Recent advances in green carbon dots (2015–2022): synthesis, metal ion sensing, and biological applications

• Aisha Kanwal,
• Naheed Bibi,
• Sajjad Hyder,
• Arif Muhammad,
• Hao Ren,
• Jiangtao Liu and
• Zhongli Lei

Beilstein J. Nanotechnol. 2022, 13, 1068–1107, doi:10.3762/bjnano.13.93

Nanoporous and nonporous conjugated donor–acceptor polymer semiconductors for photocatalytic hydrogen production

• Zhao-Qi Sheng,
• Yu-Qin Xing,
• Yan Chen,
• Guang Zhang,
• Shi-Yong Liu and
• Long Chen

Beilstein J. Nanotechnol. 2021, 12, 607–623, doi:10.3762/bjnano.12.50

• -based polymers, for example, P45 (Figure 5). The D–π–A-type compound P45 possesses an extended π-conjugation along the backbone and consequently has an enlarged visible-light absorption and enhanced electronic conductivity compared with π-linker-free pyrene–benzothiadiazole-based polymers. After

Electrostatic force spectroscopy revealing the degree of reduction of individual graphene oxide sheets

• Yue Shen,
• Ying Wang,
• Yuan Zhou,
• Chunxi Hai,
• Jun Hu and
• Yi Zhang

Beilstein J. Nanotechnol. 2018, 9, 1146–1155, doi:10.3762/bjnano.9.106

• increment in the visible region as well as the disappearance of the broad shoulder at 300 nm for samples 1–5 compared to sample 0 imply the removal of the oxygen-containing groups and the restoration of the π-conjugation network within the graphene nanosheets [11][12]. Nevertheless, except for the

Single-step process to improve the mechanical properties of carbon nanotube yarn

• Maria Cecilia Evora,
• Xinyi Lu,
• Nitilaksha Hiremath,
• Nam-Goo Kang,
• Kunlun Hong,
• Roberto Uribe,
• Gajanan Bhat and
• Jimmy Mays

Beilstein J. Nanotechnol. 2018, 9, 545–554, doi:10.3762/bjnano.9.52

• sidewall. Chemical functionalization introduces sp3-defects and disrupts the π–π conjugation of the graphitic structure. As shown in Figure 2, this functionalization process occurred in the CNT yarn structure. The ID/IG ratio increased from 0.54 for untreated CNT yarn to 0.74 for the CNT yarns treated with

• value of ID/IG increased showing an increase of defects on the sidewall due to chemical functionalization, which introduced sp3-defects and disrupted the π–π conjugation of the graphitic structure. The FIB images showed that the radiation grafting polymerization and crosslinking process took place over

Inelastic electron tunneling spectroscopy of difurylethene-based photochromic single-molecule junctions

• Youngsang Kim,
• Safa G. Bahoosh,
• Dmytro Sysoiev,
• Thomas Huhn,
• Fabian Pauly and
• Elke Scheer

Beilstein J. Nanotechnol. 2017, 8, 2606–2614, doi:10.3762/bjnano.8.261

• . From the most probable conductance values we derive a conductance switching ratio between the open and closed form of 5.9 ± 5.3 times using error propagation to determine the error for the switching ratio. The lower conductance for the open form is expected due to the breaking of π-conjugation in the

Rigid multipodal platforms for metal surfaces

• Michal Valášek,
• Marcin Lindner and
• Marcel Mayor

Beilstein J. Nanotechnol. 2016, 7, 374–405, doi:10.3762/bjnano.7.34

Raman spectroscopy as a tool to investigate the structure and electronic properties of carbon-atom wires

• Alberto Milani,
• Matteo Tommasini,
• Valeria Russo,
• Andrea Li Bassi,
• Andrea Lucotti,
• Franco Cataldo and
• Carlo S. Casari

Beilstein J. Nanotechnol. 2015, 6, 480–491, doi:10.3762/bjnano.6.49

• , Via Casilina 1626A, 00133 Roma, Italy 10.3762/bjnano.6.49 Abstract Graphene, nanotubes and other carbon nanostructures have shown potential as candidates for advanced technological applications due to the different coordination of carbon atoms and to the possibility of π-conjugation. In this context

• wavelengths with the support of first principles calculations will be reviewed. We begin by discussing the structure of ideal and as-synthesized CAWs with particular focus on π-conjugation effects and the change in electronic properties as a result of the wire length and termination. Then we review the

• (π-conjugation) for both polyynes and cumulenes (see Figure 2), similar to many other polyconjugated materials. In contrast, a detailed computational analysis on long sp-carbon chains [42] clearly demonstrated that Peierls distortion dominates over the decrease of the BLA caused by the increasing

Nano-rings with a handle – Synthesis of substituted cycloparaphenylenes

• Anne-Florence Tran-Van and
• Hermann A. Wegner

Beilstein J. Nanotechnol. 2014, 5, 1320–1333, doi:10.3762/bjnano.5.145

• structures the dihedral angle is 51.2° between substituted phenyls and unsubstituted phenyls and 78.7° between two unsubstituted phenyl rings. Therefore, π-conjugation is expected to be reduced, which corresponds to the observed shorter absorption and emission wavelengths compared to the unsubstituted [9]CPP

