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dry DMF and heated to 858C for 24 h. After adding 299 mg
(0.8 mmol, 1 equiv) Pt(COD)Cl2, the mixture is stirred at room tem-
perature for three hours and subsequently heated to 1308C for an-
other 21 hours. The solution is cooled to room temperature,
0.160 mg (1.6 mmol, 2 equiv) acetylacetone and 221 mg (1.6 mmol,
2 equiv) potassium carbonate are added and stirred at room tem-
perature for 21 hours and afterwards at 1008C for six hours. All vol-
atiles are removed in vacuo and the residue is washed with
ca. 40 mL of distilled water. The remaining solid is filtered, dried at
608C overnight and extracted with DCM. The product is purified
by flash column chromatography with DCM as eluent. The product
is obtained after washing with iso-hexanes and diethyl ether (3ꢂ
5 mL each) and drying in vacuo. (185 mg, 45%). M.p. 2208C.
1H NMR (600 MHz, CDCl3): d=8.05 (s, 1H, NCH), 7.97–7.84 (m, 1H,
PtCCH), 7.84–7.78 (m, 2H, CHortho of N3-Ph), 7.65–7.59 (m, 2H,
CHmeta of N3-Ph), 7.59–7.55 (m, 1H, CHpara of N3-Ph), 7.54 (dd, J=
7.8, 1.4 Hz, 1H, CHortho of N1-Ph), 7.18 (t, J=7.4 Hz, 1H, CHpara of
N1-Ph), 7.12 (t, J=7.5 Hz, 1H, CHmeta of N1-Ph), 5.50 (s, 1H),
2.06 ppm (s, 3H), 2.00 (s, 3H). 13C NMR (151 MHz, CDCl3): d=185.1
(CO), 184.8 (CO), 145.4 (PtCCN), 139.4 (PtCN), 136.1 (Ci of N3-Ph),
132.4 (PtCCH), 130.3 (CHpara of N3-Ph), 130.1 (CHmeta of N3-Ph),
128.0 (CHpara of N1-Ph), 127.2 (PtCCN), 124.7 (NCH), 123.5 (CHmeta
of N1-Ph), 120.8 (CHortho of N3-Ph), 113.6 (CHortho of N1-Ph), 102.2
(CHarom), 27.9 (COCH3), 27.8 ppm (COCH3). 195Pt NMR (64 MHz,
CDCl3): d=ꢀ3410.3 ppm (d, J=53 Hz). MS (ESI, m/z): 515.2
(M+H)+; 929.3 (2M-acac)+. Anal Calcd for C19H17N3O2Pt 0.08 CH2Cl2:
C 43.73, H 3.29, N 8.02; found: C 43.69, H 3.25, N 8.05.
(M+H)+. Anal Calcd for C37H37N3O2Pt 0.27 CH2Cl2: C 57.86, H 4.89,
N 5.43; found: C 57.84, H 4.88, N 5.41.
Acetylacetonat-kO,kO’-[3-(phenyl-kC2)-1-(2,4,6-trimethylphenyl)-tria-
zol-4-ylidene-kC5]platinum(ii) (5): In a flame dried Schlenk tube,
0.351 g (1 mmol) 1-phenyl-3-(2,4,6-trimethylphenyl)-1,2,3-triazolium
tetrafluoroborate (3) and 0.116 g (0.5 mmol, 0.5 equiv) silver(I)-
oxide are dissolved in 24 mL dry DMF and heated to 808C for 24 h.
After adding 374 mg (1 mmol, 1 equiv) Pt(COD)Cl2, the mixture was
stirred at room temperature for three hours and subsequently
heated to 1308C for another 21 hours. The solution is cooled to
room temperature, 0.400 mg (4 mmol, 4 equiv) acetylacetone and
553 mg (4 mmol, 4 equiv) potassium carbonate are added and
stirred at room temperature for 21 hours and afterwards at 1008C
for six hours. All volatiles are removed in vacuo and the residue is
washed with ca. 40 mL of distilled water. The remaining solid is fil-
tered, dried at 608C overnight and extracted with DCM. The prod-
uct is purified by flash column chromatography with an eluent
mixture of DCM/methanol (1% methanol). The product is obtained
after drying in vacuo. (129 mg, 23%). M.p.: 2558C. 1H NMR
(300 MHz, CDCl3): d=8.07–7.74 (m, 1H, CHarom), 7.63 (s, 1H, CHarom),
7.47 (dd, J=7.7, 1.5 Hz, 1H, CHarom), 7.18 (td, J=7.4, 1.5 Hz, 1H,
CHarom), 7.10 (td, J=7.5, 1.5 Hz, 1H, CHarom), 7.04 (s, 2H, CHarom), 5.49
(s, 1H, COCH), 2.38 (s, 3H, CCH3), 2.09 (s, 6H, CCH3), 2.06 (s, 3H,
CCH3), 1.96 ppm (s, 3H, CCH3). 13C NMR (75 MHz, CDCl3): d=185.2
(CO), 185.0 (CO), 145.9 (Ci), 141.4 (Ci), 138.8 (Ci), 135.1 (Ci), 132.8 (Ci),
132.6 (CHarom), 129.5 (CHarom), 129.2 (CHarom), 128.0 (CHarom), 127.0
(Ci), 123.6 (CHarom), 113.7 (CHarom), 102.3 (CHarom), 28.1 (CCH3), 28.0
(CCH3), 21.3 (CCH3), 17.3 ppm (CCH3). 195Pt NMR (64 MHz, CDCl3)
d=ꢀ3414.6 ppm (d, J=56.9 Hz). MS (ESI, m/z): 557.4 (M+H)+. Anal
Calcd for C22H23N3O2Pt: C 47.48, H 4.17, N 7.55; found: C 47.15, H
4.05, N 7.54.
