Switches molecular

8 Otsuki, J., Akasaka, T. and Araki, K., Molecular switches for electron and energy transfer processes based on metal complexes , Coord. Chem. Rev. 2008, 252, 32-56. 

This switching ability is highly reversible simply by alternating between irradiation by ultraviolet (about 300 nm) and visible ( 600 nm) light. Furthermore, the two states, open and closed , have very different electronic properties. The closed state contains a fully conjugated jT -system across the bridge, allowing effective electronic communication from substituent R to R via the delocalised r-system. 

2-dithienylethene unit has also been nsed to link together metal tris(bipyridyl) moieties including an nnsymmetrical Ru(II)/Os(II) complex. In the open form Inminescence from the MLCT state is observed with efficient energy transfer from ruthenium to osmium. However, the emission is quenched upon conversion to the closed form because of energy transfer to the photo-chromic 1,2-dithienylethene orbitals. 

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Small GTPases are monomeric 20 to 40 kD GTP-binding proteins that interconvert between an active (GTP-bound) and an inactive (GDP-bound) state. As molecular switches they are involved in the regulation of complex cellular processes. 

Small GTPases are not isolated molecular switches regulating cellular processes. Signalling cascades within one subfamily as well as cross-talk between... 

Feringa BL (ed) (2001) Molecular switches. Wiley-VCH, Weinheim, Germany... 

Nonadiabatic transitions definitely play crucial roles for molecules to manifest various functions. The theory of nonadiabatic transition is very helpful not only to comprehend the mechanisms, but also to design new molecular functions and enhance their efficiencies. The photochromism that is expected to be applicable to molecular switches and memories is a good example [130]. Photoisomerization of retinal is well known to be a basic mechanism of vision. In these processes, the NT type of nonadiabatic transitions play essential roles. There must be many other similar examples. Utilization of the complete reflection phenomenon can also be another candidate, as discussed in Section V.C. In this section, the following two examples are cosidered (1) photochromism due to photoisomerization between cyclohexadiene (CHD) and hexatriene (HT) as an example of photoswitching molecular functions, and (2) hydrogen transmission through a five-membered carbon ring. 

New natural polymers based on synthesis from renewable resources, improved recyclability based on retrosynthesis to reusable precursors, and molecular suicide switches to initiate biodegradation on demand are the exciting areas in polymer science. In the area of biomolecular materials, new materials for implants with improved durability and biocompatibility, light-harvesting materials based on biomimicry of photosynthetic systems, and biosensors for analysis and artificial enzymes for bioremediation will present the breakthrough opportunities. Finally, in the field of electronics and photonics, the new challenges are molecular switches, transistors, and other electronic components molecular photoad-dressable memory devices and ferroelectrics and ferromagnets based on nonmetals. 

Moonen NNP, Flood AH, Fernandez JM, Stoddart JF (2005) Towards a Rational Design of Molecular Switches and Sensors from their Basic Building Blocks. 262 99-132 Moriyama M, see Kato T (2005) 256 219-236 Moussa A, see Coleman AW (2007) 277 31-88 Murai T (2005) Thio-, Seleno-, Telluro-Amides. 251 247-272... 

Mesomorphic dendrimers containing electroactive units have potential for construction of dendrimer based molecular switches. Deschenaux et al. reported [154] the synthesis and liquid-crystalline properties of a novel dendrimer containing six mesomorphic ferrocene units. Apart from exhibiting a broad enantiotropic smectic A phase as determined by polarized optical microscopy, DSC, and XRD studies, thermogravimetry revealed the excellent thermal stability of the macromolecule. 

K. Mobius, A. Savitsky, A. Schnegg, M. Plato and M. Fuchs, High-field EPR spectroscopy applied to biological systems Characterization of molecular switches for electron and ion transfer, Phys. Chem. Chem. Phys., 2005, 7, 19. 

Further improvements to vims expression systems include trans-complementation of some of the virus functions from transgenic host plants (P12 plants for AlMV). By integrating parts of the viral vector into the plant chromosome, this system has the potential for multiple technical solutions that could overcome limitations of classical viral vectors [33]. Viral vectors can be used as molecular switches for tightly controlled, high-level transgene expression (Hull et al. unpublished data). 

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Zhang C, Du MH, Cheng HP, Zhang XG, Roitberg AE, Krause JL (2004) Coherent electron transport through an azobenzene molecule a light-driven molecular switch. Phys Rev Lett 92(15) 158301... 

Reuter MG, Sukharev M, Seideman T (2008) Laser field alignment of organic molecules on semiconductor surfaces toward ultrafast molecular switches. Phys Rev Lett 101 (20) 208303... 

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Chen F, He J, Nuckolls C, Roberts T, Klare JE, Lindsay S (2005) A molecular switch based on potential-induced changes of oxidation state. Nano Lett 5 503-506... 

Delonno E, Tseng HR, Harvey DD, Stoddard JF, Heat JR (2006) Infrared spectroscopic characterization of [2]rotaxane molecular switch tunnel junction devices. J Phys Chem B 110 7609-7612... 

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