Platinum complexes with pyrimidine-functionalized N-heterocyclic carbene ligands-Synthesis and solid state structures

Article abstract of DOI:10.1016/j.jorganchem.2011.12.014

The ligands of the two most successful systems described in the literature for the activation and functionalization of methane have been merged and a series of novel pyrimidine functionalized platinum(II)(NHC) complexes with aryl and alkyl substituents [1

Full text of DOI:10.1016/j.jorganchem.2011.12.014

Journal of Organometallic Chemistry 701 (2012) 56e61
Contents lists available at SciVerse ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Platinum complexes with pyrimidine-functionalized N-heterocyclic carbene
ligands e Synthesis and solid state structures
*
Dirk Meyer, Alexander Zeller, Thomas Strassner
Physikalische Organische Chemie, Technische Universität Dresden, Bergstrasse 66, 01062 Dresden, Germany
a r t i c l e i n f o
a b s t r a c t
Article history:
The ligands of the two most successful systems described in the literature for the activation and func-
tionalization of methane have been merged and a series of novel pyrimidine functionalized plati-
num(II)(NHC) complexes with aryl and alkyl substituents [1-(2-Pyrimidyl)-3-(aryl or alkyl)imidazoline-2-
ylidene platinum(II) chlorides] was synthesized by transmetalation via the corresponding silver
complexes. All compounds have been fully characterized by 1H and 13C-NMR spectroscopy, elemental
analysis, and with five X-ray single crystal structures. As for the related palladium(II)complexes in most
cases we observed structures of the type [Pt(L)Cl2], while for the sterically less demanding methyl
substituent a complex is formed, where two ligands are coordinated to one metal center [Pt(L)2Cl]þ.
Ó 2011 Elsevier B.V. All rights reserved.
Received 11 November 2011
Received in revised form
9 December 2011
Accepted 12 December 2011
Keywords:
Platinum
N-Heterocyclic carbene
Catalysis
Solid state structure
1. Introduction
Periana (bipyrimidine-) and Strassner (biscarbene-) systems.
Compared to the Periana system the pyrimidineeNHCeligands
One of themost prominent and successful systems for the catalytic
methane activation is a platinum(II) complex with a bipyrimidine
ligand where the metalisstabilizedbya bidentatecoordinationof two
nitrogen atoms [1]. Based on quantum chemical calculations it was
claimed that the nitrogen atom functions as an acceptor for protons in
the strongly acidic reaction mixture (oleum) [2,3]. Other active cata-
lysts are based on chelating biscarbene palladium(II) systems like the
1,10-dimethyl-3,30-methylenediimidazolin-2,20-ylidene-palladium(II)
bromide which have been developed by our group [4].They donate
significantly stronger through the two carbene carbon atoms and can
therefore stabilize the metal even better.
We recently demonstrated that [1-(2-pyrimidyl)-3-(aryl or
alkyl)-imidazoline-2-ylidene palladium(II)] complexes [(pym)
^(NHC-R)PdIICl2] are also active in the methane activation. The
ligand can be considered as a mixture of the two well known
systems (Scheme 1) [5]. The palladium catalysts prepared were
active in the methane activation reaction under the reaction
conditions established in the group (trifluoroacetic acid and
eanhydride, 30 bar methane, 90 ꢀC), but didn’t show any significant
benefit compared to the known biscarbene systems. We therefore
were interested whether the corresponding Pt(II) complexes
[(pym)^(NHCeR)PtIICl2] might be more active [6,7].
donate additional electron density and coordinate to the metal
through one nitrogen atom which has recently been demonstrated
with various metals [8e17]. The pyrimidineeNHCeligands can also
get protonated at the second nitrogen atom, combining the advan-
tages of both catalytically active systems. Chen and coworkers have
even been successful in using metal powders [18] or recently elec-
trolysis for the direct synthesis of the metal complexes [19].
Parallel to our work two platinum(II) complexes of 1-(2-
pyrimidyl)-3-(aryl or alkyl)imidazol-2-ylidene (aryl: 2,4,6-
trimethylphenyl; alkyl: methyl) have recently been published, but
in these cases with a ligand/metal ratio of 2:1 [15,20]. In the past
years, it was shown that Pt(II) complexes of bis(NHC) ligands are
active catalysts of the methane activation under the same condi-
tions established for their Pd(II) derivatives but are less stable and
therefore show lower turnover numbers (TON) [21,22]. Through the
introduction of aromatic substituents the stability of the complexes
could be increased [21] and we therefore decided to synthesize
alkyl as well as aryl substituted [1-(2-pyrimidyl)-3-imidazol-2-
ylidene platinum(II)] complexes.
