Syntheses and Structures of a Series of Acyclic Diaminocarbene Palladium(II) Complexes Derived from 3,4-Diaryl-1 H-pyrrol-2,5-diimines and Bisisocyanide Palladium(II) Complexes

Article abstract of DOI:10.1021/acs.organomet.8b00725

Reactions of 3,4-diaryl-1H-pyrrol-2,5-diimines with various bisisocyanide palladium(II) complexes were studied. The coupling proceeds with one isocyanide ligand to accomplish the acyclic diaminocarbene complexes. The structure of generated diaminocarbene

Full text of DOI:10.1021/acs.organomet.8b00725

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Cite This: Organometallics XXXX, XXX, XXX−XXX
Syntheses and Structures of a Series of Acyclic Diaminocarbene
Palladium(II) Complexes Derived from 3,4-Diaryl‑1H‑pyrrol-2,5-
diimines and Bisisocyanide Palladium(II) Complexes
Dina V. Boyarskaya,† Evgeny Bulatov,*,‡ Irina A. Boyarskaya,† Tatiana G. Chulkova,*,†
Valentin A. Rassadin,† Elena G. Tolstopjatova,† Ilya E. Kolesnikov,† Margarita S. Avdontceva,†
Taras L. Panikorovskii,† Vitalii V. Suslonov,† and Matti Haukka‡
†Saint Petersburg State University, Institute of Chemistry, 7/9 Universitetskaya Nab., Saint Petersburg, 199034 Russia
‡
̈
̈
̈
̈
Department of Chemistry, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyvaskyla, Finland
S
* Supporting Information
ABSTRACT: Reactions of 3,4-diaryl-1H-pyrrol-2,5-diimines with various bisiso-
cyanide palladium(II) complexes were studied. The coupling proceeds with one
isocyanide ligand to accomplish the acyclic diaminocarbene complexes. The
structure of generated diaminocarbene complexes depends on bulkiness of
isocyanide ligand in the bisisocyanide complexes of palladium(II). The imino-
group of 3,4-diaryl-1H-pyrrol-2,5-diimine reacts with one isocyanide ligand of cis-
[PdCl2(CN−R)2] (R = i-Pr, Cy, t-Bu, Bn), and the nitrogen atom of the pyrrole ring
is coordinated to the palladium center as the second isocyanide ligand remains
intact. In the case of cis-[PdCl2(CN−R)2] (R = 2-acyloxyphenyl, 2-sulfonylox-
yphenyl), one isocyanide ligand is displaced from the coordination sphere. Structural
features of the prepared diaminocarbene complexes have been studied by molecular
spectroscopy techniques, cyclic voltammetry, single-crystal X-ray diffraction, and
DFT calculations. The photophysical properties of the obtained acyclic
diaminocarbene complexes in solution mainly depend on the substituents in the
3,4-diaryl-1H-pyrrol-2,5-diimine moiety.
Scheme 1. Tautomeric Forms of 3,4-Diaryl-1H-pyrrol-2,5-
diimines
INTRODUCTION
■
The addition of N-nucleophiles to coordinated isocyanides is a
facile synthetic pathway to acyclic diaminocarbene palladium-
(II) complexes, which attract attention as efficient catalysts and
luminescent and bioactive compounds.1,2 The metal center in
this reaction not only activates the coordinated isonitriles
toward the nucleophilic attack but also stabilizes acyclic
diaminocarbenes (ADCs), which are unstable in free form.
While sp3-N-nucleophiles have been known to react in this
fashion already for half a century,3,4 exploration of reactivity of
sp2-N-nucleophiles toward coordinated isocyanides has been
initiated a decade ago.5,6 It is shown that the use of
polynucleophiles leads to the formation of chelating ligands
containing carbene moieties.6−10
The present work studies the reactions of polynucleophiles,
namely, 3,4-diaryl-1H-pyrrol-2,5-diimines, with bisisocyanide
palladium(II) complexes. It is well-known that imino and
pyrrole nitrogen atoms in 3,4-diaryl-1H-pyrrol-2,5-diimines
possess as nucleophilic centers. Moreover, based on computa-
tional studies, the equilibrium between imino and enamino
forms is possible in solution (Scheme 1).11,12 Therefore, these
molecules may potentially react with isocyanide palladium(II)
complexes in various modes. We reported a full study related
to regioselectivity of the nucleophilic addition reaction, as well
as the influence of steric and electronic effects of substituents
in the nucleophiles and coordinated isocyanides on the
structures and photophysical properties of diaminocarbene
products.
RESULTS AND DISCUSSION
■
Synthesis and Characterization of Complexes 4−6
and 11−13. 3,4-Diaryl-1H-pyrrol-2,5-diimines (aryl = phenyl
(1a), 4-methylphenyl (1b), 4-methoxyphenyl (1c)) were
synthesized from the appropriate arylacetonitriles according
to the previously published method.12−14
Commercially available isocyanides RNC (R = isopropyl
(2a), tert-butyl (2b), cyclohexyl (2c), benzyl (2d)) as well as
isocyanides obtained in our research group (R = 2-(tert-
b u t y l c a r b o n y l o x y ) p h e n y l ( 2 e ) , 2 -
Received: October 7, 2018
© XXXX American Chemical Society
A
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Scheme 2. Syntheses of Arylisocyanides 2e−j
Scheme 3. Reactions of 3,4-Diaryl-1H-pyrrol-2,5-diimines 1a−c and cis-[PdCl2(CN−R)2] 3a−j
(diphenylmethylcarbonyloxy)phenyl (2f), 2-(4-
cyanophenylcarbonyloxy)phenyl (2g), 2-(tert-butylcarbony-
loxy)-5-methylphenyl (2h), 2-(diphenylmethylcarbonyloxy)-
5-methylphenyl (2i))15−17 (Scheme 2) were used. In addition
to 2-isocyanophenyl esters of carboxylic acids (2e−i), 2-
isocyano-4-methylphenyl ester of p-toluenesulfonic acid (2j)
was prepared using the same synthetic approach. This is the
first example of the synthesis of 2-isocyanophenyl ethers of
sulfonic acids by this method.
The bisisocyanide palladium(II) complexes cis-[PdCl2(CN−
R)2] (R = isopropyl (3a), tert-butyl (3b), cyclohexyl (3c),
benzyl (3d), 2-(tert-butylcarbonyloxy)phenyl (3e), 2-
(diphenylmethylcarbonyloxy)phenyl (3f), 2-(4-
cyanophenylcarbonyloxy)phenyl (3g), 2-(tert-butylcarbony-
loxy)-5-methylphenyl (3h), 2-(diphenylmethylcarbonyloxy)-
5-methylphenyl (3i), 5-methyl-2-(4-methylphenylsulfonyloxy)-
phenyl (3j)) were prepared from isocyanides RNC 2a−j and
[PdCl2(CH3CN)2] by the ligand exchange reaction.4
complexes 4−6 were formed (Route A, Scheme 3). During the
reaction, one isocyanide ligand in 3a−d undergoes a
nucleophilic attack by the imino group of 1a−c, whereas the
second remains intact. The imino nitrogen atom of 1 is
attached to the carbon atom of the isocyanide group, whereas
the nitrogen atom of the pyrrole ring coordinates to the metal
center, thus closing the five-membered palladocycle. Mono-
carbene complexes were obtained as a result.
According to the previously reported DFT calculations,12
the natural charges on the nitrogen atom of the pyrrole ring
and on the nitrogen atom of the imino group in 1a−c are
−0.66 and −0.75, respectively, indicating that the sp2-
hybridized nitrogen atom of the imino group in 1a−c is
more nucleophilic than the pyrrole nitrogen atom. The
observed reaction products are in agreement with these
computations, since the coordinated isocyanides react
selectively with the imino group. It is assumed that the
reaction starts by attack of the nitrogen atom of the imino
group to the carbon atom of the isocyanide group followed by
the deprotonation and coordination of the pyrrole nitrogen
When a solution of bisisocyanide complex 3a−d and 3,4-
diaryl-1H-pyrrol-2,5-diimine 1a−c in dichloromethane was
stirred at room temperature for 2 h, chelate diaminocarbene
B
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Figure 1. Molecular structure of 4c·CH2Cl2.
atom to the palladium center accompanied by the ring closure
to give five-membered palladocycle.
1
According to the H NMR data, in some cases, along with
the main products the side products have been observed. The
reactions of 3a with 1a−c gave main products 4a−6a together
with minor side products 7a−9a (Scheme 3). In 7a−9a, the
two palladium atoms are connected through a bridging
chloride ligand and one of the 1H-pyrrol-2,5-diimine moieties.
Another binuclear byproduct 10c (Scheme 3) was detected in
the reaction between 1b and 3c. In 10c, the two palladium
centers are linked together via the CN group resulting from the
dissociation of the tert-butyl isocyanide ligand.
Single-crystal X-ray diffraction analyses were performed on
complexes 4c, 9a, and 10c after recrystallization from
dichloromethane at room temperature.
