Cyclodextrin-based rotaxanes for polymer materials: challenge on simultaneous realization of inexpensive production and defined structures

• Yosuke Akae

Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252

• synthetic study, the structural analysis of the obtained (poly)rotaxanes was performed to evaluate the fundamental relationship between the axle length and the number and directions of the CD wheels. The directions of the CDs on the PEG-based polyrotaxane framework were analyzed by scanning tunneling

• microscopy (STM) [44], clarifying that 80% of the CDs formed the head-to-head and tail-to-tail repeating patterns in which the wheels were located next to each other on the same cavity side, whereas 20% of the CDs exhibited the head-to-tail structure. This direction was induced by the different strengths of

Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes

• Michio Yamada

Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13

• through scanning tunneling microscopy [85]. For TCBDs bearing unsubstituted anilino (p-H2NC6H4–) groups, their conversion into the p-iodophenyl derivatives via the Sandmeyer reaction and subsequent post-functionalization via the Suzuki and Sonogashira coupling reactions are achieved [86]. In the reaction

Biphenylene-containing polycyclic conjugated compounds

• Cagatay Dengiz

Beilstein J. Org. Chem. 2023, 19, 1895–1911, doi:10.3762/bjoc.19.141

• ]. In their study, they effectively synthesized POA 87 utilizing 2,3-dibromotetracene (85) as substrate at a temperature of 430 K, employing ultra high vacuum conditions on Ag(111). Subsequent scanning tunneling microscopy (STM) analyses unveiled not only the linear POA 87 resulting from surface

Synthesis of new asparagine-based glycopeptides for future scanning tunneling microscopy investigations

• Laura Sršan and
• Thomas Ziegler

Beilstein J. Org. Chem. 2020, 16, 888–894, doi:10.3762/bjoc.16.80

• cell surfaces for future investigations by combined preparative mass spectroscopy and scanning tunneling microscopy (STM) using soft-landing electrospray beam deposition (ES-IBD), on metal surfaces. Keywords: amino acids; asparagine; carbohydrates; glycopeptides; peptidomimetics; Introduction

Nanopatterns of arylene–alkynylene squares on graphite: self-sorting and intercalation

• Tristan J. Keller,
• Joshua Bahr,
• Kristin Gratzfeld,
• Nina Schönfelder,
• Marcin A. Majewski,
• Marcin Stępień,
• Sigurd Höger and
• Stefan-S. Jester

Beilstein J. Org. Chem. 2019, 15, 1848–1855, doi:10.3762/bjoc.15.180

• , Uniwersytet Wrocławski, ul. F. Joliot-Curie 14, 50-383 Wrocław, Poland 10.3762/bjoc.15.180 Abstract Supramolecular nanopatterns of arylene–alkynylene squares with side chains of different lengths are investigated by scanning tunneling microscopy at the solid/liquid interface of highly oriented pyrolytic

• and non-planar coronoid polycyclic aromatic hydrocarbons (i.e., butyloxy-substituted kekulene and octulene derivatives) are found to be able to intercalate into the intramolecular nanopores. Keywords: macrocycles; scanning tunneling microscopy; self-assembled monolayers; self-sorting; solid/liquid

• alkoxy-substituted kekulene and octulene derivatives. Chemical structures of the molecular squares 1a/b, the kekulene derivative 2, and octulene derivative 3 [27]. (a)–(c) Scanning tunneling microscopy images, (d)–(f) supramolecular models, and (g)–(l) schematic models of supramolecular nanopatterns of

The LANCA three-component reaction to highly substituted β-ketoenamides – versatile intermediates for the synthesis of functionalized pyridine, pyrimidine, oxazole and quinoxaline derivatives

• Tilman Lechel,
• Roopender Kumar,
• Mrinal K. Bera,
• Reinhold Zimmer and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2019, 15, 655–678, doi:10.3762/bjoc.15.61

• this experiment was the double-coupling product OX27 and the mono-coupling product (not shown) was isolated in 5% yield [45]. A solution of the C3-symmetric compound OX28 in 1-phenyloctane was investigated by scanning tunneling microscopy (STM) to reveal its ability to form self-assembled monolayers at

