Adsorption and self-assembly of porphyrins on ultrathin CoO films on Ir(100)

• Feifei Xiang,
• Tobias Schmitt,
• Marco Raschmann and
• M. Alexander Schneider

Beilstein J. Nanotechnol. 2020, 11, 1516–1524, doi:10.3762/bjnano.11.134

• surfaces. It was shown that free-base (2H) or metalated DPP molecules assemble in two-dimensional or linear structures on metal surfaces [22][23] and that on-surface dehydrogenative polymerization reactions may be induced [24]. DPP molecules interact via the phenyl rings and the molecular macrocycle. In

• homogeneous contrast develops in Figure 4d. Such compact assemblies were previously observed for the case of the non-metalated 2H-DPP compound on Ag(110) [24] and on Au(111) [22], but, for example, not on Cu(111) [23]. For the assembly on 1BL CoO, the distance between the phenyl rings is a little larger than

• manipulated such that the rotational motion first gets modified due to the interaction between the phenyl rings of the molecule and finally stops. At a molecule–molecule distance of 2.6 nm and larger (encircled in white in Figure 5a), the appearance in STM of a molecule is not, or only slightly, modified by

Controlling the electronic and physical coupling on dielectric thin films

• Philipp Hurdax,
• Michael Hollerer,
• Larissa Egger,
• Georg Koller,
• Xiaosheng Yang,
• Anja Haags,
• Serguei Soubatch,
• Frank Stefan Tautz,
• Mathias Richter,
• Alexander Gottwald,
• Peter Puschnig,
• Martin Sterrer and
• Michael G. Ramsey

Beilstein J. Nanotechnol. 2020, 11, 1492–1503, doi:10.3762/bjnano.11.132

• pronounced six-lobe structure with a slight zig-zag appearance is seen in some of the molecules in Figure 2a. This structure is even more evident in the molecules forming the ordered island in Figure 2c. These may be associated with the six phenyl rings of the 6P molecule presenting a twisted conformation

• . In the gas phase, 6P naturally occurs with a torsional angle of 35° between its phenyl rings [26]. The observation of such a twist on MgO(100)/Ag(100) suggests that the interaction between the 6P molecules and MgO is very weak. In addition, next to the 6P molecules with a zig-zag appearance, there

• ]. It can therefore be concluded that, while neutral molecules can have a twist in different orientations on the MgO surface, the molecules that have experienced charge transfer are planarized. Therefore, they lose the 35° torsional angle between their phenyl rings and align exclusively along [001]/[010

Interfacial charge transfer processes in 2D and 3D semiconducting hybrid perovskites: azobenzene as photoswitchable ligand

• Nicole Fillafer,
• Tobias Seewald,
• Lukas Schmidt-Mende and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2020, 11, 466–479, doi:10.3762/bjnano.11.38

• ]. The extended aromatic structure, comprising two phenyl rings connected through an azo group, shows characteristic and unique photoswitching properties. Absorption of a photon in the UV region causes an isomerisation of the nitrogen–nitrogen double bond. The conformational change is accompanied not

• [45]. It is well known, that vibrations of surface-bound amines are quenched through coordination. Signals at 832, 765, 727 and 685 cm−1 can be assigned to the aromatic vibrations of the phenyl rings of azobenzene. These significant vibrations can as well be found in 3D-AzoC2 (blue), which indicates a

Amplified cross-linking efficiency of self-assembled monolayers through targeted dissociative electron attachment for the production of carbon nanomembranes

• Sascha Koch,
• Christopher D. Kaiser,
• Paul Penner,
• Michael Barclay,
• Lena Frommeyer,
• Daniel Emmrich,
• Patrick Stohmann,
• Tarek Abu-Husein,
• Andreas Terfort,
• D. Howard Fairbrother,
• Oddur Ingólfsson and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2017, 8, 2562–2571, doi:10.3762/bjnano.8.256

• upper phenyl ring. However, it should be taken into account that these compounds are also subjects to different steric restrictions determining their relative orientation. For instance, the twist angle between the phenyl rings is a result of a compensation of the repulsion of the ortho hydrogens, or

Adsorption of iron tetraphenylporphyrin on (111) surfaces of coinage metals: a density functional theory study

