Phosphorescent platinum(II) complexes based on C^C* cyclometalating aryltriazol-5-ylidenes

Article abstract of DOI:10.1021/om4004576

Two series of heteroleptic platinum(II) carbene compexes of the type [Pt(C^C)(O^O)] (O^O = acetylacetonate) with C^C* cyclometalated 4-phenyl-1,2,4-triazol-5-ylidene as well as 1-phenyl-1,2,4-triazol-5-ylidene ligands were prepared. The effect of various

Full text of DOI:10.1021/om4004576

Article
pubs.acs.org/Organometallics
Phosphorescent Platinum(II) Complexes Based on C∧C*
Cyclometalating Aryltriazol-5-ylidenes
Mario Tenne,† Stefan Metz,‡ Ingo Munster,‡ Gerhard Wagenblast,‡ and Thomas Strassner*,†
̈
†Physikalische Organische Chemie, Technische Universitat Dresden, 01069 Dresden, Germany
̈
‡BASF SE, 67056 Ludwigshafen, Germany
S
* Supporting Information
ABSTRACT: Two series of heteroleptic platinum(II) carbene
compexes of the type [Pt(C∧C*)(O∧O)] (O∧O = acetylacetonate)
with C∧C* cyclometalated 4-phenyl-1,2,4-triazol-5-ylidene as well as 1-
phenyl-1,2,4-triazol-5-ylidene ligands were prepared. The effect of
various substituents in the 4-position of the phenyl ring (4-
phenyltriazole: H, Cl, OCH3, NO2; 1-phenyltriazole: H, Cl, OCH3,
CH3) was studied. The ligand precursors were obtained by
quaternization of the corresponding aryl-1,2,4-triazoles with iodo-
methane. The complexes were synthesized by a reaction sequence
starting from the triazolium precursors via the silver(I) carbenes,
transmetalation with dichloro(1,5-cyclooctadiene)platinum(II), cyclo-
metalation reaction, and finally addition of acetylacetonate. All complexes have been characterized by standard techniques such as
1H NMR, 13C NMR, and elemental analysis. Additionally, solid-state structures of seven complexes could be obtained by single-
crystal X-ray diffraction. According to absorption and emission spectra, the complexes reveal interesting photophysical properties
with strong emissions in the blue region of the visible spectrum at room temperature, which are sensitive to the donor and
acceptor properties of the substituents at the cyclometalating ligand.
stability of [Pt(C∧C*)(O∧O)] complexes might be improved in
order to achieve longer lifetimes in lighting devices. The strong
INTRODUCTION
■
Cyclometalated platinum(II) complexes attract a lot of interest
ligand field also supports high-energy emissions due to an
increase of the LUMO energy level and raises the d−d level of
the excited state to effectively suppress thermal quenching.6
Although not many examples of platinum(II) complexes of
the general structure [Pt(C∧C*)(O∧O)] have been published
yet, most complexes (with the exception of one complex
containing a trifluoromethyl-acetylacetonato ligand7) showed
interesting photophysical properties. The known compounds of
this class are based on different 1-arylimidazol-2-ylidene
ligands.8 The first example was based on the 1-(4-
cyanophenyl)imidazol-2-ylidene and revealed strong phosphor-
escence in the deep-blue region at room temperature.8a
Substitution at the phenyl ring and extension of the π-system
alter the emission wavelength and may significantly increase the
phosphorescence quantum yields (PQYs).8b−d Modification of
the NHC moiety may offer another approach to improve the
photophysical properties and stability. We describe the
synthesis and characterization of a series of blue-phosphor-
escent [Pt(C∧C*)(O∧O)] complexes containing C∧C* cyclo-
metalating 1-aryl-1,2,4-triazol-5-ylidenes as well as 4-aryl-1,2,4-
triazol-5-ylidenes and their photophysical properties.
due to their extraordinary photoluminescence properties and
potential applications as photocatalysts,1 chemical sensors,2 and
chromophors in organic light-emitting diodes (OLEDs).3 The
platinum(II) ion induces spin−orbit coupling (SOC) leading to
triplet harvesting and allows electroluminescence quantum
yields of up to 100%, four times larger than those of common
fluorescent chromophores, which are limited to 25%.4
Furthermore, cyclometalation with aromatic systems affords
strong metal−ligand bonding, which increases the metal-
centered d−d energy gap and prevents population of the
d−d excited state, often responsible for radiationless
desactivation. In the last years the luminescence properties of
heteroleptic C∧N cyclometalated complexes with the general
formula [Pt(C∧N)(O∧O)] have been studied,5 and some of
these promising emitter molecules were used in OLED-
s.5a,g,m,p,x,aa Ancillary O∧O ligands derived from β-diketones
coordinated to the platinum center ensure solubility, stability,
and high quantum efficiency of the complexes.5k
However, irrespective of the multitude of new highly efficient
platinum(II) emitters containing C∧N chelates, the develop-
ment of blue-light-emitting phosphors with long-term stability
remains a real challenge. In this context, C∧C* cyclometalated
ligands based on N-heterocyclic carbenes (NHCs) may remedy
the deficiencies. The carbene increases the ligand field of the
cyclometalated complexes, which is associated with short
metal−carbene carbon atom bond lengths. Consequently, the
Received: May 23, 2013
© XXXX American Chemical Society
A
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(Scheme 2) is required at the beginning of the synthetic route.
The 4-aryl triazoles 1−4 have been synthesized by reaction of
4-substituted anilines with diformyl hydrazine according to a
literature procedure,9 and the 1-aryl triazoles 13−16 have been
prepared by a well-established Ullmann reaction protocol10
from 1H-1,2,4-triazole and aryl halides functionalized in the 4-
position. Quaternization with methyl iodide then leads to the
1,2,4-triazolium salts 5−8 (Scheme 1) and 17−20 (Scheme 2)
in high yields. The platinum(II) complexes 9−12 and 21−24
have been synthesized according to a modified procedure,
originally developed for the preparation of the analogous
imidazolylidene complexes.8b A silver(I) carbene complex,
formed by reaction with silver(I) oxide, is transmetalated with
dichloro(1,5-cyclooctadiene)platinum(II) (Pt(COD)Cl2) fol-
lowed by cyclometalation at the C2 carbon atom of the phenyl
ring. Addition of acetylacetone together with potassium tert-
butoxide then yielded the complexes, which were purified by
column chromatography. The complexes were fully charac-
RESULTS AND DISCUSSION
■
Synthesis and Characterization. The synthetic route to
all platinum(II) complexes described here starts with the
preparation of the corresponding aryl-substituted triazoles.
Depending on the orientation of the triazol-5-ylidene unit in
the final complexes, synthesis of either a 4-aryl-4H-1,2,4-triazole
(1−4) (Scheme 1) or a 1-aryl-1H-1,2,4-triazole (13−16)
a
Scheme 1. Formation of Cyclometalated Complexes 9−12
1
terized by H NMR and 13C NMR spectroscopy as well as
elemental analysis.
