NiII-mediated coupling between iminoisoindolinones and nitriles leading to unsymmetrical 1,3,5-triazapentadienato complexes

Article abstract of DOI:10.1021/ic702131k

Treatment of nickel acetate Ni(OAc)₂·4H₂O with 2 equiv of various 3-iminoisoindolin-1-ones in a suspension of RCN in the presence of triethanolamine leads to the formation of the nickel 1,3,5-triazapentadienato complexes [Ni{NH=C(R)N=C(C₆R ¹R²R³R⁴CON)}₂] (1-17) isolated in good 50-83% yields. The reaction proceeds under relatively mild conditions (from 5 to 7 h at 25-115°C, depending on the boiling point of the nitrile) and has a general character insofar as it was successfully conducted with various nitriles RCN bearing donor (R = Me, Et, Prⁿ, Pr ⁱ, Buⁿ), weak donor (R = CH₂Ph, CH ₂C₆H₄OMe-p), acceptor (R = CH₂Cl), and strong acceptor (R = CCl₃) groups R of different steric hindrance and also with the nonsubstituted iminoisoindolinone (3-iminoisoindolin-1-one) or the iminoisoindolinones bearing donor methyl (3-imino-5-methylisoindolin-1- one) or acceptor fluoro (4,5,6,7-tetrafluoro-3-iminoisoindolin-1-one) groups in the benzene ring.

Full text of DOI:10.1021/ic702131k

Inorg. Chem. 2008, 47, 3088-3094
NiII-Mediated Coupling between Iminoisoindolinones and Nitriles Leading
to Unsymmetrical 1,3,5-Triazapentadienato Complexes
Pavel V. Gushchin,†,‡ Konstantin V. Luzyanin,†,‡ Maximilian N. Kopylovich,† Matti Haukka,§
Armando J. L. Pombeiro,*,† and Vadim Yu. Kukushkin*,‡
Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, TU Lisbon,
AV. RoVisco Pais, 1049-001 Lisbon, Portugal, St. Petersburg State UniVersity, 198504 Stary
Petergof, Russian Federation, and Department of Chemistry, UniVersity of Joensuu, P.O. Box 111,
FI-80101, Joensuu, Finland
Received October 29, 2007
Treatment of nickel acetate Ni(OAc)2 ·4H2O with 2 equiv of various 3-iminoisoindolin-1-ones in a suspension of
RCN in the presence of triethanolamine leads to the formation of the nickel 1,3,5-triazapentadienato complexes
[Ni{NHdC(R)NdC(C6R1R2R3R4CON)}2] (1–17) isolated in good 50–83% yields. The reaction proceeds under relatively
mild conditions (from 5 to 7 h at 25–115 °C, depending on the boiling point of the nitrile) and has a general
character insofar as it was successfully conducted with various nitriles RCN bearing donor (R ) Me, Et, Prn, Pri,
Bun), weak donor (R ) CH2Ph, CH2C6H4OMe-p), acceptor (R ) CH2Cl), and strong acceptor (R ) CCl3) groups
R of different steric hindrance and also with the nonsubstituted iminoisoindolinone (3-iminoisoindolin-1-one) or the
iminoisoindolinones bearing donor methyl (3-imino-5-methylisoindolin-1-one) or acceptor fluoro (4,5,6,7-tetrafluoro-
3-iminoisoindolin-1-one) groups in the benzene ring.
Introduction
versatile [M]-N(H)dCRR′ (R ) alkyl, aryl; R′ ) OH, OR′′,
ONdCR′′2, ONR′′2, NdCPh2, and others) imino derivatives.
Following our ongoing project on reactions of metal-
activated nitriles, we recently discovered approaches to a
series of important coordination and organic compounds
derived from organonitriles and generated via metal-mediated
and/or “HON”-nucleophile-promoted processes. Thus, we
observed, an unusual transformation of alkyl nitriles RCN
to the appropriate symmetric (1,3,5-triazapentadiene)NiII
complexes (route I, Scheme 1) in the NiII/ketoxime systems.7
This route opens up a good access to 1,3,5-triazapentadienes
which otherwise are conventionally obtained by the hazard-
ous two-step Pinner synthesis.2 When phthalonitrile (Pn) is
used as an RCN source, the formation of nickel phthalocya-
nines (Pcs) instead of (1,3,5-triazapentadienes)NiII has been
achieved in the “NiII/ketoxime” or “NiII/diethyl hydroxy-
lamine” systems (route II, Scheme 1).8–10 These oxime- or
hydroxylamine-promoted reactions represent an advanced
synthetic route to phthalocyanines species, which operate at
low temperatures and do not require expensive reagents and/
Activation of organonitriles toward nucleophilic addition
upon coordination to a metal center is currently an area of
studies targeted on the exploration of synthetic transforma-
tions of RCN species at industrial or laboratory scale, and
this subject has repeatedly been surveyed1–6 (including
reviews written by some of us2–5). In the majority of cases,
coordination of organonitriles to a metal center increases
significantly the electrophilicity of the RCN species, allowing
the coupling even with very weak nucleophiles2 to give
*Towhomcorrespondenceshouldbeaddressed.E-mail:pombeiro@ist.utl.pt
(A.J.L.P.), kukushkin@VK2100.spb.edu (V.Y.K.).
†
Instituto Superior Técnico.
St.Petersburg State University.
University of Joensuu.
‡
§
(1) Michelin, R. A.; Mozzon, M.; Bertani, R. Coord. Chem. ReV. 1996,
147, 299.
(2) Pombeiro, A. J. L.; Kukushkin, V. Yu. Reactions of Coordinated
Nitriles. In ComprehensiVe Coordination Chemistry, 2nd ed.; Lever,
A. B. P., Ed.; Elsevier: New York, 2004; Vol. 1, Chapter 1.34, pp
639–660.
(3) Kukushkin, V. Yu.; Pombeiro, A. J. L. Chem. ReV. 2002, 102, 1771.
(4) Kukushkin, V. Yu.; Pombeiro, A. J. L. Inorg. Chim. Acta 2005, 358,
1.
(7) (a) Kopylovich, M. N.; Pombeiro, A. J. L.; Fischer, A.; Kloo, L.;
Kukushkin, V. Yu. Inorg. Chem. 2003, 42, 7239. (b) Kopylovich,
M. N.; Tronova, E. A.; Haukka, M.; Kirillov, A. M.; Kukushkin, V.
Yu.; Fraústo da Silva, J. J. R.; Pombeiro, A. J. L. Eur. J. Inorg. Chem.
2007, 4621.
(5) Bokach, N. A.; Kukushkin, V. Yu. Usp. Khim. (Russ. Chem. ReV.)
2005, 74, 164.