4c·CH2Cl2 is crystallized in the triclinic space group P1
̅
(Figure 1). The palladium center is coordinated by the
chelating diaminocarbene, tert-butyl isocyanide, and chloride
ligands with a distorted square-planar geometry around the
palladium center (the C6−Pd1−N1 angle in the five
membered palladocycle is 77.86(5)°). The C6−N3 and C6−
N4 bond lengths (1.302(2) and 1.396(2) Å, respectively) are
not equal and are between the typical lengths for double (1.27
Å) and single (1.47 Å) carbon−nitrogen bonds.18 The Pd1−
C6 bond length (1.985(1) Å) is on the region of the lower
boundary of the standard lengths interval of the single Pd−C
bonds (1.98−2.13 Å),19 which indicates an insignificant
contribution of the back π-donation of electrons from the
palladium atom to the carbene carbon atom. This is explained
by the population of the C6 carbon atom pπ-orbital by
electrons from the N3 and N4 atoms. The structure possesses
the intramolecular (N5)HN···Cl1 hydrogen bond (2.51(2) Å).
The structure of 4c optimized using DFT calculations is in
agreement with the experimental XRD data (see the
Supporting Information).
Figure 2. Molecular structure of 9a.
P21/c. The Pd1 and Pd2 centers have distorted square planar
geometry. The N1−Pd1−C19 and N1′−Pd2−C19′ angles are
79.8(5) and 77.5(4)°, respectively. The two palladium centers
are linked together by the 3,4-di(4-methoxyphenyl)-1H-pyrrol-
The structure of binuclear complex 9a is shown in Figure 2.
The compound is crystallized in the monoclinic space group
C
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Figure 3. Molecular structure of 10c·H2O·0.5CH2Cl2.
2,5-diimine fragment and the bridging chloride ligand. The
structure possesses the intramolecular N4···H4′A (2.27(2) Å),
Cl2···H3 (2.50(2) Å), and Cl1···H3′ (2.50(2) Å) hydrogen
bonds.
10c·H2O·0.5CH2Cl2 crystallizes in the monoclinic P21/c
space group (Figure 3). The palladium centers exhibit the
distorted square planar geometry. The Pd1 and Pd2 atoms are
linked together via the CN group. The intramolecular Cl1···
H(N1) and Cl2···H(N8) hydrogen bonds are 2.42(2) and
2.48(2) Å, respectively. The water molecule is linked to
complex 10c via two hydrogen bonds (Cl1···H(O1) (2.44(2)
Å) and Cl2···H(O1) (2.41(2) Å)).
In contrast to the aforementioned reactions of 1a−c with
3a−d, the reactions with 3e−j containing the bulky isocyanide
ligands proceed via route B (Scheme 3) and afford 11−13.
One of the isocyanide ligands in 3e−j undergoes nucleophilic
attack of the imino group of 1a−c, whereas the second
isocyanide ligand leaves the metal coordination sphere. As the
result, in the structures of 11−13, the palladium center is
bonded by one chelating diaminocarbene ligand and two
chloride ligands.
The solid-state structure of 11j was determined by X-ray
crystallography (Figure 4). 11j crystallizes from acetonitrile as
a monosolvate in the monoclinic space group P21/c. The
palladium center exhibits a distorted square planar geometry,
with N1−Pd1−C17 angle of 77.9°. The value of Pd1−C17
bond length (1.958(2) Å) is shorter than the Pd−C bond
length in 4c (1.985(1) Å). As in 4c, the C17−N3 bond
(1.318(3) Å) is shorter than the C17−N2 bond (1.385(3) Å).
The Pd1−Cl1 bond length (2.4008(6) Å) is larger than the
Pd1−Cl2 bond length (2.3187(6) Å), which can be attributed
to strong trans influence of the diaminocarbene ligand.20 In the
crystal structure of 11j, intramolecular (Cl1···H4A (2.379(3)
Å) and Cl2···H3 (2.413(3) Å)) hydrogen bonds are observed.
The bond lengths and angles in the optimized structure of 11j
are comparable with the XRD data. (see the Supporting
Information).
Figure 4. Molecular structure of 11j·CH3CN.
complexes 3e−j, reaction route B becomes more favorable
owing to the increased bulkiness of o-acyloxyphenyl sub-
stituents.
Optical Spectroscopy and Computational Studies.
The absorption and fluorescence properties of the synthesized
compounds 4−6 and 11−13 were evaluated by UV−vis
absorption and emission spectroscopies at a concentration of
5·10−5 M in chloroform (Table 1).
In order to identify the electronic transitions responsible for
the absorption bands, TD−DFT studies of compounds 4c, 11j,
and 12e were undertaken (see Figure S55 and Tables S9−
S11). The comparison of the calculated spectra with the
experimental ones showed better match with the deprotonated
forms [4c−HCl], [11j−H]−, and [12e−H]− (see Figure S55).
This confirms that the hydrogen of the iminium group has a
high acidity in the solution. The absorption spectra of 4−6
display an intense absorption band in the range of 345−380
nm (see Figure S40). A significant redshift in comparison with
the absorption spectra of 1a−c (λabs at 278−311 nm)12 can be
explained by the extended π-conjugation due to the formation
of the diaminocarbene moiety. The presence of the donor
substituents at the phenyl rings of the 1H-pyrrol-2,5-diimine
fragment leads to the redshift of the absorption band like in
Thus, the reaction of 1 and 3 depends on the bulkiness of
the isocyanide ligands. The relatively small size of R in 3a−d
favors reaction route A, allowing the formation of 4−6. For
D
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fragment generally cause red shift of the fluorescence emission
bands. Fluorescence lifetimes and quantum yields were
measured for 4−6b, 12e, and 12j. The fluorescence lifetimes
are in the range 8.6−19.8 ns. All tested compounds with the
exception of 6b possess low luminescence. The fluorescence
quantum yields for 4b, 5b, 12e, and 12j vary in the range of 1−
4%. A relatively high quantum yield (Φf = 27%) is observed for
compound 6b bearing the electron-donating methoxy groups
in the 3,4-diaryl-1H-pyrrol-2,5-diimine fragment.
Electrochemical Reduction. The electrochemical behav-
iors of complexes 4a, 5a, 5b, and 11e were analyzed by cyclic
voltammetry in acetonitrile at different scan rates from 0.1 to 1
V·s−1. At the cathodic scan, all compounds exhibit irreversible
electrochemical response with well-defined reduction peaks
(see Figure S42 and Table S1). The products of the
electrochemical reduction (palladium(0) complexes) are
electrooxidizable, producing a small anodic wave (Ep from
0.2 to 0.43 V) during the subsequent anodic scan.
Table 1. Absorption and Emission Properties of 4−6 and
11−13 in Chloroform Solution (c = 5 × 10−5 M)
compd λabs (nm) ε·× 10−4 (M−1 cm−1
)
λem (nm) Stokes shift (nm)
4a
4b
4c
5a
5b
5c
5d
6a
350
355
359
362
366
370
361
397
381
388
378
385
370
360
398
400
394
397
401
377
410
404
413
415
400
420
407
2.0
1.8
1.4
1.6
1.5
1.4
1.7
0.9
1.0
1.5
1.4
1.2
1.2
0.9
1.1
1.2
1.2
1.6
1.5
1.4
1.3
1.5
1.4
1.1
1.3
1.9
1.5
468
502
491
516
480
515
496
510
551
555
494
494
495
496
492
438
515
521
530
512
517
450
550
554
553
553
560
118
147
132
154
114
145
135
113
170
167
116
109
125
136
94
6b
6c
11e
11f
11g
11h
11i
11j
12e
12f
12g
12h
12i
12j
13e
13f
13h
13i
13j
38
CONCLUSION
■
121
124
129
135
107
46
137
139
153
133
153
The presence of steric hindrance triggers different pathways in
the reactions of 3,4-diaryl-1H-pyrrol-2,5-diimines with cis-
[PdCl2(CN−R)2]. In particular, the steric effect of isocyanide
ligands is an important factor inducing the formation of the
expected (4−6) and unexpected (11−13) products. The
reaction of 3,4-diaryl-1H-pyrrol-2,5-diimines and
[PdCl2(CNR)2], where R = i-Pr, Cy, t-Bu, Bn, leads to the
formation of complexes 4−6. In the case of bisisocyanide
complexes with the bulky isocyanide ligands, such as 2-
acyloxyphenyl isocyanides and 2-tosyloxyphenyl isocyanides,
one isocyanide ligand leaves the metal coordination sphere; as
a result, compounds 11−13 were formed. The insertion of
donor substituents into pyrrole ring leads to the red shift of the
absorption band in the UV−vis spectra. TD-DFT calculations
allowed the assignment of the absorption bands in the visible
region as predominantly intraligand transitions with a small
metal-to-ligand charge transfer contribution.
1a−c.12 In general, the greater the electron-donating ability of
a substituent toward the conjugated backbone, the more
effective the conjugation and intramolecular charge transfer.
For [4c−HCl], the important one-electron transitions are from
HOMO to LUMO (f = 0.063) and from HOMO−3 to
LUMO (f = 0.20) (see Table S9). The schematic
representations of the molecular orbitals for [4c−HCl], and
their energies were exhibited in Table S4.
EXPERIMENTAL SECTION
■
General Considerations. All solvents were dried and purified by
conventional methods and were freshly distilled under argon shortly
before use. Other reagents were used without further purification.
