A new glance at the chemosphere of macroalgal–bacterial interactions: In situ profiling of metabolites in symbiosis by mass spectrometry

• Marine Vallet,
• Filip Kaftan,
• Veit Grabe,
• Fatemeh Ghaderiardakani,
• Simona Fenizia,
• Aleš Svatoš,
• Georg Pohnert and
• Thomas Wichard

Beilstein J. Org. Chem. 2021, 17, 1313–1322, doi:10.3762/bjoc.17.91

• algal surfaces and their metabolic activities can be monitored in situ or using an imprinting method by desorption electrospray ionisation mass spectrometry [17][18]. In U. mutabilis gametophytes, matrix-assisted laser desorption ionisation mass spectrometry imaging (MALDI-MSI) was used to identify cell

• differentiation markers [19]. However, there has yet to be a thorough investigation of associated-mutualistic bacteria. MALDI-MSI has been shown to have high sensitivity and spatial resolution at the microscale in plant tissues, plankton, and other microbes [20][21]. The application of a MALDI matrix to a sample

• is an important part of the MALDI-MSI experiment. MALDI-MS can be used to identify proteins and metabolic signatures [22][23][24] from bacteria and microalgae, as well as biofilms [25]. The primary function of the applied matrix is to improve the quality of the MS spectra, particularly the signal

Structural effects of meso-halogenation on porphyrins

• Keith J. Flanagan,
• Maximilian Paradiz Dominguez,
• Zoi Melissari,
• Hans-Georg Eckhardt,
• René M. Williams,
• Dáire Gibbons,
• Caroline Prior,
• Gemma M. Locke,
• Alina Meindl,
• Aoife A. Ryan and
• Mathias O. Senge

Beilstein J. Org. Chem. 2021, 17, 1149–1170, doi:10.3762/bjoc.17.88

• were measured with a Stuart SP-10 melting point apparatus. A Bruker Advance III 400 MHz spectrometer was employed for 1H (400.13 MHz), and 13C (100.61 MHz) NMR spectra. All NMR experiments were performed at room temperature. Mass spectrometry analysis was performed with a Q-Tof Premier Waters MALDI

• quadrupole time-of-flight (Q-TOF) mass spectrometer equipped with Z-spray electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI) sources either in a positive or negative mode with DCTB (trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene]malononitrile) as the matrix. UV

• , 134.8, 137.7, 138.9, 142.1 ppm; UV–vis (DCM) λmax (log ε) 420 (5.30), 519 (3.91), 555 (3.68), 596 (3.38) nm; HRMS−MALDI (m/z): [M+] calcd for C40H29ClN4, 600.2081; found, 600.2050. Note on synthesis of chloro derivatives of porphyrins The reaction entailed an attempt to prepare a meso–meso linked

Enhanced target cell specificity and uptake of lipid nanoparticles using RNA aptamers and peptides

• Roslyn M. Ray,
• Anders Højgaard Hansen,
• Maria Taskova,
• Bernhard Jandl,
• Jonas Hansen,
• Citra Soemardy,
• Kevin V. Morris and
• Kira Astakhova

Beilstein J. Org. Chem. 2021, 17, 891–907, doi:10.3762/bjoc.17.75

• chromatography utilizing gradient elution (2–50% MeOH in DCM). The desired modified T7 peptide was characterized via MALDI-TOF spectrometry (Bruker, MA, Supporting Information File 1, Figure S1B) and isolated as a colorless powder (9 mg, 6 μmol, 6% yield). MS (m/z): [M + H]+ calcd, 1455.00; found, 1455.20. The

• crude Tat–lipid conjugate was precipitated from DMF as a white power and used without further purification. The modified Tat peptide was characterized via MALDI–TOF spectrometry (Supporting Information File 1, Figure S1C, 31 mg, 14 μmol, 15% yield). MS (m/z): [M + H]+ calcd, 2121.48; found, 2121.17

Synthesis and properties of oligonucleotides modified with an N-methylguanidine-bridged nucleic acid (GuNA[Me]) bearing adenine, guanine, or 5-methylcytosine nucleobases

