꢀ
ods for the synthesis and systematic Xꢀray structure
analysis of the Co, Ni, and Zn complexes with the
group of diimine ligands containing different substituꢀ
varying substituents R1 and R2 in DAB, several tens of
these combinations and their complexes were
obtained. It was found soon that similar iron comꢀ
plexes are also catalytically active in the same reacꢀ
tions. Moreover, the substituents at the nitrogen and
carbon atoms of the ligand were shown to affect the
spin state of the central atom and, as a consequence,
the mechanism and degree of polymerization [2, 3].
Then CO and styrene copolymerization [4], hydrosiꢀ
lylation [5], cycloisomerization [6], and other proꢀ
cesses were added to the list of reactions catalyzed by
the transition metal complexes with DAB or BIAN.
ents in the side chain (R1 = H, R2
= isoꢀPr, tertꢀBu;
R1 = CH3, R2 = 2,4,6ꢀMe3C6H2 (Mes), 2,6ꢀisoꢀ
Pr2C6H3 (Dipp)).
R2
R
R2
R2
N
– R1
R1
R1
N
R1
R1
N−
N
•–
–
+e
+e
–
–
–e
–e
N−
R2
R1
N
R2
N
R2
N
R
One of the properties of DAB attracting rapt attenꢀ
tion is the capability of reversible stepwise reducing to
the radical anion and dianion, whereas BIAN can be
reduced even to the tetraanion (scheme). This proꢀ
vides the possibility of manifesting the redox activity of
complexes even of the metals that are not characterꢀ
ized by several oxidation states. The possibility of difꢀ
ferent coordination modes of DAB also results in the
stabilization of unusual metal–metal bonds, for examꢀ
ple, Zn–Zn [7] or the shortest (found at present)
R1DABR2 (R1DABR2)– (R1DABR2)2–
BIANꢀR
Scheme.
EXPERIMENTAL
The complexes were synthesized under argon using
a standard Schlenk apparatus. The ligands MeDABDipp
and MeDABMes were kindly presented by J. Treptow
(Karlsruhe University, Germany). The ligands
Cr
⎯
Cr bond (1.8028(9) Å) [8].
In spite of progress in the synthetic chemistry of the
complexes with diimine ligands, the majority of the
HDABtBu and HDABiPr [9], as well as [Ni(Dme)Cl2
]
synthesized compounds (even the Ni(II) and Pd(II) were synthesized using described procedures [10]. Solꢀ
complexes of the most representative series) was not vents for the syntheses were dehydrated and degassed
characterized by Xꢀray structure analysis. The number by reflux and distillation in an inert atmosphere using
of the described complexes of other metals (in particꢀ the corresponding drying agents [11]. IR spectra were
ular, Zn) is much smaller. Therefore, the synthesis and recorded on a SCIMITAR FTS 2000 instrument. Eleꢀ
11

12
PETROV et al.
(s, 12H, Ar–CH3). 13C NMR (CD2Cl2;
169.78 (s, N=C), 139.75 (s, Ar– ꢀC), 137.11 (s, Ar–
C), 129.56 (s, Ar– ꢀC), 127.93 (s, Ar– ꢀC), 20.52 (s,
Ar– ꢀCH3), 18.57 (s, Ar– ꢀCH3), 18.02 (s, N=C–
CH3). IR (KBr;
, cm–1): 2968, 2920, 2859, 1647,
1598, 1479, 1443, 1373, 1228, 854. UVꢀVIS (CH2Cl2;
, nm (
, L mol–1 cm–1)): 235 (8000), 267 (1100), 374
(500).
δ
, ppm):
mental analyses of samples to C, H, and N were carꢀ
ried out on a Euro EA 3000 instrument at the Laboraꢀ
tory of Microanalysis at the Nikolaev Institute of Inorꢀ
ganic Chemistry (Siberian Branch, Russian Academy
of Sciences). UVꢀVIS spectra were recorded on a
Gelios Gamma spectrophotometer.
Synthesis of [Zn(MeDABDipp)Cl2] (I)
. Diethyl ether
Et2O (10 mL) was added to a mixture of anhydrous
i
pꢀ
m
o
p
o
ν
λ
ε
ZnCl2 (0.246 g, 1.80 mmol) and MeDABDipp (0.740 g,
1.83 mmol). A yellow solution with a jellyꢀlike yellow
precipitate that formed was stirred at ambient temperꢀ
ature for 2 days. The solvent was evaporated to dryꢀ
ness, the product was dissolved in hot tetrahydrofuran
For C22H28N2Cl2Zn
anal. calcd. (%): C, 57.8;
H, 6.1;
H, 6.3;
N, 6.1.
N, 6.1.
Found (%):
C, 58.0;
(18 mL), and the solution was kept at –18 C for
°
Synthesis of [Zn(HDABtBu)Cl2] (III)
.