2. Results and discussion
We present the synthesis of the corresponding platinum(II)
complexes which constitute the other possible combination of the
The imidazolium salts 1-(2-pyrimidyl)-3-(2,6-diisopropylphenyl)
imidazolium chloride
1 and 1-(2-pyrimidyl)-3-(2,4,6-trimethyl
phenyl)imidazolium chloride 2 are accessible by the reaction of the
N-substituted imidazole with 2-chloropyrimidine in good yields.
* Corresponding author. Tel.: þ49 351 46338571; fax: þ49 351 46339679.
E-mail address: thomas.strassner@chemie.tu-dresden.de (T. Strassner).
0022-328X/$ e see front matter Ó 2011 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2011.12.014

D. Meyer et al. / Journal of Organometallic Chemistry 701 (2012) 56e61
57
R
N
Cl
N
N
R
N
Pd
Cl
Cl
N
N
R
Pd
Cl
N
N
N
N
Cl
Cl
Pt
N
N
Scheme 1. Catalytically active systems in the conversion of methane.
Running the reaction neat in an ACE pressure tube at 80 ꢀC lead to
significantly better yields. The structure of 1 shows that the pyrimidyl
ring is almost in plane with the imidazole core while the bulky iso-
propyl substituents in 2,6-position of the aryl ring lead to an orthog-
onal geometry of the aryl ring (Fig. 1).
Fig. 2. ORTEP style plot of 3 in the solid state. Thermal ellipsoids are drawn at the 50%
probability level. Selected bond lengths (Å) and angles (ꢀ): Ag1eC1 2.072(2), Ag1eCl1
2.321(1), Ag1eN3 3.082(2), C1eAg1eN3 62.8(1), C1eAg1eCl1 174.3(1),
C1eN1eC4eN3 ꢁ23.2(2), C1eN2eC8eC9 ꢁ87.7(2).
Reaction of the imidazolium salts with Ag2O in dichloromethane
leads to the corresponding silver(I) salts in good yields [5]. We were
able to get single crystals of 3 suitable for X-ray diffraction (Fig. 2).
The C1eAgeCl angle of 174.3(1)ꢀ confirms the almost linear
coordination of the silver atom. The pyrimidine and the imidazole
ring are twisted by ꢁ23.2(2)ꢀ (C1eN1eC4eN3), while the 2,6-
compared to CH3CN used in Ref. [15]. Therefore the formation of the
1:1 vs. 2:1 complexes seems to be more dependent on the reaction
conditions than on the steric demand of the aryl/alkyl substituent
in the 3-position of the imidazole. The solid state structure of
complex 6*CH3CN shows similar bond lengths and angles as the
corresponding Pd(II) complex [5].The main difference between the
two Pt(II) complexes 5 and 6*CH3CN is the angle between the aryl
substituent and the plane of the ligand. In case of the very bulky
2,6-diisopropylphenyl substituent in 5 the torsional angle between
the phenyl ring and the plane of the imidazol ring is nearly 90ꢀ
while in case of the 2,4,6-trimethylphenyl substituted complex
6*CH3CN the aryl substituent is more in plane by almost 30ꢀ. The
steric demand of the 2,6-diisopropylphenyl substituent seems to be
responsible for the orthogonal arrangement as the corresponding
torsional angle (CleN2eC8eC9) is around 90ꢀ in the imidazolium
precursor 1 as well as in the silver complex 3. As expected, the
platinum is in a nearly perfect square-planar coordination in both
disubstituted
ring
remained
orthogonal
(C1eC2eC8eC9
e87.7(2)ꢀ). The aryl substituted platinum complexes [(pym)^(NHC-
DIPP)PtIICl2] 5 (Fig. 3) and [(pym)^(NHC-Mes)PtIICl2] 6 (Fig. 4) have
been synthesized by transmetallation of the corresponding silver
complexes [5] [(pym)^(NHC-DIPP)AgCl] 3 and [(pym)^(NHC-Mes)
AgCl] 4 with [(COD)PtIICl2] [23] (Scheme 2).
