Tuning the electronic band structures such as band-edge position and bandgap of organic semiconductors is crucial to maximize the performance of organic photovoltaic devices. We present a simple yet effective electron irradiation approach to tune the band structure of [6, 6]-phenyl-C61-butyric acid methyl ester (PCBM) that is the most widely used organic acceptor material. We have found that th...

We present a first-principles study of the coherent charge transport properties of bistable [2]catenane molecular monolayers sandwiched between Au(111) electrodes. We find that conduction channels around the Fermi level are dominated by the two highest occupied molecular orbital levels from tetrathiafulvalene (TTF) and dioxynaphthalene (DNP) and the two lowest unoccupied molecular orbital level...

  Purpose: Today considerable advances have been achieved in application of nano-particles.   Fullerene is one of the artificial forms of carbon element. Long life cycle of medicines in the   human body is a success factor in delivery of medicine to the specific place. Lots of nanoparticles   are being developed in this field and from a medical point of view, achieving such   goals is vital. Th...

Scientists have been developing sources of light with ever-shorter pulse durations, in order to study motion in systems ranging from a golfer’s swing to the motion of atoms within molecules. The shortest pulses produced to date are under 60 attoseconds, i.e. 60 × 10−18 s. One attosecond is to one second as one second is to the age of the universe. For comparison, the classical orbital period of...

für Naturforschung in cooperation with the Max Planck Society for the Advancement of Science under a Creative Commons Attribution 4.0 International License. Dieses Werk wurde im Jahr 2013 vom Verlag Zeitschrift für Naturforschung in Zusammenarbeit mit der Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. digitalisiert und unter folgender Lizenz veröffentlicht: Creative Commons Namen...

A mechanistic study of the bimolecular nucleophilic substitution (SN2) reaction for halomethane CH3X (X = Cl, Br, or I) is approached by using symmetry principles and molecular orbital theory. The electrophilicity of the functionalized sp–carbon is attributable to a 2p-orbital-based antibonding MO along the C–X bond. This antibonding MO, upon accepting an electron pair from a nucleophile, gives...

Optical absorption and ESR spectra of reduced vanadium centres in Ca2NaMg2VjOlz are reported. The spectra are interpreted as arising from tetrahedrally coordinated V" and octahedrally coordinated V". The ESR and optical data are correlated using molecular orbital (MO) theory. The composition of the flux-grown single crystals is analysed and discussed.

In order to understand various aspects of student understanding of atomic orbitals, we have built a 3-D virtual environment – “Virtual Water” – to support the learning of some concepts of Physics and Chemistry at the final high school and first-year university levels. It is centered in the microscopic structure of water and explores, among others, concepts related to atomic and molecular orbita...