Synthesis and fluorescent properties of N(9)-alkylated 2-amino-6-triazolylpurines and 7-deazapurines

• Andrejs Šišuļins,
• Jonas Bucevičius,
• Yu-Ting Tseng,
• Irina Novosjolova,
• Kaspars Traskovskis,
• Ērika Bizdēna,
• Huan-Tsung Chang,
• Sigitas Tumkevičius and
• Māris Turks

Beilstein J. Org. Chem. 2019, 15, 474–489, doi:10.3762/bjoc.15.41

• increases with the increase of solvent polarity. Additionally, X-ray analysis of 2,6-diazidopurine 2'-deoxyribonucleoside revealed the exclusive existence of the azido tautomer in the solid state [41]. The discovered ability of the azido group to be substituted with amines at C(2) position was used for the

Study on the regioselectivity of the N-ethylation reaction of N-benzyl-4-oxo-1,4-dihydroquinoline-3-carboxamide

• Pedro N. Batalha,
• Luana da S. M. Forezi,
• Maria Clara R. Freitas,
• Nathalia M. de C. Tolentino,
• Ednilsom Orestes,
• José Walkimar de M. Carneiro,
• Fernanda da C. S. Boechat and
• Maria Cecília B. V. de Souza

Beilstein J. Org. Chem. 2019, 15, 388–400, doi:10.3762/bjoc.15.35

• structure as shown in Figure 6. As can be seen in Figure 6, attached to the central oxoquinoline ring is an ethyl substituent bonded to N1 and the carboxamide group is attached to C3. The solid-state structure confirms the regioselectivity of the reaction. It is important to note from the crystalline

Computational characterization of enzyme-bound thiamin diphosphate reveals a surprisingly stable tricyclic state: implications for catalysis

• Ferran Planas,
• Michael J. McLeish and
• Fahmi Himo

Beilstein J. Org. Chem. 2019, 15, 145–159, doi:10.3762/bjoc.15.15

• for the APH+ form. However, solid-state NMR using 15N and 13C-labeled ThDP has been used to identify APH+ on pyruvate decarboxylase and the E1 component of the pyruvate dehydrogenase complex [18]. In addition to the plethora of experimental investigations, a number of computational studies have

Systematic synthetic study of four diastereomerically distinct limonene-1,2-diols and their corresponding cyclic carbonates

• Hiroshi Morikawa,
• Jun-ichi Yamaguchi,
• Shun-ichi Sugimura,
• Masato Minamoto,
• Yuuta Gorou,
• Hisatoyo Morinaga and
• Suguru Motokucho

Beilstein J. Org. Chem. 2019, 15, 130–136, doi:10.3762/bjoc.15.13

• reported in our previous study [27]. Of these, 1a has already been synthesised by other groups [10][11] as well as our group. Particularly, Kleij et al. revealed the solid-state structure of 1a via X-ray analysis [11], but the isolation and characterisation of 1d has only been reported by our group. Herein

• coupling constants match well the conformations in Figure 5 although the signal c for 1d unfortunately overlaps with other signals. The structure of 1a is in good agreement with the solid-state structure reported previously [11]. Conformations of the four LMdiols were also considered in the same manner as

• those of LM5CCs by reference to the a and c signals in Figure 4. The coupling constants for the signal a support the structures shown in Figure 5. Indeed, the equatorial position of the isopropenyl group for 2c and 2d in the solid state was confirmed by X-ray diffraction analysis, as reported previously

Fabrication of supramolecular cyclodextrin–fullerene nonwovens by electrospinning

• Hiroaki Yoshida,
• Ken Kikuta and
• Toshiyuki Kida

Beilstein J. Org. Chem. 2019, 15, 89–95, doi:10.3762/bjoc.15.10

• regardless of the incorporation of C60, and the fiber diameter is approximately 3 μm. This may be because all solutions have similar solution properties. To clarify the inner structure of the γ-CD–C60 fibers, solid-state 13C NMR and UV–vis diffuse reflectance spectroscopies were performed. As shown in Figure

•  3d, solid-state 13C NMR clarifies the presence of C60 in the fibers, but does not provide additional information. Solid-state UV–vis reflectance spectroscopy clearly suggests reflectance peaks at 260, 330, and 410 nm. This spectrum is almost the same as those of the γ-CD–C60 complex solutions (Figure