Enhancement of photocatalytic H₂ evolution of eosin Y-sensitized reduced graphene oxide through a simple photoreaction

• Weiying Zhang,
• Yuexiang Li,
• Shaoqin Peng and
• Xiang Cai

Beilstein J. Nanotechnol. 2014, 5, 801–811, doi:10.3762/bjnano.5.92

• ][25][26]. The GO contains not only hydroxy and epoxy groups in the 2D sheet, but also carbonyl and carboxyl groups at the edges of the sheet [27][28]. The oxygen-containing groups in the sheet break the sp2 π-conjugation, leading to the formation of oxidized aliphatic six-membered rings with sp3

Fullerenes as adhesive layers for mechanical peeling of metallic, molecular and polymer thin films

• Maria B. Wieland,
• Anna G. Slater,
• Barry Mangham,
• Neil R. Champness and
• Peter H. Beton

Beilstein J. Nanotechnol. 2014, 5, 394–401, doi:10.3762/bjnano.5.46

• phenyl linker groups [38], which are not in the same plane as the porphyrin macrocycle, inhibiting extended π-conjugation. Conclusion In conclusion we have shown that C60 shows an unexpected mechanical adhesion which is sufficiently strong to promote the removal of a metal film from a mica substrate

Current–voltage characteristics of single-molecule diarylethene junctions measured with adjustable gold electrodes in solution

• Bernd M. Briechle,
• Youngsang Kim,
• Philipp Ehrenreich,
• Artur Erbe,
• Dmytro Sysoiev,
• Thomas Huhn,
• Ulrich Groth and
• Elke Scheer

Beilstein J. Nanotechnol. 2012, 3, 798–808, doi:10.3762/bjnano.3.89

• under UV light irradiation forming a completely π-conjugated molecule, while the closed isomer opens the ring under visible light irradiation, restricting the π-conjugation in the side-arms. The optimum irradiation wavelengths for triggering the ring opening reaction vary slightly from species to

• conductance level in both states. Naively, the π-conjugation through the entire molecule in the closed form is supposed to show higher conductance than the broken π-system. While this has been confirmed by measurements in molecular ensembles and arrays [18][21] and single-molecule junctions [5][26], the

When “small” terms matter: Coupled interference features in the transport properties of cross-conjugated molecules

• Gemma C. Solomon,
• Justin P. Bergfield,
• Charles A. Stafford and
• Mark A. Ratner

Beilstein J. Nanotechnol. 2011, 2, 862–871, doi:10.3762/bjnano.2.95

• response, P(ν) is given by the grand canonical ensemble. The transport theory outlined above is generally applicable. Here we focus on single-molecule junctions and utilize a semiempirical Pariser–Parr–Pople (PPP) [35][36][37] π-electron Hamiltonian, which describes Coulomb interactions, π-conjugation and

Optical properties of fully conjugated cyclo[n]thiophenes – An experimental and theoretical approach

• Elena Mena-Osteritz,
• Fan Zhang,
• Günther Götz,
• Peter Reineker and
• Peter Bäuerle

Beilstein J. Nanotechnol. 2011, 2, 720–726, doi:10.3762/bjnano.2.78

• absorption band in series I indicates slightly lower π-conjugation due to bigger distorsions of the thiophenes induced by steric interactions of the increased number of alkyl chains (8 versus 6 for C16T and C15T, respectively). A closer look at the smallest macrocycles (C8T and C10T) reveals a weak, but

An MCBJ case study: The influence of π-conjugation on the single-molecule conductance at a solid/liquid interface

• Wenjing Hong,
• Hennie Valkenier,
• Gábor Mészáros,
• David Zsolt Manrique,
• Artem Mishchenko,
• Alexander Putz,
• Pavel Moreno García,
• Colin J. Lambert,
• Jan C. Hummelen and
• Thomas Wandlowski

Beilstein J. Nanotechnol. 2011, 2, 699–713, doi:10.3762/bjnano.2.76

• , Department of Physics, Lancaster LA1 4YB, England Institute of Bio- and Nanosystems IBN 3 and Center of Nanoelectronic Systems for Informational Technology, Research Center Juelich, D-52425 Juelich, Germany 10.3762/bjnano.2.76 Abstract π-Conjugation plays an important role in charge transport through single

• current–distance and current–voltage measurements revealed details of the influence of π-conjugation on the single-molecule conductance. Keywords: anthraquinone; π-conjugation; mechanically controlled break junction; single-molecule conductance; Introduction Molecular electronics has expanded

• molecular conformation [13][16] and as well as of the anchoring group and of the contacting leads [17][18] was studied to develop correlations between charge-transport characteristics and molecular structure. Furthermore, π-conjugation plays an essential role in charge transport through single molecular