The NMR spectra reveal one set of signals with chemical
shifts characteristic for both the cyclometalating ligand and the
acetylacetonate spectator ligand. The absence of a proton signal
above 9 ppm indicates deprotonation on the C2 carbon atom
of the triazole and thus formation of the carbene. Cyclo-
metalation of the phenyl ring to platinum is confirmed by a
Pt−H coupling constant observed for the proton at the C3
carbon atom of the phenyl ring. Additionally, 195Pt NMR
spectra measured for 10−12 and 21−24 exhibit signals in the
range −3447.9 to −3358.7 ppm, which are characteristic for
[Pt(C∧C*)(O∧O)]-type complexes.8c
a
(i) CH3I, THF, 100−110 °C; (ii) Ag2O, 1,4-dioxane; (iii)
Pt(COD)Cl2, 1,4-dioxane/butanone solvent mixture, 115 °C; (iv)
Hacac, KOtBu, DMF, room temperature to 100 °C.
a
Scheme 2. Formation of Cyclometalated Complexes 21−24
Details of the Molecular Structure Determination.
Single crystals of 9 suitable for X-ray diffraction could be
obtained by slow diffusion of diethyl ether into a highly
concentrated solution of the complex in dichloromethane.
Those of 10−12, 21, 23, and 24 were obtained by slow solvent
evaporation from their saturated solution in dichloromethane.
Selected bond lengths, angles, and intermolecular Pt−Pt
distances are given in Table 1. All compounds (with the
exception of 11) crystallize in the monoclinic space group P21/
c. Their asymmetric units contain only one molecule and are
devoid of solvent molecules. Compound 11 crystallizes in the
a
(i) CH3I, THF, 100−110 °C; (ii) Ag2O, 1,4-dioxane; (iii)
Pt(COD)Cl2, 1,4-dioxane/butanone solvent mixture, 115 °C; (iv)
Hacac, KOtBu, DMF, room temperature to 100 °C.
triclinic space group P1, and the asymmetric unit contains two
̅
molecules. The overall structure is similarly arranged when
Table 1. Selected Bond Lengths (Å), Bond Angles (deg), and Dihedral Angles (deg), as well as Intermolecular Pt−Pt Distances
(Å) of Complexes 9−12, 21, 23, and 24
9
10
11
12
21
23
24
Pt−C1
Pt−C5
Pt−O1
Pt−O2
1.928(6)
1.994(5)
2.068(4)
2.032(4)
80.1(2)
96.6(2)
92.6(2)
90.59(16)
127.3(7)
1.3(7)
1.932(8)
1.987(7)
2.084(4)
2.042(5)
80.0(3)
96.8(2)
92.6(2)
90.58(19)
127.7(7)
0.1(8)
1.901(10)
1.999(10)
2.086(6)
2.028(7)
80.0(4)
97.9(3)
91.7(4)
90.4(3)
126.8(10)
−2.6(12)
0.8(8)
1.932(5)
1.983(4)
2.066(3)
2.044(3)
80.43(19)
96.45(17)
92.44(16)
90.65(13)
127.2(5)
1.8(5)
1.930(4)
1.996(4)
2.082(3)
2.039(2)
80.33(15)
97.24(14)
91.41(12)
90.90(10)
127.2(4)
0.5(4)
1.937(5)
1.995(5)
2.071(4)
2.045(4)
79.9(2)
96.29(19)
92.82(18)
90.94(14)
127.3(5)
1.9(6)
1.933(5)
1.993(5)
2.075(3)
2.057(3)
79.82(19)
96.20(17)
93.33(15)
90.70(12)
127.4(5)
0.8(6)
C1−Pt1−C5
C1−Pt1−O1
C5−Pt1−O2
O1−Pt1−O2
C11−C12−C13
C1−N1−C4−C5
O2−Pt1−O1−C11
5.9(5)
0.0(6)
−5.8(4)
3.592
8.8(3)
2.8(4)
−0.1(4)
3.937
a
Pt−Pt
3.386
3.707
3.190
3.352
5.072
a
Intermolecular Pt−Pt distances.
B
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Figure 1. Molecular structure of complexes 9−12. Thermal ellipsoids are drawn at the 50% probability level.
Figure 2. Molecular structure of complexes 21 and 23, and 24. Thermal ellipsoids are drawn at the 50% probability level.
compared to the previously reported imidazolylidene complex-
es.8b,11
Photoluminescence Measurements. The absorption
spectra of the poly(methyl methacrylate) (PMMA) films of
9−11 and 21−24 are shown in Figure 3. All spectra reveal weak
The molecular structures of 9−12 (Figure 1), 21, 23, and 24
(Figure 2) are planar with a platinum center that is coordinated
by one cyclometalated aryltriazolylidene ligand on one side and
one acetylacetonato ligand on the other side. The square-planar
coordination environment of the metal atom reveals deviations
from 90°, observed for the C1−Pt1−C5, C1−Pt1−O1, and
C5−Pt1−O2 angles. The smallest values have been observed
for the C1−Pt1−C5 angle of the cyclometalated ring
(79.82(19)−80.43(19)°). This distortion is similar to those
found for related (C∧C*)Pt-type complexes7,8b,11 and causes a
widening of the C1−Pt1−O1 and C5−Pt1−O2 angles.
However, the almost ideal value is preserved for the O1−
Pt1−O2 angle (90.4(3)−90.94(14)°) due to the widening of
the acetylacetonate moiety, as shown for C11−C12−C13. The
Pt1−C1 bond lengths lie in a characteristic range also found in
other platinum(II) NHC complexes.12 The strong trans
influence of the phenyl C2 carbon atom leads to an elongation
of the Pt1−O1 bond lengths in comparison to the Pt1−O2
bond lengths opposite the carbene carbon donor atom. In the
solid state the planar complexes are arranged in molecular
stacks so that short Pt−Pt contacts can be formed. Crystal
packing diagrams (Figures S1−S7) as well as details of the
structure determination and the software13 used can be found
in the SI. The Pt−Pt distances of all complexes (with the
exception of complex 23) are about twice the van der Waals
radius of platinum (Table 1). In the solid-state structure of 23
the complexes are shifted in the plane, which significantly
increases the Pt−Pt distance (Figure S6).
Figure 3. UV−vis absorption spectra of complexes 9−11 and 21−24
(2% in PMMA).
absorptions of the complexes in the range between 220 and 340
nm. Complex 12 did not show a significant emission and was
therefore not included in Figure 4. All other complexes emit in
the blue or blue-green region of the visible spectrum with
maxima at wavelengths between 420 and 493 nm. Lifetimes of
the excited states in the microsecond range and large Stokes
shifts identify the complexes as phosphorescent emitters.