Ruthenium-based olefin metathesis catalysts with monodentate unsymmetrical NHC ligands

• Veronica Paradiso,
• Chiara Costabile and
• Fabia Grisi

Beilstein J. Org. Chem. 2018, 14, 3122–3149, doi:10.3762/bjoc.14.292

• and 25b this orientation was observed also in the solid state. Some metathesis reactions performed in this study with 24b and 25b in comparison to GII-SIMes and HGII-SIMes are summarized in Table 1. In the model RCM reaction of N,N-diallyl-p-toluenesulfonamide (26, Table 1, entry 1), catalysts 24a and

• methyl (41), octyl (42) or cyclohexyl (43, Figure 11) [25]. For all of the complexes, two rotamers were observed in solution, and the most abundant species was identified as the isomer with the indenylidene moiety located under the mesityl group. Solid-state structures of the complexes showed

• ruthenium center was detected in the species 118 by NMR spectroscopy. Evidence for coordination of the amino arm in solution and in the solid state was observed in its derived monopyridine adduct 119 (Figure 22). Complex 118 was found less active than GII-SIMes and GII-IMes in model RCM of 7 and ROMP of 16

The activity of indenylidene derivatives in olefin metathesis catalysts

• Maria Voccia,
• Steven P. Nolan,
• Luigi Cavallo and
• Albert Poater

Beilstein J. Org. Chem. 2018, 14, 2956–2963, doi:10.3762/bjoc.14.275

• generate and/or describe the activity in olefin metathesis of the new indenylidene derivatives. The phenyl substituent of the indenylidene is perpendicular to the indenyl moiety in the solid-state structure [34], as Nolan and co-workers first described in 1999 [35]. For complexes 3–6, where the phenyl ring

1,8-Bis(dimethylamino)naphthyl-2-ketimines: Inside vs outside protonation

• A. S. Antonov,
• A. F. Pozharskii,
• P. M. Tolstoy,
• A. Filarowski and
• O. V. Khoroshilova

Beilstein J. Org. Chem. 2018, 14, 2940–2948, doi:10.3762/bjoc.14.273

• -arylketimines of 1,8-bis(dimethylamonio)naphthalene with a different number of methoxy groups in an aromatic substituent were investigated in solution by NMR (acetone, DMSO, MeCN), in solid state by X-ray analysis and in the gas phase by DFT calculations. Both mono- and diprotonated species were considered. It

• for 4a, while the E-form is more stable for 5a–7a. Indeed, the X-ray analysis shows that compound 6a in the solid state exists in the E-form stabilised by the N−H···O intramolecular hydrogen bond (IHB) with an ortho-OMe group (Figure 2a), while compound 4a, as it was revealed in our previous work [7

• lowest in energy for the imines 4, 6, 7 (Figure 5). In the solid state, no proton transfer to the imino group was observed: compounds 4a·HClO4 and 6b·EtOH crystallise in forms protonated at the proton sponge moiety (Figure 6). We expected that the proton transfer to the C=N group will force the nearest

Non-native autoinducer analogs capable of modulating the SdiA quorum sensing receptor in Salmonella enterica serovar Typhimurium

• Matthew J. Styles and
• Helen E. Blackwell

Beilstein J. Org. Chem. 2018, 14, 2651–2664, doi:10.3762/bjoc.14.243

• ) [21][22]. C) The solid-state structure of the SdiA homodimer (PDB 4Y15; monomers shown in green and grey) bound to OOHL (cyan) [22]. D) Selected residues surrounding OOHL (cyan) in the SdiA ligand binding pocket (from PDB 4Y15 [22]): hydrogen bond acceptors/donors (orange), hydrophobic residues (grey

Synthesis of aryl sulfides via radical–radical cross coupling of electron-rich arenes using visible light photoredox catalysis

• Amrita Das,
• Mitasree Maity,
• Simon Malcherek,
• Burkhard König and
• Julia Rehbein

Beilstein J. Org. Chem. 2018, 14, 2520–2528, doi:10.3762/bjoc.14.228

• the limit of the scope of the method. The substrate scope is shown in Scheme 3. The structures of compounds 3a, 3d, 3e and 3i in the solid state were determined by X-ray structure analysis (Figure 2). We performed various control experiments to support the proposed reaction mechanism, which is shown

Calixazulenes: azulene-based calixarene analogues – an overview and recent supramolecular complexation studies