• Hao Tang,
• Nathalie Tarrat,
• Véronique Langlais and
• Yongfeng Wang

Beilstein J. Nanotechnol. 2017, 8, 2484–2491, doi:10.3762/bjnano.8.248

• . At the end, the relationship between the substrate and the coordination sphere of Fe is discussed in terms of molecule–surface interaction, charge transfer and work function modification. Results and Discussion Free molecule and conformations The ideal D4h symmetry, exhibiting the phenyl rings

• ]. In these assemblies, FeTPP forms a close-packed arrangement involving T-type interactions, i.e., the four phenyl rings of one molecule point their extremities perpendicularly towards the phenyl of the neighbouring FeTPP molecules (Figure 3a). In this configuration the central macrocycle has a saddle

• interaction between neighbouring FeTPP molecules is of π–π type. In the latter, all phenyl rings of a FeTPP molecule are parallel to the phenyl groups of neighbouring molecules (Figure 3b). The H atoms of two pyrrole rings (along the axis perpendicular to the figure) remain nearly in the same plane, while in

Scanning probe microscopy studies on the adsorption of selected molecular dyes on titania

• Jakub S. Prauzner-Bechcicki,
• Lukasz Zajac,
• Piotr Olszowski,
• Res Jöhr,
• Antoine Hinaut,
• Thilo Glatzel,
• Bartosz Such,
• Ernst Meyer and
• Marek Szymonski

Beilstein J. Nanotechnol. 2016, 7, 1642–1653, doi:10.3762/bjnano.7.156

• their central Zn atom located above an oxygen row and opposite pyrroles of the macrocycle oriented along that row. The molecule is slightly distorted upon adsorption, i.e., the phenyl rings of the side groups are rotated to allow for weak hydrogen bonds to form with the surface oxygen atoms

Effects of electronic coupling and electrostatic potential on charge transport in carbon-based molecular electronic junctions

• Richard L. McCreery

Beilstein J. Nanotechnol. 2016, 7, 32–46, doi:10.3762/bjnano.7.4

• orbitals to transport in an AB molecular junction will be considered below. Since the G9 aromatic systems and the AB phenyl rings are conjugated and covalently bonded, we expect that the degree of interaction between the two π-systems should depend on the dihedral angle between the G9 plane and the AB

Probing the local environment of a single OPE3 molecule using inelastic tunneling electron spectroscopy

• Riccardo Frisenda,
• Mickael L. Perrin and
• Herre S. J. van der Zant

Beilstein J. Nanotechnol. 2015, 6, 2477–2484, doi:10.3762/bjnano.6.257

• to the usual Au–S covalent bond, the molecule interacts on both sides with the outer phenyl rings. In the second geometry (20.70 Å), the molecule is more extended and interacts only on one side with the outer ring, while on the other side the binding occurs through the sulphur atoms. For the two

• originate from the phenyl rings and the ethynyl (C≡C) triple bonds, respectively. In the experiments, we observe peaks in the spectra around the energies of those modes. The peak around 180 mV is observed in all configurations, and attributed to vibrational modes involving the center and outer phenyl rings

• different intensities and/or different energies. These modes are located between 80 and 120 meV and interestingly, they are mostly related to in-plane ring modes. This could indicate that one or more phenyl rings interact differently with the metallic electrode and that the molecule–metal interface plays a

Negative differential electrical resistance of a rotational organic nanomotor

• Hatef Sadeghi,
• Sara Sangtarash,
• Qusiy Al-Galiby,
• Rachel Sparks,
• Steven Bailey and
• Colin J. Lambert

Beilstein J. Nanotechnol. 2015, 6, 2332–2337, doi:10.3762/bjnano.6.240

• branch. The backbone consists of five interconnected phenyl rings with attached methyl groups to prevent the backbone from twisting and is stabilized at either end by a fullerene, C60 terminating group. The C60 at either end not only stabilizes the molecule, but also allows the molecule to appear more

• significant overlap between one of the phenyl rings on the backbone with the aniline capped end of the branch. This suggests that these positions are stabilised by the π–π interaction between the two aromatic rings. The rotor does not rotate at a uniform distance from the backbone and therefore the charge

Controlled switching of single-molecule junctions by mechanical motion of a phenyl ring

