Synthesis and characterization of low-molecular-weight π-conjugated polymers covered by persilylated β-cyclodextrin

• Aurica Farcas,
• Ana-Maria Resmerita,
• Andreea Stefanache,
• Mihaela Balan and
• Valeria Harabagiu

Beilstein J. Org. Chem. 2012, 8, 1505–1514, doi:10.3762/bjoc.8.170

• chemical structure and the thermal and morphological properties of the resulting polyrotaxane were investigated by using NMR and FT-IR spectroscopy, TGA, DSC and AFM analysis. The encapsulation of BT inside the PS-βCD cavity results in improvements in the solubility, as well as in different surface

• the influence on the surface morphological properties induced by using 3T as an end-capping reagent instead of bromobenzene [12], AFM experiments were also performed. The 2D AFM images of the top surface of both copolymer films, within the same scan areas of 2 × 2 μm2 are shown in Figure 7a and Figure

•  7b (insets show the 3D images). They afforded the root-mean-square roughness of the formations (Sq) and the average roughness (µ) as well as the average heights (Ha), see Table 3. The 3D AFM images of the complexed PDOF-BTc film (insets Figure 7b) show more favourable surface parameters in comparison

Intraannular photoreactions in pseudo-geminally substituted [2.2]paracyclophanes

• Henning Hopf,
• Vitaly Raev and
• Peter G. Jones

Beilstein J. Org. Chem. 2011, 7, 658–667, doi:10.3762/bjoc.7.78

• the term “topochemical principle” or “topochemistry” for (non)reactivity determined by a limiting distance between the reactive groups [2][3][4]. Although the model found widespread acceptance, many exceptions to the concept were known from the very beginning [5]. Later, AFM techniques enabled

Self-assembly and semiconductivity of an oligothiophene supergelator

• Pampa Pratihar,
• Suhrit Ghosh,
• Vladimir Stepanenko,
• Sameer Patwardhan,
• Ferdinand C. Grozema,
• Laurens D. A. Siebbeles and
• Frank Würthner

Beilstein J. Org. Chem. 2010, 6, 1070–1078, doi:10.3762/bjoc.6.122

• . The charge transport ability of such elongated fibres of quaterthiophene π-system was explored by the pulse radiolysis time resolved microwave conductivity (PR-TRMC) technique and moderate mobility values were obtained. Furthermore, initial AFM and UV-vis spectroscopic studies of a mixture of our

• ability of T1 to gelate such a wide range of solvents and its significantly low CGC values can be attributed to the favourable balance between the self-assembly propensity of the gelator and good solubility due to the presence of the trialkoxybenzamide groups. AFM investigations The topology of gels of

• quaterthiophene derivative T1 was examined by atomic force microscopy (AFM) in the tapping mode. As an illustrative example, the AFM images of T1 gel in MCH deposited on highly ordered pyrolytic graphite (HOPG) are shown in Figure 1. These images clearly show interconnected long fibers a few micrometers in length

Pyridinium based amphiphilic hydrogelators as potential antibacterial agents

• Sayanti Brahmachari,
• Sisir Debnath,
• Sounak Dutta and
• Prasanta Kumar Das

Beilstein J. Org. Chem. 2010, 6, 859–868, doi:10.3762/bjoc.6.101

• microscopy (FESEM), atomic force microscopy (AFM), photoluminescence, FTIR studies, X-ray diffraction (XRD) and 2D NOESY experiments were carried out to elucidate the different non-covalent interactions responsible for the self-assembled gelation. The formation of three-dimensional supramolecular aggregates

• fluorescence spectroscopy. The topographical features of the soft matter were visualized using different microscopic techniques (scanning electron microscopy (SEM), atomic force microscopy (AFM)). Interestingly, these compounds were found to show excellent antibacterial activity against Gram-positive and Gram