FTIR spectra were recorded on Shimadzu FTIR-8400S (4000−400
cm−1) and IRAffinity-1S (4000−300 cm−1) spectrometers using KBr
Compounds 11−13 showed the maximum absorbance at
larger wavelengths (λabs at 360−420 nm) (see Figure S41)
compared to those of 1a−c (λabs at 278−311 nm).12 These
bands have a more complex structure, being broader and
having shoulders, which may be due to the participation of the
conjugated 2-acyloxyphenyl and 2-sulfonyloxyphenyl frag-
ments in electronic π−π* transitions. As in the case of 4−6,
the peak maxima of the compounds with the donor
substituents at the phenyl rings of the 1H-pyrrol-2,5-diimine
fragment are obviously red-shifted. Both groups of complexes
(4−6 and 11−13) possess weak absorption in the visible range
(at ca. 500 nm for 4−6 and ca. 550 nm for 11−13), which can
be tentatively attributed to forbidden transitions involving
metal d-orbitals. For [11j−H]−, the important one-electron
transitions are from HOMO−5 (f = 0.20) and HOMO−7 (f =
0.10) to LUMO (see Table S10). For [12e−H]−, the one-
electron transitions with the largest oscillator strength are from
HOMO−5 (f = 0.18 and 0.15) and HOMO−7 (f = 0.052) to
LUMO (see Table S11). Also, the schematic representations of
the molecular orbitals are exhibited in Tables S6 and S8.
Complexes 4−6 and 11−13 exhibit fluorescence in the
visible range of 468−560 nm (Table 1). Similar to absorption,
donor substituents at the phenyl rings of the pyrroldiimine
1
pellets. H NMR measurements were performed on a Bruker-DPX
400 instrument at ambient temperature. Electrospray ionization mass
spectra were obtained on a Bruker micrOTOF spectrometer equipped
with electrospray ionization (ESI) source using MeOH as the solvent.
The instrument was operated in both positive and negative ion modes
using a m/z range of 50−3000. The capillary voltage of the ion source
was set at −4500 V (ESI+−MS) or 3500 V (ESI−−MS) and the
capillary exit at (70−150) V. The nebulizer gas flow was 0.4 bar and
drying gas flow 4.0 L/min. The absorption spectra were recorded on a
Perkin−Elmer precision spectrophotometer Lambda 1050. The
emission spectra, excitation spectra, and measurements of the
lifetimes of excited states were measured on a modular spectro-
fluorimeter Fluorolog-3 (Horiba Jobin Yvon). Fluorescence lifetime
measurements are based on time-correlated single photon counting
(TCSPC). Device also includes an integrating sphere Quanta-φ with
fiber optics which enables direct measurement of quantum yields of
luminescence. Cyclic voltammetry experiments were performed in
acetonitrile at room temperature under argon, in a three-electrode cell
using an Autolab potentiostat (PGSTAT 20). Tetrabutylammonium
tetrafluoroborate (TBABF4) used as the supporting electrolyte for the
electrochemical investigations was prepared from NaBF4 (Acros), and
E
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n-Bu4NHSO4 (Acros), recrystallized from ethyl acetate−hexane (both
from Acros), and dried at 60 °C. The reference electrode was a
saturated calomel electrode (SCE-Tacussel), which was separated
from the solution by a bridge compartment filled with the same
solvent/supporting electrolyte (TBABF4) solution (0.1 M) as in the
cell. The counterelectrode was a 1 cm length platinum wire
(Goodfellow). A homemade glassy carbon electrode (1 mm diameter;
Goodfellow) was used as the working electrode.
CH2Cy). 13C{1H} NMR (CDCl3, 100 MHz): δ 191.5, 182.9, 171.4,
140.7, 140.5, 140.4, 139.2, 130.3, 130.1, 129.7, 129.1, 126.6, 125.3,
59.3, 55.4, 31.5, 31.3, 25.4, 24.8, 24.7, 22.9, 21.6, 21.5. HRMS (ESI+),
m/z: 634.1954 [M − Cl]+. C32H39ClN5Pd, Calcd m/z: 634.1929. IR
spectrum (KBr, selected bands, cm−1): 3427 s, ν(N−H), 3142 s,
ν(CAr−H), 2934, 2856 s, ν(C−H), 2232 s, ν(CN), 1680 s, ν(C
N), 1556 s, ν(N−CN). Anal. Calcd for C32H39Cl2N5Pd·CHCl3: C
50.15; H 5.10; N 8.86. Found: C 50.21; H 5.19; N 8.99.
1
Complexes 4−6. 3,4-Diaryl-1H-pyrrol-2,5-diimine (1a−c) (0.1
mmol) was dissolved in dichloromethane (2 mL) and added to the
solution of cis-[PtCl2(CNR)2] (3a−d) (0.1 mmol) in dichloro-
methane (2 mL). The reaction mixture was stirred at room
temperature for 2 h. Dichloromethane was evaporated under reduced
pressure. Residue was washed by acetone and recrystallized from
chloroform.
5c. Yield 70%, red crystals. H NMR (CDCl3, 400 MHz): δ 10.87
(s, 1H, NCNH), 9.91 (s, 1H, NH), 9.25 (s, 1H, NH), 7.47 (d, 2H,
3JHH = 8.0 Hz, Ar), 7.35 (d, 4H, 3JHH = 8.0 Hz, Ar), 7.23 (d, 2H, 3JHH
= 8.0 Hz, Ar), 7.14 (d, 2H, 3JHH = 8.0 Hz, Ar), 2.46 (s, 3H, Me), 2.38
(s, 3H, Me), 1.59 (s, 9H, t-Bu), 1.55 (s, 9H, t-Bu). 13C{1H} NMR
(CDCl3, 100 MHz): δ 194.5, 187.3, 177.9, 140.0, 139.5, 139.2, 138.3,
130.2, 130.1, 129.9, 129.7, 125.9, 125.1, 59.6, 57.7, 25.4, 22.9, 21.5,
21.5. HRMS (ESI+), m/z: 582.1647 [M − Cl]+. C28H35ClN5Pd, Calcd
m/z: 582.1616. IR spectrum (KBr, selected bands, cm−1): 3420 s,
ν(N−H), 3260 s, ν(CAr−H), 2965, 2925 s, ν(C−H), 2230 s, ν(C
N), 1723 s, ν(CN). Anal. Calcd for C28H35Cl2N5Pd·CHCl3: C
47.18; H 4.91; N 9.49. Found: C 47.27; H 5.04; N 9.61.
1
4a. Yield 84%, orange crystals. H NMR (CDCl3, 400 MHz): δ
11.64 (s, 1H, NCNH), 10.62 (s, 1H, NH), 10.14 (s, 1H, NH), 7.30−
7.60 (m, 10H, Ph), 4.99 (br, 1H, CH), 3.98 (br, 1H, CH), 1.56 (br,
6H, i-Pr), 1.33 (br, 6H, i-Pr). 13C{1H} NMR (CDCl3, 100 MHz): δ
191.3, 182.7, 171.4, 141.4, 140.2, 130.7, 130.2, 130.1, 129.7, 129.6,
129.2, 128.6, 128.5, 128.0, 52.0, 50.3, 22.3, 21.6. HRMS (ESI+), m/z:
526.1011 [M − Cl]+. C24H27N5ClPd Calcd m/z: 526.0990. IR
spectrum (KBr, selected bands, cm−1): 3400 w, ν(N−H), 3156, 3050
s, ν(CAr−H), 2980, 2932 s, ν(C−H), 2237 s, ν(CN), 1683 m,
ν(CN) 1554 s, ν(N−CN). Anal. Calcd for C24H27N5Cl2Pd·
CHCl3: C 44.01; H 4.14; N 10.27. Found: C 44.13; H 4.21; N 10.34.
1
5d. Yield 88%, orange crystals. H NMR (CDCl3, 400 MHz): δ
3
13.04 (s, 1H, NCNH), 10.22 (s, 1H, NH), 7.59 (d, 2H, JHH = 8.0
Hz, Ar), 7.44 (d, 2H, 3JHH = 8.0 Hz, Ar), 7.40 (d, 2H, 3JHH = 8.0 Hz,
Ar), 7.28−7.38 (m, 8H, Ar), 7.23 (d, 2H, 3JHH = 8.0 Hz, Ar), 7.15 (d,
2H, 3JHH = 8.0 Hz, Ar), 5.30−5.35 (m, 2H, CH2), 5.18−5.23 (m, 2H,
CH2), 2.45 (s, 3H, Me), 2.40 (s, 3H, Me). 13C{1H} NMR (CDCl3,
100 MHz): δ 194.0, 183.6, 172.2, 141.4, 140.0, 139.8, 139.6, 136.5,
130.8, 130.1, 129.9, 129.9, 129.3, 129.1, 129.0, 128.8, 128.5, 128.1,
127.8, 127.3, 125.9, 125.0, 51.1, 49.9, 21.6, 21.6. HRMS (ESI+), m/z:
