Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Applications, molecular electronics molecule

One of the earliest models for treating conjugated molecules is afforded by the Hiickel rr-electron model. This dates from the work of E. Hiickel in 1931. The ideas are simple and appealing, and the model enjoyed many years of successful application to individual molecules, molecular clusters and solids. [Pg.122]

The maintenance of a connection to experiment is essential in that reliability is only measurable against experimental results. However, in practice, the computational cost of the most reliable conventional quantum chemical methods has tended to preclude their application to the large, low-symmetry molecules which form liquid crystals. There have however, been several recent steps forward in this area and here we will review some of these newest developments in predictive computer simulation of intramolecular properties of liquid crystals. In the next section we begin with a brief overview of important molecular properties which are the focus of much current computational effort and highlight some specific examples of cases where the molecular electronic origin of macroscopic properties is well established. [Pg.6]

It is clear from the forgoing discussions that the important material properties of liquid crystals are closely related to the details of the structure and bonding of the individual molecules. However, emphasis in computer simulations has focused on refining and implementing intermolecular interactions for condensed phase simulations. It is clear that further work aimed at better understanding of molecular electronic structure of liquid crystal molecules will be a major step forward in the design and application of new materials. In the following section we outline a number of techniques for predictive calculation of molecular properties. [Pg.15]

Reactions on the surface are interesting. The adsorptions of unsaturated organic molecules on the surface provide a means for fabricating well-ordered monolayer films. Thin film organic layers can be used for diverse applications such as chemical and biological sensors, computer displays, and molecular electronics. [Pg.37]

The original Hohenberg-Kohn theorem was directly applicable to complete systems [14], The first adaptation of the Hohenberg-Kohn theorem to a part of a system involved special conditions the subsystem considered was a part of a finite and bounded entity regarded as a hypothetical system [21], The boundedness condition, in fact, the presence of a boundary beyond which the hypothetical system did not extend, was a feature not fully compatible with quantum mechanics, where no such boundaries can exist for any system of electron density, such as a molecular electron density. As a consequence of the Heisenberg uncertainty relation, molecular electron densities cannot have boundaries, and in a rigorous sense, no finite volume, however large, can contain a complete molecule. [Pg.67]

One difficulty with the spintronics area using molecules [139-141] has been that, like simple transport, it will change with the geometry of the interface. Nevertheless, spintronic applications are intriguing, and this has become a new focus area for molecular electronics. [Pg.26]

The discussion in this contribution has been largely qualitative, and impressionistic. This seems in keeping with a volume of this kind - most of the topics discussed here are still very much alive, and it seems that molecular electronics, defined as the understanding and technological application of electronic properties of single molecule systems or few-molecule systems, remains as a challenge to the molecular sciences of the twenty-first century. [Pg.30]

Heller, M. J. Utilization of synthetic DNA for molecular electronic and photonic-based device applications, in Lee, S. C. and Savage, L. (eds), Biological Molecules in Nanotechnology the Convergence of Biotechnology, Polymer Chemistry and Materials Science, IBC Press, Southborough, MA, USA, 1998, pp. 59-66. [Pg.555]

Carbon nanotubes are increasingly recognized as a promising tool for surface functionalization. M.J. Esplandiu presents a state-of-the-art overview of their applications in electrochemistry. As with SAM s of organic molecules the great potential of carbon nanotubes lies, among others, in biochemical applications and in molecular electronics. [Pg.278]

Quantum chemistry or molecular electronic structure theory is the application of the principles of quantum mechanics to calculate the stationary states of molecules and the transitions between these states. Today, both computational and experimental groups routinely use ab initio (meaning from first principles ) molecular orbital calculations as a means of understanding structure, bonding, reaction paths between intermediates etc. Explicit treatment of the electrons means that, in principle, one does not make assumptions concerning the bonding of a system. [Pg.401]

The truncation procedure for fiill-valence-space and N-electrons-in-N-orbitals SDTQ MCSCF waveflmctions is based on choosing split-localized molecular orbitals as configuration generators since they lead to the greatest number of deadwood configurations that can be deleted. A quite accurate estimation method of identifying the latter has been developed so that the truncation can be performed a priori. The method has been shown to be effective in applications to the molecules HNO, OCO and NCCN where, for instance, the energies of the full SDTQ[N/N] calculations are recovered to better than 1 mh by truncated expansions that require only 11.8%, 10.9% and 6.3%, respectively, of the number of determinants in the full calculations. Similar trends are observed for the FORS 1 model. [Pg.120]


See other pages where Applications, molecular electronics molecule is mentioned: [Pg.137]    [Pg.4]    [Pg.13]    [Pg.14]    [Pg.16]    [Pg.106]    [Pg.339]    [Pg.251]    [Pg.613]    [Pg.111]    [Pg.688]    [Pg.621]    [Pg.190]    [Pg.559]    [Pg.447]    [Pg.25]    [Pg.30]    [Pg.85]    [Pg.87]    [Pg.110]    [Pg.90]    [Pg.75]    [Pg.232]    [Pg.6]    [Pg.411]    [Pg.239]    [Pg.63]    [Pg.68]    [Pg.182]    [Pg.159]    [Pg.291]    [Pg.299]    [Pg.310]    [Pg.92]    [Pg.114]    [Pg.103]    [Pg.154]    [Pg.429]    [Pg.429]    [Pg.584]   
See also in sourсe #XX -- [ Pg.777 , Pg.778 , Pg.779 ]




SEARCH



Applications molecules

Electron applications

Electronics applications

Molecular applications

Molecular electronics, application

Molecule electronic

© 2024 chempedia.info