• Yuya Kitaguchi,
• Satoru Habuka,
• Hiroshi Okuyama,
• Shinichiro Hatta,
• Tetsuya Aruga,
• Thomas Frederiksen,
• Magnus Paulsson and
• Hiromu Ueba

Beilstein J. Nanotechnol. 2015, 6, 2088–2095, doi:10.3762/bjnano.6.213

• accessibility, we propose that phenyl rings are promising components in mechanical molecular devices. Keywords: density functional theory; phenyl rings; quantum transport simulations; scanning tunneling microscopy; single-molecule switches; Introduction Atomic-scale switches are key device components in

• conductance ratio between PhO and PhS was also reproduced and ascribed to different hybridization strengths with the substrate states. In summary, we propose that phenyl rings are promising as versatile units for molecular electronic devices, whose mechanics can be controlled by different triggers such as

Conductance through single biphenyl molecules: symmetric and asymmetric coupling to electrodes

• Karthiga Kanthasamy and
• Herbert Pfnür

Beilstein J. Nanotechnol. 2015, 6, 1690–1697, doi:10.3762/bjnano.6.171

• thiol bonding [46]. A similar effect is to be expected by changes of the tilt angle between the phenyl rings and electrodes during bond fluctuations [35][36] as well as by spontaneous binding and unbinding of the molecular anchor groups to the electrodes [47]. A similar signature of the fluctuation was

Synthesis, characterization, monolayer assembly and 2D lanthanide coordination of a linear terphenyl-di(propiolonitrile) linker on Ag(111)

• Zhi Chen,
• Svetlana Klyatskaya,
• José I. Urgel,
• David Écija,
• Olaf Fuhr,
• Willi Auwärter,
• Johannes V. Barth and
• Mario Ruben

Beilstein J. Nanotechnol. 2015, 6, 327–335, doi:10.3762/bjnano.6.31

• the goal to achieve increased coordination numbers (7–12) (typically for f-block elements in bulk chemistry [18][20][44]), the linker 2 was designed to reduce the steric repulsion induced by the α-C–H bonds at the terminal phenyl rings and the coordinating donor N-atom of the carbonitrile group. By

• ones by a dihedral angle of 31.56(5)° (Figure 2b). In comparison, the mono-substituted compound 3 exhibits twist angles of 33° and 10° between phenyl rings A/B and B/C, respectively (Supporting Information File 1, Figure S3). In both cases the molecules arrange within the crystal in layers (Figure 2c

• aromatic rings alternatively lifting the left and the right side of a phenyl rings up from the underlying substrate. It was found that the chevron pattern assembled from 2 is similar to that earlier reported for NC–Phn–CN linkers (whereby n = 3, 1) [43], where only two orientations of the molecules with

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

• blocks different from phenyl rings bear challenges of their own. Such structures, however, are highly interesting, as they allow for an incorporation of CPPs as defined nano-objects for other applications. Therefore, this review provides a status report about the current efforts in synthesizing CPPs

• strain in a CPP is mainly due to the deviation of the phenyl rings from planarity. However, the phenyl units in all CPPs that were synthesized so far are not fully conjugated due to a torsion between the phenyl moieties to overcome the steric interactions of the protons in ortho-position. This effect has

• 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

Controlling mechanical properties of bio-inspired hydrogels by modulating nano-scale, inter-polymeric junctions

• Seonki Hong,
• Hyukjin Lee and
• Haeshin Lee

Beilstein J. Nanotechnol. 2014, 5, 887–894, doi:10.3762/bjnano.5.101

• quinone, which typically undergo the 1,4-Michael addition reactions [27]. Considering the molecular structures of PEGs studied herein, three quinone tanning reactions are possible: (i) catechol–catechol formation through C–C coupling between phenyl rings [27][28], (ii) C–O coupling at a C-4 position by

Classical molecular dynamics investigations of biphenyl-based carbon nanomembranes

• Andreas Mrugalla and
• Jürgen Schnack

Beilstein J. Nanotechnol. 2014, 5, 865–871, doi:10.3762/bjnano.5.98

• dihedral twistings between the upper and lower phenyl rings, that following [4] remain sizable in the SAM in accord with theoretical calculations [6][7]. On top of these initial conditions we also investigated highly excited initial states. These were realized by randomly displacing individual carbon atoms