650.1370 [M − Cl]+. C34H31N5ClPd Calcd m/z: 650.1303. IR
spectrum (KBr, selected bands, cm−1): 3181 s, ν(CAr−H), 2916 s,
ν(C−H), 2250 s, ν(CN), 1683 s, ν(CN), 1574, 1541 s, ν(N−
CN). Anal. Calcd for C34H31N5Cl2Pd·CHCl3: C 52.13; H 4.00; N
8.69. Found: C 52.22; H 4.08; N 8.73.
1
4b. Yield 84%, orange crystals. H NMR (CDCl3, 400 MHz): δ
11.57 (s, 1H, NCNH), 11.12 (s, 1H, NH), 10.11 (s, 1H, NH), 7.30−
7.55 (m, 10H, Ph), 4.57 (br, 1H, CHNH), 3.61 (br, 1H, CHNC),
2.15−2.35 (m, 2H, CH2Cy), 1.70−2.00 (m, 6H, CH2Cy), 1.20−1.70
(m, 12H, CH2Cy). 13C{1H} NMR (CDCl3, 100 MHz): δ 191.2, 182.6,
171.3, 141.2, 140.0, 130.6, 130.2, 130.1, 129.7, 129.6, 129.2, 128.5,
128.4, 128.1, 59.5, 55.5, 31.4, 31.4, 25.3, 24.8, 24.2, 22.7. HRMS
(ESI+), m/z: 606.1667 [M − Cl]+. C30H35N5ClPd, Calcd m/z:
606.1616. IR spectrum (KBr, selected bands, cm−1): 3415 w, ν(N−
H), 3172, 3066 m, ν (C−HAr), 2935, 2856 s, ν(C−H), 2236 s, ν(C
N), 1684 m, ν(CN) 1554 s, ν(N−CN). Anal. Calcd for
C30H35N5Cl2Pd·CHCl3: C 48.84; H 4.76; N 9.19. Found: C 48.89; H
4.81; N 9.27.
6a. Yield 85%, red crystals. 1H NMR (CDCl3, 400 MHz): δ 11.59
(s, 1H, NCNH), 10.29 (s, 1H, NH), 10.08 (s, 1H, NH), 7.51 (d, 2H,
3JHH = 8.8 Hz, Ar), 7.40 (d, 2H, 3JHH = 8.0 Hz, Ar), 7.01 (d, 2H, 3JHH
3
= 8.0 Hz, Ar), 6.86 (d, 2H, JHH = 8.8 Hz, Ar), 4.90−5.00 (m, 1H,
CHNH), 4.05−4.15 (m, 1H, CHNC), 3.88 (s, 3H, OMe), 3.84 (s,
3H, OMe), 1.56 (br, 6H, CH(CH3)2), 1.33 (br, 6H, CH(CH3)2).
13C{1H} NMR (CDCl3, 100 MHz): δ 191.2, 183.3, 171.9, 161.3,
161.1, 138.8, 138.3, 131.8, 131.3, 121.8, 120.5, 115.3, 114.0, 55.5,
55.4, 51.9, 50.3, 22.3, 21.6. HRMS (ESI+), m/z: 586.1227 [M − Cl]+.
C26H31N5O2ClPd Calcd m/z: 586.1201. IR spectrum (KBr, selected
bands, cm−1): 3397 s, ν(N−H), 3165 s, ν(CAr−H), 2974 s, ν(C−H),
2236 s, ν(CN), 1683 s, ν(CN), 1554 s, ν(N−CN). Anal.
Calcd for C26H31N5O2Cl2Pd·CHCl3: C 43.69; H 4.34; N 9.43.
Found: C 43.72; H 4.38; N 9.48.
1
4c. Yield 75%, orange crystals. H NMR (CDCl3, 400 MHz): δ
11.50 (s, 1H, NCNH), 10.91 (s, 1H, NH), 10.20 (s, 1H, NH), 7.30−
7.50 (m, 10H, Ph), 1.65 (s, 9H, t-Bu), 1.40 (s, 9H, t-Bu). 13C{1H}
NMR (CDCl3, 100 MHz): δ 192.6, 183.4, 171.8, 140.8, 139.6, 130.6,
130.2, 130.0, 129.9, 129.9, 129.1, 128.6, 128.5, 128.0, 59.6, 57.7, 29.8,
29.5. HRMS (ESI+), m/z: 554.1351 [M − Cl]+. C26H31N5ClPd, Calcd
m/z: 554.1303. IR spectrum (KBr, selected bands, cm−1): 3400 w,
ν(N−H), 3220, 3050 m, ν(CAr−H), 2982, 2930 s, ν(C−H), 2224 s,
ν(CN), 1681 m, ν(CN) 1538 s, ν(N−CN). Anal. Calcd for
C26H31N5Cl2Pd·CHCl3: C 45.66; H 4.54; N 9.86. Found: C 46.07; H
4.60; N 10.02.
6b. Yield 85%, red-orange crystals. 1H NMR (CDCl3, 400 MHz): δ
11.53 (s, 1H, NCNH), 10.36 (s, 1H, NH), 10.09 (s, 1H, NH), 7.53
5a. Yield 80%, red-orange crystals. 1H NMR (CDCl3, 400 MHz): δ
11.84 (s, 1H, NCNH), 10.17 (s, 1H, NH), 9.65 (s, 1H, NH), 7.43 (d,
2H, 3JHH = 8.0 Hz, Ar), 7.31 (m, 4H, Ar), 7.16 (d, 2H, 3JHH = 8.0 Hz),
3
3
(d, 2H, JHH = 8.8 Hz, Ar), 7.40 (d, 2H, JHH = 8.8 Hz, Ar), 7.01 (d,
3
3
2H, JHH = 8.8 Hz, Ar), 6.85 (d, 2H, JHH = 8.8 Hz, Ar), 4.53−4.67
(m, 1H, CHNH), 4.00−4.10 (m, 1H, CHNC), 3.89 (s, 3H, OMe),
3.76 (s, 3H, OMe), 2.20−2.40 (m, 2H, CH2Cy), 1.73−2.00 (m, 6H,
CH2Cy), 1.20−1.70 (m, 12H, CH2Cy). 13C{1H} NMR (CDCl3, 100
MHz): δ 191.3, 183.1, 171.9, 161.3, 161.2, 138.6, 138.1, 131.8, 131.2,
121.8, 120.4, 115.3, 114.0, 63.8, 59.5, 55.5, 55.4, 31.5, 31.4, 25.4, 24.8,
3
3
5.00 (dsept, 1H, JHH = 6.4 Hz, JHH = 6.4 Hz, CH(CH3)2), 4.18
(sept, 1H, 3JHH = 6.0 Hz, CH(CH3)2), 2.43 (s, 3H, Me), 2.38 (s, 3H,
Me), 1.56 (d, 6H, 3JHH = 6.4 Hz, CH(CH3)2), 1.36 (d, 6H, 3JHH = 6.0
Hz, CH(CH3)2). 13C{1H} NMR (CDCl3, 100 MHz): δ 191.2, 182.9,
171.6, 141.0, 140.7, 140.4, 139.5, 130.4, 130.0, 129.5, 129.3, 129.2,
126.4, 125.2, 52.0, 50.3, 22.3, 21.6, 21.6, 21.5. HRMS (ESI+), m/z:
554.1313 [M − Cl]+. C26H31N5ClPd Calcd m/z: 554.1303. IR
spectrum (KBr, selected bands, cm−1): 3423 s, ν(N−H), 3226 s,
ν(CAr−H), 2925 s, ν(C−H), 2224 s, ν(CN), 1718 s, ν(CN),
1526 s, ν(N−CN). Anal. Calcd for C26H31N5Cl2Pd·CHCl3: C
45.66; H 4.54; N 9.86. Found: C 46.01; H 4.58; N 9.92.
24.7, 22.7. HRMS (ESI+), m/z: 666.1909 [M
−
Cl]+.
C32H39N5O2ClPd, Calcd m/z: 666.1827. IR spectrum (KBr, selected
bands, cm−1): 3433 w, ν(N−H), 3152 s, ν(C−HAr), 2934, 2856 s,
ν(C−H), 2245 s, ν(CN), 1690 m, ν(CN) 1541 s, ν(N−CN).
Anal. Calcd for C32H39N5O2Cl2Pd·CHCl3: C 48.20; H 4.90; N 8.52.
Found: C 48.27; H 4.96; N 8.69.
5b. Yield 90%, red crystals. 1H NMR (CDCl3, 400 MHz): δ 11.42
(s, 1H, NCNH), 11.19 (s, 1H, NH), 10.07 (s, 1H, NH), 7.41 (d, 2H,
3JHH = 8.0 Hz, Ar), 7.34 (d, 2H, 3JHH = 8.0 Hz, Ar), 7.27 (d, 2H, 3JHH
= 8.0 Hz, Ar), 7.13 (d, 2H, 3JHH = 8.0 Hz, Ar), 4.56 (s, 1H, CHNH),
3.49 (s, 1H, CHNC), 2.40 (s, 3H, Me), 2.37 (s, 3H, Me), 2.20−2.30
(m, 2H, CH2Cy), 1.80−2.00 (m, 6H, CH2Cy), 1.20−1.70 (m, 12H,
6c. Yield 80%, brown crystals. H NMR (CDCl3, 400 MHz): δ
1
11.15 (s, 1H, NCNH) 10.72 (s, 1H, NH), 10.13 (s, 1H, NH), 7.46
3
3
(d, 2H, JHH = 8.8 Hz, Ar), 7.42 (d, 2H, JHH = 8.8 Hz, Ar), 6.96 (d,
2H, 3JHH = 8.8 Hz, Ar), 6.83 (d, 2H, 3JHH = 8.8 Hz, Ar), 3.85 (s, 3H,
OMe), 3.83 (s, 3H, OMe), 1.66 (s, 9H, t-Bu), 1.42 (s, 9H, t-Bu).