[Bis-1,3-(2,4,6-trimethylphenyl)propane-1,3-dionato-kO,kO’][1-phenyl-
3-(phenyl-kC2)-triazol-4-ylidene-kC4]platinum(II) (4b): Prepared anal-
ogously to 4a (see Supporting Information). 0.493 mg (1.6 mmol,
2 equiv) bis-1,3-(2,4,6-trimethylphenyl)propane-1,3-dione were
used instead of acetylacetone and 180 mg (1.6 mmol, 2 equiv) po-
tassium tert-butoxide instead of potassium carbonate (146 mg,
Acknowledgements
1
25%). M.p. 2698C. H NMR (300 MHz, CDCl3): d=8.02 (s, 1H), 7.98–
7.70 (m, 3H), 7.66–7.48 (m, 4H), 7.17–7.04 (m, 2H), 6.86 (d, J=
3.7 Hz, 4H), 5.67 (s, 1H), 2.38 (s, 6H), 2.35 (s, 6H), 2.31 (s, 3H),
2.30 ppm (s, 3H). 13C NMR (75 MHz, CDCl3): d=184.9 (CO), 184.3
(CO), 145.6 (Ci), 139.8 (Ci), 139.6 (2 Ci), 137.7 (Ci), 137.6 (Ci), 136.3
(Ci), 134.3 (Ci), 134.1 (Ci), 133.1 (CHarom), 130.4 (CHarom), 130.3
(CHarom), 128.6 (CHarom), 128.3 (CHarom), 128.2 (CHarom), 127.1 (Ci),
125.0 (CHarom), 123.8 (CHarom), 120.8 (CHarom), 113.7 (CHarom), 107.1
(CHarom), 21.2 (2 CCH3), 20.0 (CCH3), 19.8 ppm (CCH3). 195Pt NMR
(64 MHz, CDCl3): d=ꢀ3350.4 ppm. MS (ESI, m/z): 723.4 (M+H)+.
Anal Calcd for C35H33N3O2Pt: C 58.16, H 4.60, N 5.81; found: C
58.34, H 4.57, N 5.42.
We would like to thank the ZIH Dresden for allocating compu-
tational time on their high performance computing facility. J.S.
would also like to thank the Studienstiftung des Deutschen
Volkes for funding.
Conflict of interest
The authors declare no conflict of interest.
Keywords: excited state
phosphorescence · platinum
·
mesoionic
·
OLEDs
·
[Bis-1,3-(2,3,5,6-tetramethylphenyl)-propane-1,3-dionato-kO,kO’][1-
phenyl-3-(phenyl-kC2)-triazol-4-ylidene-kC4]platinum(II) (4c): Pre-
pared analogously to 4a (see Supporting Information). 0.538 mg
(1.6 mmol, 2 equiv) bis-1,3-(2,3,5,6-tetramethylphenyl)propane-1,3-
dione were used instead of acetylacetone and 180 mg (1.6 mmol,
2 equiv) potassium tert-butoxide instead of potassium carbonate
[3] a) C. A. Bignozzi, R. Argazzi, R. Boaretto, E. Busatto, S. Carli, F. Ronconi,
d) A. Hagfeldt, G. Boschloo, L. Sun, L. Kloo, H. Pettersson, Chem. Rev.
1
(246 mg, 41%). M.p. >3258C. H NMR (300 MHz, CDCl3): d=8.05 (s,
1H, NCH), 7.89–7.82 (m, 1H, CHarom), 7.82–7.75 (m, 2H, CHarom),
7.65–7.50 (m, 4H, CHarom), 7.18–7.05 (m, 2H, CHarom), 6.95 (d, J=
4.7 Hz, 2H, CHarom), 5.64 (s, 1H, COCH), 2.28 (s, 6H, CCH3), 2.25 (s,
6H, CCH3), 2.24 (s, 6H, CCH3), 2.22 ppm (s, 6H, CCH3). 13C NMR
(75 MHz, CDCl3): d=185.8 (Ci), 185.3 (Ci), 145.4 (Ci), 142.7 (Ci), 142.5
(Ci), 139.5 (Ci), 136.1 (Ci), 133.7 (Ci), 133.6 (Ci), 133.0 (CHarom), 132.0
(CHarom), 131.0 (CHarom), 131.0 (CHarom), 130.2 (CHarom), 130.1 (CHarom),
129.7 (Ci), 129.5 (Ci), 128.0 (CHarom), 127.0 (Ci), 124.9 (CHarom), 123.6
(CHarom), 120.6 (CHarom), 113.5 (CHarom), 107.5 (CHarom), 19.7 (CCH3),
19.6 (CCH3), 16.5 (CCH3), 16.3 ppm (CCH3). MS (ESI, m/z): 751.4
[4] Highly Efficient OLEDs with Phosphorescent Materials (Ed.: H. Yersin),
Wiley, Weinheim, 2008.
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Chem. Eur. J. 2018, 24, 1 – 8
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