The platinum(II) complexes have been fully characterized by
NMR spectroscopy, elemental analysis and solid state structures
(Figs. 3 and 4). Complex 6 crystallized with one molecule acetoni-
trile as 6*CH3CN.
It is interesting to note that 6*CH3CN in our hands crystallizes in
a different geometry compared to what had been observed before.
But in our case we also did not observe the formation of the AgCl2ꢁ
counterion, probably due to the lower solubility in CH2Cl2,
Fig. 3. ORTEP style plot of complexes 5 in the solid state. Thermal ellipsoids are drawn
at the 50% probability level. Selected bond lengths (Å) and angles (ꢀ): Pt1eC1 1.946(4),
Pt1eCl1 2.339(1), Pt1eCl2 2.269(1), Pt1eN3 2.029(3), C1ePt1eN3 80.1(2),
C1ePt1eCl1 173.7(1), C1ePt1eCl2 96.8(1), N3ePt1eCl2 176.5(1), C1eN1eC4eN3
0.0(5), C1eN2eC8eC9 ꢁ89.3(3).
Fig. 1. ORTEP style plot of 1 in the solid state. Thermal ellipsoids are drawn at the 50%
probability level. Selected bond lengths (Å) and angles (ꢀ): N2eC4 1.434(2), N2eC1
1.345(2), N1eC1 1.325(2), N1eC8 1.452(3), N1eC1eN2 108.8(2), C1eN1eC8 127.0(2),
C1eN2eC4 125.4(2), C1eN2eC4eN3 ꢁ6.4(3), C1eN1eC8eC9 ꢁ84.9(2).

58
D. Meyer et al. / Journal of Organometallic Chemistry 701 (2012) 56e61
interaction to the certainly most acidic hydrogen atom of the
molecule.
Attempts were made to synthesize platinum(II) complexes with
aliphatic substituents (R ¼ methyl, cyclohexyl) following the same
protocol used for the synthesis of the complexes with aromatic
substituents 5 and 6*CH3CN, but led to different results. In case of
the cyclohexyl substituent the [(pym)^(NHC-Cy)PtIICl2] complex 12
was obtained, while in case of the methyl substituent the 2:1
complex [((pym)^(NHC-Me))2PtIICl]Cl 9 was formed (Schemes 3
and 4). We had expected that the methyl substituted ligand
might lead to a different structure as we had observed the forma-
tion of a [Pd(L)2Cl][Pd(DMSO)Cl3] complex for the corresponding
palladium species with a methyl substituent [5]. Similar complexes
for palladium and platinum are also known from the literature [20].
The structure of the previously reported complex [((pym)
^(NHC-Me))2PtIICl] PF6 differs from the solid state structure of 9
only by some degrees in the angles, but the bond lengths are quite
similar. As already observed in the palladium complex [5], the two
ligands in 9 lead to different signal sets and were also characterized
as two different coordinating ligands in the solid state structure
(Fig. 5). The quantitative formation (97% isolated yield) of 9 can be
achieved by using an excess (2 eq.) of the silver precursor 8.
As already mentioned the structure of complex 9 could be
proven by X-Ray analysis, confirming the 2:1 coordination geom-
etry that was assumed from the two different signal sets in the
NMR-spectra. A similar structure containing a PFꢁ6 counterion
instead of Clꢁ was published earlier [20].
Fig. 4. ORTEP style plot of complexes 6*CH3CN in the solid state. Thermal ellipsoids are
drawn at the 50% probability level. One molecule acetonitrile has been omitted for
clarity. Selected bond lengths (Å) and angles (ꢀ): Pt1eC1 1.949(2), Pt1eCl1 2.351(1),
Pt1eCl2 2.299(1), Pt1eN3 2.029(2), C1ePt1eN3 79.5(1), C1ePt1eCl1 172.2(1),
C1ePt1eCl2 97.3(1), N3ePt1eCl2 176.7(1), C1eN1eC4eN3 ꢁ2.9(3), C1eN2eC8eC9
118.0(3).