The emission spectra given in Figures 4 and 5 exhibit
different line shapes due to the normalization, and the quantum
yields of complexes 9−11 are significantly lower compared to
complexes 21−24. They all possess a vibronic-like progression
C
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Table 3. Photoluminescence Data for Complexes 9−11 and
21−24 (2% in PMMA)
a
b
c
d
e
λexc [nm]
CIE x;y
λem [nm]
Φ
τ0 [μs]
9
330
325
340
335
325
330
330
0.169; 0.194
0.192; 0.272
0.174; 0.200
0.166; 0.180
0.193; 0.261
0.169; 0.227
405, 431, 456
411, 436, 465, 493
421, 445, 468
428, 455, 483
432, 459, 488
470
0.11
0.12
0.14
0.30
0.41
0.38
0.38
15
9
10
11
21
22
23
24
18
13
11
16
14
0.165; 0.201
435, 462, 489
a
b
c
Excitation wavelength. CIE coordinates at rt. Max. emission
d
e
wavelength. Quantum yield at λexc, N2 atmosphere. Decay lifetimes
(excited by laser pulses (355 nm, 1 ns)) given as τo = τv/ϕ.
Figure 4. Normalized emission spectra of complexes 9−11, 2% in
PMMA (excitation wavelengths: 330 nm (9), 325 nm (10), 340 nm
(11)).
16 μs; 24: 14 μs), when compared to the corresponding
imidazole complexes (24−25 μs).
The complexes are also strongly emissive in neat films, as
shown for 9, 21−22, and 24 (Figure 6, Table 4). For 10, 11,
Figure 5. Normalized emission spectra of complexes 21−24, 2% in
PMMA (excitation wavelengths: 335 nm (21), 325 nm (22), 330 nm
(23, 24)).
Figure 6. Emission spectra of complexes 9, 21, 22, and 24 (neat films).
of ca. 1100 to 1500 cm−1 (Figures 4 and 5). This is a common
feature for phosphorescent platinum(II) complexes where the
emission process involves an intraligand (3IL) charge transfer
transition and suggests a strong participation of the C∧C*
cyclometalating ligand in the emission process.5g,k,l,u,14
Table 4. Photoluminescence Data for Complexes 9, 21, 22,
and 24 (Neat Films)
a
b
c
d
e
λexc [nm]
CIE x;y
λem [nm]
Φ
τ0 [μs]
9
330
355
330
330
0.151; 0.290
0.178; 0.395
0.495; 0.487
487
499
584
551
0.45
0.39
0.23
2
2
4
4
As shown in Figures 4 and 5 the C∧C* cyclometalated ligand
significantly influences the emission process. Therefore
modifications of this ligand show an effect on the emission as
seen for complexes 10, 11, and 22−24. Substitution at the 4-
position of the phenyl unit shifts the emission slightly to lower
energies and therefore allows a fine-tuning of the emission
wavelength. The electron-donating methoxy group causes the
largest shifts (11: 14 nm; 23: 15 nm).
21
22
24
0.404; 0.529
0.23
a
b
c
Excitation wavelength. CIE coordinates at rt. Max. emission
d
e
wavelength. Quantum yield at λexc, N2 atmosphere. Decay lifetimes
(excited by laser pulses (355 nm, 1 ns)) given as τo = τv/ϕ.
and 23 we were not able to measure neat amorphous emitter
films, as these films rapidly crystallize during preparation. In
contrast to the emission spectra measured from PMMA, neat
films of complexes 9, 21−22, and 24 emit at higher
wavelengths with only one maximum. To shed light on the
origin of the emissions in neat film and the additional low-
energy emission in the spectrum of 10 (Figure 4), the emission
spectra of 9, 10, 21, and 23 in PMMA films at different
concentrations from 0.5 to 4 wt % were measured (Figures S8−
S11). At least for compounds 9 and 10 at higher concentrations
the emission is shifted toward longer wavelengths. The low-
energy emission observed for 9 in the neat film corresponds
nicely to the new maximum found already in the 4 wt %
PMMA film (Figure S8). The low-energy emission of 10 in 2
wt % PMMA (493 nm, Figure 4) becomes more pronounced in
the 4 wt % PMMA film, and we expect that a neat film of 10
The structural effects on the phosphorescence quantum yield
are more pronounced (Table 3). For the 1-aryl triazole
complexes 22−24 quantum yields of up to 40% could be
observed, while the PQY of the corresponding 4-aryl triazole
complexes is found to be only 11−14%. Also the substituent
effects on the 4-aryl triazoles is negligible, as can be seen from
the barely enhanced PQYs of 10 and 11. The 4-aryl triazole
complexes 9−11 reveal quantum yields in a range comparable
to those of the corresponding imidazole complexes reported
previously.8b However, remarkably higher quantum efficiencies
have been detected for 21−24. With a PQY of 41%, the chloro-
substituted 1-aryl triazole complex 22 represents the most
efficient emitter of these examples.
Moreover, the additional nitrogen atom in the carbene unit
leads to shorter decay times of the excited state (11: 18 μs; 23:
D
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dichloromethane. The organic layer was washed with water and brine
and dried over Na2SO4. The solvent was removed under reduced
pressure, and the crude product was purified by flash column
chromatography or recrystallization.
would show a similar emission around 503 nm. Additionally it
is already known that platinum(II) complexes tend to form
aggregated species, which emit at lower energies compared to
the monomers.5a,15 Especially the phenyl triazole complexes 9
and 21 are strongly emissive in neat film with quantum yields of
45% and 39%, respectively. In contrast to 21, complexes 22 and
24 emit with lower PQYs of 23%. The significant red-shift and
the broadened line shape of the emissions suggest that the
emission process in neat film reflects a broad density of states
for the emitter molecules.
General Procedure B. In a pressure tube iodomethane was added
to a solution of the respective triazole in THF. The mixture was stirred
at 100−110 °C for 17−22 h. After cooling to ambient temperature, the
precipitate was filtered, washed with THF, and dried in vacuo.
General Procedure C. A dry Schlenk tube was charged with
triazolium iodide and silver(I) oxide. The reactants were dried in
vacuo, and the Schlenk tube was refilled with argon. After addition of
20 mL of 1,4-dioxane the mixture was stirred at room temperature in
the dark for 21 h under a positive pressure of argon. Afterward,
dichloro(1,5-cyclooctadiene)platinum(II)8b and 10 mL of butanone
were added, and the mixture was heated and stirred at 115 °C for 21 h.
The solvents were removed under reduced pressure, and the resulting
solid was dissolved in 20 mL of anhydrous DMF. Potassium tert-
butoxide and acetylacetone were added, and the mixture was stirred for
21 h at room temperature and another 6 h at 100 °C. After removing
the DMF under reduced pressure the residue was washed with water
and the crude product was purified by flash column chromatography.