Tetrahydrofuꢀ
3 days. A yellow precipitate that formed was separated
and washed with ether. The solution was concentrated
by evaporation to 1/2 volume, and Et2O (10 mL) was
ran (15 mL) was added to a mixture of anhydrous
ZnCl2 (0.274 g, 2.01 mmol) and HDABtBu (0.372 g,
2.21 mmol). A white precipitate was immediately
formed. The mixture was stirred at ambient temperaꢀ
ture for 5 h, then the solvent was evaporated to dryꢀ
ness, and the residue was dissolved in CH2Cl2. The
slow diffusion of Et2O to this solution resulted in the
formation of crystals suitable for Xꢀray structure analꢀ
ysis. The yield was 0.612 g (70%).
added. The mixture cooled to –18 C was kept for
°
6 days. The precipitate was filtered off and washed
with Et2O. The yield was 0.668 g (70%). The crystals
suitable for Xꢀray structure analysis were formed in
7 days from a saturated (at ambient temperature) and
cooled to +2
1H NMR ((CD3)2CO;
3.06 (s, 2H, CH(CH3)2), 2.76 (s, 3H, N=C–CH3),
1.32, 1.13 (2s, 12H, CH(CH3)2). IR (KBr;
, cm–1):
2964, 2925, 2868, 1654, 1607, 1464, 1443, 1378, 1209,
°C
solution of the complex in MeCN.
δ
, ppm): 7.36 (s, 3H Ar–H),
1H NMR ((CD3)2CO;
1.50 (s, 18H, CH3). C NMR ((CD3)2CO;
δ
, ppm): 8.50 (s, 2H, CH),
, ppm):
13
ν
δ
156.7 (s, CH), 61.5 (s, C(CH3)3), 29.5 (s, CH3). IR
, cm–1): 2977, 2932, 1662, 1598, 1473, 1386,
788. UVꢀVIS (CH2Cl2;
λ
, nm (
, L mol–1 cm–1)): 234
ε
(KBr;
ν
(11000), 358 (800).
1244, 1205, 992, 901. UVꢀVIS (CH2Cl2;
L mol–1 cm–1)): 235 (9400).
λ
, nm (ε,
For C28H40N2Cl2Zn
For C10H20N2Cl2Zn
anal. calcd. (%): C, 62.2;
Found (%): C, 61.7;
H, 7.4;
H, 7.4;
N, 5.2.
N, 5.1.
anal. calcd. (%): C, 39.4;
H, 6.6;
H, 6.5;
N, 9.2.
N, 9.2.
Found (%):
C, 39.5;
Synthesis of [Zn(MeDABMes)Cl2] (II)
tion of ZnCl2 (0.098 g, 0.72 mmol) in tetrahydrofuran
.
(1) A soluꢀ
Synthesis of [Zn(HDABiPr)Cl2] (IV)
. Anhydrous
ZnCl2 (0.135 g, 0.99 mmol) was dissolved in Et2O
(5 mL), and the obtained solution was added to a soluꢀ
tion of HDABiPr (0.150 g, 1.07 mmol) in Et2O (5 mL).
A milkꢀwhite jellyꢀlike precipitate was immediately
formed. Methylene chloride (7 mL) was added to the
complete dissolution of the precipitate. Crystals suitꢀ
able for Xꢀray structure analysis were formed in 4 days
(10 mL) was added to MeDABMes (0.254 g,
0.792 mmol). A yellow jellyꢀlike precipitate was
formed immediately, and the solution turned yellow.
The mixture was refluxed with a reflux condenser for
6 h. The solvent was evaporated to dryness, the residue
was dissolved in MeCN (7 mL), Et2O (10 mL) was
added, and the mixture was cooled to +2 C. After
°
from the solution cooled to +2 C. The yield was
°
4 days, the yellow crystals that formed were filtered off
and washed with Et2O. The yield was 0.327 g (57%).
0.095 g (35%).
IR (KBr;
, cm–1): 2976, 2932, 2874, 1655, 1595,
ν
(2) Tetrahydrofuran (10 mL) was added to a mixꢀ
ture of anhydrous CrCl3 (0.104 g, 0.656 mmol),
MeDABMes (0.197 g, 0.616 mmol), and zinc dust
1464, 1402, 1383, 1310, 1157, 1127, 993, 909.
For C8H16N2Cl2Zn
(0.025 g, 0.38 mmol). The mixture was refluxed for
8 h. The obtained brown solution was kept at +2 C for
°
anal. calcd. (%): C, 34.7;
Found (%): C, 34.9;
H, 5.8;
H, 5.8;
N, 10.1.
N, 10.1.
several days. Yellowꢀgreen transparent crystals suitable
for Xꢀray structure analysis were formed, filtered, and
washed with Et2O. The yield was ~5%.
Synthesis of [Co(MeDABDipp)Cl2] (V)
.
Tetrahydrofuꢀ
1H NMR (CD2Cl2;
2.33 (s, 6H, Ar–CH3), 2.30 (s, 6H, N=C
δ
, ppm): 7.02 (s, 4H Ar–H), ran (15 mL) was added to a mixture of anhydrous
⎯
CH3), 2.22 CoCl2 (0.452 g, 3.48 mmol) and MeDABDipp (1.415 g,
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SYNTHESES AND STRUCTURES OF THE COBALT, NICKEL
13
3.502 mmol). The mixture was refluxed for 12 h. A dissolution of the reactants, the solvent was evaporated
blue precipitate was dissolved, and a dark green soluꢀ to dryness and the residue was dissolved in MeCN. A
tion with a green precipitate was formed. The mixture double volume of Et2O was added, and the mixture
was cooled to –18 C. After 6 days the precipitate was
°
was kept at +2°C. The yield was 0.16 g (45%).
filtered off and washed with ether. The yield was
1.510 g (80%). The product was purified by recrystalꢀ
lization from a MeCN–Et2O mixture.
IR (KBr;
ν
, cm–1): 2975, 2876, 2718, 2611, 2507,
1650, 1598, 1463, 1400, 1367, 1173, 1136, 1014, 910.