• Naohiro Horie,
• Takao Yamaguchi,
• Shinji Kumagai and
• Satoshi Obika

Beilstein J. Org. Chem. 2021, 17, 622–629, doi:10.3762/bjoc.17.54

• , CDCl3 (δ = 77.0 ppm) for 13C NMR, and 5% H3PO4 (δ = 0 ppm) for 31P NMR. Infrared (IR) spectra were recorded using a JASCO FT/IR-4200 spectrometer. The optical rotation was recorded using a JASCO P-2200 instrument. A MALDI–TOF mass spectrometer (SpiralTOF JMS-S3000) was used to measure the mass spectra

• , 128.84, 129.94, 130.01, 132.87, 133.31, 135.21, 135.47, 140.48, 144.26, 149.38, 150.80, 152.55, 158.52, 164.76; HRMS–MALDI (m/z): [M + Na]+ calcd for C43H42N8O7Na, 805.3069; found, 805.3063. (1R,3R,4R,7S)-5-(N'-Acetyl-N-methylcarbamimidoyl)-1-(4,4'-dimethoxytrityl)oxymethyl-3-(O6-diphenylcarbamoyl-N2

• , 127.90, 128.02, 129.18, 129.94, 129.99, 135.31, 135.52, 141.55, 144.34, 150.26, 151.60, 153.12, 156.07, 158.50, 162.61, 174.91; HRMS (MALDI) (m/z): [M + Na]+ calcd. for C53H53N9O9Na, 982.3858; found, 982.3856. (1R,3R,4R,7S)-5-(N'-Acetyl-N-methylcarbamimidoyl)-1-(4,4'-dimethoxytrityl)oxymethyl-3-(O6

Synthesis of (Z)-3-[amino(phenyl)methylidene]-1,3-dihydro-2H-indol-2-ones using an Eschenmoser coupling reaction

• Lukáš Marek,
• Lukáš Kolman,
• Jiří Váňa,
• Jan Svoboda and
• Jiří Hanusek

Beilstein J. Org. Chem. 2021, 17, 527–539, doi:10.3762/bjoc.17.47

• ) and 39.6 ppm (13C). High-resolution mass spectra were recorded on a MALDI LTQ Orbitrap XL equipped with a nitrogen UV laser (337 nm, 60 Hz, 8–20 μJ) in the positive ion mode. For the CID experiment using the linear trap quadrupole (LTQ) helium was used as the collision gas and 2,5-dihydroxybenzoic

• acid (DHB) or (2-methylprop-2-en-1-yliden)malononitrile (DCTB) as the MALDI matrix. Elemental analyses were performed on a Flash 2000 Organic Elemental Analyser (Thermofisher). For samples containing chlorine mercurimetric titration was used. IR spectra were recorded on a Nicolet iS50 equipped with an

The synthesis of chiral β-naphthyl-β-sulfanyl ketones via enantioselective sulfa-Michael reaction in the presence of a bifunctional cinchona/sulfonamide organocatalyst

• Deniz Tözendemir and
• Cihangir Tanyeli

Beilstein J. Org. Chem. 2021, 17, 494–503, doi:10.3762/bjoc.17.43

• by chiral HPLC chromatography using Agilent instrument. All new products were further analyzed by LC/MS–HRMS–TOF or MALDI–ESI–TOFMS. Synthesis of organocatalyst 5 A solution of quinineamine 2 (226.40 mg, 0.70 mmol) and triethylamine (107 μL, 0.77 mmol) in CH2Cl2 was added to a screw-capped reaction

Construction of pillar[4]arene[1]quinone–1,10-dibromodecane pseudorotaxanes in solution and in the solid state

• Xinru Sheng,
• Errui Li and
• Feihe Huang

Beilstein J. Org. Chem. 2020, 16, 2954–2959, doi:10.3762/bjoc.16.245

• . Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI–TOF MS) was conducted to investigate the complexation properties. However, no signal related to the complex but only peaks of H were found, implying weak host–guest interactions between H and G (Figures S3 and S4