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

• ][89]. An ordered array of molecules enables the possibility of concerted switching. The fixed orientation on a surface allows studying molecules with sophisticated techniques such as scanning tunneling microscopy. Furthermore, redox-switchable AMMs, containing for example TTF moieties, can be

New electroactive asymmetrical chalcones and therefrom derived 2-amino- / 2-(1H-pyrrol-1-yl)pyrimidines, containing an N-[ω-(4-methoxyphenoxy)alkyl]carbazole fragment: synthesis, optical and electrochemical properties

• Daria G. Selivanova,
• Alexei A. Gorbunov,
• Olga A. Mayorova,
• Alexander N. Vasyanin,
• Igor V. Lunegov,
• Elena V. Shklyaeva and
• Georgii G. Abashev

Beilstein J. Org. Chem. 2017, 13, 1583–1595, doi:10.3762/bjoc.13.158

• scanning tunneling microscopy. Results and Discussion Synthetic toolbox The objective of the presented work involves the design and further synthesis of 4,6-diaryl-substituted 2-(pyrrol-1-yl)pyrimidines, embedding 9-[ω-(4-methoxyphenoxy)alkyl]carbazole moieties as substituents, one of which is directly

Creating molecular macrocycles for anion recognition

• Amar H. Flood

Beilstein J. Org. Chem. 2016, 12, 611–627, doi:10.3762/bjoc.12.60

• geometrically appealing to work with. In our stables we have triangles, squares and pentagons represented by triacarb, triazolophane and cyanostar macrocycles. The analogy to donut shapes is obvious and the hole in their middles can be both filled with anions and observed using real-space scanning tunneling

• microscopy (STM) imaging. Their shape persistence makes them ideal for the study of structure–property relationships to enable deep understanding of anion recognition phenomena. The identification of 1,2,3-triazoles as linkers, ligands and building blocks. The synthetic creation of macrocycles sets the scene

Star-shaped tetrathiafulvalene oligomers towards the construction of conducting supramolecular assembly

• Masahiko Iyoda and
• Masashi Hasegawa

Beilstein J. Org. Chem. 2015, 11, 1596–1613, doi:10.3762/bjoc.11.175

• hand, the conductivities of the corresponding neutral nanoobjects are determined by pulse-radiolysis or flash-photolysis time-resolved microwave conductivity techniques [48][49]. Current-sensing atomic force microscopy (CS-AFM) and combination of scanning tunneling microscopy and spectroscopy (STM/STS

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• synthesized hexa-peri-hexabenzocoronene cyclophane 201a–c. They studied their properties by carrying out differential scanning calorimetry (DSC), optical microscopy, wide-angle X-ray scattering (WAXD), and scanning tunneling microscopy (STM). Tunneling spectroscopy reveals a diode-like behavior which

Mono- and multilayers of molecular spoked carbazole wheels on graphite

• Stefan-S. Jester,
• A. Vikas Aggarwal,
• Daniel Kalle and
• Sigurd Höger

Beilstein J. Org. Chem. 2014, 10, 2783–2788, doi:10.3762/bjoc.10.295

• -persistent macrocycle with an intraannular spoke/hub system) and its synthetic precursor are investigated by scanning tunneling microscopy (STM) at the liquid/solid interface of 1-octanoic acid and highly oriented pyrolytic graphite. The submolecularly resolved STM images reveal that the molecules indeed

• the second layer. Keywords: molecular spoked wheels; scanning tunneling microscopy; self-assembled monolayers; solid/liquid interface; template; Introduction Molecular spoked wheels (MSWs) have gained increasing interest as two-dimensional (2D) carbon-based objects of adjustable sizes [1][2][3][4][5

Self-assembled monolayers of shape-persistent macrocycles on graphite: interior design and conformational polymorphism

• Joscha Vollmeyer,
• Friederike Eberhagen,
• Sigurd Höger and
• Stefan-S. Jester

Beilstein J. Org. Chem. 2014, 10, 2774–2782, doi:10.3762/bjoc.10.294

• -dimensional (2D) crystalline monolayer patterns are obtained by in situ scanning tunneling microscopy. A concentration-dependent conformational polymorphism is found, and open and more dense packing motifs are observed. For all three compounds alike lattice parameters are found, therefore the intermolecular