IR (KBr;
1464, 1442, 1379, 1209, 788. UVꢀVIS (CH2Cl2;
, L mol–1 cm–1)): 310 (1765), 591 (127), 658 (127),
ν
, cm–1): 2962, 2924, 2867, 1641, 1588,
, nm
For C16H32N4Cl4Co2
λ
anal. calcd. (%): C, 35.5;
Found (%): C, 35.4;
H, 5.9;
H, 5.6;
N, 10.4.
N, 10.2.
(
ε
711 (313).
Synthesis of [Ni(MeDABDipp)Cl2] (IX)
.
Acetonitrile
(10 mL) was added to a mixture of anhydrous NiCl2
For C28H40N2Cl2Co
(0.067 g, 0.52 mmol) and MeDABDipp (0.386 g,
0.955 mmol), the mixture was refluxed for 4 h, and a
dark brown solution with a light yellow precipitate was
formed. The solution was filtered, the solvent was
evaporated to dryness, and the residue was dissolved in
CH2Cl2 (10 mL). The crystals suitable for Xꢀray strucꢀ
ture analysis were grown by the slow diffusion of Et2O
to this solution. The yield was 0.040 g (15%).
anal. calcd. (%): C, 62.9;
H, 7.5;
H, 7.4;
N, 5.2.
N, 5.1.
Found (%):
C, 61.9;
Synthesis of [Co(MeDABMes)Cl2] (VI)
.
Methylene
chloride (30 mL) was added to a mixture of anhydrous
CoCl2 (0.147 g, 1.13 mmol) and MeDABMe (0.394 g,
1.23 mmol). The mixture was stirred at ambient temꢀ
perature. A blue precipitate was dissolved, and a dark
green solution with a green precipitate was formed.
The precipitate was filtered off and purified
by recrystallization from CH2Cl2 followed by washing
of the crystals with Et2O. The solution was cooled to
IR (KBr;
1464, 1442, 1381, 1212, 789. UVꢀVIS (CH2Cl2;
, L mol–1 cm–1)): 240 (17 000), 311 (5300), 365
(2433), 421 (832).
ν
, cm–1): 2963, 2924, 2867, 1641, 1585,
, nm
λ
(
ε
⎯
18°C. After a day the crystals that formed were filꢀ
tered off, washed with Et2O, and dried. The yield was For C28H40N2Cl2Ni
0.360 g (70%). The crystals suitable for Xꢀray structure
analysis were grown by the slow diffusion of Et2O to a
solution of the complex in MeCN.
anal. calcd. (%): C, 62.8;
Found (%): C, 63.1;
H, 7.5;
H, 7.5;
N, 5.2.
N, 5.2.
Synthesis of [Ni(MeDABMes)Cl2] (X)
.
The product
IR (KBr;
, cm–1): 2964, 2918, 2859, 1640, 1597,
ν
was obtained similarly to complex IX. The crystals
suitable for Xꢀray structure analysis were grown by the
slow diffusion of Et2O to a solution of the complex in
CH2Cl2. The yield was 85%.
1477, 1374, 1231, 856. UVꢀVIS (CH2Cl2;
λ
, nm ( ,
ε
L mol–1 cm–1)): 298 (2900), 404 (1100), 600 (180),
658 (180), 705 (450).
IR (KBr; n, cm–1): 3000, 2953, 2918, 2859, 1647,
1587, 1476, 1376, 1233, 856.
For C22H28N2Cl2Ni
For C22H28N2Cl2Co
anal. calcd. (%): C, 58.7;
Found (%): C, 58.8;
H, 6.2;
H, 6.3;
N, 6.2.
N, 6.2.
anal. calcd. (%): C, 58.6;
Found (%): C, 58.6;
H, 6.2;
H, 6.1;
N, 6.2.
N, 6.2.
Synthesis of [Co(HDABtBu)Cl2] (VII)
was obtained from CoCl2 and HDABtBu using the same
.
The product
Synthesis of [Ni(HDABtBu)Cl2]2 (XI)
.
The product
method as that for complex
V. The yield was 50%.
IR (KBr;
ν
, cm–1): 2975, 2903, 1648, 1593, 1472,
was obtained similarly to complex IX. The yield was
55%. The crystals suitable for Xꢀray structure analysis
were grown by the slow diffusion of Et2O to a solution
of the complex in CH2Cl2.
1384, 1243, 1205, 990, 897.
For C10H20N2Cl2Co
IR (KBr;
1480, 1384, 1367, 1226, 1212, 996, 889. UVꢀVIS
(CH2Cl2; , nm (
, L mol–1 cm–1)): 233 (14 000), 253
ν
, cm–1): 2974, 2929, 2874, 1659, 1607,
anal. calcd. (%): C, 40.2;
H, 6.7;
H, 6.7;
N, 9.4.
N, 9.3.
Found (%):
C, 40.4;
λ
ε
(9600), 296 (4300), 386 (1100).
Synthesis of [Co(HDABiPr)Cl2]2 (VIII)
.
Tetrahyꢀ
drofuran (THF) (10 mL) was added to a mixture of
anhydrous CoCl2 (0.178 g, 1.37 mmol) and HDABiPr
(0.206 g, 1.47 mmol). The mixture was stirred for
For C20H40N4Cl4Ni2
anal. calcd. (%): C, 40.3;
C, 39.8;
H, 6.7;
H, 6.8;
N, 9.4.
N, 9.2.
30 min at ambient temperature. After the complete Found (%):
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14
PETROV et al.