13C{1H} NMR (CDCl3, 100 MHz): δ 192.6, 184.2, 172.4, 161.4,
F
DOI: 10.1021/acs.organomet.8b00725
Organometallics XXXX, XXX, XXX−XXX

Organometallics
Article
161.4, 138.3, 138.0, 131.7, 130.9, 121.6, 120.3, 115.8, 114.0, 59.3,
55.6, 55.4, 55.3, 30.0, 29.5. HRMS (ESI+), m/z: 614.1577 [M − Cl]+.
C28H35N5O2ClPd, Calcd m/z: 614.1514. IR spectrum (KBr, selected
bands, cm−1): 3402 s, ν(N−H), 3154 s, ν(CAr−H), 2971 s, ν(C−H),
2226 s, ν(CN), 1683 s, ν(CN), 1549 s, ν(N−CN). Anal.
Calcd for C28H35N5O2Cl2Pd·CHCl3: C 45.22; H 4.71; N 9.09.
Found: C 45.31; H 4.79; N 9.14.
6.98−7.02 (m, 1H, Ar), 5.63 (s, 1H, CHPh2), 2.11 (s, 3H, Me).
13C{1H} NMR (CDCl3, δ, ppm): 192.7, 186.3, 172.3, 170.3, 140.6,
140.2, 140.2, 137.8, 136.3, 130.9, 130.6, 130.3, 130.2, 129.3, 129.1,
128.9, 128.8, 128.7, 128.4, 128.2, 128.0, 127.5, 125.0, 121.8, 56.6,
21.0. HRMS (ESI−), m/z: 749.0716 [M − H]−. C38H29Cl2N4O2Pd,
Calcd m/z: 749.0702. IR spectrum (KBr, selected bands, cm−1):
3428, 3372 w, ν(N−H), 3168, 3056 s, ν(C−HAr), 2998 s, ν(C−H),
1766 s, ν(C=O), 1678 m, ν(CN), 1532 s, ν(N−CN). Anal.
Calcd for C38H30Cl2N4O2Pd·CH3CN: C 60.58; H 4.19; N 8.83.
Found: C 60.56; H 4.17; N 8.76.
Complexes 11−13. 3,4-Diaryl-1H-pyrrol-2,5-diimine (0.1 mmol)
was dissolved in acetonitrile (2 mL) and added to the solution of cis-
[PdCl2(CNR)2] (0.1 mmol) in acetonitrile (2 mL). The reaction
mixture was left overnight at room temperature. The precipitated
solid was filtered.
1
11j. Yield 58%, brown crystals. H NMR (CDCl3, δ, ppm): 11.03
(s, 1H, NCNH), 10.74 (s, 1H, NH), 8.08 (s, 1H, Ar), 7.85 (d, 3JHH
=
11e. Yield 55%, red crystals. 1H NMR (CDCl3, 400 MHz): δ 11.25
8.0 Hz, 2H, Ar), 7.59 (d, 3JHH = 8.4 Hz, 2H, Ar), 7.20−7.50 (m, 12H,
(s, 1H, NCNH), 10.91 (s, 1H, NH), 8.99 (d, 1H, 3JHH = 9.2 Hz, Ar),
3
Ar, NH), 7.08 (d, JHH = 8.0 Hz, 1H, Ar), 2.41 (s, 3H, Me), 2.32 (s,
3
3H, Me). 13C{1H} NMR (CDCl3, δ, ppm): 195.0, 186.4, 172.6, 146.1,
141.0, 140.4, 138.1, 137.7, 131.0, 130.6, 130.4, 130.3, 130.2, 129.9,
129.5, 129.3, 129.0, 128.9, 128.3, 128.2, 127.3, 123.2, 21.8, 21.1.
HRMS (ESI−), m/z: 709.0064 [M − H]−. C31H25Cl2N4O3SPd, Calcd
m/z: 709.0059. IR spectrum (KBr, selected bands, cm−1): 3380, 3344
w, ν(N−H), 3198, 3046 s, ν(Ar−H), 2960, 2934 s, ν(C−H), 1684 m,
ν(CN), 1538 s, ν(N−CN), 1374 s, ν(SO2). Anal. Calcd for
C31H26Cl2N4O3SPd·CH3CN: C 52.64; H 3.88; N 9.30. Found: C
52.59; H 3.87; N 9.23.
7.50−7.60 (m, 5H, Ph), 7.30−7.50 (m, 4H, Ar), 7.25 (t, 2H, JHH
=
3
3
7.6 Hz, Ar), 7.16 (t, 1H, JHH = 8.8 Hz, Ar), 7.11 (d, 1H, JHH = 8.0
Hz, Ar), 7.06 (s, 1H, NH), 1.43 (s, 9H, t-Bu). 13C{1H} NMR
(CDCl3, 100 MHz): δ 194.5, 186.3, 176.7, 172.4, 143.4, 140.4, 140.3,
130.9, 130.7, 130.2, 130.2, 129.2, 129.1, 129.0, 128.5, 128.4, 128.1,
126.5, 125.8, 122.6, 39.6, 27.3. HRMS (ESI−), m/z: 625.0395 [M −
H]−. C28H25Cl2N4O2Pd, Calcd m/z: 625.0389. IR spectrum (KBr,
selected bands, cm−1): 3396 s, ν(N−H), 3176, 3044 s, ν(CAr−H),
2980 s, ν(C−H), 1757 s, ν(C=O), 1678 s, ν(CN), 1526 s, ν(N−
CN). Anal. Calcd for C28H26Cl2N4O2Pd·CH3CN: C 53.87; H 4.37;
N 10.47. Found: C 53.85; H 4.36; N 10.40.
1
12e. Yield 53%, brown crystals. H NMR (CDCl3, δ, ppm): 11.32
(s, 1H, NCNH), 10.95 (s, 1H, NH), 7.94 (d, 3JHH = 8.0 Hz, 1H, Ar),
1
3
11f. Yield 49%, brown crystals. H NMR (CDCl3, δ, ppm): 11.44
7.47 (d, JHH = 8.0 Hz, 2H, Ar), 7.30−7.40 (m, 3H, Ar), 7.15−7.25
(s, 1H, NCNH), 10.94 (s, 1H, NH), 7.76 (d, 3JHH = 8.4 Hz, 2H, Ar),
(m, 4H, Ar), 7.06 (d, 3JHH = 8.0 Hz, 2H, Ar), 6.89 (s, 1H, NH), 2.46
(s, 3H, Me), 2.34 (s, 3H, Me), 1.47 (s, 9H, t-Bu). 13C{1H} NMR
(CDCl3, δ, ppm): 194.6, 186.5, 176.6, 172.6, 143.4, 141.4, 141.4,
139.5, 139.3, 135.9, 130.9, 130.1, 129.2, 129.0, 128.9, 126.4, 125.8,
125.7, 125.2, 122.7, 39.6, 27.3, 21.6, 21.6.HRMS (ESI−), m/z:
653.0719 [M − H]−. C30H29Cl2N4O2Pd, Calcd m/z: 653.0702. IR
spectrum (KBr, selected bands, cm−1): 3400 w, ν(N−H), 2976 s,
ν(C−H), 1760, 1781 s, ν(C=O), 1681 m, ν(CN) 1525 s, ν(N−
CN). Anal. Calcd for C30H30Cl2N4O2Pd·CH3CN: C 55.15; H 4.77;
N 10.05. Found: C 55.13; H 4.71; N 9.98.
3
7.45−7.60 (m, 12H, Ar), 7.36 (t, JHH = 7.6 Hz, 5H, Ar), 7.17−7.21
(m, 2H, Ar), 7.10−7.15 (m, 2H, Ar), 6.90 (t, 3JHH = 7.6 Hz, 1H, Ar),
5.61 (s, 1H, CHPh2). 13C{1H} NMR (CDCl3, δ, ppm): 192.9, 187.2,
172.8, 169.9, 161.4, 161.3, 142.5, 138.1, 137.7, 131.9, 131.2, 129.0,
129.0, 128.9, 128.8, 128.4, 127.5, 125.8, 124.6, 122.1, 121.3, 120.5,
115.6, 113.8, 56.6. HRMS (ESI−), m/z: 735.0551 [M − H]−.
C37H27Cl2N4O2Pd, Calcd m/z: 735.0546. IR spectrum (KBr, selected
bands, cm−1): 3406 w, ν(N−H), 3164, 3052, 3029 s, ν(C−HAr), 1764
s, ν(C=O), 1676 m, ν(CN) 1534 s, ν(N−CN). Anal. Calcd for
C37H28Cl2N4O2Pd·CH3CN: C 60.13; H 4.01; N 8.99. Found: C
60.14; H 4.00; N 8.92.
