Synthesis of mesogenic phthalocyanine-C₆₀ donor–acceptor dyads designed for molecular heterojunction photovoltaic devices

• Yves Henri Geerts,
• Olivier Debever,
• Claire Amato and
• Sergey Sergeyev

Beilstein J. Org. Chem. 2009, 5, No. 49, doi:10.3762/bjoc.5.49

• example of LC phthalocyanine-C60 dyads. Keywords: donor–acceptor dyad; fullerene; liquid crystals; phthalocyanine; phthalonitrile; Introduction Among sustainable energy technologies, photovoltaic (PV) conversion of solar energy is considered as a promising solution. Although currently the market is

• heterojunction” architecture, featuring blends of the two immiscible materials: a donor and an acceptor of electrons [4][5][6][7]. After absorption of a photon, an initially formed exciton is dissociated at the donor/acceptor interface into a positive charge (hole) and a negative charge (electron), which are

Convenient methods for preparing π-conjugated linkers as building blocks for modular chemistry

• Jiří Kulhánek,
• Filip Bureš and
• Miroslav Ludwig

Beilstein J. Org. Chem. 2009, 5, No. 11, doi:10.3762/bjoc.5.11

• use as building blocks in Suzuki–Miyaura or Sonogashira coupling reactions. Keywords: boronic acid; donor/acceptor; linker; Sonogashira reaction; property tuning; push-pull; Suzuki–Miyaura reaction; Introduction Development of new organic compounds with improved and advanced properties is one of the

Synthesis and redox behavior of new ferrocene- π-extended- dithiafulvalenes: An approach for anticipated organic conductors

• Abdelwareth A. O. Sarhan,
• Omar F. Mohammed and
• Taeko Izumi

Beilstein J. Org. Chem. 2009, 5, No. 6, doi:10.3762/bjoc.5.6

• characterized a donor-acceptor dyad system involving tetrathiafulvalene (TTF) as electron donor attached by a flexible spacer to perylene derivatives as electron acceptor [5]. They have shown that the fluorescence of the tetrathiafulvalene–perylene derived dyad can be reversibly modulated by the transformation

The role of an aromatic group in remote chiral induction during conjugate addition of α-sulfonylallylic carbanions to ethyl crotonate

• Shlomo Levinger,
• Ranjeet Nair and
• Alfred Hassner

Beilstein J. Org. Chem. 2008, 4, No. 32, doi:10.3762/bjoc.4.32

• interaction between the aromatic π-system and the Li+ leads to stabilization. However, the lowest energy interaction is expected to produce the N(1)R*,3R*,4S* configured adduct 4. Therefore, it is the slightly less stable, but more reactive intermediary donor–acceptor complex that is apparently responsible

Inversion symmetry and local vs. dispersive interactions in the nucleation of hydrogen bonded cyclic n-mer and tape of imidazolecarboxamidines

• Sihui Long,
• Venkatraj Muthusamy,
• Peter G. Willis,
• Sean Parkin and
• Arthur Cammers

Beilstein J. Org. Chem. 2008, 4, No. 23, doi:10.3762/bjoc.4.23

• be made about the most popular hydrogen bond motif followed by caveats regarding the use of crystal-structure derived atomic parameters to broadly characterize hydrogen bonding energies. 1: An intuitive prediction regarding the relationship between crude hydrogen bond donor/acceptor directionality

Electronic differentiation competes with transition state sensitivity in palladium- catalyzed allylic substitutions

• Dominik A. Lange and
• Bernd Goldfuss

Beilstein J. Org. Chem. 2007, 3, No. 36, doi:10.1186/1860-5397-3-36

• phospha-benzene-pyridine ligands. Although donor/acceptor substitutions at P and N ligand sites were expected to increase the site selectivity, i.e. the preference for "trans to P" attack at the allylic intermediate, acceptor/acceptor substitution yields the highest selectivity. Energetic and geometrical

• -acceptor combinations (Figure 5, Figure 6, Figure 7 and Figure 8), but is highest for X and Y = NO2 (ΔEaTS = 0.33 kcal mol-1, Table 1). Likewise, the smallest electronic site "trans to P" selectivity is not found for X, Y donor-acceptor combinations, but for strong donating X and Y = NHMe. Here, the

• , Y combinations trans to P, due to the stronger π*/σ* acidity at P in phosphabenzene relative to N in pyridine (Table 1).[44] Surprisingly however, this electronic site selectivity, as it is measured from relative energies of the transition structures (ΔEaTS), is not largest for different X, Y donor

A hydrogen- bonded channel structure formed by a complex of uracil and melamine

• Reji Thomas and
• G. U. Kulkarni

Beilstein J. Org. Chem. 2007, 3, No. 17, doi:10.1186/1860-5397-3-17

• molecules of melamine and uracil in the asymmetric unit. In this 1:1 complex, both melamine and uracil offer several donor-acceptor sites for hydrogen bonding and each melamine molecule engages in hydrogen bonding via N-H...O and N-H...N bonds with three uracil and two melamine molecules, as shown in Figure

• . We show one perspective in Figure 3, where the channels run along the a-direction. It is interesting to note that melamine engages in hydrogen bonding utilizing all the donor-acceptor sites, much the same way it does in the cyanuric acid adduct. [1] However, the channel structure is somewhat