The analogous Pd(II) complexes have been shown to be active
catalysts for the methane activation [5]. In order to investigate
whether the Pt(II) complexes show a catalytic reaction as well,
methane activation experiments were conducted with compounds
5, 6 and 9. Under the same reaction conditions as used before the
complexes were stirred with K2S2O8 as oxidant and a mixture of
trifluoroacetic acid and its anhydride as solvent in a 160 mL Has-
telloy C-2000 autoclave (Parr) under an atmosphere of 30 bars
methane at 90 ꢀC. Although no formation of platinum black could
be observed and the platinum(II) complexes seem to be stable in
concentrated trifluoroacetic acid, we were not able to observe any
catalytic activity in the methane oxidation, a very unexpected
result.
Scheme 2. Synthesis of platinum(II) complexes 5 and 6.
complexes 5 and 6*CH3CN. In contrast, the pyrimidine ring deviates
significantly in the silver complex 3, indicating that no coordination
from the pyrimidine N to Ag occurs. In the solid state structure of 1
the dihedral angle between the imidazol- and the pyrimidine
heterocycle is 6.4ꢀ. The chloride counterion in the molecular
structure of 1 is found quite close (2.437 Å) to the hydrogen atom
bound to the C1 carbon atom, indicating a weak hydrogen bond
Scheme 3. Preparation and reaction of the silver complex 8 with dichloridoecyclooctadieneeplatinum(II).
Scheme 4. Synthesis of the cyclohexyl substituted Pt(II) complex 12.

D. Meyer et al. / Journal of Organometallic Chemistry 701 (2012) 56e61
59
16 h under exclusion of light. The resulting yellow solution was
separated from the white residue by filtration and the solvent was
evaporated in vacuo. The yellow precipitate was washed with
diethylether and dried in vacuo. Yield: 0.19 g (80%). M.p. >350 ꢀC.
1H NMR (DMSO-d6): 1.11 (d, J ¼ 6.8 Hz, 6H, CH3), 1.25 (d, J ¼ 6.8 Hz,
6H, CH3), 2.61 (sept, J ¼ 6.9 Hz, 2H, CH), 7.28 (d, J ¼ 7.7 Hz, 2H, m-H
of ph), 7.47 (t, 1H, J ¼ 7.7 Hz, p-H of ph), 7.76 (t, J ¼ 5.4 Hz, 1H, p-H of
pym), 7.81 (d, J ¼ 2.1 Hz, 1H, NCH), 8.36 (d, J ¼ 2.1 Hz, 1H, NCH), 9.15
(m, 1H, m-H pym), 9.76 (m, 1H, m-H pym). 13C NMR (DMSO-d6) :
d
¼ 22.9 (CH3), 24.2 (CH3), 27.9 (CH), 116.9 (p-CH of pym), 119.8
(NCH), 123.4 (m-CH of ph), 126.9 (NCH), 129.9 (p-CH of ph), 134.0
(ipso-C of ph), 143.7 (Carbene-C), 144.5 (o-C of ph), 156.4 (m-CH of
pym), 157.6 (ipso-C of pym), 160.3 (m-CH of pym). Anal. Calcd for
C19H22Cl2N4Pt: C 39.87%; H 3.87%; N 9.79% found C 40.21%; H 3.68%;
N 9.95%.
4.2.2. Dichloro(1-(2-pyrimidyl)-3-(2,4,6-trimethylphenyl)imidazol-
2-ylidene)platinum(II) 6*CH3CN [(pym)^(NHC-Mes)PtIICl2]
Fig. 5. ORTEP style plot of complex 9 in the solid state. Thermal ellipsoids are drawn at
the 50% probability level. Selected bond lengths (Å) and angles (ꢀ): Pt1eC1 1.963(7),
Pt1eC9 1.972(7), Pt1eCl1 2.337(2), Pt1eN3 2.081(6), C1ePt1eN3 79.4(3), C1ePt1eCl1
172.2(2), C1ePt1eC9 98.8(3), C9ePt1eN3 177.0(3), C1eN1eC4eN3 ꢁ3.6(9),
C9eN5eC12eN7 ꢁ16.6(11).
0.30 g (0.7 mmol) silver carbene complex 4 and 0.28 g
(0.7 mmol) dichloro-cyclooctadiene-platinum(II) were stirred in
a Schlenk tube in 40 mL dichloromethane at room temperature for
16 h under exclusion of light. The resulting yellow solution was
separated from the white residue by filtration and the solvent was
evaporated in vacuo. The yellow precipitate was washed with
diethylether and dried in vacuo. Yield: 0.19 g (80%). M.p. >350 ꢀC.