1-Methyl-4-phenyl-1,2,4-triazolium Iodide (5). 4-Phenyl-4H-
1,2,4-triazole 116 (290 mg, 2.00 mmol) was reacted with iodomethane
(573 mg, 0.25 mL, 4.00 mmol) in 2 mL of THF for 17 h at 110 °C
according to general procedure B. Compound 5 was isolated as a white
CONCLUSION
■
We were able to synthesize and fully characterize new C∧C*
cyclometalated platinum(II) complexes with aryl triazole
ligands. The 4-aryl-1,2,4-triazol-5-ylidenes 9−11 and 1-aryl-
1,2,4-triazol-5-ylidenes 21−24 are emissive at room temper-
ature (measured in PMMA) with emission wavelengths in the
blue and blue-green region of the visible spectrum. The
emission data reveal that cyclometalated 1-aryl-1,2,4-triazol-5-
ylidenes lead to significantly higher quantum yields. Compared
to the respective 4-aryl-1,2,4-triazol-5-ylidenes, substitution at
the phenyl ring leads to a red-shifted emission. X-ray diffraction
analysis of seven compounds confirms the planar structure of
the platinum(II) complexes, leading to molecular stacking in
the solid state.
1
powder (470 mg, 1.64 mmol, 82%). Mp: 208 °C. H NMR (300.13
MHz, DMSO-d6): δ 10.71 (s, 1 H, NCHN), 9.74 (s, 1 H, NCHN),
3
7.80 (d, JHH = 7.4 Hz, 2 H, C2Harom and C6Harom), 7.75−7.60 (m, 3
H, C3Harom−C5Harom), 4.15 (s, 3 H, CH3). 13C NMR (75.48 MHz,
DMSO-d6): δ 142.8 (NCHN), 142.1 (NCHN), 132.1 (C1arom), 130.5
(C4Harom), 130.3 (C3Harom and C5Harom), 122.5 (C2Harom and
C6Harom), 38.9 (CH3). Anal. Calcd for C9H10IN3: C, 37.65; H, 3.51;
N, 14.64. Found: C, 37.77; H, 3.46; N, 14.61.
EXPERIMENTAL SECTION
■
General Experimental Methods. Dimethylformamide (DMF)
and 1,4-dioxane were dried according to standard methods and stored
over 4 Å molecular sieves under an argon atmosphere. Dichloro(1,5-
cyclooctadiene)platinum(II), 4-aryl-4H-1,2,4-triazoles 116 and 2−4,17
and 1-phenyl-1H-1,2,4-triazole 1318 were synthesized according to
literature procedures.8b,9,10 Potassium tetrachloroplatinate(II) was
purchased from Pressure Chemicals Co. and was used as received.
Other chemicals were obtained from common suppliers and were used
without further purification. 1H NMR, 13C NMR, and 195Pt NMR
4-(4-Chlorophenyl)-1-methyl-1,2,4-triazolium Iodide (6). 4-
(4-Chlorophenyl)-4H-1,2,4-triazole 217 (205 mg, 1.14 mmol) was
reacted with iodomethane (327 mg, 0.14 mL, 2.28 mmol) in 3 mL of
THF for 22 h at 110 °C according to general procedure B. Compound
6 was isolated in the form of brown crystals (258 mg, 0.89 mmol,
1
78%). Mp: 247 °C. H NMR DMSO-d6 (300.13 MHz, DMSO-d6): δ
10.70 (s, 1 H, CH3NCHN), 9.72 (s, 1 H, NCHN), 7.83 (s, 4 H,
CHarom), 4.15 (s, 3 H, CH3). 13C NMR (125.75 MHz, DMSO-d6): δ
142.9 (NCHN), 142.2 (NCHN), 135.1 (Cipso), 131.0 (Cipso), 130.2
(CHarom), 124.5 (CHarom), 38.8 (CH3). Anal. Calcd for C9H9ClIN3: C,
33.62; H, 2.82; N, 13.07. Found: C, 33.22; H, 2.46; N, 13.05.
4-(4-Methoxyphenyl)-1-methyl-1,2,4-triazolium Iodide (7).
4-(4-Methoxyphenyl)-4H-1,2,4-triazole 317 (701 mg, 4.00 mmol)
was reacted with iodomethane (1136 mg, 0.50 mL, 8.00 mmol) in 3
mL of THF for 19 h at 100 °C according to general procedure B.
Compound 7 was isolated as a white powder (1120 mg, 3.53 mmol,
88%). Mp: 227 °C. 1H NMR (300.13 MHz, DMSO-d6): δ 10.61 (s, 1
1
spectra were recorded on a Bruker NMR spectrometer. H NMR and
13C NMR spectra were referenced internally using the resonances of
the solvent (1H: 7.26, 13C: 77.0 for CDCl3; H: 2.50, 13C: 39.43 for
1
DMSO-d6). 195Pt NMR spectra were referenced externally using
potassium tetrachloroplatinate(II) in D2O (−1617.2 (PtCl42−),
−2654.1 (PtCl2)). Shifts are given in ppm; coupling constants J in Hz.
Elemental analyses were performed by the analytical laboratory of
the department using a Eurovektor Hekatech EA-3000 elemental
analyzer. Melting points are not corrected. Photoluminescence
measurements have been performed in thin PMMA films doped
with 0.5 wt %, 2 wt %, and 4 wt % of the emitter or from neat emitter
films. The films were prepared by doctor blading a solution of emitter
in a 10 wt % PMMA solution in dichloromethane on a substrate with a
60 μm doctor blade. The film was dried, and the emission was
measured under nitrogen. The excitation was carried out at a
wavelength of 325−340 nm (Xe-lamp with monochromator), and the
emission was detected with a calibrated quantum-yield detection
system (Hamamatsu, model C9920-02). The phosphorescence decay
was measured by excitation with pulses of a THG-NdYAG laser (355
nm, 1 ns) and time-resolved photon counting by the multichannel
scaling technique.
General Procedure A. According to a modified literature
procedure,10 a dry and argon-flushed Schlenk tube was charged with
Cu2O, 1,10-phenanthroline, triazole, and K2CO3. The reactants were
dried in vacuo at room temperature before the Schlenk tube was
refilled with argon. Dry DMF was added, followed by the respective
aryl halide. The mixture was stirred for 48 h at 120 °C under a positive
pressure of argon. The reaction mixture was cooled to room
temperature before 20 mL of dichloromethane was added. The
suspension was filtered through a plug of Celite and rinsed with
3
H, NCHN), 9.65 (s, 1 H, NCHN), 7.73 (d, JHH = 9.0 Hz, 2 H,
3
CHarom), 7.25 (d, JHH = 9.0 Hz, 2 H, CHarom), 4.14 (s, 3 H, CH3),
3.86 (s, 3 H, CH3). 13C NMR (75.48 MHz, DMSO-d6): δ 160.5
(C1arom), 143.0 (NCHN), 142.0 (NCHN), 124.9 (C4arom), 124.2
(C2Harom and C6Harom), 123.6 (C3Harom and C5Harom), 55.8 (CH3),
38.7 (CH3). Anal. Calcd for C10H12IN3O: C, 37.87; H, 3.81; N, 13.25.