Synthesis of [Ni2(HDABiPr)2(THF)Cl4] (XII)
.
(0 1 0/1 0 0/0 0 1) was used for refinement. The strucꢀ
tures of compounds VI and are chiral with the Fleck
HDABiPr (0.199 g, 1.42 mmol) was added to a suspenꢀ
sion of [Ni(Dme)Cl2] (Dme is 1,2ꢀdimethoxyethane)
(0.312 g, 1.42 mmol) in THF (25 mL). The solution
turned reddish, and a greenꢀyellow precipitate was
formed. After 3 h of stirring at ambient temperature,
the mixture was heated to boiling and the solution was
X
parameters 0.002(7) and 0.003(8), respectively. The
most important crystallographic data and refinement
parameters of the structures are given in Tables 1
and 2. Selected bond lengths and angles are listed in
Tables 3–5. The coordinates of nonꢀhydrogen
atoms were deposited with the Cambridge Crystalloꢀ
graphic Data Centre (nos. 857852–857863 for comꢀ
filtered and cooled to +2 C. The yellowꢀgreen crystals
°
suitable for Xꢀray structure analysis were formed in
2 days. They were filtered off and dried. The solid resꢀ
idue obtained in the previous filtration was joined with
the mother liquor and crystallized similarly. The total
yield was 0.200 g (46%).
pounds
I
⎯
IV
and
VI–
XIII
,
respectively;
deposit@ccdc.cam. ac.uk or http://www.ccdc.
cam.ac.uk/data_request/cif) and can be available
from the authors.
IR (KBr;
1608, 1465, 1401, 1366, 1323, 1261, 1172, 1134, 1070,
1037, 1021, 920, 879, 802. UVꢀVIS (CH2Cl2; , nm
, L mol–1 cm–1)): 236 (9200), 290 (1600), 361 (220).
ν
, cm–1): 2972, 2932, 2874, 1660, 1630,
RESULTS AND DISCUSSION
λ
As it was found, the interaction of solutions of
ZnCl2 and the ligand in diethyl ether or THF at ambiꢀ
ent temperature is a convenient method for the synꢀ
thesis of the Zn(II) derivatives. Already several minꢀ
utes after, light yellow precipitates of complexes I–IV
began to form. After recrystallization, the yields of the
products ranged from 35 to 75%. Single crystals suitꢀ
able for Xꢀray structure analysis were obtained by
cooling solutions of the complexes in CH2Cl2, THF, or
MeCN.
(
ε
For C20H40N4OCl4Ni2
anal. calcd. (%): C, 39.5;
H, 6.6;
H, 6.6;
N, 9.2.
N, 8.2.
Found (%):
C, 38.9;
Synthesis of [Ni3(HDABiPr)3Cl5]2[Ni4(HDABiPr)2
(MeCN)2Cl10] (XIII) Methylene chloride (15 mL)
.
was added to a mixture of [Ni(Dme)Cl2] (0.312 g,
Complex II was also isolated when attempting to
obtain the Cr(II) complex with the diimine ligand
using Zn as a reducing agent. The reaction of CrCl3
1.42 mmol) and HDABiPr (0.202 g, 1.44 mmol). The
solution turned brown, and a greenꢀyellow precipitate
was formed. After stirring the solution at ambient temꢀ
perature, the precipitate turned green within a day.
The precipitate was separated and dried in vacuo and
then dissolved in MeCN. The green crystals suitable
for Xꢀray structure analysis were grown by the slow difꢀ
fusion of Et2O to this solution. The yield was 0.090 g
(25%).
with MeDABMes and zinc dust affords a solution from
which complex II was isolated in the crystalline form
on cooling in 5% yield. No chromium complex was
observed in the reaction mixture. The synthesis of the
diamagnetic chromium complexes of stoichiometry
[CrLCl2] (L = MeDABMes
,
MeDABDipp, BIANꢀDipp,
BIANꢀC6H4ꢀ ꢀMe) obtained by the reaction of
o
IR (KBr;
1401, 1367, 1327, 1174, 1135, 1020, 898. UVꢀVIS
(CH2Cl2; , nm (
, L mol–1 cm–1)): 235 (50000), 291
(9200), 362 (1000).
ν
, cm–1): 2972, 2933, 2873, 1623, 1466,
[Cr(THF)3Cl3], MeDABMes, and Zn in a ratio of 1 : 3 : 5
has earlier been reported [14]. However, it has been
shown later than the compounds isolated [14] are the
Zn complexes [15].
λ
ε
The Co(II) complexes (V–VIII) were obtained by
For C72H140N20Cl20Ni10
reflux of anhydrous CoCl2 and ligand (1 : 1) in THF or
MeCN followed by the recrystallization of the product
from CH2Cl2. Single crystals suitable for Xꢀray strucꢀ
ture analysis were grown on cooling of a solution of the
complex in CH2Cl2 or by the slow diffusion of Et2O to
solutions in MeCN. The obtained complexes are staꢀ
ble in air and can be stored without decomposition for
a prolonged time, except for [Co(HDABiPr)Cl2]2
anal. calcd. (%): C, 33.7;
H, 5.5;
H, 5.8;
N, 10.9.
N, 10.5.