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3088 Inorganic Chemistry, Vol. 47, No. 8, 2008
10.1021/ic702131k CCC: $40.75  2008 American Chemical Society
Published on Web 02/22/2008

Coupling between Iminoisoindolinones and Nitriles
Scheme 1
or unconventional techniques (e.g., microwave irradiation)
for their preparation.8–10 Noteworthy, the hydroxylamine-
assisted reaction shows higher promoting ability and versatil-
ity than those in the case of the oxime, and it can be applied
for the preparation of various metal-bound phthalocyanines,
viz. Ni, Zn, Co, and Cd (route II, Scheme 1).10
The latter method is one of the most advantageous for the
preparation of these heterocyclic species useful as precursors
for the manufacture of pigments (e.g., phthalocyanines), heat-
sensitive colorants, some components for thermal-recording
sheets, charge-controlling agents for electrophotographic
toners, stabilizers for plastics, pharmaceuticals, and cosmet-
ics, and also for the synthesis of other heterocycles.14,15
In all the above-mentioned examples, only one aliphatic
or aromatic organonitrile was used as the starting material.
However, treatment of a mixture of both alkylnitrile and
nonsubstituted phthalonitrile (route IV, Scheme 1), in the
presence of Ni(OAc)2 · 4H2O, provides an easy single-pot
entry to a series of new unsymmetrical (1,3,5-triazapenta-
dienato)NiII compounds.16 Inspecting the structure of
[Ni{NHdC(R)NdC(C6H4CON)}2], we assumed that the
unsymmetrical (1,3,5-triazapentadienato)NiII species are gen-
erated upon a previously unreported nucleophilic attack of
In a recent kinetic study,11 we estimated that in the addition
of HON species (such as diethyl hydroxylamines or oximes)
to metal-activated nitriles the former are ca. 104 times better
nucleophiles than the latter.11 Taking into account the known
higher reducing abilities of hydroxylamines vs oximes,12 we
studied the promoting ability of the hydroxylamine species
in the conversion of Pns to Pcs and observed that Et2NOH
can so greatly enhance the cyclotetramerization of Pns in
alcohols that this reaction could even proceed without a metal
source (route IIA, Scheme 1). Curiously, the latter metal-
free transformation of Pn promoted by Et2NOH shows a
dramatic solvent dependence. Thus, in alcohols the reaction
furnishes free Pcs (route IIA, Scheme 1), while if chloroform
is used instead of an alcohol, it proceeds in another direction,
yielding 3-iminoisoindolin-1-ones (route III, Scheme 1).10,13
(14) (a) Pendrak, I.; Barney, S.; Wittrock, R.; Lambert, D. M.; Kingsbury,
W. E. J. Org. Chem. 1994, 59, 2623. (b) de Clerck, E. J. Med. Chem.
1995, 38, 2491. (c) Perard-Viret, J.; Prange, T.; Tomas, A.; Royer, J.
Tetrahedron 2002, 58, 5103. (d) Butner, L.; Huang, Y.; Tse, E.; Hall,
Ih. Biomed. Pharmacother. 1996, 50, 290. (e) Kato, Y.; Takemoto,
M.; Achiwa, K. Chem. Pharm. Bull. 1993, 41, 2003. (f) Hall, I. H.;
Wang, O. T. Anti-Cancer Drugs 1994, 5, 207. (g) Murthy, A. R. K.;
Wong, O. T.; Reynolds, D. J.; Hall, I. H. Pharm. Res. 1987, 4, 21. (h)
Voorstad, P. J.; Cocolas, G. H.; Hall, I. H. Pharm. Res. 1984, 6, 250.
(15) (a) McKeown, N. B. Phthalocyanines. In ComprehensiVe Coordination
Chemistry, 2nd ed.; Elsevier: Amsterdam, 2003; Vol. 1, Chapter 1.24,
pp 507-514 and references therein. (b) Oonishi, K.; Komya, K. Chem.
Abstr. 1996, 125, 250377. ; Japan Pat. JP 08193065. (c) Hiraishi, S.;
Koike, N.; Kabashima, K.; Kitaoka, A. Chem. Abstr. 1987, 107, 68254.
; Pat. JP 61205183. (d) Koecher, M.; Raue, R.; Wunderlich, K. Chem.
Abstr. 1993, 119, 49226. ; German Pat. DE 4128080. (e) Tadokoro,
K.; Shoshi, M.; Namba, M.; Shimada, T.; Tanaka, C. Chem. Abstr.
2001, 134, 78627. ; Europ. Pat. EP 1063264. (f) Habeck, T.; Haremza,
S.; Trauth, H.; Schehlmann, V.; Westenfelder, H. Chem. Abstr. 1999,
131, 74483. ; Europ. Pat. EP 924246.
(8) Kopylovich, M. N.; Kukushkin, V. Yu.; Haukka, M.; Luzyanin, K. V.;
Pombeiro, A. J. L. J. Am. Chem. Soc. 2004, 126, 15040.
(9) Pombeiro, A. J. L.; Kopylovich M. N.; Kukushkin, V. Yu.; Luzyanin,
K. V. Patent PT-103130Y, June 2, 2004.
(10) Luzyanin, K. V.; Kukushkin, V. Yu.; Kopylovich, M. N.; Nazarov,
A. A.; Galanski, M.; Pombeiro, A. J. L. AdV. Synth. Catal. 2008, 350,
135.
(11) Luzyanin, K. V.; Kukushkin, V. Yu.; Kuznetsov, M. L.; Ryabov, A. D.;
Galanski, M.; Haukka, M.; Tretyakov, E. V.; Ovcharenko, V. I.;
Kopylovich, M. N.; Pombeiro, A. J. L. Inorg. Chem. 2006, 45, 2296.
(12) (a) Sayo, H.; Ozaki, S.; Masui, M. Chem. Pharm. Bull. 1973, 21, 1988.
(b) Serve, D. Electrochim. Acta 1975, 20, 469. (c) De Lijser, H. J. P.;
Kim, J. S.; McGrorty, S. M.; Ulloa, E. M. Can. J. Chem. 2003, 81,
575.
(13) Pombeiro, A. J. L.; Luzyanin, K. V.; Kukushkin, V. Yu.; Kopylovich,
M. N. Pat. PT-103718, Apr 13, 2007.
(16) Kopylovich, M. N.; Haukka, M.; Kirillov, M. A.; Kukushkin, V. Yu.;
Pombeiro, A. J. L. Chem.sEur. J. 2007, 13, 786.
Inorganic Chemistry, Vol. 47, No. 8, 2008 3089

Gushchin et al.