• architecture of 2 at the aggregated state was further confirmed by Atomic Force Microscopic (AFM) images. Two and three dimensional AFM images of xerogel 2 (Figure 3c, d) showed the involvement of fibrillar networks in self-assembled hydrogelation. The dimension of the fibril network observed in the AFM image

Self-assembled ordered structures in thin films of HAT5 discotic liquid crystal

• Piero Morales,
• Jan Lagerwall,
• Paolo Vacca,
• Sabine Laschat and
• Giusy Scalia

Beilstein J. Org. Chem. 2010, 6, No. 51, doi:10.3762/bjoc.6.51

• compared to the bulk situation, where the same material crystallizes into a polymorphic structure at 68 °C. Keywords: AFM; discotic liquid crystals; hexapentyloxytriphenylene; self-organization; thin films; Introduction Discotic liquid crystals are an interesting type of organic semiconductors that allow

• ensured thinner films had a uniformly black aspect. The origin of the black background is the extremely small thickness of the LC film, giving negligible effective birefringence, even for a director in planar orientation. The analysis of these regions thus relied mainly on atomic force microscopy (AFM

• ellipse in the top and bottom pictures of Figure 2. It was possible to localize these structures by AFM as shown in Figure 3. Here an example with overall diameter in the order of 1.5–2 μm (similar to the lines detected optically) is shown, together with small elongated aggregates. The substrate roughness

New diarylmethanofullerene derivatives and their properties for organic thin- film solar cells

• Daisuke Sukeguchi,
• Surya Prakash Singh,
• Mamidi Ramesh Reddy,
• Hideyuki Yoshiyama,
• Rakesh A. Afre,
• Yasuhiko Hayashi,
• Hiroki Inukai,
• Tetsuo Soga,
• Shuichi Nakamura,
• Norio Shibata and
• Takeshi Toru

Beilstein J. Org. Chem. 2009, 5, No. 7, doi:10.3762/bjoc.5.7

• observed in the case of PCBM [32][33][34], which possibly makes the conjugation length of P3HT longer. AFM measurements were performed on P3HT:1a and P3HT:PCBM films with different annealing temperatures. Different results were obtained between P3HT/1a and P3HT/PCBM: substantially similar low roughness

• values were observed in the AFM image of P3HT/1a annealed at 100, 130, 140 °C (r.m.s. = 0.9–1.1 nm). On the other hand, films of P3HT/PCBM showed similar roughness at 130 and 140 °C (r.m.s. = 1.4–1.6 nm), but a coarser surface was observed at 100 °C (r.m.s. = 2.2–2.6 nm). The P3HT/PCBM cell showed the

• obtained at a lower annealing temperature (100 °C). Their spectral responsivities and the AFM measurements suggested a change of the P3HT alignment depending on the annealing temperatures. These observations will lead the way to further development of highly efficient acceptors for organic thin-film solar

Synthesis of thienyl analogues of PCBM and investigation of morphology of mixtures in P3HT

• Fukashi Matsumoto,
• Kazuyuki Moriwaki,
• Yuko Takao and
• Toshinobu Ohno

Beilstein J. Org. Chem. 2008, 4, No. 33, doi:10.3762/bjoc.4.33

• thieno[3,2-b]thiophene (3c, 3d) were synthesized and characterized. The morphology of the thin films prepared from the mixtures of these methanofullerenes with regioregular poly(3-hexylthiophene) (P3HT) was investigated by AFM measurement and UV-Vis absorption spectroscopy. A solubility test of these

• hetero films of these novel methanofullerenes were spin coated on glass substrates and were characterized by using AFM and UV-Vis absorption spectroscopy in order to study and compare their morphological features. 3-BThCBM (3b) and TThCBM (3c) were excluded because their high-concentration solutions

• glass plate and dried for 24 h at room temperature under vacuum. Tapping-mode AFM measurements were performed on a film area of 500 × 500 nm. All films had a very flat surface and almost the same roughness (r.m.s. value of 0.2–0.24 nm). However in the phase image (Figure 2), (A) PCBM and (B) ThCBM