Found (%):
C, 33.8;
Xꢀray structure analysis. The crystallographic and
Xꢀray diffraction data for the determination of strucꢀ
tures of 12 compounds were obtained on a Bruker X8
Apex CCD automated diffractometer (graphite
monochromator, (MoK ) = 0.71073 Å). An absorpꢀ
λ
α
(
VIII), which decomposes within several weeks. The
use of CoCl2 6H2O as the starting substance results
only in the formation of complexes containing no
DAB. The reflux of CoCl2
6H2O with MeDABMe
(1 : 1) in MeCN affords molecular
tion correction was applied semiempirically using the
SADABS program [12]. The structures were solved by
a direct method and refined by least squares in the
anisotropic approximation (SHELXTL) [13]. Hydroꢀ
gen atoms were localized geometrically and refined
in the rigid body approximation. A crystal of comꢀ
pound XII is a pseudomerohedral twin with the weight
of the main component 61.8%. The twinning matrix
⋅
⋅
[Co(MeCN)4(H2O)2]Cl2 [16], whereas the same reacꢀ
tion in THF affords the chain polymer complex
[{Co4(μꢀCl)6Cl2(THF)4(H2O)2}
⋅
2THF] [17]. The
∞
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15
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SYNTHESES AND STRUCTURES OF THE COBALT, NICKEL
Table 3. Selected interatomic distances and angles in molecules of the complexes in structures
17
I–IV and VI
I
⋅
CH3CN
II
⋅
C4H8O
III
IV
VI
Bond; d, Å
Zn(1)–Cl(1)
2.2085(7)
Zn(1)–Cl(1)
2.2055(4)
Zn(1)–Cl(1)
2.2163(3)
Zn(1)–Cl(1)
2.2095(4)
Co(1)–Cl(1)
2.2216(5)
Co(2)–Cl(3)
2.2336(5)
Zn(1)–Cl(2)
2.2026(8)
Zn(1)–Cl(2)
2.2130(4)
Zn(1)–Cl(2)
2.2110(3)
Co(1)–Cl(2)
2.2291(5)
Co(2)–Cl(4)
2.2102(6)
Zn(1)–N(1)
2.0873(15)
Zn(1)–N(1)
2.0647(12)
Zn(1)–N(1)
2.0754(8)
Zn(1)–N(1)
2.0754(10)
Co(1)–N(1)
2.0358(16)
Co(2)–N(3)
2.0423(16)
Zn(1)–N(2)
2.0699(12)
Zn(1)–N(2)
2.0825(9)
Co(1)–N(2)
2.0538(16)
Co(2)–N(4)
2.0464(16)
Angle, deg
Cl(1)Zn(1)Cl(2) Cl(1)Zn(1)Cl(2) Cl(1)Zn(1)Cl(1)' Cl(1)Co(1)Cl(2) Cl(3)Co(2)Cl(4)
Cl(1)Zn(1)Cl(2)
116.73(3)
116.568(16)
115.254(10)
121.47(3)
112.63(2)
113.05(2)
N(1)Zn(1)N(1)'
77.67(8)
N(1)Zn(1)N(2)
78.89(5)
N(1)Zn(1)N(2)
81.10(3)
N(1)Zn(1)N(1)'
80.35(5)
N(1)Co(1)N(2)
79.54(6)
N(3)Co(2)N(4)
80.06(6)
both products were identified by the unit cell parameꢀ
ters of the single crystal.
The synthesized compounds were characterized by
IR and UVꢀVIS spectroscopy. The coordination of the
ligand shifts the absorption bands of the multiple
bonds (1700–1400 cm–1). In addition, the coordinaꢀ
tion of MeDABMes results in the appearance of an addiꢀ
tional absorption band of the complex at approxiꢀ
mately 1590–1600 cm–1, which is absent from the
spectrum of the free ligand. Diamagnetic zinc comꢀ
plexes I–III were characterized by the NMR method.
Various sources of the metal were used for the synꢀ
thesis of the nickel complexes. Reflux of a mixture of
anhydrous NiCl2 and ligand in a ratio of 1 : 1 in MeCN
results in the disappearance of the starting chloride
and the formation of a lemonꢀyellow precipitate preꢀ
sumably representing mixed acetonitrile–chloride
nickel(II) complexes. After this precipitate was filtered
off from the solution, the solution was concentrated by
evaporation, and the solid residue was recrystallized,
the following complexes were obtained in moderate
13
The signals in the C NMR spectrum of complex II
yields: [Ni(MeDABDipp)Cl2] (IX), [Ni(MeDABMes)Cl2
), and [Ni(HDABtBu)Cl2]2
XI). We failed to obtain
the complexes with HDABiPr by this method.
]
C(4)
(
X
(
C(3)
C(5)
C(612)
The reactions of [Ni(Dme)Cl2] with HDABiP give
different products, depending on the conditions.
Reflux of a mixture of [Ni(Dme)Cl2] with HDABiPr in
C(2)
C(211)
C(212)
C(61)
C(1)
C(611)
THF affords the binuclear complex [Ni2(
μ
ꢀ
Cl)3(HDABiPr)2(THF)Cl]
⋅
0.25THF (XII · 0.25THF),
N(1)
C(21)
C(8)
C(7)
whereas the reaction in THF or CH2Cl2 and crystalliꢀ
zation from an acetonitrile–Et2O mixture result
in [Ni3(μ3ꢀCl)2(μꢀCl)3(HDABiPr)3]2[Ni2(μꢀCl)2(HDABiPr)2
Zn(1)
Cl(2)
Cl(1)
(СH3CN)2(NiCl4)2]
ionic part of compound XIII is the trinuclear complex
[Ni3(μ3ꢀCl)2( in which two
ꢀCl)3(HDABiPr)3]+ (XIIIa
μ3ꢀCl ligands are coordinated to the Ni3 triangle and
each edge is coordinated by the ꢀCl ligand. The
ꢀCl)2(HDABiPr)2(СH3CN)2
XIIIb) can be presented as a dimeric comꢀ
⋅
MeCN (XIII · MeCN). The catꢀ
μ
)
μ
anionic
part
[Ni2(μ
(NiCl4)2]2–
(
plex with two chloride bridges in which the terminal
ligands HDABiPr and MeCM are additionally coordiꢀ
nated to each nickel atom. In addition, the anionic
Fig. 1. Structure of complex
I with the enumeration of
complex
2− acts as a terminal ligand in this case.