•  4a–c) and dense (“high concentration”, Figure 4d–f) adsorbate patterns, depend on the compound concentrations, as observed by scanning tunneling microscopy (STM). Bright and dark parts in the STM images correspond to regions covered by aromatic backbones and alkoxy side chains, respectively [23

• macrocycle sizes are induced by the intraannular strands and vary by less than 2 Å. (b) and (c) are adapted with permission from [22]. Copyright 2012 The Royal Society of Chemistry. Scanning tunneling microscopy images and supramolecular models of (a)–(c) porous (= polymorph A) and (d)–(f) dense patterns

Molecular ordering at electrified interfaces: Template and potential effects

• Thanh Hai Phan and
• Klaus Wandelt

Beilstein J. Org. Chem. 2014, 10, 2243–2254, doi:10.3762/bjoc.10.233

• Department, Quynhon University, 170 An Duong Vuong; Quynhon, Vietnam Institute of Experimental Physics, University of Wroclaw, MaxaBorna 9, 50-204, Wroclaw, Poland 10.3762/bjoc.10.233 Abstract A combination of cyclic voltammetry and in situ scanning tunneling microscopy was employed to examine the

• effects, in the structure formation process of DBV cations on these modified Cu electrode surfaces. Keywords: cyclic voltammogram; scanning tunneling microscopy; self-assembly; template effect; viologen; Introduction The precise control of the self-organization of molecular layers on either conducting

• investigated by means of cyclic voltammetry and in situ scanning tunneling microscopy. Current waves in the cyclic voltammogram clearly indicate the potentials where reduction of the dications occurs first to the monocation radicals and then to the neutral molecules. At positive electrode potentials the

Lateral ordering of PTCDA on the clean and the oxygen pre-covered Cu(100) surface investigated by scanning tunneling microscopy and low energy electron diffraction

• Stefan Gärtner,
• Benjamin Fiedler,
• Oliver Bauer,
• Antonela Marele and
• Moritz M. Sokolowski

Beilstein J. Org. Chem. 2014, 10, 2055–2064, doi:10.3762/bjoc.10.213

• ) surface [referred to as (√2 × 2√2)R45° – 2O/Cu(100)] by scanning tunneling microscopy (STM) and low energy electron diffraction (LEED). Our results confirm the (4√2 × 5√2)R45° superstructure of PTCDA/Cu(100) reported by A. Schmidt et al. [J. Phys. Chem. 1995, 99,11770–11779]. However, contrary to Schmidt

• energy electron diffraction (LEED) measurements. Scanning tunneling microscopy (STM) data has not been reported yet. Therefore, the aim of our combined LEED and STM investigation was twofold: on the one hand to clarify the superstructure of PTCDA on Cu(100), and on the other hand to gain new information

Syntheses and properties of thienyl-substituted dithienophenazines

• Annemarie Meyer,
• Eva Sigmund,
• Friedhelm Luppertz,
• Gregor Schnakenburg,
• Immanuel Gadaczek,
• Thomas Bredow,
• Stefan-S. Jester and
• Sigurd Höger

Beilstein J. Org. Chem. 2010, 6, 1180–1187, doi:10.3762/bjoc.6.135

• functional theory at the B3LYP/TZVP level and verify the experimental data. Adsorption of the dithienophenazines on highly ordered pyrolytic graphite (HOPG) was investigated by scanning tunneling microscopy, showing that one of the compounds forms highly organized self-assembled monolayers. Keywords

• : oligothiophenes; phenazines; scanning tunneling microscopy; self-assembled monolayers; TD-DFT calculations; Introduction Thiophene based oligomers and polymers have drawn considerable interest as active materials in various fields of organic electronics such as organic light-emitting diodes (OLEDs), organic thin

• scanning tunneling microscopy (STM). Synthesis The synthesis of 4 is shown in Scheme 1. It is obtained in three steps from commercially available starting materials. The synthesis of 3 has previously been reported by benzoin condensation of the corresponding bithiophene derivative [18]. Alternatively, we