• configuration as it could possibly be realized during the electron exposition and in panel (B) the resulting state (local minimum) found by steepest descent. Panel (C) shows the highlighted region of (B); this structure consists of intact phenyl rings in the middle part that are laterally not cross-linked and

• investigations of a loss of aromaticity of terphenylthiol SAMs when being irradiated [17]. Nevertheless, the (remaining) intact phenyl rings seem to play an important role as a kind of matrix that stabilizes the resulting structures [28]. Such structures as depicted in Figure 4 tend to contradict our

Fabrication of carbon nanomembranes by helium ion beam lithography

• Xianghui Zhang,
• Henning Vieker,
• André Beyer and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2014, 5, 188–194, doi:10.3762/bjnano.5.20

• conducted by exposure to electrons [10] and photons [11]. Electron irradiation induces the dissociation of C–H bonds at the phenyl rings. The consequent cross-linking between adjacent aromatic moieties is a critical step in the formation of CNMs. Both electron beam lithography and extreme ultraviolet (EUV

X-ray spectroscopy characterization of self-assembled monolayers of nitrile-substituted oligo(phenylene ethynylene)s with variable chain length

• Hicham Hamoudi,
• Ping Kao,
• Alexei Nefedov,
• David L. Allara and
• Michael Zharnikov

Beilstein J. Nanotechnol. 2012, 3, 12–24, doi:10.3762/bjnano.3.2

• latter resonance with the increasing chain length. The resonance 2 is presumably comprised of several different contributions, including a conjugation between the π* orbital of the rings and C≡C groups [53]. There are also contributions from the phenyl rings themselves, as seen in the spectrum of TPT/Au

• Figure 6, through the example of NC-OPE3, which presumably takes a planar conformation in the densely packed SAM (see below). The π* orbitals of the phenyl rings (πph*) are perpendicular to the molecular plane; the respective TDMph, which is perpendicular to the molecular plane as well, is shown as a

• case of the nitrile substitution due to the presence of the π1* and π3* orbitals of the nitrile group, which are perpendicular to each other and one of which is aligned with the π1* orbitals of the phenyl rings. In this case, both β and γ can be directly derived from the NEXAFS data at the N K-edge

Direct monitoring of opto-mechanical switching of self-assembled monolayer films containing the azobenzene group

• Einat Tirosh,
• Enrico Benassi,
• Silvio Pipolo,
• Marcel Mayor,
• Michal Valášek,
• Veronica Frydman,
• Stefano Corni and
• Sidney R. Cohen

Beilstein J. Nanotechnol. 2011, 2, 834–844, doi:10.3762/bjnano.2.93

• this local functionality of the molecule (the inner phenyl rings) rather than being delocalized as for trans. This provides a microscopic rationale for the observation that the cis dominant mode has a force constant larger than the trans dominant mode, yielding an overall stiffer molecule. Experimental

Mechanical characterization of carbon nanomembranes from self-assembled monolayers

• Xianghui Zhang,
• André Beyer and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2011, 2, 826–833, doi:10.3762/bjnano.2.92

• by X-ray photoelectron spectroscopy (XPS) to be ~1.6 nm for CBPS SAMs, which was larger than that of NBPT SAMs (~1.2 nm) and BPT SAMs (~0.9 nm) [9][18][19]. As cross-linking occurs between the phenyl rings, a comparable thickness is expected for the corresponding CNMs. The CNM can be modeled as a

Septipyridines as conformationally controlled substitutes for inaccessible bis(terpyridine)-derived oligopyridines in two-dimensional self-assembly

• Daniel Caterbow,
• Daniela Künzel,
• Michael G. Mavros,
• Axel Groß,
• Katharina Landfester and
• Ulrich Ziener

Beilstein J. Nanotechnol. 2011, 2, 405–415, doi:10.3762/bjnano.2.46

• the contrast. Thus, we suggest a tentative model, which shows reasonable hydrogen bonding interactions primarily between the peripheral para-connected pyridine units. The model implies dense packing, such that the phenyl rings cannot be coplanar. Rather, they must stand upright, stabilizing the