Incorporation of a metal-mediated base pair into an ATP aptamer – using silver(I) ions to modulate aptamer function

• Marius H. Heddinga and
• Jens Müller

Beilstein J. Org. Chem. 2020, 16, 2870–2879, doi:10.3762/bjoc.16.236

• ), 8% sucrose), and desalted using NAP 10 columns. MALDI–TOF spectrometry was used to characterize the oligonucleotides either in a 3-hydroxypicolinic acid (3-HPA)/ammonium acetate matrix or in a 3-HPA in TA50 solvent matrix (50:50, v/v acetonitrile/0.1% TFA in water) containing 10 mg/mL diammonium

• ATP, oligonucleotide sequences, MALDI–TOF spectra of the oligonucleotides and HPLC traces to confirm the oligonucleotide purity. Acknowledgements We thank D. Defayay for performing the HPLC analysis of the oligonucleotides.

Changed reactivity of secondary hydroxy groups in C8-modified adenosine – lessons learned from silylation

• Jennifer Frommer and
• Sabine Müller

Beilstein J. Org. Chem. 2020, 16, 2854–2861, doi:10.3762/bjoc.16.234

• Supporting Information File 1). The presence of the modified ribonucleotide in the synthesized sequence was confirmed by MALDI–TOF MS (Figure S1, Supporting Information File 1). Conclusion Oligonucleotides carrying a specific modification or functional entity at a pre-defined position are in high demand for

• equiv TEA, DCM, room temperature, 1 h, 52%. Variation of reaction conditions for 2’-/3’-O silylation of adenosine derivative 7. Supporting Information Supporting Information File 434: Experimental procedures, RNA synthesis, characterization data (1H, 13C NMR, MALDI–TOF MS, PAGE), copies of 1H and 13C

• , Universität Greifswald, Germany, 2019. We kindly thank Robert Hieronymus for carrying out MALDI–TOF measurements and PAA Gel Electrophoreses.

Synthesis and characterization of S,N-heterotetracenes

• Astrid Vogt,
• Florian Henne,
• Christoph Wetzel,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2020, 16, 2636–2644, doi:10.3762/bjoc.16.214

• -heterotetracenes and -hexacene were clearly identified, fully characterized, and their structures confirmed by 1H and 13C NMR spectroscopy and high-resolution mass spectrometry (HRMS) via matrix-assisted laser desorption/ionization (MALDI) (Supporting Information File 1, Figures S1–S5). In the 1H NMR spectra, the

• are shifted down-field (Hα 7.67, Hß 7.49 ppm) compared to SN4 13. MALDI–HRMS of all synthesized S,N-heteroacenes showed only a single peak for the molecular ions accounting for their purity. Optical and redox properties of S,N-heteroacenes 9, 13, 19, 22, and 33 in comparison to tetrathienoacene (TTA

Particle size effect in the mechanically assisted synthesis of β-cyclodextrin mesitylene sulfonate

• Stéphane Menuel,
• Sébastien Saitzek,
• Eric Monflier and
• Frédéric Hapiot

Beilstein J. Org. Chem. 2020, 16, 2598–2606, doi:10.3762/bjoc.16.211

• preparation of the investigated compound. Acknowledgements We thank N. Kania for BET analysis, J. Ternel for NMR experiments and J. Hachani for MALDI–TOF mass spectrometry. We are grateful to Dr. A. Fadel and Dr. A. Addad for their contribution in setting up the SEM measurements. Funding The SEM facility in

Water-soluble host–guest complexes between fullerenes and a sugar-functionalized tribenzotriquinacene assembling to microspheres

• Si-Yuan Liu,
• Xin-Rui Wang,
• Man-Ping Li,
• Wen-Rong Xu and
• Dietmar Kuck

Beilstein J. Org. Chem. 2020, 16, 2551–2561, doi:10.3762/bjoc.16.207

• of three magnetically equivalent tentacles at the rigid, prochiral TBTQ skeleton. The mass spectrometric characterization of TBTQ-(OAcG)6 turned out to be quite difficult. The MALDI-(+) mass spectrum (see Figure S10 and Table S1 in Supporting Information File 1), recorded with α-cyano-4