• Paris E. Georghiou,
• Shofiur Rahman,
• Abdullah Alodhayb,
• Hidetaka Nishimura,
• Jaehyun Lee,
• Atsushi Wakamiya and
• Lawrence T. Scott

Beilstein J. Org. Chem. 2018, 14, 2488–2494, doi:10.3762/bjoc.14.225

•  1) and on its mechanochemically-generated solid-state complex of C60-fullerene [17]. This all-hydrocarbon, wide-rim octaphenyl-functionalized calix[4]azulene was designed to evaluate its potential for encapsulating C60 or C70 fullerenes. The lack of sufficient solubility of 5 in common organic

• solvents prevented a fuller examination of its potential supramolecular properties with fullerenes, a topic of particular interest to us [18]. Therefore, the solid state supramolecular complexation properties of 5 were experimentally studied using solid state NMR and XRD experiments, and also theoretically

• , using a DFT analysis [17]. We previously used a similar solid-state NMR approach to study the solid-state supramolecular properties of tetra-6-tert-butylcalix[4]azulene (4) [19]. Unlike these two studies, however, in our first study on calixazulenes which we reported in 2015, we were able to demonstrate

Nucleoside macrocycles formed by intramolecular click reaction: efficient cyclization of pyrimidine nucleosides decorated with 5'-azido residues and 5-octadiynyl side chains

• Jiang Liu,
• Peter Leonard,
• Sebastian L. Müller,
• Constantin Daniliuc and
• Frank Seela

Beilstein J. Org. Chem. 2018, 14, 2404–2410, doi:10.3762/bjoc.14.217

• and 1H,1H-NMR coupling constants. The sugar conformation (N vs S) was different in solution as compared to the solid state. Keywords: click cyclization; conformation; macrocycles; nucleosides; X-ray; Introduction The field of macrocycles was initiated by the work of Ruzicka and his structure

• new lead for a diversity of molecules. From the cyclic molecule a single crystal X-ray analysis was obtained. The sugar conformation was studied in solution and in solid state. Results and Discussion The octadiynyl derivative 1 of dC [32][33][34][35] was the starting material for the synthesis of 5

• decrease. Next, a X-ray analysis was performed from the dU macrocycle 8, which was crystallized from methanolic solution containing traces of water. Colorless needles with a melting point of 260–265 °C (decomp.) were obtained. The solid state structure of the macrocycle is displayed in Figure 2. The X- ray

Determining the predominant tautomeric structure of iodine-based group-transfer reagents by ¹⁷O NMR spectroscopy

• Nico Santschi,
• Cody Ross Pitts,
• Benson J. Jelier and
• René Verel

Beilstein J. Org. Chem. 2018, 14, 2289–2294, doi:10.3762/bjoc.14.203

• over 50 kcal/mol, a high kinetic barrier suppresses the [a → b] isomerization (Figure 1) [5][6]. With SCF3 reagent 5a/5b, structure determination was notably challenging and solely provides a solid-state structural perspective. Thus, we wondered whether a correct structural assignment of reagent 5a/b

• represent 4c in solution. Does the compound resemble the molecular structure obtained in the solid state with oxygen still coordinated to iodine or would a free alcohol be a more accurate representation? In order to generate 4c, reagent 4a was treated with five equivalents of trifluoroacetic acid (TFA) and

• prefers the "cyclic" iodane. Since 17O NMR experiments are easily implemented on contemporary spectrometers, this method may provide the most convenient spectroscopic handle to re-evaluate known structures, facilitate further mechanistic studies, and provide a complimentary approach to solid-state

Selective formation of a zwitterion adduct and bicarbonate salt in the efficient CO₂ fixation by N-benzyl cyclic guanidine under dry and wet conditions

• Yoshiaki Yoshida,
• Naoto Aoyagi and
• Takeshi Endo

Beilstein J. Org. Chem. 2018, 14, 2204–2211, doi:10.3762/bjoc.14.194

• characterized in detail by elemental analysis, FTIR-ATR, solid-state NMR, TGA, and DFT calculation. These analytical results obviously revealed the formation of a zwitterion adduct and bicarbonate salt from N-benzyl cyclic guanidine and CO2. Especially, the zwitterion adduct of the monocyclic guanidine