1
12f. Yield 48%, brown crystals. H NMR (CDCl3, δ, ppm): 11.27
(s, 1H, NCNH), 10.89 (s, 1H, NH), 7.56 (d, 3JHH = 8.0 Hz, 1H, Ar),
7.42−7.52 (m, 9H, Ph), 7.31−7.39 (m, 6H, Ar), 7.30 (s, 1H, Ar), 7.27
(s, 1H, Ar), 7.16−7.24 (m, 2H, Ar), 6.86−6.92 (m, 1H, Ar), 6.78 (d,
3JHH = 8.4 Hz, 2H, Ar), 5.60 (s, 1H, CHPh2), 2.45 (s, 3H, Me), 2.17
(s, 3H, Me). 13C{1H} NMR (CDCl3, δ, ppm): 193.1, 186.9, 172.5,
169.9, 142.6, 141.2, 141.0, 140.1, 139.0, 137.7, 130.8, 130.2, 129.4,
129.0, 128.9, 128.8, 128.3, 127.5, 125.9, 125.7, 125.4, 124.8, 122.0,
56.6, 21.6, 21.4. HRMS (ESI+), m/z: 763.0879 [M − H]−.
C39H31Cl2N4O2Pd, Calcd m/z: 763.0859. IR spectrum (KBr, selected
bands, cm−1): 3468, 3423 w, ν(N−H), 3160, 3108, 3062, 3032 s,
ν(CAr−H), 2952, 2923 s, ν(C−H), 1760, 1774 s, ν(C=O), 1675 m,
ν(CN) 1542 s, ν(N−CN). Anal. Calcd for C39H32Cl2N4O2Pd·
CH3CN: C 61.02; H 4.37; N 8.68. Found: C 61.04; H 4.39; N 8.61.
12g. Yield 46%, brown crystals. 1H NMR (CDCl3, δ, ppm): 11.70
(s, 1H, NCNH), 10.99 (s, 1H, NH), 8.44 (d, 3JHH = 8.4 Hz, 2H, Ar),
8.26 (d, 3JHH = 8.4 Hz, 1H, Ar), 7.85 (d, 3JHH = 8.4 Hz, 2H, Ar), 7.47
(m, 4H, Ar), 7.36 (d, 3JHH = 8.0 Hz, 2H, Ar), 7.26 (d, 3JHH = 8.0 Hz,
11g. Yield 42%, brown crystals. 1H NMR (CDCl3, δ, ppm): 11.68
(s, 1H, NCNH), 10.99 (s, 1H, NH), 8.42 (d, 3JHH = 8.8 Hz, 2H, Ar),
3
3
8.27 (d, JHH = 8.0 Hz, 1H, Ar), 7.83 (d, JHH = 8.8 Hz, 2H, Ar),
3
7.50−7.60 (m, 5H, Ph), 7.40−7.45 (m, 5H, Ph), 7.33 (t, JHH = 8.0
Hz, 3H, Ar). 13C{1H} NMR (CDCl3, δ, ppm): 193.9, 186.5, 170.1,
162.8, 146.0, 142.3, 140.2, 132.7, 132.5, 131.8, 131.3, 131.1, 131.0,
130.3, 130.1, 130.0, 129.9, 129.0, 129.0, 128.8, 128.6, 126.6, 125.6,
122.9, 117.5. HRMS (ESI−), m/z: 670.0068 [M − H]−.
C31H20Cl2N5O2Pd, 670.0029. IR spectrum (KBr, selected bands,
cm−1): 3530, 3425 m, ν(N−H), 3055 m, ν(CAr−H), 2986 m, ν(C−
H), 2229 w, ν(CN), 1746 s, ν(C=O), 1678 s, ν(CN), 1583 m,
ν(CN), 1534 s, ν(N−CN). Anal. Calcd for C31H21Cl2N5O2Pd·
CH3CN: C 55.52; H 3.39; N 11.77. Found: C 55.50; H 3.38; N
11.71.
11h. Yield 54%, brown crystals. 1H NMR (CDCl3, δ, ppm): 11.29
(s, 1H, NCNH), 10.88 (s, 1H, NH), 8.08 (d, 4JHH = 1.6 Hz, 1H, Ar),
7.61 (d, 3JHH = 7.2 Hz, 2H, Ar), 7.34−7.60 (m, 7H, Ar), 7.12 (d, 3JHH
= 7.2 Hz, 2H, Ar), 6.97 (d, 3JHH = 8.0 Hz, 1H, Ar), 2.34 (s, 3H, Me),
1.42 (s, 9H, t-Bu).13C{1H} NMR (CDCl3, δ, ppm): 193.8, 186.2,
177.0, 172.3, 141.0, 140.5, 135.9, 130.8, 130.6, 130.3, 130.2, 129.5,
129.2, 128.8, 128.6, 128.4, 128.1, 126.6, 122.1, 39.5, 27.3, 21.0.HRMS
(ESI−), m/z: 639.0551 [M − H]−. C29H27Cl2N4O2Pd, Calcd m/z:
639.0546. IR spectrum (KBr, selected bands, cm−1): 3469 w, ν(N−
H), 3200, 3180, 3054 s, ν(CAr−H), 2972, 2928 s, ν(C−H), 1750 s,
ν(C=O), 1675 m, ν(CN), 1543 s, ν(N−CN). Anal. Calcd for
C29H28Cl2N4O2Pd·CH3CN: C 54.52; H 4.58; N 10.25. Found: C
54.51; H 4.56; N 10.19.
3
2H, Ar), 7.13 (d, JHH = 8.4 Hz, 2H, Ar), 2.46 (s, 3H, Me), 2.39 (s,
3H, Me). 13C{1H} NMR (CDCl3, δ, ppm): 194.3, 186.5, 172.7, 164.2,
142.3, 141.7, 139.4, 138.9, 132.5, 131.8, 131.4, 131.4, 131.1, 130.0,
129.6, 129.4, 129.0, 128.7, 126.5, 125.7, 125.6, 125.0, 117.6, 112.6,
109.7, 21.60, 21.57. HRMS (ESI−), m/z: 698.0358 [M − H]−.
C33H24Cl2N5O2Pd, Calcd m/z: 698.0342. IR spectrum (KBr, selected
bands, cm−1): 3182 m, ν(CAr−H), 2998 m, ν(C−H), 2246 w, ν(C
N), 1747 s, ν(C=O), 1686 s, ν(CN), 1609 m, ν(CN), 1527 s,
ν(N−CN). Anal. Calcd for C33H25Cl2N5O2Pd·CH3CN: C 56.66;
H 3.80; N 11.33. Found: C 56.64; H 3.76; N 11.26.
12h. Yield 58%, brown crystals. 1H NMR (CDCl3, δ, ppm): 11.29
(s, 1H, NCNH), 10.87 (s, 1H, NH), 7.97 (d, 4JHH = 1.6 Hz, 1H, Ar),
7.51 (d, 3JHH = 8.0 Hz, 2H, Ar), 7.35 (d, 3JHH = 8.0 Hz, 2H, Ar), 7.30
1
11i. Yield 52%, brown crystals. H NMR (CDCl3, δ, ppm): 11.54
(s, 1H, NCNH), 10.86 (s, 1H, NH), 7.95 (d, 4JHH = 1.6 Hz, 1H, Ar),
7.57 (d, 3JHH = 7.6 Hz, 2H, Ar), 7.52 (m, 5H, Ar), 7.47 (d, 3JHH = 7.2
Hz, 4H, Ar), 7.35 (t, 3JHH = 7.2 Hz, 4H, Ar), 7.24−7.32 (m, 3H, Ar),
3
3
4
(d, JHH = 8.0 Hz, 2H, Ar), 7.14 (dd, JHH = 8.4 Hz, JHH = 1.6 Hz,
1H, Ar), 7.09 (d, 3JHH = 8.0 Hz, 2H, Ar), 7.01 (d, 3JHH = 8.4 Hz, 1H,
Ar), 6.97 (s, 1H), 2.45(s, 3H, Me), 2.36 (s, 3H, Me), 2.36 (s, 3H,
3
3
7.19 (t, JHH = 7.6 Hz, 2H, Ar), 7.06 (d, JHH = 7.6 Hz, 1H, Ar),
G
DOI: 10.1021/acs.organomet.8b00725
Organometallics XXXX, XXX, XXX−XXX

Organometallics
Article
Me), 1.44 (s, 9H, t-Bu). 13C{1H} NMR (CDCl3, δ, ppm): 194.0,
186.2, 176.9, 172.5, 141.4, 141.0, 139.7, 139.3, 135.8, 131.0, 130.1,
129.6, 129.2, 128.8, 128.7, 126.5, 126.0, 125.3, 122.3, 39.6, 27.3, 21.6,
9H, t-Bu). 13C{1H} NMR (CDCl3, δ, ppm): 193.9, 186.8, 176.9,
172.8, 161.5, 161.4, 140.9, 138.6, 137.7, 135.8, 132.0, 130.8, 129.5,
128.7, 126.5, 122.2, 121.5, 120.4, 115.8, 114.0, 55.6, 55.4, 39.5, 27.3,
21.1. HRMS (ESI−), m/z: 699.0782 [M − H]−. C31H31Cl2N4O4Pd,
Calcd m/z: 699.0757. IR spectrum (KBr, selected bands, cm−1): 3358
w, ν(N−H), 3172, 3032 s, ν(CAr−H), 2970, 2930, 2838 s, ν(C−H),
1754 s, ν(C=O), 1677 m, ν(CN) 1521 s, ν(N−CN). Anal.
