Dainius Janeliunas - Academia.edu (original) (raw)
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Papers by Dainius Janeliunas
Organic & Biomolecular Chemistry, 2013
In this study we designed a new class of symmetrical facial oligothiophene amphiphiles, which cou... more In this study we designed a new class of symmetrical facial oligothiophene amphiphiles, which could be obtained in fewer steps than for previously reported analogues, but still possess the specific substituent sequence to control their backbone curvature. This novel design allows the late-stage introduction of hydrophilic groups, aiding both purification and ease of structure variation. Following the new synthetic scheme, symmetrical ter- and sexi-thiophenes were synthesized, analysed and their properties were compared to their non-symmetrical analogues. Surprisingly, the self-assembly behaviour in water, aggregate morphologies and photo-physical properties turned out to be significantly different despite the same ratio of hydrophilic and hydrophobic substituents. The new substitution pattern resulted in a drastic decrease of the critical aggregation concentration and an increase of the aggregate size. The symmetrical positioning of the substituents also heavily influenced the photo-physical properties. The changes were observed as large blue shifts in the absorption and emission spectra in water when compared to similar regio-regular oligothiophene amphiphiles.
Journal of Materials Chemistry, 2010
Chemistry - A European Journal, 2010
Chemistry - A European Journal, 2010
Angewandte Chemie International Edition, 2008
Angewandte Chemie International Edition, 2013
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Tetrahedron, 2009
An efficient synthetic method for 3,6-epoxy[1,5]dioxocines via the condensation of salicyl aldehy... more An efficient synthetic method for 3,6-epoxy[1,5]dioxocines via the condensation of salicyl aldehydes and epichlorohydrin, using benzyl triethylammonium chloride as catalyst, is described. The use of neutral or electron-deficient salicyl aldehydes in all cases was found to give 3,6-epoxy[1,5]dioxocine derivatives in good yields. The structural features were resolved by IR, NMR spectroscopy, mass spectrometry, and ultimately proved by X-ray crystallographic analysis.
Molecular Crystals and Liquid Crystals, 2008
Arylmethylene-1,3-indandione-based molecular glasses were synthesized starting from 1,3-indandion... more Arylmethylene-1,3-indandione-based molecular glasses were synthesized starting from 1,3-indandione. These compounds were found to constitute novel charge transporting materials and were examined by various techniques including differential scanning calorimetry, electron photoemission, cyclic voltammetry, and xerographic time-of-flight techniques. The electron photoemission spectra of the layers showed the ionization potentials of 5.8–5.9 eV. The cyclic voltammograms and the charge carrier mobilities measured by the
Angewandte Chemie International Edition, 2010
New Journal of Chemistry, 2011
Conjugated self-assembled systems in water are of great interest because of their potential appli... more Conjugated self-assembled systems in water are of great interest because of their potential application in biocompatible supramolecular electronics, but so far their supramolecular chemistry remains almost unexplored. Here we present amphiphilic terthiophenes as a general self-assembling platform for the construction of conjugated aggregates, providing access to aggregates with different morphologies without changing the basic molecular design. We explored the design parameters of these amphiphilic terthiophenes in detail, leading to the selection and synthesis of in total 8 new amphiphilic oligothiophenes. Their aggregation behaviour was investigated by absorbance and fluorescence spectroscopy, dynamic light scattering, and cryo-transmission electron microscopy. Critical micelle concentrations as low as 0.01 mM were found and different sized aggregates ranging from several nanometres up to 200 nm. The aggregate morphology could also be tuned by changing the substitution pattern of hydrophilic and hydrophobic moieties, leading to different types of aggregates ranging from globular-and elongated micelles to bilayers. Remarkably, aggregation had only little effect on the electronic and spectroscopic properties of the oligothiophenes, which will be of interest for their application in supramolecular electronics.
Organic & Biomolecular Chemistry, 2013
In this study we designed a new class of symmetrical facial oligothiophene amphiphiles, which cou... more In this study we designed a new class of symmetrical facial oligothiophene amphiphiles, which could be obtained in fewer steps than for previously reported analogues, but still possess the specific substituent sequence to control their backbone curvature. This novel design allows the late-stage introduction of hydrophilic groups, aiding both purification and ease of structure variation. Following the new synthetic scheme, symmetrical ter- and sexi-thiophenes were synthesized, analysed and their properties were compared to their non-symmetrical analogues. Surprisingly, the self-assembly behaviour in water, aggregate morphologies and photo-physical properties turned out to be significantly different despite the same ratio of hydrophilic and hydrophobic substituents. The new substitution pattern resulted in a drastic decrease of the critical aggregation concentration and an increase of the aggregate size. The symmetrical positioning of the substituents also heavily influenced the photo-physical properties. The changes were observed as large blue shifts in the absorption and emission spectra in water when compared to similar regio-regular oligothiophene amphiphiles.
Journal of Materials Chemistry, 2010
Chemistry - A European Journal, 2010
Chemistry - A European Journal, 2010
Angewandte Chemie International Edition, 2008
Angewandte Chemie International Edition, 2013
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Tetrahedron, 2009
An efficient synthetic method for 3,6-epoxy[1,5]dioxocines via the condensation of salicyl aldehy... more An efficient synthetic method for 3,6-epoxy[1,5]dioxocines via the condensation of salicyl aldehydes and epichlorohydrin, using benzyl triethylammonium chloride as catalyst, is described. The use of neutral or electron-deficient salicyl aldehydes in all cases was found to give 3,6-epoxy[1,5]dioxocine derivatives in good yields. The structural features were resolved by IR, NMR spectroscopy, mass spectrometry, and ultimately proved by X-ray crystallographic analysis.
Molecular Crystals and Liquid Crystals, 2008
Arylmethylene-1,3-indandione-based molecular glasses were synthesized starting from 1,3-indandion... more Arylmethylene-1,3-indandione-based molecular glasses were synthesized starting from 1,3-indandione. These compounds were found to constitute novel charge transporting materials and were examined by various techniques including differential scanning calorimetry, electron photoemission, cyclic voltammetry, and xerographic time-of-flight techniques. The electron photoemission spectra of the layers showed the ionization potentials of 5.8–5.9 eV. The cyclic voltammograms and the charge carrier mobilities measured by the
Angewandte Chemie International Edition, 2010
New Journal of Chemistry, 2011
Conjugated self-assembled systems in water are of great interest because of their potential appli... more Conjugated self-assembled systems in water are of great interest because of their potential application in biocompatible supramolecular electronics, but so far their supramolecular chemistry remains almost unexplored. Here we present amphiphilic terthiophenes as a general self-assembling platform for the construction of conjugated aggregates, providing access to aggregates with different morphologies without changing the basic molecular design. We explored the design parameters of these amphiphilic terthiophenes in detail, leading to the selection and synthesis of in total 8 new amphiphilic oligothiophenes. Their aggregation behaviour was investigated by absorbance and fluorescence spectroscopy, dynamic light scattering, and cryo-transmission electron microscopy. Critical micelle concentrations as low as 0.01 mM were found and different sized aggregates ranging from several nanometres up to 200 nm. The aggregate morphology could also be tuned by changing the substitution pattern of hydrophilic and hydrophobic moieties, leading to different types of aggregates ranging from globular-and elongated micelles to bilayers. Remarkably, aggregation had only little effect on the electronic and spectroscopic properties of the oligothiophenes, which will be of interest for their application in supramolecular electronics.