• adduct and bicarbonate salt between CO2 and N-benzyl cyclic guanidine 1. The structures of the zwitterionic adduct and bicarbonate salt were analyzed in detail and proved by elemental analysis, FTIR-ATR, solid-state NMR, TGA, and DFT calculations. In this report, the zwitterionic adduct of the monocyclic

• ). Characterization of zwitterion adduct 2 and bicarbonate salt 3 by FTIR-ATR and solid-state 13C-CPMAS NMR IR spectra of 2 and 3 were measured by FTIR-ATR methods (Figure 3). The two peaks were clearly observed at 1573 cm−1 and 1706 cm−1 due to carbonyl and imine moieties, respectively, in the spectrum of 2. On the

Synthesis and post-functionalization of alternate-linked-meta-para-[2ⁿ.1ⁿ]thiacyclophanes

• Wout De Leger,
• Koen Adriaensen,
• Koen Robeyns,
• Luc Van Meervelt,
• Joice Thomas,
• Björn Meijers,
• Mario Smet and
• Wim Dehaen

Beilstein J. Org. Chem. 2018, 14, 2190–2197, doi:10.3762/bjoc.14.192

• Figure 1). The conformation in the solid state is stabilised by intramolecular O–H···S hydrogen bonds (O···S distances 3.2081 (16) and 3.4179 (17) Å) and shows no central void. The formation of the [3 + 3] product is favoured by stronger bases and shorter reaction times. Therefore, in entry 8 of Table 1

Tetrathiafulvalene – a redox-switchable building block to control motion in mechanically interlocked molecules

• Hendrik V. Schröder and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2018, 14, 2163–2185, doi:10.3762/bjoc.14.190

• oxidized or reduced without chemical side reactions or decomposition. TTF is perhaps one of the most popular examples and exists as a classical Weitz type redox system [22] in three different stable oxidation states. The stability of TTF, both in solution and in the solid state [23], makes it an ideal

• -type arrangement in the dimer [34]. Furthermore, the equilibrium between a paramagnetic monomer and a diamagnetic dimer makes the use of electron paramagnetic resonance (EPR) spectroscopy ideal to follow the dimerization process [36]. Mixed-valence and radical-cation interactions in the solid state are

Evaluation of dispersion type metal···π arene interaction in arylbismuth compounds – an experimental and theoretical study

• Ana-Maria Preda,
• Małgorzata Krasowska,
• Lydia Wrobel,
• Philipp Kitschke,
• Phil C. Andrews,
• Jonathan G. MacLellan,
• Lutz Mertens,
• Marcus Korb,
• Tobias Rüffer,
• Heinrich Lang,
• Alexander A. Auer and
• Michael Mehring

Beilstein J. Org. Chem. 2018, 14, 2125–2145, doi:10.3762/bjoc.14.187

• the analysis of single crystal X-ray diffraction data and computational studies. First, the crystal structures of polymorphs of Ph3Bi (1) are described emphasizing on the description of London dispersion type bismuth···π arene interactions and other van der Waals interactions in the solid state and

• crystal structures of substituted arylbismuth compounds of the type Ar3Bi [Ar = C6H4-CH═CH2-4 (2a, 2b), C6H4-OMe-4 (3)], Ar'3Bi (4) and Ar'2BiCl (5, Ar' = C6H3-t-Bu2-3,5) were analyzed with regard to their packing in the solid state. Electronic structure calculations were carried out on Ph3Bi···C6H6 and

• dispersion type interactions including bismuth···π interaction in the solid state. This prompted us to have a closer look at these simple organometallic compounds. Noteworthy, the first report on the synthesis of Ph3Bi dates back to 1887, which was based on the reaction of sodium alloy and bromobenzene [46

A hemicryptophane with a triple-stranded helical structure

• Augustin Long,
• Olivier Perraud,
• Erwann Jeanneau,
• Christophe Aronica,
• Jean-Pierre Dutasta and
• Alexandre Martinez

Beilstein J. Org. Chem. 2018, 14, 1885–1889, doi:10.3762/bjoc.14.162

• hemicryptophane 1 bearing both amide and amine functions in its three likers. In solution, the 1H NMR spectrum shows a C3 symmetrical cage, which is also observed in the solid state by X-ray crystallography. Moreover, in the solid, amide and amine functional groups of different linkers interact through hydrogen

