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Université de Fribourg

Puckering behavior in six new phosphoric triamides containing aliphatic six- and seven-membered ring groups and a database survey of analogous ring-containing structures

Alviri, Banafsheh Vahdani ; Pourayoubi, Mehrdad ; Saneei, Anahid ; Keikha, Mojtaba ; Lee, Arie van der ; Crochet, Aurélien ; Ajees, A. Abdul ; Nečas, Marek ; Fromm, Katharina M. ; Damodaran, Krishnan ; Jenny, Titus A.

In: Tetrahedron, 2018, vol. 74, no. 1, p. 28–41

The influence of a N heteroatom on the ring conformations of six- and seven- membered aliphatic rings in six new C(O)NHP(O)-based phosphoric triamide structures (analysed by X-ray crystallography) is investigated. Additionally the influence of steric and crystal packing effects is also studied by the analysis of Hirshfeld surfaces. The results are compared to analogous structures with three-...

Université de Fribourg

Laterally stretched polycyclic aromatic hydrocarbons: synthesis of dibenzophenanthroheptaphene and tetrabenzotriphenylenopyranthrene derivatives

Alameddine, Bassam ; Anju, Rajamohanan Sobhana ; Shetty, Suchetha ; Baig, Noorullah ; Al-Sagheer, Fakhreia ; Al-Mousawi, Saleh ; Jenny, Titus A.

In: New Journal of Chemistry, 2017, vol. 41, no. 13, p. 6025–6032

Efficient methods for the synthesis of dibenzophenanthroheptaphene (DBPH) and tetrabenzotriphenylenopyranthrene (TBTP) were developed. As a result, a series of unprecedented derivatives of DBPH (1a–c) and TBTP (2a–b) were conventionally obtained from the Scholl cyclodehydrogenation reaction of their respective tribenzopentaphene synthons. An alternative convergent synthesis of DBPH is also...

Université de Fribourg

Tribenzopentaphene derivatives with lateral aromatic groups: the effect of the nature and position of substituents on emission properties

Alameddine, Bassam ; Anju, Rajamohanan Sobhana ; Al-Sagheer, Fakhreia ; Jenny, Titus A.

In: New Journal of Chemistry, 2016, vol. 40, no. 12, p. 10363–10370

Nine new derivatives of the trapezoidal tribenzopentaphene (TBP) polycyclic aromatic hydrocarbon (PAH) were synthesized via the Suzuki–Miyaura palladium catalyzed cross-coupling reaction. The novel TBP derivatives, which bear various rigid and flexible aromatic groups either at their more accessible (R1) or congested (R2) bases, were fully characterized using high resolution mass...

Université de Fribourg

Chemical nucleation of diamond films

Mandal, Soumen ; Thomas, Evan L. H. ; Jenny, Titus A. ; Williams, Oliver A.

In: ACS Applied Materials & Interfaces, 2016, vol. 8, no. 39, p. 26220–26225

With the large differences in surface energy between film and substrate in combination with the low sticking coefficient of hydrocarbon radicals, nanocrystalline diamond growth on foreign substrates typically results in poor nucleation densities. A seeding technique is therefore required to realize pinhole-free and thin coalesced films. In this work, a chemical nucleation method for growth of...

Université de Fribourg

Influence of linear and branched perfluoroalkylated side chains on the π–π stacking behaviour of hexa-peri-hexabenzocoronene and thermotropic properties

Alameddine, Bassam ; Aebischer, Olivier Frédéric ; Heinrich, Benoît ; Guillon, Daniel ; Donnio, Bertrand ; Jenny, Titus A.

In: Supramolecular Chemistry, 2014, vol. 26, no. 2, p. 125–137

The thermotropic properties and self-assembly of two different series of hexa-peri-hexabenzocoronenes (HBC) bearing either linear or branched perfluoroalkylated side chains, each with a wide range of alkyl spacer and perfluorinated tail lengths, have been studied. Correlations between thermogravimetric analysis, differential scanning calorimetry, polarised optical microscopy and small-angle X-ray...

Université de Fribourg

Theoretical study of the stacking behavior of selected polycondensed aromatic hydrocarbons with various symmetries

Antony, Jens ; Alameddine, Bassam ; Jenny, Titus A. ; Grimme, Stefan

In: The Journal of Physical Chemistry A, 2012, vol. 117, no. 3, p. 616–625

Stacked dimers of four polycondensed aromatic hydrocarbons, with structures varying from high to reduced symmetries, have been calculated with dispersion-corrected density functional theory. The configurations of the stacked dimers are readily classified by two in-plane displacements and a relative rotation. The potential energy surface in these three coordinates was calculated with rigid...

Université de Fribourg

Synthesis of alkyl-Substituted tribenzopentaphenes as versatile polycondensed aromatic hydrocarbon π-π stacking building blocks

Alameddine, Bassam ; Caba, Sofia Martin ; Schindler, Mauro ; Jenny, Titus A.

In: Synthesis, 2012, vol. 44, p. 1928-1934

We show the versatile synthesis of four tribenzopentaphene derivatives bearing alkyl side chains at three different positions. Substitutions on two of these positions led to subtle intensity changes at the lines of the blue emission, whereas alkylation in the bay region led to dimerization of the pentaphene derivative, resulting in a distortion of the chromophore geometry and an emission shift to...

Université de Fribourg

Synthesis of Hexa-peri-hexobenzocoronenes Carrying Linear or Branched Perfluoroalkylated Side Chains

Aebischer, Olivier F. ; Muñoz, David T. ; Tondo, Patrick ; Débieux, Jean-Luc ; Jenny, Titus A.

In: Synthesis, 2010, vol. 7, p. 1123-1140

Substituted disc-shaped perfluoroalkylated hexa-peri-hexabenzocoronenes (HBC), known to self-assemble into conducting ordered architectures, were synthesized and characterized. A systematic variation of the linear or branched perfluoroalkylated side chains was performed in order to screen the influence of the lateral chain on their one-dimensional self-aggregation.