Scheme 2
The addition of TEA is crucial for conducting the coupling
andthebestresultswereobtainedatamolarratioNi(OAc)2 ·4H2O:
TEA equal to 2:1. The increase of TEA amount to 1:(1-2)
and subsequent increase of pH value results in lowering the
yield of the 1,3,5-triazapentadienato complexes and their
substantial contamination with byproducts. We believe that
the promoting role of TEA is dual. On one hand, the amine
affects the acidity of the reaction mixture and the buffering
prevents protonation of the iminoisoindolinones and also
allows the isolation of the neutral (1,3,5-triazapentadienato-
)NiII complexes in one distinct protolytic form. On the other
hand, TEA promotes the dissolution of the solid nickel
acetate by complexation to the nickel(II) center,17 thus
allowing the performance of the reaction in the homogeneous
liquid phase. In accord with these assumptions, application
in the synthesis of other sterically demanded amines such
as triethylamine and trioctylamine, which cannot form NiII
chelates, brings about formation of a broad mixture of
products, where the target 1,3,5-triazapentadienato complexes
are strongly contaminated with yet unidentified products. The
nature of the anion of the nickel salt NiX2 is also important,
and usage of a weak acid salt, i.e. Ni(OAc)2 · 4H2O, was
proved to be significant for the conductance of the coupling,
while the synthesis fails when the anion of NiX2 is a
derivative of a strong acid, e.g., X ) Cl, NO3.
Table 1. Compounds Numbering and Yields
R
no. yield, %
R
no. yield, %
R1-R4 ) H
Me
Et
1
2
3
4
50
60
57
55
Bun
CH2Cl
CCl3
5
6
7
8
9
60
67
77
58
83
Prn
Pri
CH2Ph
CH2C6H4OMe-p
R1, R3, R4 ) H Me 10
55
51
52
Pri
CCl3
CH2Ph
13
14
15
45
73
57
R2 ) Me
Et
11
Prn 12
R1-R4 ) F
Et
16
50
CCl3
17
71
It is important to mention that (i) the iminoisoindolinones
under the reaction conditions do not react with RCN species
in the absence of the promoting metal center, and this gives
an indication that the observed coupling is NiII-mediated and
the promoting effect of the metal is conceivably due to the
activation of ligated RCN toward nucleophilic attack and
also to the stabilization of the 1,3,5-triazapentadiene formed
by chelation and (ii) the obtained data shed light on the
mechanism of the previously reported single-pot synthesis
of unsymmetrical (1,3,5-triazapentadienato)NiII complexes
(route III, Scheme 3). Thus, phthalonitrile in the presence
of a HON-nucleophile (oxime or hydroxylamine) is subject
to transformation to 3-iminoisoindolin-1-one species via a
known procedure (route I, Scheme 3).10,13 The nitrile, which
is used as both solvent and reactant in the one pot synthesis16
and also in this work, upon coordination to a metal center
leads to the formation of a metal-organonitrile complex,
M-NtCR. The 3-iminoisoindolin-1-one attack on the
complexed nitrile furnishes 1,3,5-triazapentadienato com-
plexes (route II, Scheme 3).
the 3-iminoisoindolin-1-one (formed in situ in accord with
our observations10,13) on the nitrile at a nickel center.
Consequently, the main goals of the current work are (i)
to study the nucleophilic properties of 3-iminoisoindolin-1-
ones toward metal-bound organonitriles and to shed light
on the mechanism of the one-pot formation of (1,3,5-
triazapentadienato)NiII and (ii) to establish a new synthetic
route to (1,3,5-triazapentadienato)NiII complexes starting
from various nonsubstituted and substituted 3-iminoisoin-
dolin-1-ones. All our results are reported in this article.
Results and Discussion
NiII-Mediated Coupling between Iminoisoindolinones
and Nitriles. Treatment of nickel acetate Ni(OAc)2 · 4H2O
with 2 equiv of the iminoisoindolinones (Scheme 2) in a
suspension of RCN in the presence of triethanolamine (TEA)
leads to the formation of 1,3,5-triazapentadienato complexes
1–17 (Scheme 2, Table 1) isolated in good (with two
exceptions, i.e., 10 and 13) 50–83% yields. The reaction has
a general character, and it was successfully conducted with
(i) various nitriles bearing donor (R ) Me, Et, Prn, Pri, Bun),
weak donor (R ) CH2Ph, CH2C6H4OMe-p), acceptor (R )
CH2Cl), and strong acceptor (R ) CCl3) groups R of different
steric hindrance and (ii) the nonsubstituted iminoisoindoli-
none (3-iminoisoindolin-1-one) or the iminoisoindolinones
bearing donor methyl (3-imino-5-methylisoindolin-1-one) or
acceptor fluoro (4,5,6,7-tetrafluoro-3-iminoisoindolin-1-one)
groups in the benzene ring. Temperature range (25-115 °C)
and the reflux/heating time (5-7 h) for the reaction depend
on the boiling point of the nitrile, the degree of RCN
activation, and the solubility of the starting iminoisoindoli-
nones.
Characterization of (1,3,5-Triazapentadienato)NiII
Complexes. The formulation of complexes 1–17 was sup-
ported by satisfactory C, H, and N microanalyses. The FAB+/
ESI+ mass spectra of 1–17 display peaks from [M]+ or [M
+ H]+ ions. The complexes were also characterized by IR
and 1D 1H, 13C{1H}, and 2D 1H,1H-COSY, 1H,13C-HMQC,
1H,13C-HSQC, and 1H,13C-HMBC NMR spectroscopies; 16
(17) (a) Singh, A.; Mehrotra, R. C. Coord. Chem. ReV. 2004, 248, 101. (b)
Verkade, J. G. Acc. Chem. Res. 1993, 26, 483. (c) Saalfrank, R. W.;
Bernt, I.; Hampel, F. Angew. Chem., Int. Ed. 2001, 40, 1700. (d) Plass,
W.; Pohlmann, A.; Rautengarten, J. Angew. Chem., Int. Ed. 2001, 40,
4207. (e) Chen, F. T.; Li, D. F.; Gao, S.; Wang, X. Y.; Li, Y. Z.;
Zheng, L. M.; Tang, W. X. Dalton Trans. 2003, 3283. (f) Oshio, H.;
Saito, Y.; Ito, T. Angew. Chem., Int. Ed. Engl. 1997, 36, 2673.
3090 Inorganic Chemistry, Vol. 47, No. 8, 2008

Coupling between Iminoisoindolinones and Nitriles
Scheme 3
Figure 1. Thermal ellipsoid view of complex 16 with atomic numbering
scheme. Thermal ellipsoids are drawn with 50% probability.
and 17 were additionally characterized by 19F NMR spec-
troscopy and 16 by X-ray diffraction. Moreover, compounds
1–4 were previously synthesized in the single-pot synthesis,16
and the authenticity of those samples with those obtained in
the current study was confirmed by elemental analyses, IR,
1H, and 13C{1H} NMR spectroscopies.
The IR spectra of 1–17 compounds display strong ν(CdO),
ν(CdN), and δ(N-H) bands in the ranges of 1721–1689,
1631-1605, and 1563–1544 cm-1, respectively, and ν(N-H)
stretching vibrations in the range between 3186 and 3003
cm-1. These frequency intervals agree well with the ap-
propriate values for the ν(CdN) (1665-1612 cm-1) and
δ(N-H) (1542-1523 cm-1) bands and of the N-H stretch-
ing vibrations (3165–3094 cm-1) for the previously prepared
symmetric (1,3,5-triazapentadiene/ato)NiII complexes.16 In
the IR spectrum of 9, the weak ν(CtN) vibrations due to
the solvation NtCCH2C6H4OMe-p molecule were also
observed.