• 1 than for 6 with Δδ = 0.38 ppm for the CH2NH and of Δδ = 0.19 ppm for the Ar–O–CH2–Ar of 1, compared to 0.07 ppm and 0.05 ppm for 6, respectively (Figure 3). This is consistent with a more rigid structure of cage 1 in solution, as suggested by the solid-state structure. Conclusion In summary, we

• observed in solid state. NMR studies suggest that this propeller-like arrangement also occurs in solution. Further investigations are in progress in order to propagate the chirality of the CTV to even more remote opposite sites through the formation of such triple helical structures. 1H NMR spectrum of 1

Synthesis of 9-arylalkynyl- and 9-aryl-substituted benzo[b]quinolizinium derivatives by Palladium-mediated cross-coupling reactions

• Siva Sankar Murthy Bandaru,
• Darinka Dzubiel,
• Heiko Ihmels,
• Mohebodin Karbasiyoun,
• Mohamed M. A. Mahmoud and
• Carola Schulzke

Beilstein J. Org. Chem. 2018, 14, 1871–1884, doi:10.3762/bjoc.14.161

• in the solid state. A preference of such anti-ht arrangement was observed before in the crystal structures of two series of 9-substituted benzo[b]quinolizinium salts with halides or small alkyl substituents [45][46]. Stratford et al. attributed this observation to repulsion forces between the

• slightly more pronounced delocalization of π-electrons within the diarylalkyne unit of compound 2a, at least in the solid state. Absorption and emission properties of 9-(arylethynyl)benzo[b]quinolizinium derivatives 2a–d In general, compounds 2a–d have a low solubility in water and derivative 2d is

• tuning of the stereoelectronic or steric properties of substituents. Structures of 9-substituted benzo[b]quinolizinium derivatives 1 and 2. Molecular structures of derivatives 2a (top) and 2b (bottom) in the solid state. Ellipsoids are shown at the 50% probability level. The counter anions and solvent

Host–guest complexes of conformationally flexible C-hexyl-2-bromoresorcinarene and aromatic N-oxides: solid-state, solution and computational studies

• Rakesh Puttreddy,
• Ngong Kodiah Beyeh,
• S. Maryamdokht Taimoory,
• Daniel Meister,
• John F. Trant and
• Kari Rissanen

Beilstein J. Org. Chem. 2018, 14, 1723–1733, doi:10.3762/bjoc.14.146

• 1H NMR spectroscopy. In the solid state, of the nine obtained X-ray crystal structures, eight were consistent with the formation of BrC6-N-oxide endo complexes. The lone exception was from the association between 4-phenylpyridine N-oxide and BrC6, in that case the host forms a self-inclusion complex

• form endo complexes according to 1H NMR; however, in more polar CD3OD/DMSO-d6 (9:1 v/v), only three N-oxides with electron-donating groups form solution-phase endo complexes with BrC6. In solid-state studies, 3-methylpyridine N-oxide+BrC6 crystallises with both the upper- and lower-rim BrC6 cavities

• , has investigated the impact of host cavity flexibility, guest’s steric and electronic demands, and solvent effects, in both solution and the solid state [36][37][38]. For example, we recently studied C-ethyl-2-bromoresorcinarene (BrC2) [39] and C-propyl-2-bromoresorcinarene (BrC3) [40] to understand

Design, synthesis and structure of novel G-2 melamine-based dendrimers incorporating 4-(n-octyloxy)aniline as a peripheral unit

• Cristina Morar,
• Pedro Lameiras,
• Attila Bende,
• Gabriel Katona,
• Emese Gál and
• Mircea Darabantu

Beilstein J. Org. Chem. 2018, 14, 1704–1722, doi:10.3762/bjoc.14.145

• to self-organise in solution and to self-assembly in the solid state. Keywords: amination; dendrimers; melamines; nano-aggregates; 4-(n-octyloxy)aniline; Introduction N-Substituted melamine (2,4,6-triamino-1,3,5-triazine)-based dendrimers are a class of macromolecules reported as early as 2000 by E

• protonated site in ionic dendrimers 7b, 8 and 9 could not be attributed accurately either in solution (1H NMR), or in the solid state (IR). Consequently, their proposed cationic structures shown in Figure 1 and Scheme 4 (linker P-1 as piperazin-1-ium moiety) should be seen intuitively, a proton sponge-like