• -hydroxycinnamic acid (CHCA) as a matrix, exhibits the base peak at m/z 2879 along with an adjacent intense peak at m/z 2896, which are assigned to the [M + Na]+ and [M + K]+ molecular adduct ions, respectively. Unfortunately, attempts to perform accurate mass measurements were unsuccessful. However, the MALDI

• mass spectrum also shows the characteristic losses of up to at least three tentacle residues from both the [M + Na]+ and [M + K]+ molecular ions [44][45][46]. In contrast to the MALDI mass spectrum, the high-resolution ESI-(+) mass spectrum of TBTQ-(OAcG)6 (see Figure S11 and Table S2) exhibits a sole

Naphthalene diimide bis-guanidinio-carbonyl-pyrrole as a pH-switchable threading DNA intercalator

• Poulami Jana,
• Filip Šupljika,
• Carsten Schmuck and
• Ivo Piantanida

Beilstein J. Org. Chem. 2020, 16, 2201–2211, doi:10.3762/bjoc.16.185

• : s, singlet; d, doublet, m, multiplet; br, broad. MALDI–TOF mass spectra were recorded on a Bruker BioTOF III. The UV–vis spectra were recorded on a Varian Cary 100 Bio spectrophotometer and CD spectra on JASCO J815 spectrophotometer at 25 °C using appropriate 1 cm path quartz cuvettes. The

• (m, 15H, aliphatic proton); 13C NMR (75 MHz, DMSO-d6, Figure S30, Supporting Information File 1) δ 171.1, 162.8, 159.8, 158.7, 155.3, 132.2, 130.2, 126, 125.9, 120, 118, 116.1, 114.1, 113.7, 38.6, 26.6, 22.4; MALDI–TOF–HRMS, Figure S31, Supporting Information File 1, (m/z): [M + H]+ calcd for

pH- and concentration-dependent supramolecular self-assembly of a naturally occurring octapeptide

• Goutam Ghosh and
• Gustavo Fernández

Beilstein J. Org. Chem. 2020, 16, 2017–2025, doi:10.3762/bjoc.16.168

• of the peptide (Figure S2, Supporting Information File 1). The identity of the peptide was confirmed by MALDI–TOF mass spectrometry (Figure S3, Supporting Information File 1). The yield of the purified PEP-1 was 42%. Self-assembly and secondary-structure formation CD, FTIR spectroscopy, and ThT

Palladium-catalyzed regio- and stereoselective synthesis of aryl and 3-indolyl-substituted 4-methylene-3,4-dihydroisoquinolin-1(2H)-ones

• Valeria Nori,
• Antonio Arcadi,
• Armando Carlone,
• Fabio Marinelli and
• Marco Chiarini

Beilstein J. Org. Chem. 2020, 16, 1084–1091, doi:10.3762/bjoc.16.95

• ppm) or tetramethylsilane (δ = 0 ppm). Mass spectrometry was performed using a MALDI–TOF spectrometer AB SCIEX TOF/TOF 5800 system using 3-hydroxycoumarin or α-cyano-4-hydroxycinnamic acid as a matrix in combination with KI for the ionization. Unless otherwise stated, all starting materials, catalysts

Fabclavine diversity in Xenorhabdus bacteria

• Sebastian L. Wenski,
• Harun Cimen,
• Natalie Berghaus,
• Sebastian W. Fuchs,
• Selcuk Hazir and
• Helge B. Bode

Beilstein J. Org. Chem. 2020, 16, 956–965, doi:10.3762/bjoc.16.84

• unknown derivatives were identified and confirmed by MALDI–MS and MALDI–MS2 experiments in combination with an optimized sample preparation. This led to a total number of 22 novel fabclavine derivatives in eight strains, increasing the overall number of fabclavines to 32. Together with the identification