The 1H NMR spectra of all (1,3,5-triazapentadienato)NiII
complexes display one broad singlet from the NH proton
resonating in the range between 11 and 10 ppm. The position
of these signals at such a low field gives indirect evidence
that the NH proton is involved in hydrogen bonding in
solution probably with the neighboring oxygen carbonyl atom
of the 3-iminoisoindolin-1-one fragment of the 1,3,5-triaza-
pentadienato ligands; this H-bonding was also observed for
complex 16 in the solid state (see later). 1H NMR spectra of
10–15 show the presence of two isomers (with the methyl
group in 5- and 6-position) for each compound obtained upon
nucleophilic addition of an isomeric mixture of 3-imino-5-
methylisoindolin-1-one/3-imino-6-methylisoindolin-1-one. The
spectra of 9 and 10 indicate the presence of the solvated
NtCCH2C6H4OMe-p and CH3CO2H molecules. Compounds
16 and 17, which do not have protons in the aromatic ring
of the 3-iminoisoindolin-1-one fragment, were additionally
characterized by 19F NMR spectroscopy, and a typical
multiplet due to JF-F was observed in both spectra. The
13C{1H} spectra of 1–17 show no evidence for the CtN
group (which typically resonates in the range of 120–130
ppm) but indicate the presence of the signals from the newly
formed imine CdN moiety; these peaks appear in the range
of 165–175 ppm, which is typical for the CdN groups.
The accurate assignment of the 1H and 13C signals for 1–17
was performed using 2D (1H,1H-COSY, 1H,13C-HMQC,
1H,13C-HSQC, and 1H,13C-HMBC) NMR correlation experi-
ments. H,13C-HMQC and H,13C-HSQC approaches were
found to be particularly useful for studies of compounds
containing groups with very close 13C chemical shifts, e.g.
for compound 11 (see Figure S1, Supporting Information).
1
1
1
The H,13C-HMBC experiment allows to discriminate the
quaternary CdN signal of the imine fragment from the CdO
resonance of the 3-iminoisoindolin-1-one moiety, due to the
observed 2JH-C and 3JH-C couplings, e.g., in case of the imine
HNdC group between the imine carbon and the protons of
the nitrile residue (performed for 1–7, 9–13, and 15–17).
The structure of 16 has been determined by X-ray
diffraction (Figure 1). The complex exhibits the square-planar
geometry with two uninegatively charged 1,3,5-triazapen-
tadienato species. The ligands have distinct single and double
CN bonds and almost no electron delocalization within the
Ni(1)N(1)C(1)N(2)C(4)N(3) ring. The bond lengths N(1)-C(1)
and N(2)-C(4) [1.296(4) and 1.295(4) Å, respectively] have
values typical for the corresponding NdC bonds in PtII,18
PdII,19 and (1,3,5-triazapentadiene/ato)NiII complexes16 and,
within 3σ, for the NdC bond in compounds bearing the
CAr-CdN-C moiety20 [mean value 1.279(8) Å]. The bond
length N(2)-C(1) [1.374(4) Å] has a value typical for the
corresponding N-C bonds in (1,3,5-triazapentadiene/ato)M
(M ) PtII, PdII, NiII) complexes.16–20 The bond distance
N(3)-C(4) is longer than the N-C single bonds of the
previously reported PtII unsymmetrical and PdII, NiII sym-
metrical 1,3,5-triazapentadiene complexes. The bond distance
O(1)-C(11) [1.217(3) Å] within 3σ agrees with the Csp2dO
(18) Bokach, N. A.; Kuznetsova, T. V.; Simanova, S. A.; Haukka, M.;
Pombeiro, A. J. L.; Kukushkin, V. Yu. Inorg. Chem. 2005, 44, 5152.
(19) Guo, J.-P.; Wong, W.-K.; Wong, W.-Y. Eur. J. Inorg. Chem. 2006,
3634.
(20) (a) Orpen, A. G.; Brammer, L.; Allen, F. H.; Kennard, O.; Watson,
D. G.; Taylor, R. J. Chem. Soc., Dalton Trans. 1989, S1. (b) Allen,
F. H.; Kennard, O.; Watson, D. G.; Brammer, L.; Orpen, A. G.; Taylor,
R. J. Chem. Soc., Perkin Trans. 2 1987, S1.
Inorganic Chemistry, Vol. 47, No. 8, 2008 3091

Gushchin et al.
double bond in amides having the NH2-C(-Csp3)dO [mean
value 1.234(12) Å20] functionality. Intramolecular hydrogen
bonding is observed between the NH group and the O
carbonyl atom; the distance H(1)•••O(1)#1 is 1.872(18) Å.
Atoms of the metallacycle lie in one plane with the maximum
deviationof-0.041(2)ÅforN(3)intheNi(1)N(1)C(1)N(2)C(4)N(3)
plane, and the rms of the deviations for this ring is 0.041-
(3) Å.
Table 2. Crystal Data
16
[Ni{NHdC(CCl3)NC(CCl3)dNH}2]
empirical formula
fw
temp (K)
λ (Å)
cryst syst
space group
a (Å)
C
22H12F8N6NiO2
C14H16Cl12N6NiO2
603.09
120(2)
784.44
120(2)
0.71073
monoclinic
C2/m
12.8243(6)
9.4600(6)
13.3469(7)
90
115.994(3)
90
1455.42(14)
2
1.790
1.795
11635
1781
0.0432
0.0271
0.0569
0.71073
triclinic
j
P1
5.6247(5) Å
8.8801(11)
11.1999(11)
100.583(5)
102.770(6)
100.797(6)
520.92(10)
1
b (Å)
c (Å)
R (deg)
ꢀ (deg)
Final Remarks
γ (deg)
V (Å3)
The study establishes a novel type of high yielding metal-
mediated coupling, i.e., between iminoisoindolinones and
nitriles, which proceeds at a NiII center and does not require
any of “NOH” promoters. The observed reaction shed light
on the mechanism of the single-pot synthesis of unsym-
metrical (1,3,5-triazapentadienato)NiII complexes16 and sug-
gests that the latter process consists of two principal steps,
i.e., oxime-promoted generation of a iminoisoindolinone from
Pn followed by the coupling of the iminoisoindolinone and
alkylnitrile at a NiII center.
This work adds more on the synthetic routes to unsym-
metrical 1,3,5-triazapentadiene/ato complexes, which are rare
and the known cases involve species obtained previously by
us at PtII and PtIV centers (via the nitrile-amidine coupling18)
and at a NiII center (via the oxime-mediated single-pot
reaction of nitriles and phthalonitriles16). Further studies
directed toward widening the family of unsymmetrical 1,3,5-
triazapentadiene complexes to other metal centers are cur-
rently under way in our group with particular emphasis on
compounds, which cannot be achieved in the oxime-mediated
single-pot synthesis16 (e.g., of CuII, PdII, and PtII).