3. Conclusion
We were able to synthesize platinum(II) complexes with a C^N
donor ligand. The aryl- and alkyl substituted [1-(2-pyrimidyl)-3-
(aryl or alkyl)imidazol-2-ylidene platinum(II)] complexes could be
fully characterized, most also by solid state structures. The
complexes are stable under strongly acidic conditions, but do not
show any catalytic activity in the catalytic methane activation
under the conditions used.
1H NMR (DMSO-d6):
d
¼ 2.07 (s, 6H, o-CH3), 2.31 (s, 3H, p-CH3), 7.00
(s, 2H, m-H of ph), 7.62 (d, J ¼ 1.8 Hz,1H, NCH), 7.76 (t, J ¼ 5.1 Hz,1H,
p-H of pym), 8.35 (d, J ¼ 1.8 Hz, 1H, NCH), 9.15 (m, 1H, m-H of pym),
9.75 (m, 1H, m-H of pym). 13C NMR (DMSO-d6):
d
¼ 17.3 (o-CH3),
20.6 (p-CH3), 117.3 (p-CH of pym), 119.8 (NCH), 125.6 (NCH), 128.4
(m-CH of ph), 134.1 (o-C of ph), 134.4 (p-C of ph), 138.3 (ipso-C of
ph), 143.2 (Carbene-C), 156.5 (m-CH of pym), 157.6 (ipso-C pym),
160.3 (m-CH pym). Anal. Calcd for C16H16Cl2N4Pt: C 36.24%, H
3.04%, N 10.56% found C 36.02%, H 2.97%, N 10.48%.
4. Experimental section
4.1. General experimental methods
4.2.3. Chlorobis(1-(2-pyrimidyl)-3-(methyl)imidazol-2-ylidene)
platinum(II) chloride [((pym)^(NHC-Me))2PtIICl]Cl 9
1H and 13C spectra were recorded on a Bruker AC 300 P or a Bruker
DRX-500 spectrometer. Elemental analyses were performed by the
microanalytical laboratory of our institute using an EuroVektor Euro
EA-300 Elemental Analyzer. Melting points have been determined
using a Wagner and Munz PolyTherm A system. Chemicals were
supplied by Acros, Fluka and Aldrich, solvents were dried by standard
procedures before use. 1-(2-pyrimidyl)-3-(2,6-diisopropylphenyl)
imidazolium chloride [(pym)^(NHC-DIPP)]Cl 1, 1-(2-pyrimidyl)-3-
(2,4,6-trimethylphenyl)imidazolium chloride [(pym)^(NHC-Mes)]Cl
2, 1-(2-pyrimidyl)-3-(2,6-diisopropylphenyl)imidazoline-2-ylidene
silver(I) chloride [(pym)^(NHC-DIPP)AgCl] 3, 1-(2-pyrimidyl)-3-
(2,4,6-trimethylphenyl) -imidazoline-2-ylidene silver(I) chloride
[(pym)^(NHC-Mes)AgCl] 4, 1-(2-pyrimidyl)-3-(methyl)imidazolium
chloride [(pym)^(NHC-Me)]Cl 7, 1-(2-pyrimidyl)-3-(methyl)imida-
zol-2-ylidene silver(I) chloride [(pym)^(NHC-Me)AgCl] 8, 1-(2-
pyrimidyl)-3-(cyclohexyl)-imidazolium chloride [(pym)^(NHC-Cy)]
Cl 10, 1-(2-pyrimidyl)-3-(cyclohexyl)imidazol-2-ylidene silver(I)
chloride [(pym)^(NHC-Cy)AgCl] 115 and dichlorido-cyclo-octadiene-
platinum(II) [23] [(COD)PtIICl2] were prepared according to known
procedures.
0.08 g (0.3 mmol) of the silver complex 8 and 0.05 g (0.1 mmol)
[Pt(COD)Cl2] were dissolved in 5 mL DMSO. Under exclusion of light
the reaction mixture is stirred in an inertgas atmosphere for 14 h.