• fabclavine derivatives, high-resolution MALDI–MS measurements to determine the exact mass and MALDI–MS2 fragmentation patterns of selected derivatives were acquired. If necessary, the measurements were repeated from mutants cultivated in 13C media in order to determine the number of carbons in the sum

• confirmation and elucidation by MALDI–MS2, they are only shown as proposed minor derivatives in the supplementary results (Figure S33, Supporting Information File 1). As we were not able to generate a promoter-exchange mutant in X. innexi DSM 16336, its fabclavine derivatives were identified in the wild type

One-pot synthesis of dicyclopenta-fused peropyrene via a fourfold alkyne annulation

• Ji Ma,
• Yubin Fu,
• Junzhi Liu and
• Xinliang Feng

Beilstein J. Org. Chem. 2020, 16, 791–797, doi:10.3762/bjoc.16.72

• a dark red solid in 5% yield after purification. The obtained product showed an intense peak at 1058.3910 during MALDI–TOF mass analysis (positive mode, dithranol as the matrix) that matched well with the expected molecular mass of m/z 1058.3913 (calcd for C84H50: [M]+) for dicyclopenta-fused

• -fused PAHs in large π-systems. High-resolution MALDI-TOF mass spectrum of 1. Inset: isotopic distribution compared to mass spectrum simulated for C84H50. Single-crystal X-ray structure of 1. (a) Top view and (b) side view of the (P,P) isomer. c) Crystal packing of the enantiomer pairs (P,P and M,M) of 1

Towards triptycene functionalization and triptycene-linked porphyrin arrays

• Gemma M. Locke,
• Keith J. Flanagan and
• Mathias O. Senge

Beilstein J. Org. Chem. 2020, 16, 763–777, doi:10.3762/bjoc.16.70

• Hz); IR (neat)/cm−1) ν̃: 2921 (w), 2851 (w), 1560 (m), 1535 (m), 1412 (m), 1386 (s), 1257 (s), 1154 (m), 1103 (s), 1070 (s), 982 (m), 912 (m), 750 (s), 739 (m), 638 (m), 580 (w); UV–vis (CHCl3): λmax [nm] (log ε): 367 (5.57), 506 (5.97); HRMS–MALDI (m/z): [M]+ calcd for C54H32N4F4B2, 834.2749; found

• , 126.2, 123.2, 121.6, 96.8, 88.9, 54.639.2, 35.8, 31.9, 30.4, 22.7, 14.0; UV–vis (CHCl3) λmax [nm] (log ε): 434 (6.06), 564 (4.28), 610 (4.20); IR (neat)/cm−1) ν̃: 2921 (m), 2851 (m), 1451 (m), 1305 (m), 1211 (m), 1072 (m), 1008 (s), 939 (m), 787 (s), 750 (s), 708 (s), 639 (s); HRMS–MALDI (m/z): [M

• , 94.4, 89.9, 54.4, 53.9, 39.1, 35.8, 32.1, 30.5, 29.8, 22.9, 19.0, 14.3, 11.7 ppm; IR (neat)/cm−1) ν̃: 2921 (m), 2851 (m), 1451 (m), 1305 (m), 1211 (m), 1072 (m), 1008 (s), 939 (m), 787 (s), 750 (s), 708 (s), 639 (s); UV–vis (CHCl3) λmax [nm] (log ε): 430 (5.84), 563 (4.30), 608 (4.35); HRMS–MALDI (m/z

Direct borylation of terrylene and quaterrylene

• Haruka Kano,
• Keiji Uehara,
• Kyohei Matsuo,
• Hironobu Hayashi,
• Hiroko Yamada and
• Naoki Aratani

Beilstein J. Org. Chem. 2020, 16, 621–627, doi:10.3762/bjoc.16.58

• -dioxane (5 mL) under Ar at 105 °C for 30 h gave a deep orange solution (Scheme 1). Matrix assisted laser desorption/ionization (MALDI) mass spectrometry of the reaction mixture detected a single parent ion peak at m/z = 880.4687 (calcd for C54H60B4O8 = 880.4660 [M]+), making us expect its selective tetra