Z
Fcalc (Mg/m3)
µ (Mo KR) (mm-1
no. reflns.
unique reflns
Rint
1.922
1.041
9081
2377
0.0655
0.0452
0.0893
)
R1a (I g 2σ)
wR2b (I g 2σ)
a R1 ) Σ||Fo| - |Fc||/Σ|Fo|. b wR2 ) [Σ[w(Fo - Fc )2]/ Σ[w(Fo )2]]1/2
.
2
2
2
Å). The Denzo-Scalepack21 or EvalCCD22 program packages were
used for cell refinements and data reductions. The structure was
solved by direct methods using the SIR200423 or SHELXS-9724
with the WinGX25 graphical user interface. An empirical absorption
correction (SORTAV26 or SADABS27) was applied to the data.
Structural refinements were carried out using SHELXL-97.28 In
[Ni{NHdC(CCl3)NC(CCl3)dNH}2], the oxygen and the methyl
carbon atoms in the solvent of crystallization (acetone) were
disordered over two sites with equal occupancies. In 16, the NH
hydrogen atom was located from the difference Fourier map but
refined with fixed N-H ) 0.880 Å. In 16, the NH hydrogen atoms
were located from the difference Fourier map but constrained to
ride on their parent atom, with Uiso ) 1.5. Other hydrogens were
positioned geometrically and constrained to ride on their parent
atoms, with C-H ) 0.98–0.99 Å and Uiso ) 1.2–1.5Ueq (parent
atom). The crystallographic details are summarized in Table 2 and
selected bond lengths and angles in Table 3.
Synthetic Work. Reaction of Ni(OAc)2 ·4H2O, 3-Iminoiso-
indolin-1-one [or 5-Methyl-3-iminoisoindolin-1-one, or
4,5,6,7-Tetrafluoro-3-iminoisoindolin-1-one] (2 equiv), and
RCN. Nickel acetate Ni(OAc)2 ·4H2O (249 mg, 1 mmol) was added
to a flask with neat RCN (5 mL for R ) Me, Et, Prn, Pri; 2 mL for
R ) Bun, CH2Cl, CCl3, CH2Ph, CH2C6H4OMe-p), equipped with
a magnetic stirrer, and the emerald-green suspension was refluxed
(R ) Me, Et, Prn, Pri, CH2Cl, CCl3) or heated at 100 °C (R ) Bun,
CH2Ph, CH2C6H4OMe-p) for 15 min. Triethanolamine (75 mg, 0.5
mmol) was added, and the suspension was refluxed (R ) Me, Et,
Prn, Pri, CH2Cl, CCl3) or heated for an additional 20 min at 100 °C
Experimental Section
Materials and Instrumentation. Solvents, Ni(OAc)2 ·4H2O, and
all organonitriles were obtained from commercial sources and used
as received. 3-Iminoisoindolin-1-one and its substituted derivatives
were prepared in accord with a previously reported procedure.10,13
C, H, and N elemental analyses were carried out by the Microana-
lytical Service of the Instituto Superior Técnico. For TLC, Merck
UV 254 SiO2 plates have been used. FAB+ and FAB- mass spectra
were obtained on a Trio 2000 instrument by bombarding 3-ni-
trobenzyl alcohol (NBA) matrices of the samples with 8 keV (ca.
1.28 × 1015 J) Xe atoms. Mass calibration for data system
acquisition was achieved using CsI. ESI+ mass spectra were
obtained on VARIAN 500-MS LC ion trap mass spectrometer.
Infrared spectra (4000–400 cm-1) were recorded on a BIO-RAD
FTS 3000MX instrument in KBr pellets. 1D NMR experiments,
(21) Otwinowski Z.; Minor, W. Processing of X-ray Diffraction Data
Collected in Oscillation Mode. Methods in Enzymology, Macromo-
lecular Crystallography, Part A; Carter, C. W., Jr., Sweet, R. M., Eds.;
Academic Press: New York, 1997; Vol. 276, pp 307–326.
(22) Duisenberg, A. J. M.; Kroon-Batenburg, L. M. J.; Schreurs, A. M. M.
J. Appl. Crystallogr. 2003, 36, 220.
(23) Burla, M. C.; Camalli, M.; Carrozzini, B.; Cascarano, G. L.; Giaco-
vazzo, C.; Polidori, G.; Spagna, R. J. Appl. Crystallogr. 2005, 38,
381.
(24) Sheldrick, G. M. SHELXS-97, Program for Crystal Structure Deter-
mination; University of Göttingen: Göttingen, Germany, 1997.
(25) Farrugia, L. J. J. Appl. Crystallogr. 1999, 32, 837.
(26) Blessing, R. H. Acta Crystallogr., Sect. A 1995, A51, 33.
(27) Sheldrick, G. M.; SADABS-Bruker Nonius Scaling and Absorption
Correction, version 2.10; Bruker AXS, Inc.: Madison, WI, 2003.
(28) Sheldrick, G. M. SHELXL-97, Program for Crystal Structure Refine-
ment; University of Göttingen: Göttingen, Germany, 1997.
1
1
1
i.e., 1D H, 13C{1H}, 19F, and 2D H,1H-COSY, H,13C-HMQC,
1H,13C-HSQC, and 1H,13C-HMBC spectra were recorded on Bruker
Avance II 300 and 400 MHz (UltraShield Magnet) spectrometers
at ambient temperature.
X-ray Structure Determinations. The crystals of 16 and
[Ni{NHdC(CCl3)NC(CCl3)dNH}2] were immersed in cryo-oil,
mounted in a Nylon loop, and measured at a temperature of 120
K. The X-ray diffraction data were collected by means of a Nonius
KappaCCD diffractometer using Mo KR radiation (λ ) 0.710 73
3092 Inorganic Chemistry, Vol. 47, No. 8, 2008

Coupling between Iminoisoindolinones and Nitriles
Table 3. Selected Bond Lengths (Å) and Angles (deg)
7.62–7.57 (m, 4H) (Ar’s). The compound is poorly soluble in the
most common deuterated solvents, and this precluded 13C{1H}
NMR measurements.
16
[Ni{NHdC(CCl3)NC(CCl3)dNH}2]
Ni1-N1
1.846(2)
1.942(2)
1.854(2)
1.863(2)
1.299(3)
[Ni{NHdC(CH2Ph)NdC(C6H4CON)}2]·1/2H2O (8). Anal. Cal-
cd for C32H25N6NiO2.5: C, 64.89; H, 4.25; N, 14.19. Found: C,
64.91; H, 4.10; N, 14.34%. FAB+-MS, m/z: 583 [Ni{NHdC-
(CH2Ph)NdC(C6H4CON)}2]+. IR (KBr, selected bands, cm-1):
3179 (m-w), 3123 (m-w), ν(N-H); 3060 (m-w), ν(C-H from Ar);
2919 (w), ν(C-H from CH2); 1693 (s), ν(CdO); 1608 (s), ν(CdN);
Ni1-N3
N3-C3
N3-C4
1.387(3)
C3-N2
1.333(3)
C4-N2
1.295(4)
1.374(4)
1.296(4)
88.29(10)
N2-C1
1.330(3)
1.299(3)
89.43(9)
118.3(2)
C1-N1
N1-Pt1-N3
C1-N2-C3
C1-N2-C4
N1-C1-N2
N3-C3-N2
N3-C4-N2
1
1544 (s), δ(N-H); 725 (vs), 698 (s), δ(C-H from Ar). H NMR
(CDCl3, δ): 10.44 (s, br, 2H, NH), 7.89–7.86 (m), 7.79–7.75 (m),
7.61–7.58 (m), 7.53–7.49 (m) (18H, Ar’s), 3.81 (s, 4H, CH2Ph).