Found: C, 37.96; H, 3.80; N, 13.30.
1-Methyl-4-(4-nitrophenyl)-1,2,4-triazolium Iodide (8). 4-(4-
Nitrophenyl)-4H-1,2,4-triazole 417 (380 mg, 2.00 mmol) was reacted
with iodomethane (341 mg, 0.37 mL, 2.40 mmol) in 3 mL of THF for
22 h at 100 °C according to general procedure B. Compound 8 was
isolated as a white powder (364 mg, 1.1 mmol, 55%). Mp: 242 °C. 1H
NMR (300.13 MHz, DMSO-d6): δ 10.89 (s, 1 H, NCHN), 9.88 (s, 1
H, NCHN), 8.59 (d, 3JHH = 8.9 Hz, 2 H, C3Harom and C5Harom), 8.11
(d, 3JHH = 8.9 Hz, 2 H, C2Harom and C6Harom), 4.19 (s, 3 H, CH3). 13
C
NMR (150.93 MHz, DMSO-d6): δ 148.0 (C4arom), 142.7 (NCHN),
142.3 (NCHN), 136.5 (C1arom), 125.5 (C3Harom and C5Harom), 123.6
(C2Harom and C6Harom), 38.9 (CH3). Anal. Calcd for C9H9IN4O2: C,
32.55; H, 2.73; N, 16.87. Found: C, 32.23; H, 2.53; N, 16.71.
E
dx.doi.org/10.1021/om4004576 | Organometallics XXXX, XXX, XXX−XXX

Organometallics
Article
(Pentan-2,4-dionato-κ2O,O′)(4-phenyl-κC2-1-methyl-1,2,4-
triazol-5-ylidene-κC5)platinum(II) (9). Triazolium iodide 5 (230
mg, 0.8 mmol), silver(I) oxide (93 mg, 0.4 mmol), dichloro(1,5-
cyclooctadiene)platinum(II) (299 mg, 0.8 mmol), potassium tert-
butoxide (359 mg, 3.2 mmol), and pentane-2,4-dione (0.33 mL, 320
mg, 3.2 mmol) were reacted according to general procedure C.
Compound 9 was isolated as a white powder (106 mg, 0.234 mmol,
CH2Cl2: C, 32.26; H, 2.80; N, 10.38. Found: C, 32.46; H, 2.53; N,
10.51.
1-(4-Chlorophenyl)-1H-1,2,4-triazole (14). 1H-1,2,4-Triazole
(2.00 g, 29 mmol), 1-chloro-4-iodobenzene (10.50 g, 44 mmol),
1,10-phenanthroline (1.06 g, 5.8 mmol), copper(I) oxide (0.43 g, 3
mmol), and potassium carbonate (12.20 g, 88 mmol) were reacted in
20 mL of DMF according to general procedure A. The product was
washed with diethyl ether and dried in vacuo. Compound 14 was
obtained in the form of colorless needles (489 mg, 2.72 mmol, 9%).
1
29%). Mp: 248 °C. H NMR (300.13 MHz, CDCl3): δ 8.22 (s, 1 H,
NCHN), 7.81 (t, 3JPtH = 26.8 Hz, 1 H, C3Harom), 7.10−6.95 (m, 3 H,
C4Harom - C6Harom), 5.53 (s, 1 H, CCHC), 4.23 (s, 3 H, NCH3), 2.08
(s, 3 H, CCH3), 2.00 (s, 3 H, CCH3). 13C NMR (75.48 MHz,
CDCl3): δ 185.3 (CO), 185.1 (CO), 152.7 (NCN), 143.4 (C1arom),
135.8 (NCHN), 132.4 (C3Harom), 125.4 (CHarom), 124.3 (C2arom),
123.8 (C5Harom), 110.8 (CHarom), 102.1 (CH), 37.4 (NCH3), 27.9
(CCH3), 27.8 (CCH3). Anal. Calcd for C14H15N3O2Pt H2O: C, 35.75;
H, 3.64; N, 8.93. Found: C, 35.65; H, 3.32; N, 8.95.
1
Mp: 98 °C. H NMR (300.13 MHz, DMSO-d6): δ 8.55 (s, 1 H,
NCHN), 8.12 (s, 1 H, NCHN), 7.65 (d, 3JHH = 8.9 Hz, 2 H, CHarom),
7.50 (d, 3JHH = 8.9 Hz, 2 H, CHarom). 13C NMR (75.48 MHz, DMSO-
d6): δ 152.7 (NCHN), 140.9 (NCHN), 135.4 (Cipso), 133.8 (Cipso),
129.9 (CHarom), 121.1 (CHarom). Anal. Calcd for C8H6ClN3: C, 53.50;
H, 3.37; N, 23.40. Found: C, 53.36; H, 3.40; N, 23.30.
1-(4-Methoxyphenyl)-1H-1,2,4-triazole (15). 1H-1,2,4-Triazole
(1.00 g, 14.5 mmol), 4-iodoanisole (5.15 g, 22.0 mmol), 1,10-
phenanthroline (0.53 g, 2.9 mmol), copper(I) oxide (0.22 g, 1.5
mmol), and potassium carbonate (6.08 g, 44 mmol) were reacted in 10
mL of DMF according to general procedure A. After flash
chromatography with ethyl acetate (silica gel KG60) 15 was obtained
(Pentan-2,4-dionato-κ2O,O′)[4-(4-chlorophenyl-κC2)-1-meth-
yl-1,2,4-triazol-5-ylidene-κC5]platinum(II) (10). Triazolium iodide
6 (257 mg, 0.8 mmol), silver(I) oxide (93 mg, 0.4 mmol),
dichloro(1,5-cyclooctadiene)platinum(II) (299 mg, 0.8 mmol),
potassium tert-butoxide (359 mg, 3.2 mmol), and pentane-2,4-dione
(0.33 mL, 320 mg, 3.2 mmol) were reacted according to general
procedure C. The resulting solid was washed with diethyl ether and
dried in vacuo to yield compound 10 in the form of white crystals (106
mg, 0.218 mmol, 27%). Mp: 231 °C. 1H NMR (300.13 MHz, CDCl3):
δ 8.20 (s, 1 H, NCHN), 7.73 (t, 3JPtH = 29.5 Hz, 1 H, C3Harom), 7.07
1
as a white powder (1.39 g, 7.92 mmol, 55%). Mp: 71 °C. H NMR
(300.13 MHz, DMSO-d6): δ 8.62 (s, 1 H, NCHN), 8.13 (s, 1 H,
NCHN), 7.60 (d, 3JHH = 8.9 Hz, 2 H, C2Harom and C6Harom), 7.03 (d,
3JHH = 8.9 Hz, 2 H, C3Harom and C5Harom), 3.87 (s, 3 H, OCH3). 13
C
NMR (125.75 MHz, DMSO-d6): δ 159.6 (Cipso), 151.7 (NCHN),
140.6 (NCHN), 130.3 (Cipso), 121.9 (C2Harom and C6Harom), 114.9
(C3Harom and C5Harom), 55.6 (OCH3). Anal. Calcd for C9H9N3O: C,
61.70; H, 5.18; N, 23.99. Found: C, 61.48; H, 5.31; N, 24.24.