NiCl4
atoms (independent part); hydrogen atoms are omitted.
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PETROV et al.
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SYNTHESES AND STRUCTURES OF THE COBALT, NICKEL
19
Table 5. Selected interatomic distances and angles in complexes XII and XIII
XII 0.25C4H8O XIIIa
⋅
XIIIb
Bond; d, Å
Ni(1)–Ni(2)3.0632(15)
Ni(3)–Ni(4)3.0527(13)
Ni(1)–Ni(2) 3.123(1)
Ni(1)–Ni(3) 3.127(2)
Ni(2)–Ni(3) 3.140(2)
Ni(4)–Ni(4)' 3.617(2)
Ni(1)–Cl(1) 2.4482(8)
Ni(1)–Cl(3) 2.4741(8)
Ni(2)–Cl(1) 2.4367(9)
Ni(2)–Cl(3) 2.4694(8)
Ni(3)–Cl(1) 2.5246(8)
Ni(3)–Cl(3) 2.4305(9)
Ni(1)–Cl(1) 2.423(2)
Ni(1)–Cl(2) 2.478(3)
Ni(1)–Cl(3) 2.469(2)
Ni(2)–Cl(1) 2.408(2)
Ni(2)–Cl(2) 2.393(2)
Ni(2)–Cl(3) 2.431(2)
Ni(3)–Cl(5) 2.449(2)
Ni(3)–Cl(6) 2.502(2)
Ni(3)–Cl(7) 2.430(2)
Ni(4)–Cl(5) 2.419(2)
Ni(4)–Cl(6) 2.412(2)
Ni(4)–Cl(7) 2.408(2)
Ni(1)–Cl(2) 2.4248(8)
Ni(1)–Cl(5) 2.4055(8)
Ni(2)–Cl(2) 2.4335(8)
Ni(2)–Cl(4) 2.4265(9)
Ni(3)–Cl(5) 2.4304(9)
Ni(3)–Cl(4) 2.4461(9)
Ni(4)–Cl(6) 2.4156(9)
Ni(4)–Cl(6)' 2.4403(9)
Ni(4)–Cl(54) 2.5343(9)
Ni(5)–Cl(54) 2.3028(9)
Ni(1)–Cl(4) 2.378(2)
Ni(3)–Cl(8) 2.381(2)
Ni(5)–Cl(51) 2.2357(10)
Ni(5)–Cl(52) 2.2576(9)
Ni(5)–Cl(53) 2.2623(10)
Ni(1)–N(2
Ni(1)–N(5
Ni(2)–N(2
Ni(2)–N(5
A
) 2.059(7)
) 2.057(7)
Ni(3)–N(2
Ni(3)–N(5
Ni(4)–N(2
Ni(4)–N(5
C
) 2.066(7)
) 2.053(8)
Ni(1)–N(2
Ni(1)–N(5
Ni(2)–N(2
Ni(2)–N(5
Ni(3)–N(2
Ni(3)–N(5
A
) 2.050(2)
) 2.034(2)
Ni(4)–N(2
Ni(4)–N(5
Ni(4)–N(1
D
) 2.092(3)
) 2.062(3)
A
C
A
D
B
) 2.088(7)
) 2.089(6)
D
D
) 2.059(6)
) 2.083(7)
B
B
C
C
) 2.047(2)
) 2.037(3)
) 2.044(3)
) 2.074(2)
S
) 2.055(3)
B
Ni(2)–O(1) 2.114(7)
Ni(4)–O(2) 2.105(6)
Angle, deg
Ni(1)Ni(2)Ni(3) 59.91(1)
Ni(2)Ni(3)Ni(1) 59.78(1)
Ni(3)Ni(1)Ni(2) 60.31(1)
Cl(1)Ni(1)Cl(2) 84.17(9)
Cl(1)Ni(1)Cl(3) 83.57(7)
Cl(3)Ni(1)Cl(2) 83.09(7)
Cl(4)Ni(1)Cl(1) 92.95(8)
Cl(5)Ni(3)Cl(6) 83.77(7)
Cl(7)Ni(3)Cl(5) 84.69(8)
Cl(7)Ni(3)Cl(6) 83.23(7)
Cl(8)Ni(3)Cl(5) 94.84(8)
Cl(5)Ni(1)Cl(2) 160.41(3) Ni(4)Cl(6)Ni(4)' 96.28(3)
Cl(2)Ni(2)Cl(4) 159.84(3) Ni(4)Cl(54)Ni(5) 122.11(4)
Cl(4)Ni(3)Cl(5) 158.50(3)
Cl(4)Ni(1)Cl(2) 176.94(10) Cl(8)Ni(3)Cl(6) 177.66(8)
Cl(4)Ni(1)Cl(3) 97.64(7)
Cl(1)Ni(2)Cl(3) 84.71(7)
Cl(2)Ni(2)Cl(1) 86.36(8)
Cl(2)Ni(2)Cl(3) 85.70(9)
Cl(8)Ni(3)Cl(7) 94.79(8)
Cl(6)Ni(4)Cl(5) 86.33(7)
Cl(7)Ni(4)Cl(5) 85.83(8)
Cl(7)Ni(4)Cl(6) 85.63(7)
N(5
A
)Ni(1)N(2
A
) 79.1(3)
) 78.8(3)
N(5
C
)Ni(3)N(2
C
) 77.8(3)
) 79.3(2) N(2
N(2
N(2
A
)Ni(1)N(5
A
) 80.55(10) N(2
) 80.51(10)
) 80.45(10)
D)Ni(4)N(5D) 79.74(10)
N(2B
)Ni(2)N(5
B
N(2D
)Ni(4)N(5
D
B
)Ni(2)N(5
B
C
)Ni(3)N(5
C
Ni(2)Cl(1)Ni(1) 78.70(6)
Ni(2)Cl(2)Ni(1) 77.90(6)
Ni(2)Cl(3)Ni(1) 77.37(6)
Ni(4)Cl(5)Ni(3) 77.68(7)
Ni(4)Cl(6)Ni(3) 76.79(6)
Ni(4)Cl(7)Ni(3) 78.25(7)
Ni(1)Cl(2)Ni(2) 80.01(3)
Ni(2)Cl(4)Ni(3) 80.23(3)
Ni(3)Cl(5)Ni(1) 80.57(3)
Cl(6)Ni(4)Cl(6)' 83.72(3)
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20
PETROV et al.