13C{1H} NMR (CDCl3, δ): (carbons in Ar), 45.00 (CH2Ph).
[Ni{NHdC(CH2C6H4OMe-p)NdC(C6H4CON)}2]·NtCCH2-
C6H4OMe-p·1/2H2O (9). Anal. Calcd for C43H38N7NiO5.5: C, 64.60;
H, 4.79; N, 12.26. Found: C, 64.33; H, 4.62; N, 12.24%. FAB+-
MS, m/z: 661 [Ni{NHdC(CH2C6H4OMe-p)NdC(C6H4CON)}2 +
H2O]+. IR (KBr, selected bands, cm-1): 3178 (w), 3123 (w),
ν(N-H); 3065 (w), ν(C-H from Ar); 2909 (w), 2834 (w), ν(C-H
from CH2 and/or CH3); 2249 (w), ν(CtN) from the solvated nitrile;
1690 (m-s), ν(CdO); 1616 (m-s), ν(CdN); 1548 (m), δ(N-H);
720 (vs), δ(C-H from Ar). 1H NMR (CDCl3, δ): 10.34 (s, br, 2H,
NH), 7.89–7.75 (m), 6.89–7.27 (m) (16H, Ar’s), 3.82 (s, 4H,
CH2Ph), 3.69 (s, 6H, OMe). The compound is poorly soluble in
the most common deuterated solvents, and this precluded 13C{1H}
NMR measurements.
118.9(2)
124.5(3)
128.1(2)
128.1(2)
130.9(3)
(R ) Bun, CH2Ph, CH2C6H4OMe-p) to give a bright yellowish-
green solution. Then, 3-iminoisoindolin-1-one (5-methyl-3-imi-
noisoindolin-1-one/6-methyl-3-iminoisoindolin-1-one or 4,5,6,7-
tetrafluoro-3-iminoisoindolin-1-one can also be used) (2 mmol) was
added to the solution, and the reaction mixture was refluxed for
7 h (R ) Me, Et) or 5 h (R ) Prn, Pri, CH2Cl) or left at 20–25 °C
for 2 h with a following slow heating up to 50 °C and heating for
5 h at 50 °C (R ) CCl3) or heated for 5 h at 100 °C (R ) Bun,
CH2Ph, CH2C6H4OMe-p). During heating the color of the solution
turned from bright yellowish green to dark brownish orange,
followed by the release of a bright orange precipitate. The latter
was filtered off, washed with five 5 mL portions of acetone and
two 5 mL portions of Et2O, and dried in air at 20–25 °C. Yields
ranges from 35 to 83% (Scheme 2) depending on solubilities of
the final complexes and corresponding difficulties in their isolation.
Compounds 1–4 were previously synthesized in the single-pot
synthesis;16 the authenticity of the samples was confirmed by
[Ni{NHdC(Me)NdC(C6H3(Me)CON)}2]·2MeCO2H (10). De-
spite the addition of TEA, the complex releases from the reaction
mixture as the bis-acetate, and it is anticipated that the acetic acid
derives from a metal-mediated hydrolysis of MeCN. Complex 10
was isolated from the reaction mixture in 35% yield, while
evaporation of the filtrate to dryness, followed by washing of the
latter with cold acetone (5 mL, 10 °C), allows the isolation of
additional amount of 10 (ca. 20%), which was treated in an identical
way. In the presence of higher quantities of TEA (up to 2 mmol)
the reactions becomes not selective and 10 is isolated in lower yields
along with other yet unidentified products. Total yield is 55%. Anal.
Calcd for C26H28N6NiO6: C, 53.91; H, 4.87; N, 14.51. Found: C,
54.14; H, 4.77; N, 14.57%. FAB+-MS, m/z: 459 [Ni{NHdC-
(Me)NdC(C6H3(Me)CON)}2]+. IR (KBr, selected bands, cm-1):
3174 (m-w), 3138 (m-w), ν(N-H); 2922 (m-w), 2860 (m-w),
ν(C-H from Me and/or CH3CO2H); 1701 (vs), ν(CdO); 1631 (s),
1
elemental analyses, IR, H, and 13C{1H} NMR spectroscopies.
[Ni{NHdC(Bun)NdC(C6H4CON)}2] (5). Anal. Calcd for
C26H28N6NiO2: C, 60.61; H, 5.48; N, 16.31. Found: C, 60.79; H,
5.28; N, 15.83%. FAB+-MS, m/z: 515 [M]+. IR (KBr, selected
bands, cm-1): 3181 (m-w), 3128 (m-w), ν (N-H); 3086 (m-w), ν
(C-H from Ar); 2958 (m-w), 2927 (m-w), 2859 (m-w), ν(C-H
from Bu); 1690 (m-s), ν(CdO); 1622 (s), ν(CdN); 1553 (s),
1
δ(N-H); 723 (s), δ(C-H from Ar). H NMR (CDCl3, δ): 10.49
(s, br, 2H, NH), 7.82 (br, 2H), 7.65 (d, 6 Hz, 2H), 7.52 (q, 6 Hz,
4H) (Ar’s), 2.54 (t, 7.2 Hz, 4H), 1.69 (q, 7.2 Hz, 4H), 1.39 (sec,
7.2 Hz, 4H) (CH2 from Bu), 0.95 (t, 7.2 Hz, 6H, CH3 from Bu).
13C{1H} NMR (CDCl3, δ): 184.5 (CdO), 172.0, 166.4 (CdN),
138.6, 134.3, 132.8, 131.6, 122.3, 121.6 (carbons in Ar), 40.3 (R-
CH2), 28.4 (ꢀ-CH2), 22.2 (γ-CH2), 13.8 (CH3) (Bu).
[Ni{NHdC(CH2Cl)NdC(C6H4CON)}2] (6). Anal. Calcd for
C20H14N6Cl2NiO2: C, 48.05; H, 2.82; N, 16.81. Found: C, 47.48;
H, 2.71; N, 16.41%. FAB+-MS, m/z: 499 [M - H]+. IR (KBr,
selected bands, cm-1): 3151 (w), 3090 (m-w), ν(N-H); 3043 (m-
w), ν(C-H from Ar); 2975 (w), 2928 (w), ν(C-H from CH2); 1705
(s), ν(CdO); 1627 (s), ν(CdN); 1556 (s), δ(N-H); 721 (vs),
δ(C-H from Ar). 1H NMR (CDCl3, δ): 7.83–7.45 (m, 10H, Ar’s),
4.30 (s, 4H, CH2Cl). The compound is poorly soluble in the most
common deuterated solvents, and this precluded 13C{1H} NMR
measurements.