The resulting suspension was filtrated through a celite pad, the
solvent was removed in vacuo. The residue was dissolved
dichloromethane and precipitated by the addition of diethyl ether.
The white product was filtrated and dried in vacuo. Yield: 0.07 g
(97%). M.p. 200 ꢀC. 1H NMR (DMSO-d6):
d
¼ 3.09 (s, 3H, CH3), 4.01 (s,
3H, CH3), 7.61 (m, 2H, p-H of pym and NCH), 7.86 (m, 2H, p-H of pym
and NCH), 8.16 (d, J ¼ 2.2 Hz, 1H, NCH), 8.28 (d, J ¼ 2.2 Hz, 1H, NCH),
8.89 (d, J ¼ 4.9 Hz, 2H, m-H of pym), 9.22 (m, 1H, m-H of pym), 9.44
(m,1H, m-H of pym).13C NMR (DMSO-d6):
d
¼ 35.9 (CH3), 40.4 (CH3),
116.7 (p-CH of pym), 120.2 (p-CH of pym), 121.1 (NCH), 124.7 (NCH),
125.4 (NCH), 156.0 (m-CH of pym), 157.1 (ipso-C of pym), 159.2 (m-
CH of pym), 161.8 (m-CH of pym). Anal. Calcd for C16H17Cl2N8Pt. 1.1
AgCl: C 25.79%, H 2.30%, N 15.04% found C 25.97%, H 2.04%, N 14.80%.
4.2.4. Dichloro(1-(2-pyrimidyl)-3-(cyclohexyl)imidazol-2-ylidene)
platinum(II) [(pym)^(NHC-Cy) PtIICl2] 12
0.20 g (0.5 mmol) of the silver complex 11 and 0.20 g (0.5 mmol)
[Pt(COD)Cl2] were dissolved in 5 mL DMSO. Under exclusion of light
and inert atmosphere the reaction mixture is stirred for 9 h. The
resulting suspension was filtrated through a celite pad, the solvent
was removed in vacuo. The residue was dissolved in dichloro-
methane and precipitated by the addition of diethyl ether. The
yellow product was filtrated and dried in vacuo. Yield: 0.09 g (35%).
4.2. Synthesis of the metal complexes
4.2.1. Dichloro(1-(2-pyrimidyl)-3-(2,6-diisopropylphenyl)imidazol-
2-ylidene)platinum(II) [(pym)^(NHC-DIPP)PtIICl2] 5
0.27 g (0.7 mmol) silver carbene complex 3 and 0.25 g
(0.7 mmol) dichloro-cyclooctadiene-platinum(II) were stirred in
a Schlenk tube in 40 mL dichloromethane at room temperature for
M.p. >350 ꢀC. 1H NMR (DMSO-d6):
cyc), 5.67 (m, 1H, NCH of cyc), 7.70 (t, J ¼ 5.1 Hz, 1H, p-H of pym),
d
¼ 1.23e1.96 (2m, 10H, CH2 of

60
D. Meyer et al. / Journal of Organometallic Chemistry 701 (2012) 56e61
Table 1
Crystallographic data for complexes 1, 3, 5, 6*CH3CN and 9.