1-(4-Methylphenyl)-1H-1,2,4-triazole (16). 1H-1,2,4-Triazole
(2.00 g, 29 mmol), 1-bromotoluene (7.53 g, 44 mmol), 1,10-
phenanthroline (1.06 g, 5.8 mmol), copper(I) oxide (0.43 g, 3 mmol),
and potassium carbonate (12.20 g, 88 mmol) were reacted in 20 mL of
DMF according to general procedure A. After flash chromatography
with ethyl acetate (silica gel KG60) 16 was obtained as a white powder
3
3
(d, JHH = 8.2 Hz, 1 H, C5Harom), 7.00 (d, JHH = 8.2 Hz, 1 H,
C6Harom), 5.55 (s, 1 H, CH), 4.23 (s, 3 H, NCH3), 2.11 (s, 3 H,
CCH3), 2.02 (s, 3 H, CCH3). 13C NMR (150.93 MHz, CDCl3): δ
185.4 (CO), 135.8 (NCHN), 132.0 (C3Harom), 130.5 (C4arom), 127.0
(C2arom), 123.5 (C5Harom), 111.7 (C6Harom), 102.3 (CH), 37.5
(NCH3), 27.9 (CCH3), 27.8 (CCH3). 195Pt NMR (129.01 MHz,
CDCl3): δ −3359.7. Anal. Calcd for C14H14ClN3O2Pt: C, 34.54; H,
2.90; N, 8.63. Found: C, 34.21; H, 2.64; N, 8.50.
(Pentan-2,4-dionato-κ2O,O′)[4-(4-methoxyphenyl-κC2)-1-
methyl-1,2,4-triazol-5-ylidene-κC5]platinum(II) (11). Triazolium
iodide 7 (254 mg, 0.8 mmol), silver(I) oxide (93 mg, 0.4 mmol),
dichloro(1,5-cyclooctadiene)platinum(II) (449 mg, 1.2 mmol),
potassium tert-butoxide (359 mg, 3.2 mmol), and pentane-2,4-dione
(0.33 mL, 320 mg, 3.2 mmol) were reacted according to general
procedure C. The resulting solid was washed with diethyl ether and
isohexane and dried in vacuo to yield compound 11 in the form of
1
(1.94 g, 12.20 mmol, 42%). Mp: 62 °C. H NMR (300.13 MHz,
DMSO-d6): δ 8.51 (s, 1 H, NCHN), 8.09 (s, 1 H, NCHN), 7.55 (d,
3
3JHH = 8.5 Hz, 2 H, C2Harom and C6Harom), 7.31 (d, JHH = 8.4 Hz, 2
H, CHarom), 2.41 (s, 3 H, CH3). 13C NMR (125.75 MHz, DMSO-d6):
δ 152.4 (NCHN), 140.7 (NCHN), 138.3 (C4arom), 134.7 (C1arom),
130.3 (C3Harom and C5Harom), 120.0 (C2Harom and C6Harom), 21.0
(CH3). Anal. Calcd for C9H9N3:C, 67.91; H, 5.70; N, 26.40. Found: C,
67.74; H, 5.70; N, 26.42.
1
white crystals (72 mg, 0.149 mmol, 19%). Mp: 162 °C. H NMR
CDCl3 (300.13 MHz, CDCl3): δ 8.16 (s, 1 H, NCHN), 7.38 (td, 3JPtH
= 30.1 Hz, 3JHH = 2.7 Hz, 1 H, C3Harom), 7.01 (dd, 3JHH = 8.5 Hz, 3JHH
= 2.7 Hz, 1 H, C6Harom), 6.62 (d, 3JHH = 8.5 Hz, 1 H, C5Harom), 5.53
(s, 1 H, CH), 4.23 (s, 3 H, NCH3), 3.86 (s, 3 H, OCH3), 2.09 (s, 3 H,
CCH3), 2.01 (s, 3 H, CCH3). 13C NMR (75.48 MHz, CDCl3): δ 185.3
(CO), 185.1 (CO), 156.9 (C4arom), 151.7 (NCN), 137.2 (C1arom),
135.4 (NCHN), 126.2 (C2arom), 117.5 (C3Harom), 111.4 (C6Harom),
108.6 (C5Harom), 102.1 (CH), 55.4 (OCH3), 37.4 (NCH3), 27.9
(CCH3), 27.8 (CCH3). 195Pt NMR (129.01 MHz, CDCl3): δ −3368.2.
Anal. Calcd for C15H17N3O3Pt: C, 37.35; H, 3.55; N, 8.71. Found: C,
37.66; H, 3.40; N, 8.78.
4-Methyl-1-phenyl-1,2,4-triazolium Iodide (17). 1-Phenyl-1H-
1,2,4-triazole 1318 (581 mg, 4.00 mmol) was reacted with iodo-
methane (1136 mg, 0.50 mL, 8.00 mmol) in 3 mL of THF for 17 h at
110 °C according to general procedure B. Compound 17 was isolated
as a white powder (1000 mg, 3.49 mmol, 87%). Mp: 127 °C. 1H NMR
(300.13 MHz, DMSO-d6): δ 10.82 (s, 1 H, NCHN), 9.36 (s, 1 H,
2
NCHN), 7.90 (d, JHH = 7.9 Hz, 2 H, C2Harom and C6Harom), 7.78−
7.60 (m, 3 H, C3Harom−C5Harom), 3.98 (s, 3 H, CH3). 13C NMR
(125.75 MHz, DMSO-d6): δ 145.8 (NCHN), 142.2 (NCHN), 134.9
(C1arom), 130.5 (C4Harom), 130.3 (C3Harom and C5Harom), 120.6
(C2Harom and C6Harom), 34.4 (CH3). Anal. Calcd for C9H10IN3: C,
37.65; H, 3.51; N, 14.64. Found: C, 37.43; H, 3.40; N, 14.66.