[Ni{NHdC(CCl3)NdC(C6H4CON)}2] (7). Anal. Calcd for
C20H10N6Cl6NiO2: C, 37.67; H, 1.58; N, 13.18. Found: C, 37.49;
H, 1.66; N, 12.90%. FAB+-MS, m/z: 637 [M]+. IR (KBr, selected
bands, cm-1): 3139 (w), 3048 (w), 3003 (w), ν(N-H and/or C-H
from Ar); 1708 (m-s), ν(CdO); 1605 (m-s), ν(CdN); 1549 (m-s),
δ(N-H); 723 (m-s), δ(C-H from Ar). 1H NMR (CDCl3, δ): 11.09
(s, br, 2H, NH), 7.92 (d, 1H), 7.90 (d, 1H), 7.73–7.70 (m, 2H),
1
ν(CdN); 1554 (s), δ(N-H); 741 (s), δ(C-H from Ar). H NMR
(CDCl3, δ): 10.67 (s, br, 2H, NH), 7.66 (d, 7.5 Hz), 7.60 (s), 7.51
(d, 7.5 Hz), 7.43 (s), 7.32 (d, 7.5 Hz), 7.30 (d, 7.5 Hz) (6H, Ar’s),
2.45 (s), 2.43 (s) (6H, Me), 2.32 (s), 2.31 (s) (6H, HNdCMe), 1.26
(s, 6H, CH3CO2H). 13C{1H} NMR (CDCl3, δ): 185.1, 185.0 (CdO),
168.6, 168.5, 166.7 (CdN), 143.9, 142.5, 138.8, 135.9, 134.7, 133.5,
132.3, 131.8, 122.9, 122.4, 122.0, 121.3 (carbons in Ar), 29.7
(CH3CO2H), 27.1 (HNdCCH3), 21.8, 21.7 (CH3).
[Ni{NHdC(Et)NdC(C6H3(Me)CON)}2] (11). Anal. Calcd for
C24H24N6NiO2: C, 59.17; H, 4.96; N, 17.25. Found: C, 58.62; H, 4.68;
N, 17.23%. FAB+-MS, m/z: 487 [M]+. IR (KBr, selected bands, cm-1):
3174 (m), 3127 (m), ν(N-H); 3068 (m-w), ν(C-H from Ar); 2975
(m-w), 2922 (m-w), ν(C-H from CH2 and/or CH3); 1695 (s), ν(CdO);
1615 (s), ν(CdN); 1554 (s), δ(N-H); 741 (s), δ(C-H from Ar). 1H
NMR (CDCl3, δ): 10.45 (s, br, 2H, NH), 7.67 (d, 7.5 Hz, 2H), 7.60
(s, 2H), 7.51 (d, 7.5 Hz, 2H), 7.44 (s, 2H), 7.30 (d + s, 4H) (Ar’s),
2.57 (q, 7.5 Hz, 4H, CH2 from Et), 2.44 (s, 3H), 2.42 (s, 3H) (Me),
1.27 (t, 7.5 Hz, 3H), 1.26 (t, 7.5 Hz, 3H) (CH3 from Et). 13C{1H}
NMR (CDCl3, δ): 184.6, 184.5 (CdO), 172.9, 172.8, 166.5, 166.4
Inorganic Chemistry, Vol. 47, No. 8, 2008 3093

Gushchin et al.
(CdN), 143.8, 142.4, 139.0, 136.1, 134.7, 133.4, 132.2, 131.8, 122.9,
122.2, 122.0, 121.4 (carbons in Ar), 33.7 (CH2), 21.8, 21.7 (CH3),
10.8, 10.7 (CH3 from Et).
selected bands, cm-1): 3172 (m-w), 3123 (m-w), ν(N-H); 3060
(m-w), 3028 (m-w), ν(C-H from Ar); 2921 (w), ν(C-H from CH2
and/or Me); 1689 (s), ν(CdO); 1612 (s), ν(CdN); 1553 (s),
1
[Ni{NHdC(Prn)NdC(C6H3(Me)CON)}2] (12). Anal. Calcd for
C26H28N6NiO2: C, 60.61; H, 5.48; N, 16.31. Found: C, 60.41; H,
5.25; N, 16.30%. FAB+-MS, m/z: 515 [M]+. IR (KBr, selected
bands, cm-1): 3177 (m-w), 3128 (m-w), ν(N-H); 2959 (m-w), 2928
(m-w), 2871 (m-w), ν(C-H from CH2 and/or CH3); 1693 (s),
ν(CdO); 1616 (s), ν(CdN); 1548 (s), δ(N-H); 746 (m-s), δ(C-H
δ(N-H); 725 (s), 698 (m), δ(C-H from Ar). H NMR (CDCl3,
δ): 10.43 (s, br, 2H, NH), 7.64 (d, 7.5 Hz), 7.57 (s), 7.47 (d, 7.5
Hz), 7.39–7.28 (m) (16H, Ar’s), 3.81 (s, 4H, CH2Ph), 2.46 (s), 2.43
(s) (6H, Me). 13C{1H} NMR (CDCl3, δ): 184.0 (CdO), 170.3, 167.4
(CdN), 144.1, 142.8, 135.7, 135.1, 131.4, 129.4, 128.7, 127.1, 122.3
(carbons in Ar), 46.6 (CH2Ph), 21.8, 21.6 (Me).
[Ni{NHdC(Et)NdC(C6F4CON)}2] (16). Anal. Calcd for
C22H12N6F8NiO2: C, 43.82; H, 2.01; N, 13.94. Found: C, 43.75; H,
2.17; N, 13.66%. ESI+-MS, m/z: 611 [M + Li + 2H]+. IR (KBr,
selected bands, cm-1): 3192 (m-w), 3143 (m-w), ν(N-H); 2981
(m-w), 2932 (m-w), ν(C-H from CH2 and/or CH3); 1710 (s),
ν(CdO); 1618 (s), ν(CdN); 1559 (s), δ(N-H). 1H NMR (CDCl3,
δ): 10.16 (s, br, 2H, NH), 2.58 (q, 7.5 Hz, 4H, CH2), 0.89 (t, 7.5
Hz, 6H, CH3) (Et). The compound is poorly soluble in the most
common deuterated solvents, and this precluded 13C{1H} NMR
measurements. 19F NMR (CDCl3, δ): -137.1 (t, JF-F ) 21 Hz),
-139.9 (t, JF-F ) 20.2 Hz), -145.3 (t, JF-F ) 14.5 Hz), -147.2
(t, JF-F ) 21.8 Hz).