Calcd for C31H32Cl2N4O4Pd·CH3CN: C 53.35; H 4.75; N 9.43.
Found: C 53.33; H 4.74; N 9.36.
21.6, 21.0. HRMS (ESI−), m/z: 667.0871 [M
−
H]−.
C31H31Cl2N4O2Pd, Calcd m/z: 667.0859. IR spectrum (KBr, selected
bands, cm−1): 3390 w, ν(N−H), 3174, 3038 s, ν(CAr−H), 2973 s,
ν(C−H), 1755 s, ν(C=O), 1678 m, ν(CN), 1536 s, ν(N−CN).
Anal. Calcd for C31H32Cl2N4O2Pd·CH3CN: C 55.75; H 4.96; N 9.85.
Found: C 55.73; H 4.94; N 9.78.
1
1
12i. Yield 58%, brown crystals. H NMR (CDCl3, δ, ppm): 11.57
13i. Yield 55%, brown crystals. H NMR (CDCl3, δ, ppm): 11.58
(s, 1H, NCNH), 10.92 (s, 1H, NH), 7.93 (d, 4JHH = 1.6 Hz, 1H, Ar),
7.49 (m, 6H, Ar), 7.32−7.40 (m, 8H, Ar), 7.29 (s, 1H, Ar), 7.25−7.28
(s, 1H, NCNH), 10.91 (s, 1H, NH), 7.97 (d, 4JHH = 1.6 Hz, 1H, Ar),
7.57 (d, 3JHH = 8.8 Hz, 2H, Ar), 7.50 (d, 3JHH = 7.6 Hz, 4H, Ar), 7.42
(d, 3JHH = 8.4 Hz, 2H, Ar), 7.37 (t, 3JHH = 7.6 Hz, 4H, Ar), 7.25−7.30
(m, 1H, Ar), 7.13 (s, 1H, Ar), 7.50−7.10 (m, 2H, Ar), 7.00 (d, 3JHH
=
3
(m, 1H, Ar), 7.15 (d, 3JHH = 8.4 Hz, 1H, Ar), 7.08 (t, JHH = 8.0 Hz,
8.4 Hz, 2H, Ar), 5.67 (s, 1H, CHPh2), 2.45 (s, 3H, Me), 2.29 (s, 3H,
Me), 2.21 (s, 3H, Me). 13C{1H} NMR (CDCl3, δ, ppm): 192.9,
186.2, 172.6, 170.3, 141.5, 141.5, 140.5, 139.5, 139.2, 137.8, 136.1,
131.0, 130.1, 129.3, 129.2, 128.9, 128.8, 128.8, 128.3, 127.4, 125.9,
125.2, 125.1, 122.0, 34.9, 21.6, 21.1, 18.9. HRMS (ESI−), m/z:
776.0943 [M − H]−. C40H32Cl2N4O2Pd, Calcd m/z: 776.0937. IR
spectrum (KBr, selected bands, cm−1): 3474, 3422 w, ν(N−H), 3164,
3030 s, ν(CAr−H), 2964, 2918 s, ν(C−H), 1772 s, ν(C=O), 1673 m,
ν(CN) 1547 s, ν(N−CN). Anal. Calcd for C40H33Cl2N4O2Pd·
CH3CN: C 61.59; H 4.31; N 8.55. Found: C 61.58; H 4.28; N 8.49.
3
4H, Ar), 6.72 (d, JHH = 8.4 Hz, 2H, Ar), 5.68 (s, 1H, CHPh2), 3.90
(s, 3H, OMe), 3.76 (s, 3H, OMe) 2.25 (s, 3H, Me). 13C{1H} NMR
(CDCl3, δ, ppm): 192.9, 186.9, 172.9, 170.3, 161.6, 161.5, 143.5,
140.5, 138.6, 137.8, 137.3, 136.0, 131.9, 130.7, 129.2, 128.9, 128.8,
128.8, 128.3, 127.5, 125.0, 121.9, 120.3, 115.8, 114.0, 62.7, 55.6, 55.4,
21.0. HRMS (ESI−), m/z: 809.0919 [M − H]−. C40H33Cl2N4O4Pd,
Calcd m/z: 809.0913. IR spectrum (KBr, selected bands, cm−1): 3412
w, ν(N−H), 3178, 3058, 3029 s, ν(CAr−H), 2930, 2836 s, ν(C−H),
1762 s, ν(C=O), 1659 m, ν(CN), 1520 s, ν(N−CN). Anal.
Calcd for C40H34Cl2N4O4Pd·CH3CN: C 59.13; H 4.37; N 8.21.
Found: C 59.10; H 4.33; N 8.15.
1
12j. Yield 59%, red crystals. H NMR (CDCl3, δ, ppm): 11.03 (s,
1H, NCNH), 10.83 (s, 1H, NH), 7.85−7.90 (m, 3H, Ar), 7.48 (d,
3JHH = 8.0 Hz, 2H, Ar), 7.37 (m, 4H, Ar), 7.32 (d, 3JHH = 7.6 Hz, 2H,
Ar), 7.12−7.17 (m, 2H, Ar), 7.08 (d, 3JHH = 8.0 Hz, 2H, Ar), 2.42 (s,
3H, Me), 2.39 (s, 3H, Me), 2.35 (s, 6H, Me). 13C{1H} NMR (CDCl3,
δ, ppm): 194.9, 186.4, 172.7, 169.8, 146.0, 141.2, 139.6, 138.5, 137.5,
131.2, 130.8, 130.3, 130.1, 129.6, 129.3, 129.1, 129.0, 128.9, 127.1,
126.1, 125.3, 123.5, 21.8, 21.6, 21.5, 21.1. HRMS (ESI−), m/z:
737.0378 [M − H]−. C33H29Cl2N4O3SPd, Calcd m/z: 737.0372. IR
spectrum (KBr, selected bands, cm−1): 3388 w, ν(N−H), 3190, 3040
s, ν(CAr−H), 2976, 2918 s, ν(C−H), 1674 m, ν(CN), 1538 s,
ν(N−CN), 1390 s, ν(SO2). Anal. Calcd for C33H30Cl2N4O3SPd·
CH3CN: C 53.82; H 4.26; N 8.97. Found: C 53.79; H 4.23; N 8.90.
1
13j. Yield 52%, brown crystals. H NMR (CDCl3, δ, ppm): 10.96
(s, 1H, NCNH), 10.66 (s, 1H, NH), 7.85−7.90 (m, 2H, Ar), 7.57 (d,
3JHH = 8.8 Hz, 2H, Ar), 7.49 (s, 1H, NH), 7.43 (d, 3JHH = 8.4 Hz, 2H,
Ar), 7.34 (d, 3JHH = 8.0 Hz, 2H, Ar), 7.32 (d, 3JHH = 8.4 Hz, 2H, Ar),
7.11 (s, 3JHH = 8.4 Hz, 1H, Ar), 7.03 (d, 3JHH = 8.8 Hz, 2H, Ar), 6.77
3
(d, JHH = 8.8 Hz, 2H, Ar), 3.84 (s, 3H, OMe), 3.81 (s, 3H, OMe),
2.40 (s, 3H, Me), 2.32 (s, 3H, Me). 13C{1H} NMR (CDCl3, δ, ppm):
194.8, 140.7, 138.7, 138.5, 137.7, 137.4, 134.7, 131.9, 131.6, 131.3,
130.8, 130.5, 130.3, 129.6, 129.3, 128.9, 128.4, 126.8, 123.6, 121.5,
120.4, 115.8, 114.0, 55.5, 55.4, 21.8, 21.1. HRMS (ESI−), m/z:
769.0286 [M − H]−. C33H29Cl2N4O5SPd, Calcd m/z: 769.0270. IR
spectrum (KBr, selected bands, cm−1): 3392 w, ν(N−H), 3178, 3042
s, ν(CAr−H), 2994, 2964 s, ν(C−H), 1676 m, ν(CN), 1520 s,
ν(N−CN), 1376 s, ν(SO2). Anal. Calcd for C33H30Cl2N4O5SPd·
CH3CN: C 51.70; H 4.09; N 8.61. Found: C 51.68; H 4.08; N 8.53.
X-ray Structure Determinations. The crystals of 4c·CH2Cl2, 9a,
10c·H2O·0.5CH2Cl2, and 11j·CH3CN were obtained by a slow
evaporation of solvent at room temperature. Crystals of compounds
4c·CH2Cl2, 9a, 10c·H2O·0.5CH2Cl2, and 11j·CH3CN were immersed
in cryo-oil, mounted in a nylon loop, and analyzed at a temperature of
100 K. The X-ray diffraction data were collected on an Agilent
Technologies Excalibur Eos and Supernova Atlas diffractometers. The
temperature for all experiments was kept at 100 K. The structures
have been solved by the direct methods and refined by means of the
SHELXL−9721 program incorporated in the OLEX2 program
package.22 The carbon-bound H atoms were placed in calculated
positions and were included in the refinement in the “riding” model
approximation, with Uiso(H) set to1.5Ueq(C) and C−H 0.96 Å for
CH3 groups, Uiso(H) set to 1.2Ueq(C) and C−H 0.93 Å for the CH
groups, and Uiso(H) set to 1.2Ueq(N) and N−H 0.86 Å for the NH
groups. Empirical absorption correction was applied in CrysAlisPro
program complex23 using spherical harmonics, implemented in
SCALE3 ABSPACK scaling algorithm.