C(11A)
C(6)
C(12A)
Cl(1)
C(3)
C(1
A)
C(5)
N(1)
Cl(3)
N(2
A
)
N(2B)
Ni(2)
Ni(1)
Cl(2)
C(3A)
Cl(4)
C(1)
N(5B)
Co(1)
C(4A)
N(5A)
Cl(2)
N(2)
C(7)
C(4)
C(4T)
O(1)
C(2)
Cl(1)
C(6A)
C(62A)
C(1T)
C(61A)
C(8)
C(3T)
C(2T)
Fig. 3. Structure of complex XII with the enumeration of
atoms. One of the crystallographically independent moleꢀ
cules is shown; hydrogen atoms are omitted.
Fig. 2. Structure of complex VIII with the enumeration of
atoms (independent part); hydrogen atoms are omitted.
were assigned on the basis of the spectrum of free coordination polyhedron of the Co atom is a slightly
MeDABMes described in the literature [18].
distorted trigonal bipyramid, whose equatorial posiꢀ
tions are occupied by the N(2), Cl(1), and Cl(2)
atoms. The deviation of the terminal chloride ion
Cl(2) from the Co(1)Cl(2)Co(1)'Cl(2)' plane is
1.81 Å, and the dihedral angle between the
Co(1)Cl(2)Co(1)'Cl(2)' and Co(1)N(1)C(1)C(2)N(2)
The Zn complexes with all ligands studied
H
(
MeDABMes
,
MeDABDipp, DABtBu, and HDABiPr) are
mononuclear. The coordination node ZnN2Cl2 in
complexes I–IV has the structure of a distorted tetraꢀ
hedron, and the dihedral angle between the ZnN2 and
ZnCl2 planes varies from 85° to 90°. The molecular
planes is 55 . It should be mentioned that the monoꢀ
°
meric structure with the tetrahedral coordination
node has earlier been postulated for the complexes of
stoichiometry [Co(HDABiPr)Hal2] (Hal = Cl, Br) on
the basis of the UV spectra and magnetic susceptibility
data, although the complexes were not characterized
by Xꢀray structure analysis [20].
structure of complex I is shown in Fig. 1.
The Co complexes, except for complex VIII
with HDABiPr, are mononuclear. The structure of
complex
V turned out to be identical to the structure
described earlier [19], and the unit cell parameters
coincide with allowance for the temperature factor.
Complex VI has earlier been characterized structurally
The crystals of the nickel complexes
[
Ni(MeDABDipp)Cl2] (IX) and [Ni(MeDABMes)Cl2] (
X)
as a solvate with methylene chloride VI
⋅
CH2Cl2 [19].
are isostructural to the crystals of the
The average bond lengths Co–N (2.045 and 2.050 Å)
and Co–Cl (2.22 and 2.20 Å) in VI and VI ⋅ CH2Cl2
are consistent with each other.
Another polymorphous modification (VII') has
earlier been described for compound VII [20]. The
volume of the monoclinic unit cell in VII' is twofold
lower than that observed for VII, and this unit cell is
transformed into that similar to VII by the axis transꢀ
formation matrix (–1 0 0/0 –1 0/0 0 2). The
corresponding cobalt complexes and VI. Interestꢀ
V
ingly, the crystals of IX are also isostructural to the
crystals of [Co(HDABDipp)(CO)(NO)] [21] and
[
Ni(HDABDipp)(CO)2] [22] containing more bulky
ligands CO or NO instead of halides and containing
no methyl substituents in the side chain of DAB.
