Due to its polyionic character the DNA double helix is stable and biologically active only in salty aqueous media where its charge is compensated by solvent counterions. Monovalent metal ions are ubiquitous in DNA environment and they are usually considered as the possible driving force of sequence-dependent modulations of DNA structure that make it recognizable by proteins. In an effort to dir...

The Cu(I)-catalyzed Ullmann condensation reaction between aliphatic alcohols and sym-pentachlorocorannulene provides a convenient entry to 1,3,5,7,9-pentaalkoxycorannulenes. The latter are easily converted to novel deca-heterosubstituted derivatives, such as 1,3,5,7,9-penta-X-2,4,6,8,10-penta-Y-corannulenes by electrophilic aromatic substitution.

We predict streaming current inversion with multivalent counterions in hydrodynamically driven polymer translocation events from a correlation-corrected charge transport theory including charge fluctuations around mean-field electrostatics. In the presence of multivalent counterions, electrostatic many-body effects result in the reversal of the DNA charge. The attraction of anions to the charge...

The concentration profiles of monomers and counterions in star-branched polyelectrolyte micelles are calculated through Monte Carlo simulations, using the freely jointed chain model. We have investigated the onset of different regimes corresponding to the spherical and Manning condensation of counterions as a function of the strength of the Coulomb coupling. The Monte Carlo results are in fair ...

A series of lanthanide amide complexes supported by bridged bis(amidinate) ligand L, LLnNHAr(1)(DME) (L = [Me(3)SiNC(Ph)N(CH(2))(3)NC(Ph)NSiMe(3)], Ar(1) = 2,6-(i)Pr(2)C(6)H(3), DME = dimethoxyethane, Ln = Y (1), Pr (2), Nd (3), Gd (4), Yb (5)), [Yb(μ(2)-NHPh)](2)(μ(2)-L)(2) (6) and [LYb](2)(μ(2)-NHAr(2))(2) (7) (Ar(2) = (o-OMe)C(6)H(4)), were synthesized by reaction of LLnCl(THF)(2) with the c...

Polyaniline (PANI) with electrodonating and electrowithdrawing substituents were electrodeposited and studied as sensing materials in resistors and heterojunctions. Whereas the dimethoxyaniline leads to a highly conductive material, the tetrafluoroaniline leads to a poor conducting polymer. However, this latter was used in heterojunctions, associated with a highly conductive material, the lutet...

A theory is presented which allows us to accurately calculate the density profile of monovalent and multivalent counterions in suspensions of polarizable colloids or nanoparticles. In the case of monovalent ions, we derive a weak-coupling theory that explicitly accounts for the ion-image interaction, leading to a modified Poisson-Boltzmann equation. For suspensions with multivalent counterions,...

We present an analytical approach for similarly and highly charged planar interfaces in the presence of counterions. The procedure is physically transparent and based on an exact low temperature expansion around the ground state formed by the two-dimensional Wigner crystal of counterions. The one plate problem is worked out, together with the two plates situation. Unlike previous approaches, th...

The electronic properties of conjugated polyelectrolytes (CPEs) with poly(fluorene-co-phenylene) backbones and different counterions and charges have been investigated using absorption and ultraviolet photoelectron spectroscopy (UPS). The optical energy band gap of CPEs depends mainly on their conjugated backbone and are nearly insensitive to the charges or counterions. UPS measurements reveal ...

Tin-oxo cage ions undergo Sn–C bond cleavage upon (V)UV excitation. Counterions influence further fragmentation, as they form covalent bonds to the cage.