1
from Ar). H NMR (CDCl3, δ): 10.34 (s, br, 2H, NH), 7.49 (d, 8
Hz), 7.43 (s), 7.34 (d, 8 Hz), 7.27 (s), 7.15–7.09 (m) (6H, Ar’s),
2.33 (t, 7.3 Hz, 4H, NtCCH2 from Prn), 2.27 (s), 2.25 (s) (6H,
Me), 1.58 (sec, 7.3 Hz, 4H, NtCCH2CH2 from Prn), 0.82 (t, 7.3
Hz, 6H) (CH3 from Prn). 13C{1H} NMR (CDCl3, δ): 184.8, 184.7
(CdO), 171.8, 171.7, 166.5, 166.4 (CdN), 143.8, 142.4, 139.0,
136.1, 134.8, 133.4, 132.2, 131.8, 122.9, 122.2, 122.0, 121.4
(carbons in Ar), 42.6 (NtCCH2 from Prn), 21.8, 21.7 (CH3), 19.8
(NtCCH2CH2 from Prn), 13.6 (CH3 from Prn).
[Ni{NHdC(Pri)NdC(C6H3(Me)CON)}2] (13). Anal. Calcd for
C26H28N6NiO2: C, 60.61; H, 5.48; N, 16.31. Found: C, 60.08; H,
5.24; N, 16.31%. FAB+-MS, m/z: 515 [M]+. IR (KBr, selected
bands, cm-1): 3176 (m-w), 3128 (m-w), ν(N-H); 2969 (m-w), 2922
(m-w), 2867 (m-w), ν(C-H from CH and/or CH3); 1694 (s),
ν(CdO); 1615 (s), ν(CdN); 1553 (s), δ(N-H); 762 (vs), 723 (s),
[Ni{NHdC(CCl3)NdC(C6F4CON)}2]·11/2H2O (17). Anal. Cal-
cd for C20H5N6Cl6F8NiO3: C, 29.70; H, 0.62; N, 10.39. Found: C,
29.97; H, 0.76; N, 9.78%. ESI+-MS, m/z: 777 [Ni{NHd
C(CCl3)NdC(C6F4CON)}2 - F + H2O]+. IR (KBr, selected bands,
cm-1): 1721 (s), ν(CdO); 1608 (s), ν(CdN); 1563 (s), δ(N-H).
1H NMR (CDCl3, δ): 11.12 (s, br, 2H, NH). The compound is
poorly soluble in the most common deuterated solvents, and this
precluded 13C{1H} NMR measurements. 19F NMR (CDCl3, δ):
-137.5 (t, JF-F ) 20.2 Hz), -140.1 (t, JF-F ) 20.2 Hz), -144.3
(t, JF-F ) 14.1 Hz), -148.2 (t, JF-F ) 22.0 Hz).
1
δ(C-H from Ar). H NMR (CDCl3, δ): 10.31 (s, br, 2H, NH),
7.69 (d, br), 7.63 (s), 7.53 (d, 7.5 Hz), 7.46 (s), 7.31 (t, 7.5 Hz)
(6H, Ar’s), 2.76 (sep, 6.9 Hz) (2H, CHMe2), 2.46 (s), 2.43 (s) (6H,
Me), 1.25 (d, 6.9 Hz), 1.23 (d, 6.9 Hz) (12H, CHMe2). 13C{1H}
NMR (CDCl3, δ): 184.5 (CdO), 176.4, 166.7 (CdN), 143.9, 142.5,
139.3, 136.4, 134.9, 133.5, 132.4, 132.0, 123.0, 122.4, 122.2, 121.6
(carbons in Ar), 39.2 (NtCCH from Pri), 22.0, 21.9 (CH3), 20.3
(NtCCH(CH3)2 from Pri).
Acknowledgment. This work has been partially supported
by the Fundação para a Ciência e a Tecnologia (FCT),
Portugal, and its POCI 2010 program (FEDER funded).
P.V.G. thanks Complexo I, Instituto Superior Técnico, for
an Initiation Grant, K.V.L. expresses gratitude to FCT and
the POCI program (FEDER funded), Portugal, for a fellow-
ship (grant SFRH/BPD/27094/2006), and V.Y.K. is grateful
to the FCT (Cientista Convidado/Professor at the Instituto
Superior Técnico, Portugal). This work has also been
supported by the Russian Fund for Basic Research (grants
06-03-32065 and 06-03-90901) and the Academy of Finland
(grant 110465).
[Ni{NHdC(CCl3)NdC(C6H3(Me)CON)}2] (14). Anal. Calcd
for C22H14N6Cl6NiO2: C, 39.69; H, 2.12; N, 12.62. Found: C, 39.32;
H, 1.91; N, 12.38%. ESI+-MS, m/z: 667 [M + H]+. IR (KBr,
selected bands, cm-1): 3139 (m-w), 3059 (m-w), 3006 (m-w),
ν(N-H and/or C-H from Ar); 2941 (m-w), 2831 (m-w), ν(C-H
from Me); 1705 (s), ν(CdO); 1611 (s), ν(CdN); 1558 (m),
δ(N-H); 743 (m-s), δ(C-H from Ar). 1H NMR (CDCl3, δ): 11.05
(s, br, 2H, NH), 7.77 (d, 7.6 Hz), 7.69 (s), 7.61 (d, 7.6 Hz), 7.58
(d, 7.6 Hz), 7.53 (s), 7.51 (s), 7.37 (t, 8.5 Hz) (6H, Ar’s), 2.49 (s),
2.45 (s) (6H, Me). 13C{1H} NMR (CDCl3, δ): 182.3 (CdO), 171.2,
167.6 (CdN), 143.1, 142.9, 136.7, 135.0, 131.0, 130.1, 128.6, 123.5
(carbons in Ar), 56.8 (CCl3), 22.9, 21.8 (Me). The filtrate after
performing the synthesis was a subject of slow evaporation in air
at 20–25 °C to give crystals of the symmetrical byproduct, i.e.
[Ni{NHdC(CCl3)NC(CCl3)dNH}2], which is formed upon the
known nucleophile-mediated coupling.7 The latter compound has
been characterized by X-ray crystallography and also by IR and
1H and 13C{1H} NMR spectroscopies (see Supporting Information).
[Ni{NHdC(CH2Ph)NdC(C6H3(Me)CON)}2] (15). Anal. Calcd
for C34H28N6NiO2: C, 66.80; H, 4.62; N, 13.75. Found: C, 66.04;
H, 4.46; N, 13.70%. FAB+-MS, m/z: 613 [M + 2H]+. IR (KBr,
Supporting Information Available: High-field region of the
1H,13C-HSQC spectrum of complex 11 (Figure S1), molecular
structure of [Ni{NHdC(CCl3)NC(CCl3)dNH}2] (Figure S2), and
its IR and NMR data; crystallographic data in CIF format for
complexes 16 and [Ni{NHdC(CCl3)NC(CCl3)dNH}2]. This mate-
rial is available free of charge via the Internet at http://pubs.acs.org.
IC702131K
3094 Inorganic Chemistry, Vol. 47, No. 8, 2008