• occurrence of a starburst effect. The “salt”-like nature of the G-2 dendrimers (obtained by a carboxyl/amino 1:3 stoichiometric trimerisation) could be unambiguously assigned by means of 1H NMR (in solution) and IR (solid state), confirming the existence of the only tris-carboxylate anions. TEM analysis

Synthesis of diamido-bridged bis-pillar[5]arenes and tris-pillar[5]arenes for construction of unique [1]rotaxanes and bis-[1]rotaxanes

• Ying Han,
• Li-Ming Xu,
• Cui-Yun Nie,
• Shuo Jiang,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2018, 14, 1660–1667, doi:10.3762/bjoc.14.142

• ][55][56][57]. Recently, we have successfully constructed a couple of pseudo[1]rotaxane and [1]rotaxane both in solution and in solid state developed by using mono-functionalized pillar[5]arene Schiff base, urea and pyridylimine derivatives [58][59][60][61][62][63]. In continuation of our effort on the

• , 4, 6) in moderate yields (Scheme 2). It has been reported that the chain of N-(ω-aminoalkyl)oxyacetamide inserted in the cavity of pillar[5]arene in the amido-functionalized pillar[5]arene 4a–d (n = 2, 3, 4, 6) to form pseudo[1]rotaxanes both in solution and in solid state [58]. The diamido-bridged

A conformationally adaptive macrocycle: conformational complexity and host–guest chemistry of zorb[4]arene

• Liu-Pan Yang,
• Song-Bo Lu,
• Arto Valkonen,
• Fangfang Pan,
• Kari Rissanen and
• Wei Jiang

Beilstein J. Org. Chem. 2018, 14, 1570–1577, doi:10.3762/bjoc.14.134

• -ray crystal structure of free ZB4 shows it to exist as a self-inclusion conformation in the solid state (Figure 1a). This conformation is different from the ones containing different lower-rim alkyl groups reported earlier [37][38]. Crystals were obtained by slow evaporation of the compounds’ CH3CN

• solutions and the different conformations in the solid state may result from the packing of the different lower-rim alkyl groups. For the conformers with cavities (Scheme 1b), three out of the four have been predominantly selected by three different guests. For example, guests 2+ and 3+ induced conformers

Hyper-reticulated calixarene polymers: a new example of entirely synthetic nanosponge materials

• Alberto Spinella,
• Marco Russo,
• Antonella Di Vincenzo,
• Delia Chillura Martino and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2018, 14, 1498–1507, doi:10.3762/bjoc.14.127

• was assessed by means of FTIR and 13C{1H} CP-MAS solid-state NMR techniques, whereas morphological characterization was provided by SEM microghaphy. The materials were proved to possess pH-dependent sequestration abilities, due to the presence of the weakly basic triazole linkers. Sequestration

• ; solid-state NMR; Introduction Nanosponges (NSs) [1][2][3] constitute an emerging area of both materials chemistry and supramolecular chemistry due to their peculiar properties, which have been object of an increasing interest during the last years. These materials are constituted by hyper-reticulated

• different alkyl diazides A1–A4 (Scheme 1b), in which the two azido groups are separated by spacers having different length and rigidity. The materials obtained were characterized by means of combined spectroscopic (FTIR, solid state 13C{1H} CP-MAS NMR), calorimetric (DSC) and imaging (SEM) techniques. Then

Recent advances in phosphorescent platinum complexes for organic light-emitting diodes

• Cristina Cebrián and
• Matteo Mauro

Beilstein J. Org. Chem. 2018, 14, 1459–1481, doi:10.3762/bjoc.14.124

• easy generation of anionic ligands from azoles, the same group described the preparation of neutral platinum(II) complexes resulting from the combination of dianionic with neutral chelates (Figure 4) [27]. Compounds 8 and 9 were weakly emissive in solution. Nevertheless, the solid-state emission of

• supplementary interactions reinforced the ligand–metal bond, which explains well the remarkable phosphorescence efficiency obtained in solid-state thin films being PLQY of 0.52 and 0.83 for 8 and 9, respectively. Such findings prompted the authors to fabricate non-doped OLEDs with an architecture as follows

• solution. On the contrary, they became strong emitters in the solid state owing to the switching of the nature of the excited state that becomes 3MMLCT in nature. Their EL properties were evaluated by fabrication of non-doped OLEDs. Compound 10 was embedded into an OLED device with the following