Three squaraine [2]catenanes are synthesized and found to have bright, deep-red fluorescence and high chemical stability. The interlocked molecules undergo two large-amplitude dynamic processes, twisting of the squaraine macrocycle and skipping over the partner tetralactam.

Boron, discovered as an element in 1808 and produced in pure form in 1909, has still remained the last elemental material, having stable natural isotopes, with the ground state crystal phase to be unknown. It has been a subject of long-standing controversy, if α-B or β-B is the thermodynamically stable phase at ambient pressure and temperature. In the present work this enigma has been resolved ...

As an important two-dimensional material which shows exceptional mechanical and chemical stability, superior electronic properties, along with broad applications, the hexagonal-BN (h-BN) has drawn great attention recently. Here we report a systematic study on the structural stability, electronic and magnetic properties of various h-BN edges, including both bare and hydrogen-terminated ones. It ...

We report on the passivation properties of molecularly modified, oxide-free Si(111) surfaces. The reaction of 1-alcohol with the H-passivated Si(111) surface can follow two possible paths, nucleophilic substitution (SN) and radical chain reaction (RCR), depending on adsorption conditions. Moderate heating leads to the SN reaction, whereas with UV irradiation RCR dominates, with SN as a secondar...

Molecular dynamics simulations are used to probe the structure and stability of alkanethiolate self-assembled monolayers (SAMs) on gold nanoparticles. We observed that the surface of gold nanoparticles becomes highly corrugated by the adsorption of the SAMs. Furthermore, as the temperature is increased, the SAMs dissolve into the gold nanoparticle, creating a liquid mixture at temperatures much...

the oil extracted from three major canola cultivars (hyolla401, hyolla420 and rgs003) grown in golestan province was analyzed for physico-chemical properties, fatty acid composition, minerals content, and stability during 16 weeks of storage. according to the results, the highest iodine value and refractive index belonged to hyolla401. the highest saponification value was observed in hyolla420....

the supercapacitive behavior of polyaniline/mno2-carbon black (pani/mno2-cb), mno2-cb nanocompositesand cb was studied. mno2-cb made by the in situ direct coating method to deposit mno2 onto cb; then pani coating was coated on it. morphology of the nanocomposite was studied by x-ray diffraction (xrd), fourier transform infrared (ft-ir) spectroscopy and scanning electron microscopy (sem). the el...

Supercapacitors, as one of the energy storage devices, exhibit ultrahigh capacitance, high power density, and long cycle. High specific surface area, mechanical and chemical stability, and low cost are often required for supercapacitor materials. Graphene, as a new emerging carbon material, has attracted a lot of attention in energy storage field due to its intrinsic properties. Polymers are of...

A squaraine dye with bulky end groups is employed as the thread component in two Leigh-type amide rotaxanes. The rotaxanes are synthesized in a simple two-step process. X-ray crystal structures of the rotaxanes show that the pyridyl-containing macrocycle is more rigid and wraps more tightly around the cyclobutene core of the squaraine thread compared to the isophthalamide-containing macrocycle....

Open-shell organic molecules possessing more than two unpaired electrons and sufficient stability even at room temperature are very unusual, but few were recently synthesized that promise a number of fascinating applications. Unfortunately, reliable structural information is not available and only lower limits can be estimated for energy splittings between the different spin states. On these gr...