We have designed and synthesized a new ligand, 6-(2-pyridinyl)-4-[3'-(3-pyridinyl)[1,1'-biphenyl]-3-yl]-2,2'-bipyridine (2). 2 reacted with Pt(cod)(MeCN)(2)(BF(4))(2) to quantitatively give the molecular dimer, 1.BF(4) (2(2).Pt(II)(2).4BF(4)(-)), by self-assembly. The (1)H NMR and UV-vis titration showed that the complexation affinity of 1.BF(4) toward benzenediol guests decreases in the order ...

Base stacking is important for the base pair interaction of a DNA duplex, DNA replication by polymerases, and single-stranded nucleotide overhangs. To study the mechanisms responsible for DNA stacking interactions, we measured the thermal stability of DNA duplexes containing a non-natural nucleotide tethered to a simple aromatic hydrocarbon group devoid of dipole moments and hydrogen bonding si...

We demonstrate that intermolecular stacking is capable of forming one-dimensional arrays of a blunt-ended 3-helix DNA motif. The array can be visualized in the atomic force microscopy through conjugated streptavidin nanoparticles. We estimate the strength of the triple stacking interaction to be -8.6 kcal mol(-1).

Force-induced structural transitions both in relatively random and in designed single-stranded DNA (ssDNA) chains are studied theoretically. At high salt conditions, ssDNA forms compacted hairpin patterns stabilized by base-pairing and base-pair stacking interactions, and a threshold external force is needed to pull the hairpinned structure into a random coiled one. The base-pair stacking inter...

The aggregation of polypeptides into amyloid fibrils is associated with a number of human diseases. Because these fibrils--or intermediates on the aggregation pathway--play important roles in the etiology of disease, considerable effort has been expended to understand which features of the amino acid sequence promote aggregation. One feature suspected to direct aggregation is the π-stacking of ...

We show that diradicaloid helical conjugated molecules can display strong through-space bonding interactions. These interactions are analogous to π-stacking pancake bonding widely observed for dimers and other aggregates of stable π-conjugated radicals. We show that these multicenter interactions can have a significant stabilizing effect, but they depend in subtle ways on the specific overlap a...

Classical hard spheres crystallize at equilibrium at high enough density. Crystals made up of stackings of 2-dimensional hexagonal close-packed layers (e.g. fcc , hcp , etc.) differ in entropy by only about 10−3kB per sphere (all configurations are degenerate in energy). To readily resolve and study these small entropy differences, we have implemented two different multicanonical Monte Carlo al...

A novel method for the on-column sample stacking of proteins is described. The strategy takes advantage of interactions between protein molecules and sodium dodecyl sulfate (SDS) monomers. A long plug of a protein sample (either acidic or basic) is injected into a capillary filled with a background electrolyte (BGE) containing SDS. When a potential is applied, the proteins interact with SDS mon...

Low stacking fault energy face centered cubic (FCC) materials contain characteristic defect structures. Stacking fault tetrahedral are one of those rare structures that occur under special experimental conditions. For the first time, stacking fault tetrahedral were observed in Fe-30Mn-3Al-3Si twinning induced plasticity (TWIP) steel. Their presence resulted from a quenching heat treatment.

We characterize intercalative complexes as either "high charge" and "low charge". In low charge complexes, stacking interactions appear to dominate stability and structure. The dominance of stacking is evident in structures of daunomycin, nogalamycin, ethidium, and triostin A/echinomycin. By contrast in a DNA complex with the tetracationic metalloporphyrin CuTMPyP4 [copper (II) meso-tetra(N-met...