• ]. However, the crude product was not completely purified by Soxhlet extraction and by crystallization in our hands. The borylation reaction of hardly soluble crude quaterrylene gave a deep green suspension. MALDI mass spectrometry of the reaction mixture detected an ion peak at m/z = 1004.5018 (calcd for

• 2,5,10,13-tetramesitylterrylene (TM4) in 58% yield. TM4 was successfully isolated through a silica gel pad and by reprecipitation. The structure of TM4 was characterized by mass spectrometry and 1H and 13C NMR spectroscopy. High-resolution MALDI mass spectrometry detected the parent ion peak at m/z

Six-fold C–H borylation of hexa-peri-hexabenzocoronene

• Mai Nagase,
• Kenta Kato,
• Akiko Yagi,
• Yasutomo Segawa and
• Kenichiro Itami

Beilstein J. Org. Chem. 2020, 16, 391–397, doi:10.3762/bjoc.16.37

• –Ishiyama borylation step is possibly increased by further conditions screening. The thus-obtained 1 was identical to the product from the C–H borylation of HBC according to 1H NMR spectroscopy, and the 13C NMR and HRMS by MALDI–TOF MS results also supported the identification. The hexaborylated HBC 1 was

• JEOL JMS-S3000 SpiralTOF (MALDI–TOF MS). Nuclear magnetic resonance (NMR) spectra were recorded on a JEOL ECS-600 (1H 600 MHz, 13C 150 MHz) spectrometer or a JEOL ECA 600II spectrometer with UltraCoolTM probe (1H 600 MHz, 13C 150 MHz). Chemical shifts for 1H NMR are expressed in parts per million (ppm

• (1.1 mg, 0.8% yield based on 2) as an orange solid. 1H NMR (600 MHz, CDCl3) δ 9.78 (s, 1H), 1.61 (s, 6H); 13C NMR (150 MHz, CDCl3) δ 25.6, 84.4, 122.4, 127.0, 127.3, 128.8, 129.9; HRMS (MALDI–TOF MS) m/z: [M]+ calcd for C78H84B6O12, 1278.6571; found, 1278.6582. X-ray crystallography Details of the

Room-temperature Pd/Ag direct arylation enabled by a radical pathway

• Amy L. Mayhugh and
• Christine K. Luscombe

Beilstein J. Org. Chem. 2020, 16, 384–390, doi:10.3762/bjoc.16.36

• ring. Finally, branching is evidenced by the discrepancy in molecular weight as calculated for a linear polymer by 1H NMR compared with that indicated by MALDI–TOF MS (Figure 2). Due to the high regioselectivity in small molecule couplings, defects to this extent were unexpected. MALDI–TOF MS was

• Scheme 1. The region from 4–4.5 ppm indicates the interior indole repeat units compared with the terminal indole units. MALDI–TOF MS of PIn, indicating octylindole repeat units with three different types of end groups. These include 2-nitrophenyl, iodine, and hydrogen. A high yielding, highly selective

Photocontrolled DNA minor groove interactions of imidazole/pyrrole polyamides

• Sabrina Müller,
• Jannik Paulus,
• Jochen Mattay,
• Heiko Ihmels,
• Veronica I. Dodero and
• Norbert Sewald

Beilstein J. Org. Chem. 2020, 16, 60–70, doi:10.3762/bjoc.16.8

• in DMF for the synthesis of P2. However, in the case of P1 and P3, the formation of tetramethylguanidinium side products was detected by MALDI–TOF MS. This irreversible N-guanylation of the polyamide N-terminus resulted from slow carboxy activation of the building block by HBTU and the presence of an

• 2.5% TFA in dichloromethane. The free C-terminus of the polyamides was modified in solution with N,N-dimethylaminopropylamine by using PyBOP as an activating reagent to install the corresponding end group. The completeness of all reaction stages was checked by MALDI–TOF MS. Purification of the final

Acid-catalyzed rearrangements in arenes: interconversions in the quaterphenyl series