Compound
1
3
5
6*CH3CN
9
Empirical formula
Formula weight
Temperature
C19 H23 Cl N4
342.86
198(2) K
C19 H22 Ag Cl N4
449.73
198(2) K
C19 H22 Cl2 N4 Pt
572.40
198(2) K
C16 H16 Cl2 N4 Pt *C2 H3
571.37
198(2) K
N
C16 H16 Cl2 N8 Pt
586.36
198(2) K
Wavelength
0.71073 Å
0.71073 Å
0.71073 Å
0.71073 Å
0.71073 Å
Crystal system
Space group
Unit cell dimensions
Orthorhombic
P n a 21
Monoclinic
P21/c
Monoclinic
P21/c
Monoclinic
P21/c
Triclinic
P ꢁ1
a ¼ 16.269(1) Å
b ¼ 11.977(1) Å
c ¼ 9.828(1) Å
a ¼ 11.154(1) Å
b ¼ 14.918(1) Å
c ¼ 15.541(1) Å
a ¼ 8.887(1) Å
b ¼ 17.872(2) Å
c ¼ 14.497(1) Å
a ¼ 10.486(1) Å
b ¼ 14.026(1) Å
c ¼ 13.824(1) Å
a ¼ 7.057(2) Å
b ¼ 11.143(4) Å
c ¼ 12.544(3) Å
a
b
g
¼ 90ꢀ
¼ 90ꢀ
¼ 90ꢀ
a
b
g
¼ 90ꢀ
a
b
g
¼ 90ꢀ
a
b
g
¼ 90ꢀ
a
b
g
¼ 99.52(3)ꢀ
¼ 99.59(2)ꢀ
¼ 90.06(3)ꢀ
¼ 127.88(1)ꢀ
¼ 90ꢀ
¼ 120.28(1)ꢀ
¼ 90ꢀ
¼ 105.96(1)ꢀ
¼ 90ꢀ
Volume
Z
1915.0(3) Å3
4
2041.1(2) Å3
4
1988.5(3) Å3
4
1954.8(3) Å3
4
958.8(4) Å3
2
Absorption coefficient
F(000)
0.207 mmꢁ1
728
1.127 mmꢁ1
912
7.336 mmꢁ1
1104
7.463 mmꢁ1
1096
7.615 mmꢁ1
560
Crystal size [mm3]
Theta range for data
collection
0.39 ꢂ 0.32 ꢂ 0.27
0.60 ꢂ 0.50 ꢂ 0.23
0.38 ꢂ 0.27 ꢂ 0.06
0.51 ꢂ 0.31 ꢂ 0.15
0.17 ꢂ 0.08 ꢂ 0.08
4.85e26.40ꢀ
4.83e26.40ꢀ
4.84e26.40ꢀ
4.81e26.39ꢀ
4.80e26.40ꢀ
Reflections collected
Independent reflections
Max. and min. transmission
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices
16,107
24,244
20,941
24,487
17,218
3755 [R(int) ¼ 0.0391]
0.9463 and 0.9234
3755/1/222
4154 [R(int) ¼ 0.0252]
0.7754 and 0.5458
4154/0/226
4046 [R(int) ¼ 0.0607]
0.6406 and 0.1598
4046/0/239
3969 [R(int) ¼ 0.0277]
0.4087 and 0.1141
3969/0/239
3905 [R(int) ¼ 0.0843]
0.5706 and 0.3593
3905/0/246
1.109
1.288
1.040
1.331
1.101
R1 ¼ 0.0355,
R1 ¼ 0.0212,
R1 ¼ 0.0252,
R1 ¼ 0.0171,
R1 ¼ 0.0412,
[I > 2sigma(I)]
R indices (all data)
wR2 ¼ 0.0834
R1 ¼ 0.0518,
wR2 ¼ 0.0522
R1 ¼ 0.0318,
wR2 ¼ 0.0466
R1 ¼ 0.0454,
wR2 ¼ 0.0434
R1 ¼ 0.0205,
wR2 ¼ 0.0906
R1 ¼ 0.0567,
wR2 ¼ 0.0905
wR2 ¼ 0.0557
wR2 ¼ 0.0514
wR2 ¼ 0.0449
wR2 ¼ 0.0968
Largest diff. peak and hole
0.122 and ꢁ0.137e.Åꢁ3
0.446 and ꢁ0.423e.Åꢁ3
0.605 and ꢁ0.635e.Åꢁ3
0.578 and ꢁ1.358e.Åꢁ3
1.798 and ꢁ1.317e.Åꢁ3
7.89 (d, J ¼ 2.4 Hz, 1H, NCH), 8.11 (d, J ¼ 2.3 Hz, 1H, NCH), 9.09 (m,
for this paper. These data can be obtained free of charge from The
Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/
data_request/cif.
1H, m-H of pym), 9.78 (m, 1H, m-H of pym). 13C NMR (DMSO-d6):
d
¼ 24.4 (p-CH2 of cyc), 25.0 (m-CH2 of cyc), 32.3 (o-CH2 of cyc), 56.9
(NCH of cyc), 117.1 (p-CH of pym), 119.5 (NCH), 120.9 (NCH), 140.1
(Carbene-C), 156.4 (m-CH of pym), 157.6 (ipso-C pym), 160.4 (m-CH
pym). Anal. Calcd for C13H16Cl2N4Pt: C 31.59%, H 3.26%, N 11.34%
found C 31.76%, H 3.13%, N 11.14%.
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