1-(4-Chlorophenyl)-4-methyl-1,2,4-triazolium Iodide (18). 1-
(4-Chlorophenyl)-1H-1,2,4-triazole 1417 (359 mg, 2.00 mmol) was
reacted with iodomethane (568 mg, 0.25 mL, 4.00 mmol) in 3 mL of
THF for 22 h at 100 °C according to general procedure B. Compound
18 was isolated as a white powder (555 mg, 1.73 mmol, 86%). Mp:
(Pentan-2,4-dionato-κ2O,O′)[4-(4-nitrophenyl-κC2)-1-meth-
yl-1,2,4-triazol-5-ylidene-κC5]platinum(II) (12). Triazolium iodide
8 (266 mg, 0.8 mmol), silver(I) oxide (93 mg, 0.4 mmol),
dichloro(1,5-cyclooctadiene)platinum(II) (449 mg, 1.2 mmol),
potassium tert-butoxide (359 mg, 3.2 mmol), and pentane-2,4-dione
(0.33 mL, 320 mg, 3.2 mmol) were reacted according to general
procedure C. The resulting solid was washed with isohexane and dried
in vacuo to yield compound 12 as a green powder (71 mg, 0.143
1
248 °C. H NMR (300.13 MHz, CDCl3): δ 10.87 (s, 1 H, NCHN),
3
9.38 (s, 1 H, NCHN), 7.88−7.98 (d, JHH = 8.9 Hz, 2 H, CHarom),
1
3
7.74−7.85 (d, JHH = 8.9 Hz, 2 H, CHarom), 3.98 (s, 3 H, CH3). 13C
mmol, 18%). Mp: 260 °C. H NMR (300.13 MHz, CDCl3): δ 8.63
(td, 3JPtH = 29.8 Hz, 3JHH = 2.5 Hz, 1 H, C3Harom), 8.02 (dd, 3JHH = 8.6
Hz, 3JHH = 2.5 Hz 1 H, CHarom), 7.18 (d, 3JHH = 8.5 Hz, 1 H, CHarom),
5.59 (s, 1 H, CH), 4.27 (s, 3 H, CH3), 2.16 (s, 3 H, CH3), 2.05 (s, 3 H,
CH3). 13C NMR (150.93 MHz, CDCl3): δ 185.7 (CO), 185.5 (CO),
136.2 (NCHN), 127.1 (C3Harom), 120.4 (C5Harom), 110.7 (C6Harom),
102.4 (CH), 37.6 (NCH3), 27.9 (CCH3), 27.8 (CCH3). 195Pt NMR
(129.01 MHz, CDCl3): δ −3358.7. Anal. Calcd for C14H14N4O4Pt·0.5
NMR (75.48 MHz, DMSO-d6): δ 145.9 (NCHN), 142.5 (NCHN),
134.9 (Cipso), 133.8 (Cipso), 130.3 (CHarom), 122.5 (CHarom), 34.4
(CH3). Anal. Calcd for C9H9N3ClI: C, 33.62; H, 2.82; N, 13.07.
Found: C, 33.81; H, 2.76; N, 13.13.
1-(4-Methoxyphenyl)-4-methyl-1,2,4-triazolium Iodide (19).
1-(4-Methoxyphenyl)-1H-1,2,4-triazole 1519 (526 mg, 3.00 mmol) was
reacted with iodomethane (639 mg, 0.28 mL, 4.50 mmol) in 3 mL of
F
dx.doi.org/10.1021/om4004576 | Organometallics XXXX, XXX, XXX−XXX

Organometallics
Article
THF for 22 h at 110 °C according to general procedure B. Compound
19 was isolated as a white powder (812 mg, 2.56 mmol, 85%). Mp:
C3Harom), 7.19 (d, 1 H, 3JHH = 8.4 Hz, C6Harom), 6.63 (dd, 1 H, 3JHH
=
3
8.4 Hz, JHH = 2.7 Hz, C5Harom), 5.51 (s, 1 H, CH), 4.05 (s, 1 H,
NCH3), 3.86 (s, 3 H, OCH3), 2.07 (s, 3 H, CCH3), 1.97 (s, 3 H,
CCH3). 13C NMR (150.93 MHz, CDCl3): δ 185.0 (CO), 185.0 (CO),
157.0 (C4arom), 152.0 (NCN), 141.2 (NCHN), 139.1 (C1arom), 123.4
(C2arom), 116.9 (C3Harom), 112.1 (C6Harom), 108.2, (C5Harom), 102.1
(CH), 55.5 (OCH3), 32.7 (NCH3), 27.9 (CCH3), 27.8 (CCH3). 195Pt
NMR (129.01 MHz, CDCl3): δ −3421.4. Anal. Calcd for
C15H17N3O3Pt: C 37.35; H, 3.55; N, 8.71. Found: C, 37.44; H,
3.50; N, 8.69.
1
212 °C. H NMR (300.13 MHz, CDCl3): δ 10.72 (s, 1 H, NCHN),
3
9.33 (s, 1 H, NCHN), 7.81 (d, JHH = 9.0 Hz, 2 H, C2Haromand
C6Harom), 7.24 (d, 3JHH = 9.0 Hz, 2 H, C3Harom and C5Harom), 3.97 (s,
3 H, NCH3), 3.86 (s, 3 H, OCH3). 13C NMR (150.93 MHz, DMSO-
d6): δ 160.5 (C1arom), 145.6 (NCHN), 141.6 (NCHN), 128.1
(C4arom), 122.4 (C2Harom and C6Harom), 115.2 (C3Harom and
C5Harom), 55.8 (OCH3), 34.3 (NCH3). Anal. Calcd for
C10H12IN3O: C, 37.87; H, 3.81; N, 13.25. Found: C, 38.15; H, 3.84;
N, 13.35.