• Sarah L. Skraba-Joiner,
• Carter J. Holt and
• Richard P. Johnson

Beilstein J. Org. Chem. 2019, 15, 2655–2663, doi:10.3762/bjoc.15.258

• , even at increased reaction times. Minor products with more downfield chemical shifts were also observed via 1H NMR of these crude product mixtures; these were easily separated from quaterphenyl isomers using flash column chromatography. Analysis of the crude product mixtures by MALDI–TOF–MS confirmed

• through time-of-flight matrix assisted laser desorption ionization (MALDI–TOF–MS) mass spectrometry, using sulfur as a matrix. Suzuki–Miyaura coupling to form m,p’-quaterphenyl (13) [35]: 4-Biphenylboronic acid (0.18 g, 0.91 mmol) and 1 M K2CO3 (1.5 mL) were added to a 10 mL Pyrex microwave tube. 3

• the general rearrangement procedure. The crude product was purified via CombiFlash with hexanes to yield an off-white solid (7 mg, 70% yield) consisting of 13 (81%) and 14 (19%). Minor products were eluted with ethyl acetate. MALDI–TOF–MS analysis indicated oligomerization (m/z = 344, 673). o,m

Nanangenines: drimane sesquiterpenoids as the dominant metabolite cohort of a novel Australian fungus, Aspergillus nanangensis

• Heather J. Lacey,
• Cameron L. M. Gilchrist,
• Andrew Crombie,
• John A. Kalaitzis,
• Daniel Vuong,
• Peter J. Rutledge,
• Peter Turner,
• John I. Pitt,
• Ernest Lacey,
• Yit-Heng Chooi and
• Andrew M. Piggott

Beilstein J. Org. Chem. 2019, 15, 2631–2643, doi:10.3762/bjoc.15.256

• an Apollo II ESI/MALDI Dual source or a Q Exactive Plus hybrid quadrupole-Orbitrap mass spectrometer (Thermo Fisher Scientific, Bremen, Germany) by direct infusion. NMR data were recorded in DMSO-d6 on either a Bruker Avance III 500 or a Bruker Avance II DRX-600K spectrometer. All NMR spectra were

Aggregation-induced emission effect on turn-off fluorescent switching of a photochromic diarylethene

• Luna Kono,
• Yuma Nakagawa,
• Ayako Fujimoto,
• Ryo Nishimura,
• Yohei Hattori,
• Toshiki Mutai,
• Nobuhiro Yasuda,
• Kenichi Koizumi,
• Satoshi Yokojima,
• Shinichiro Nakamura and
• Kingo Uchida

Beilstein J. Org. Chem. 2019, 15, 2204–2212, doi:10.3762/bjoc.15.217

• follows: s (singlet); d (doublet); dd (double doublet); t (triplet); q (quartet); m (multiplet) and br (broad). Chemical shifts are denoted in δ (ppm) referenced to the residual protic solvent peaks. Coupling constants J are denoted in Hz. Mass spectra were recorded on a MALDI-Spiral-TOF-MS mass

• , 123.9, 123.0, 122.5, 122.2, 121.7, 121.2, 119.4, 117.5, 113.2, 111.0, 55.5, 14.7, 14.77; 19F NMR (376 MHz, CDCl3, ppm) δ −113.1 (s, 2F), −113.3 (s, 2F), −135.0 (s, 2F); HRMS (MALDI–TOF) m/z: calcd for C35H24F6N2OS2, 666.1234; found, 666.1229. Diarylethene (1o) To 5 mL of dichloromethane anhydrous

• , 142.8, 142.6, 142.1, 141.4, 137.7, 133.4, 130.1, 129.2, 129.2, 128.2, 126.3, 125.9, 125.9, 125.8, 125.8, 124.6, 123.7, 122.5, 121.5, 120.7, 119.2, 117.9, 117.0, 116.1, 107.3, 14.7, 14.7; 19F NMR (376 MHz, CDCl3, ppm) δ −113.1 (s, 2F), −113.3 (s, 2F), −135.0 (s, 2F); HRMS (MALDI–TOF) m/z: calcd for