Published as part of the Special Section 13th EuCheMS Organic Division Young Investigator Workshop
Mesyl and Triflyl Functionalized N-Heterocyclic Carbenes as Acceptor Fragments in Luminescent Carbene-Metal-Amide Complexes
Armands Ruduss
a
Institute of Applied Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, 3/7 Paula Valdena Str., Riga 1048, Latvia
,
Zanis Sisojevs
a
Institute of Applied Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, 3/7 Paula Valdena Str., Riga 1048, Latvia
,
Sergey Belyakov
b
Latvian Institute of Organic Synthesis, 21 Aizkraukles Str., Riga 1006, Latvia
a
Institute of Applied Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, 3/7 Paula Valdena Str., Riga 1048, Latvia
› Author AffiliationsThis research was funded by the Latvian Council of Science (Latvijas Zinātnes Padome; lzp-2019/1-0231).
Synthetic procedures providing access to mesyl and triflyl functionalized derivatives of 1,3-bis(2,6-diisopropylphenyl)imidazolidin-2-ylidene (SIPr) have been provided in detail. New luminescent carbene-metal-amide (CMA) Cu(I) complexes based on acceptor group functionalized SIPr have been prepared. The effect of the LUMO energy in the sulfonyl functionalized N-heterocyclic carbene (NHC) series on the emissive properties of the CMAs has been investigated.
3a
Di D,
Romanov AS,
Yang L,
Richter JM,
Rivett JP. H,
Jones S,
Thomas TH,
Abdi Jalebi M,
Friend RH,
Linnolahti M,
Bochmann M,
Credgington D.
Science 2017; 356: 159
6e
Duda E,
Hall D,
Bagnich S,
Carpenter-Warren CL,
Saxena R,
Wong MY,
Cordes DB,
Slawin AM. Z,
Beljonne D,
Olivier Y,
Zysman-Colman E,
Köhler A.
J. Phys. Chem. B 2022; 126: 552
8b
Romanov AS,
Jones ST. E,
Gu Q,
Conaghan PJ,
Drummond BH,
Feng J,
Chotard F,
Buizza L,
Foley M,
Linnolahti M,
Credgington D,
Bochmann M.
Chem. Sci. 2020; 11: 435
16 Compound 18a: A mixture of 1,3-bis(2,6-diisopropyl-4-(methylthio)phenyl)-4,5-dihydro-1H-imidazol-3-ium chloride (16a) (2.00 g, 3.43 mmol) and KHMDS (0.72 g, 3.61 mmol) in anhydrous THF (200 mL) was stirred for 1 h at r.t. Then CuCl (0.34 g, 3.43 mmol) was added and the mixture was stirred for additional 2.5 h at r.t. The formed precipitate containing product was separated by filtration. The solid was collected and purified using a Soxhlet apparatus (24 h, solvent: acetonitrile) to afford the product as a greenish solid. Yield: 1.34 g (60%). 1H NMR (DMSO-d6, 500 MHz): δ = 7.88 (s, 4 H), 4.16 (s, 4 H), 3.36 (s, 6 H), 3.18 (hept, J = 6.7 Hz, 4 H), 1.38 (d, J = 6.7 Hz, 12 H), 1.31 (d, J = 6.7 Hz, 12 H). 13C NMR data not obtained due to the low solubility of compound 18a.
17
Santoro O,
Collado A,
Slawin AM. Z,
Nolan SP,
Cazin CS. J.
Chem. Commun. 2013; 49: 10483
18 Compound 18b: A mixture of 1,3-bis(2,6-diisopropyl-4-((trifluoromethyl)sulfonyl)phenyl)-4,5-dihydro-1H-imidazol-3-ium chloride (17b) (2.16 g, 3.13 mmol), CuCl (0.38 g, 3.84 mmol) and K2CO3 (0.70 g, 5.06 mmol) in acetone (200 mL) was stirred and heated at reflux for 24 h. The precipitate containing product was separated by filtration, washed with H2O and dried at r.t. The solid was purified by using a Soxhlet apparatus (48 h, solvent: acetonitrile) to afford the product as a greenish solid. Yield: 1.72 g (73%). 1H NMR (DMSO-d6, 500 MHz): δ = 8.03 (s, 2 H), 4.25 (s, 4 H), 3.24–3.20 (m, 4 H), 1.38 (d, J = 6.8 Hz, 12 H), 1.31 (d, J = 6.8 Hz, 12 H). 13C NMR data not obtained due to the low solubility of compound 18b. 19F NMR (DMSO-d6, 471 MHz): δ = –78.26.
19 Compound 19a: To a solution of 9H-carbazole (0.093 g, 0.556 mmol) in anhydrous degassed THF (45 mL), KOtBu (0.063 g, 0.561 mmol) was added and the mixture was stirred at r.t. for 30 min. Then compound 18a (0.300 g, 0.465 mmol) was added and the mixture was stirred for an additional 3 h. Then mixture was filtered via syringe filter into anhydrous degassed hexane (250 mL) to precipitate the product. The obtained mixture was filtered and washed with hexane (50 mL) to obtain the product as an off-white solid. Yield: 0.234 g (65%). 1H NMR (DMSO-d6, 500 MHz): δ = 8.04 (s, 4 H), 7.76 (d, J = 7.5 Hz, 2 H), 6.83 (t, J = 7.5 Hz, 2 H), 6.73 (t, J = 7.3 Hz, 2 H), 5.83 (d, J = 8.1 Hz, 2 H), 4.36 (s, 4 H), 3.43 (s, 6 H), 3.35 (m, 4 H), 1.42 (d, J = 6.7 Hz, 12 H), 1.27 (d, J = 6.7 Hz, 12 H). 13C NMR (DMSO-d6, 125.77 MHz): δ = 202.70, 149.15, 148.86, 142.41, 138.90, 123.32, 123.24, 123.03, 118.98, 115.15, 112.99, 53.56, 43.17, 28.59, 24.63, 23.19. A similar method was used for the synthesis of compounds 19b and 20a (see the Supporting Information).
20 CCDC 2214035 (19a) and 2214034 (20a) contain the supplementary crystallographic data for this paper. The data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/structures