(Pentan-2,4-dionato-κ2O,O′)[1-(4-methylphenyl-κC2)-4-
methyl-1,2,4-triazol-5-ylidene-κC5]platinum(II) (24). Triazolium
iodide 20 (241 mg, 0.8 mmol), silver(I) oxide (93 mg, 0.4 mmol),
dichloro(1,5-cyclooctadiene)platinum(II) (449 mg, 1.2 mmol),
potassium tert-butoxide (359 mg, 3.2 mmol), and pentane-2,4-dione
(0.33 mL, 320 mg, 3.2 mmol) were reacted according to general
procedure C. The solid was washed with isohexane and diethyl ether
and dried in vacuo to yield compound 24 as a white powder (108 mg,
4-Methyl-1-(4-methylphenyl)-1,2,4-triazolium Iodide (20). 1-
(4-Methylphenyl)-1H-1,2,4-triazole 1620 (637 mg, 4.00 mmol) was
reacted with iodomethane (1136 mg, 0.50 mL, 8.00 mmol) in 3 mL of
THF for 22 h at 100 °C according to general procedure B. Compound
20 was isolated as a white powder (1121 mg, 3.72 mmol, 93%). Mp:
169 °C. 1H NMR (300.13 MHz, DMSO-d6): δ 10.77 (s, 1 H, NCHN),
3
9.34 (s, 1 H, NCHN), 7.78 (d, JHH = 8.4 Hz, 2 H, CHarom), 7.51 (d,
1
3JHH = 8.6 Hz, 2 H, CHarom), 3.97 (s, 3 H, CCH3). 13C NMR (75.48
0.232 mmol, 29%). Mp: 206 °C. H NMR (300.13 MHz, CDCl3): δ
7.82 (s, 1 H, NCHN), 7.58 (t, 3JPtH = 28.4 Hz, 1 H, C3Harom), 7.15 (d,
3JHH = 7.8 Hz, 1 H, C6Harom), 6.88 (d, 3JHH = 7.8 Hz, 1 H, C5Harom),
5.52 (s, 1 H, CH), 4.07 (s, 3 H, NCH3), 2.39 (s, 3 H, CH3), 2.10 (s, 3
H, CCH3), 1.98 (s, 3 H, CCH3). 13C NMR (150.93 MHz, CDCl3): δ
185.0 (CO), 153.0 (NCN), 143.0 (C1arom), 141.3 (NCHN), 134.9
(C4arom), 131.8 (C3Harom), 124.3 (C5Harom), 121.2 (C2arom), 110.9
(C6Harom), 102.1 (CH), 32.7 (NCH3), 28.5 (CCH3), 28.3 (CCH3),
21.7 (CCH3). 195Pt NMR (129.01 MHz, CDCl3): δ −3436.3. Anal.
Calcd for C15H17N3O2Pt: C, 38.63; H, 3.67; N, 9.01. Found: C, 38.37;
H, 3.59; N, 8.92.
MHz, DMSO-d6): δ 145.7 (NCHN), 141.8 (NCHN), 140.5 (Cipso),
132.7 (Cipso), 130.6 (CHarom), 120.4 (CHarom), 34.3 (NCH3), 20.65
(CCH3). Anal. Calcd for C10H12IN3: C, 39.89; H, 4.02; N, 13.95.
Found: C, 40.09; H, 4.05; N, 14.05.
(Pentan-2,4-dionato-κ2O,O′)(1-phenyl-κC2-4-methyl-1,2,4-
triazol-5-ylidene-κC5)platinum(II) (21). Triazolium iodide 17 (230
mg, 0.8 mmol), silver(I) oxide (93 mg, 0.4 mmol), dichloro(1,5-
cyclooctadiene)platinum(II) (449 mg, 1.2 mmol), potassium tert-
butoxide (359 mg, 3.2 mmol), and pentane-2,4-dione (0.33 mL, 320
mg, 3.2 mmol) were reacted according to general procedure C. The
solid was washed with diethyl ether and isohexane and dried in vacuo
to yield compound 21 as a white powder (160 mg, 0.354 mmol, 44%).
Mp: 235 °C. 1H NMR (300.13 MHz, CDCl3): δ 7.85 (s, 1 H,
NCHN), 7.79 (t, 3JPtH = 27.2 Hz, 1 H, C3Harom), 7.35−7.25 (m, 1 H,
C6Harom), 7.14−7.03 (m, 2 H, C4Harom and C5Harom), 5.52 (s, 1 H,
CH), 4.09 (s, 3 H, NCH3), 2.08 (s, 3 H, CCH3), 1.98 (s, 3 H, CCH3).
13C NMR (125.75 MHz, CDCl3): δ 185.1 (CO), 185.0 (CO), 153.7
ASSOCIATED CONTENT
* Supporting Information
CIF files, text, tables, and figures giving experimental details,
crystallographic data, and detailed spectra. This material is
available free of charge via the Internet at http://pubs.acs.org.
■
S
(NCN), 145.2 (C1arom), 141.5 (NCHN), 131.1 (C3Harom), 125.2
(CHarom),123.9 (CHarom),121.6 (C2arom), 111.5 (C6Harom), 102.1
(CH), 32.7 (NCH3), 27.9 (CCH3), 27.8 (CCH3). 195Pt NMR
(129.01 MHz, CDCl3): δ −3447.9. Anal. Calcd for C14H15N3O2Pt: C,
37.17; H, 3.34; N, 9.29. Found: C, 36.86; H, 3.28; N, 9.11.
AUTHOR INFORMATION
Corresponding Author
*Fax: 49 351 46339679. Tel: 49 351 46338571. E-mail: thomas.
strassner@chemie.tu-dresden.de.
■
(Pentan-2,4-dionato-κ2O,O′)[1-(4-chlorophenyl-κC2)-4-meth-
yl-1,2,4-triazol-5-ylidene-κC5]platinum(II) (22). Triazolium iodide
18 (257 mg, 0.8 mmol), silver(I) oxide (93 mg, 0.4 mmol),
dichloro(1,5-cyclooctadiene)platinum(II) (449 mg, 1.2 mmol),
potassium tert-butoxide (359 mg, 3.2 mmol), and pentane-2,4-dione
(0.33 mL, 320 mg, 3.2 mmol) were reacted according to general
procedure C. The solid was washed with diethyl ether and isohexane
and dried in vacuo to yield compound 22 as a white powder (90 mg,
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
We are grateful for the support of the project by the BMBF
(FKZ: 13N10477) and thank Dr. Lennartz (BASF) for helpful
■
discussions and J. Sollner for triazole syntheses. We also thank
̈
1
0.19 mmol, 23%). Mp: 163 °C. H NMR (300.13 MHz, CDCl3): δ
the ZIH for computation time at their high-performance
computing facility.
3
3
7.81 (s, 1 H, NCHN), 7.70 (td, JPtH = 30.2 Hz, JHH = 2.2 Hz, 1 H,
C3Harom). 7.18 (d, 3JHH = 8.2 Hz, 1 H, C6Harom), 7.07 (dd, 3JPtH = 8.2
Hz, JHH = 2.2 Hz, 1 H, C5Harom), 5.52 (s, 1 H, CH), 4.05 (s, 3 H,
3
REFERENCES
NCH3), 2.10 (s, 3 H, CCH3), 1.98 (s, 3 H, CCH3). 13C NMR (150.93
MHz, CDCl3): δ 185.2 (CO), 185.1 (CO), 153.2 (NCN), 143.8
(C1arom), 141.6 (NCHN), 130.7 (C3Harom), 130.2 (C4arom), 124.2
(C2arom), 123.6 (C5Harom), 112.4 (C6Harom), 102.2 (CH), 32.7
(NCH3), 27.8 (CCH3), 27.8 (CCH3). 195Pt NMR (129.01 MHz,
CDCl3): δ −3397.8. Anal. Calcd for C14H14ClN3O2Pt: C, 34.54; H,
2.90; N, 8.63. Found: C, 34.71; H, 2.90; N, 8.50.
■
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3
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G
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