Unlike mononuclear cobalt complex VII, the nickel
complex with HDABtBu
(XI) has the pseudosymmetric
binuclear structure with two bridging Cl atoms. The
central fragment Ni(1)Cl(1)Ni(2)Cl(3) is almost plaꢀ
nar (the deviation of the atoms from the plane does not
exceed 0.03 Å), and the dihedral angles between this
space group of VII' (P21) is the subgroup P21/n in
which structure VII is solved. An attempt to solve
structure VII in the unit cell of VII' and space group
P21 results in the high value of R factor (~11%). Thus,
fragment and the Ni(1)N(1
Ni(2)N(1 )C(2 )C(2 )N(2
77.9
nation polyhedra in complex XI are similar to a square
pyramid with a distorted base formed by three Cl
B
)C(2
planes are 78.0
B
)C(2
B
)N(2
B
°
)
and
and
there is a topotaxial correspondence between these
modifications. The IR spectra of complexes V–VII
coincide with the published data.
A
A
A
A
)
°
, respectively. Unlike complex VIII, the coordiꢀ
The cobalt complex [Co(HDABiPr)Cl2]2
(VIII) has
a centrosymmetric binuclear structure, and the Cl(1) atoms and one N atom. The deviation of the terminal
atom performs the bridging function (Fig. 2). The chloride ions Cl(2) and Cl(4) from the
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SYNTHESES AND STRUCTURES OF THE COBALT, NICKEL
21
(Tmeda is N,N,N',N'ꢀtetramethylethylenediamine)
[23] and the complex with the dimine ligand [Ni3(μ3
Br)2(
ꢀBr)3(MeDABAr)3]+ (Ar is 2ꢀmethylꢀ4ꢀchloꢀ
rophenyl) [24]. The geometric characteristics of catꢀ
ionic complex XIIIa are similar to those for [Ni3(μ3
Сl)2( μ3ꢀСl)
ꢀСl)3(Tmeda)3]+: Ni–Ni 3.165, Ni
2.427(2), Ni–( ꢀСl) 2.471(2) Å. The Ni–Br distances
in the complex [Ni3(μ3ꢀBr)2(μꢀBr)3(MeDABAr)3]+ [24]
are somewhat longer (Ni–(μ3ꢀBr) 2.549(3), Ni
Br) 2.595(3) Å), which can be explained by the longer
ion radius of Br–
Complex anion XIIIb is a centrosymmetric dimer.
Two ꢀchloride ligands bind two Ni atoms. One
(а)
ꢀ
μ
N(5
N(2
Ni(2)
B
)
ꢀ
B)
μ
⎯(
Cl(4)
Cl(2)
μ
Cl(3)
Ni(1)
⎯
(μꢀ
N(5
A
)
Ni(3)
Cl(1)
.
N(2
A
)
μ
Cl(5)
(
HDABiPr molecule and one MeCN molecule are addiꢀ
tionally coordinated to each Ni atom. In addition, the
Ni(4) atom is bound through the bridging Cl(54) atom
to the Ni(5) atom, which is in the tetrahedral coordiꢀ
nation of four Cl atoms. Thus, it can be imagined that
2−
b)
Cl(53)
C(3
C(2
S
)
Cl(52)
S
)
the complex fragment
acts, in this case, as a
NiCl4
Ni(5)
Cl(51)
ligand with respect to the Ni(4) atom. The search in
the CSD [25] showed that this coordination mode of
Ni(1S)
Cl(54)
⎯
NiHal24 has not previously been known. On the one
Cl(6)
Ni(4)
hand, the closest analogs of this structure are two comꢀ
C(1
D)
plexes of the [L2Ni(
bidentateꢀcoordinated ligand [25, 26]. On the other
hand, the examples for the {M1–( ꢀHal)–M2Hal3}
μ
ꢀBr)2NiBr2] type, where L is the
C(6D)
N(2
D
D
)
N(5D)
μ
C(3
)
C(4D)
fragment (M1 and M2 are metals of the first transition
row) are rather numerous (43 notations in the CSD).
The Ni(4)–Ni(4)' distance in XIIIb is ~3.62 Å, and
the Ni(4)–Ni(5) distance is ~4.23 Å.
The C–C and C–N bond lengths of the diimine
fragment in all studied complexes range within 1.44–
1.52 and 1.23–1.30 Å, respectively, which unambiguꢀ
ously indicates the zero oxidation state of the ligand.
Fig. 4. Structures of the (a) anionic and (b) cationic parts
of complex XIII with the enumeration of atoms of the
independent part; hydrogen atoms are omitted.
Ni(1)Cl(1)Ni(2)Cl(3) plane is 0.88 and 0.93 Å,
respectively.
Unlike binuclear complexes VIII and XI
,
ACKNOWLEDGMENTS
complex XII Ni2(
(
μ
ꢀCl)3(HDABiPr)2(THF)Cl]) conꢀ
This work was supported by the Russian Foundaꢀ
tion for Basic Research (project nos. 10ꢀ03ꢀ00385, 12ꢀ
03ꢀ31530, and 12ꢀ03ꢀ90820), the Siberian Branch of
the Russian Academy of Sciences (integration project
nos. 17 and 105), and the state contract
no. 02.740.11.0628.
tains three bridging chloride ligands. The crystalline
phase of the complex includes two crystallographically
independent molecules. The coordination of the Ni
atoms is supplemented to the octahedral one by
diimine and one more terminal ligand (Cl for Ni(1)
and Ni(3), THF for Ni(2) and Ni(4)). The molecular
structure of complex VIII is shown in Fig. 3.
The crystalline phase of complex XIII consists of
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solvate acetonitrile molecules. The average Ni–Ni
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Ni–( ꢀСl) distances are 2.47(3) and 2.428(13) Å,
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