Signatures of the exciton coherence size, which controls the nonlinear optical response and luminescence of conjugated systems, in the electronic dynamic structure factor S(q,omega) are calculated. We find that for small molecules the momentum dependence of the lowest exciton resonance is purely geometric, reflecting the molecular size rather than a universal exciton size, as suggested recently...

the adhesion molecules are involved in adhesion of leukocytes to endothelial cells and other immune cells. not only adhesion molecules have membrane form, but they also have soluble form. in this paper, we attempted to investigate the concen¬tration of soluble adhesion molecules in the type 1 diabetic patients (n = 40) and healthy subjects (n = 10). the results indicated that there was an incre...

Dehydroannulenes are a fascinating class of carbon-rich molecules which have been studied intensively.[1] With the development of improved synthetic methodologies, these macrocycles are now being exploited for their potential material properties. Recent applications employ such annulenes as conjugated scaffolds for nonlinear optical applications[2] and as precursors for carbon nanotube synthesi...

A semiconductor is a type of material which has electrical properties in between an insulator and a conductor. A conductor can be thought of as a group of atoms surrounded by a sea of free electrons, which are free to move throughout the material; in contrast, the electrons in an insulator are tightly localized on a specific atom or molecule. In a semiconductor, the electrons are localized as i...

A series of unsymmetrical π-conjugated small molecules have been constructed from meso-alkyl substituted porphyrins as the central unit and 3-ethylrhodanine as the terminal group. Using PC71BM as an acceptor, and these small molecules as electron donors in solution-processed bulk-heterojunction solar cells, a high power conversion efficiency of 6.49% has been achieved.