1
13e. Yield 46%, brown crystals. H NMR (CDCl3, δ, ppm): 11.11
(s, 1H, NCNH), 10.71 (s, 1H, NH), 7.84 (d, 3JHH = 8.4 Hz, 1H, Ar),
7.56 (d, 3JHH = 8.8 Hz, 2H, Ar), 7.43 (d, 3JHH = 8.4 Hz, 2H, Ar), 7.34
3
(d, 3JHH = 8.0 Hz, 1H, Ar), 7.16 (d, JHH = 8.0 Hz, 2H, Ar), 7.11 (d,
3JHH = 8.0 Hz, 1H, Ar), 7.04 (d, 3JHH = 8.4 Hz, 2H, Ar), 6.72 (d, 3JHH
= 8.8 Hz, 2H, Ar), 3.88 (s, 3H, OMe), 3.78 (s, 3H, OMe), 1.44 (s,
9H, t-Bu). 13C{1H} NMR (CDCl3, δ, ppm): 194.3, 187.0, 176.6,
172.8, 161.5, 161.4, 143.3, 138.4, 137.8, 132.0, 130.9, 129.0, 129.0,
126.3, 125.7, 122.6, 121.4, 120.4, 115.7, 114.0, 55.6, 55.4, 39.5, 27.3.
HRMS (ESI+), m/z: 685.0617 [M − H]−. C30H29Cl2N4O4Pd, Calcd
m/z: 685.0601. IR spectrum (KBr, selected bands, cm−1): 3356 w,
ν(N−H), 3176, 3040 s, ν(CAr−H), 2972 s, ν(C−H), 1757 s,
ν(C=O), 1678 m, ν(CN) 1521 s, ν(N−CN). Anal. Calcd for
C30H30Cl2N4O4Pd·CH3CN: C 52.72; H 4.56; N 9.61. Found: C
52.70; H 4.53; N 9.54.
1
13f. Yield 47%, brown crystals. H NMR (CDCl3, δ, ppm): 11.36
3
(s, 1H, NCNH), 10.81 (s, 1H, NH), 7.78 (d, JHH = 8.0 Hz, 1H,
Ar),7.45−7.55 (m, 11H, Ar), 7.34−7.38 (m, 9H, Ar), 7.18−7.24 (m,
3
4H, Ar), 6.51 (d, JHH = 8.4 Hz, 2H, Ar), 5.65 (s, 1H, CHPh2), 3.88
(s, 3H, OMe), 3.67 (s, 3H, OMe).13C{1H} NMR (CDCl3, δ, ppm):
192.9, 187.2, 172.8, 169.9, 161.4, 161.3, 142.5, 138.1, 138.0, 137.7,
131.9, 131.2, 129.0, 129.0, 128.9, 128.8, 128.4, 127.5, 125.8, 124.6,
122.1, 121.3, 120.5, 115.6, 55.6, 55.2, 30.9. HRMS (ESI−), m/z:
795.0774 [M − H]−. C39H31Cl2N4O4Pd, Calcd m/z: 795.0757. IR
spectrum (KBr, selected bands, cm−1): 3410 w, ν(N−H), 3180, 3056,
3029, 3002 s, ν(CAr−H), 2838 s, ν(C−H), 1765 s, ν(C=O), 1676 m,
ν(CN) 1520 s, ν(N−CN). Anal. Calcd for C39H32Cl2N4O4Pd·
CH3CN: C 58.69; H 4.20; N 8.35. Found: C 58.66; H 4.19; N 8.28.
13h. Yield 54%, brown crystals. 1H NMR (CDCl3, δ, ppm): 11.23
(s, 1H, NCNH), 10.78 (s, 1H, NH), 7.97 (d, 4JHH = 1.6 Hz, 1H, Ar),
7.61 (d, 3JHH = 8.8 Hz, 2H, Ar), 7.39 (d, 3JHH = 8.8 Hz, 2H, Ar), 7.14
The crystal structures and crystallographic details are given in
Table S2. Crystal data have been deposited at the Cambridge
Crystallographic Data Centre (CCDC) with deposition numbers
CCDC 1818370, CCDC 1817631, CCDC 1817212, and CCDC
1822187 for 4c·CH2Cl2, 9a, 10c·H2O·0.5CH2Cl2, and 11j·CH3CN,
respectively.
Computational Details. The full geometry optimization, total
energies, MO energies and composition, and electron transitions in
the UV−vis spectra have been carried out at the DFT hybrid level of
theory using Becke’s three parameter hybrid exchange functional in
combination with the gradient-corrected correlation functional of Lee,
Yang, and Parr (B3LYP)24−27 and standard basis 6-31+G(d,p) for
3
4
3
(dd, JHH = 8.4 Hz, JHH = 1.6 Hz, 1H, Ar), 7.06 (d, JHH = 8.8 Hz,
2H, Ar), 6.99 (d, 3JHH = 8.4 Hz, 1H, Ar), 6.79 (d, 3JHH = 8.8 Hz, 2H,
Ar), 3.90 (s, 3H, OMe), 3.82 (s, 3H, OMe), 2.35 (s, 3H, Me), 1.44 (s,
H
DOI: 10.1021/acs.organomet.8b00725
Organometallics XXXX, XXX, XXX−XXX

Organometallics
Article
light atoms and pseudopotential CEP 1−21G28 for palladium using
the Gaussian 0329 program package. Natural charges have been
determined by NBO analysis.30 Twenty singlet vertical electron
transitions in UV spectra have been calculated by time-dependent
method.31
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Novel palladium(II)-Isocyanide Complexes. Inorg. Chem. 1970, 9 (9),
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Enhanced π-Hole···π Interactions Involving Isocyanides: Effect of π-
Hole···π Noncovalent Bonding on Conformational Stabilization of
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6733.
ASSOCIATED CONTENT
* Supporting Information
■
S
The Supporting Information is available free of charge on the
ACS Publications website at DOI: 10.1021/acs.organo-
met.8b00725.
Experimental data for characterization of 4−6 and 11−
13, NMR, UV−vis absorption, and emission spectra,
crystallographic table for 4c·CH2Cl2, 9a, 10c·H2O·
0.5CH2Cl2, and 11j·CH3CN, and computational details
for 4c, 11j, and 12e (PDF)
Cartesian coordinates (XYZ)
Accession Codes
(9) Mikherdov, A. S.; Kinzhalov, M. A.; Novikov, A. S.; Boyarskiy, V.
P.; Boyarskaya, I. A.; Dar’in, D. V.; Starova, G. L.; Kukushkin, V. Y.
Difference in Energy between Two Distinct Types of Chalcogen
Bonds Drives Regioisomerization of Binuclear (Diaminocarbene)Pd-
(II) Complexes. J. Am. Chem. Soc. 2016, 138 (42), 14129−14137.
(10) Kinzhalov, M. A.; Timofeeva, S. A.; Luzyanin, K. V.; Boyarskiy,
V. P.; Yakimanskiy, A. A.; Haukka, M.; Kukushkin, V. Y. Palladium-
(II)-Mediated Addition of Benzenediamines to Isocyanides: Gen-
eration of Three Types of Diaminocarbene Ligands Depending on the
Isomeric Structure of the Nucleophile. Organometallics 2016, 35 (2),
218−228.
CCDC 1817212, 1817631, 1818370, and 1822187 contain the
supplementary crystallographic data for this paper. These data
can be obtained free of charge via www.ccdc.cam.ac.uk/
data_request/cif, or by emailing data_request@ccdc.cam.ac.
uk, or by contacting The Cambridge Crystallographic Data
Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: +44
1223 336033.
AUTHOR INFORMATION
Corresponding Authors
*E-mail: evgeny.e.bulatov@jyu.fi.
*E-mail: t.chulkova@spbu.ru.
■
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S.; Panikorovskii, T. L.; Panin, A. I.; Vereshchagin, A. N.; et al.
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ORCID
Tatiana G. Chulkova: 0000-0001-6997-627X
Taras L. Panikorovskii: 0000-0002-2323-1413
Matti Haukka: 0000-0002-6744-7208
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
We are grateful to Prof. V. Yu. Kukushkin (Saint Petersburg
State University) for helpful discussions and insightful
comments. We also thank the Centre for Optical and Laser
Materials Research, Research Centre for X-ray Diffraction
Studies, Educational Resource Center of Chemistry, Centre for
Chemical Analysis and Materials Research, and Centre of
Magnetic Resonance (all belong to Saint Petersburg State
University) for physicochemical measurements. Evegny
Bulatov expresses his gratitude to Russian Science Foundation
for grant No. 14−43-00017p.
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DOI: 10.1021/acs.organomet.8b00725
Organometallics XXXX, XXX, XXX−XXX