Molecular gyroscopes

Molecular-beam epitaxy, for semiconductor growth, with Group 3 nitrides, 12, 4-5 Molecular gyroscopes, via iron carbonyls, 6, 51 Molecular mass distributions, in olefin polymerization, 4,1113 Molecular materials, and crystal engineering, 12, 555 Molecular mechanics future directions, 1, 666 in hybrid computational chemistry, 1, 664 Rh-catalyzed hydroformylation, 7, 239 Molecular modeling, arene chromium tricarbonyls, 5, 255 Molecular orbitals, and photoelectron spectroscopy variations,... 

C.A. Shalley, Of Molecular Gyroscopes, Matroshka Dolls, and Other Nano -Toys , Angew. Chem. Int. Ed., 41 1513 (2002)... 

Oligothiophenes substituted by terminal alkoxy-chains exhibit a peculiar phenomena of differential mobility between the core and the chain ends. In fact, the chain ends present gauche conformations that slow down their motion. On the contrary, the thiophene core, appended to the alkoxy plugs, shows exceptionally high librational mobility in both the ground and excited states as a molecular gyroscope [60]. 

A number of interesting applications of CB[n] molecules have been reported which make use of their rigid shape and cavity (besides their use as nanoreactors, the focus of this chapter) some of these will be briefly listed here for the sake of interest. Mock and Pierdpont reported one of the first practical applications of cucurbituril, in the construction of a pH-activated molecular switch [44]. Blanch et al. have made use to the rigid hollow spherical nature of CB[ ]s to construct a molecular ball bearing from an inclusion complex of CB[7] [45] and a molecular gyroscope from the inclusion of CB[5] within CB[10] [46]. Kim has made extensive studies of the use of cucurbiturils as beads in a... 

Schalley CA, Angew. Of molecular gyroscopes, Matroshka doUs, and other Nano -toys. Chem Int Ed 2002 41 1513-5. 

Molecular gyroscopes were synthesized in which an Fe(CO)3 unit is bound axially to two phosphorus atoms (Scheme 57). Reaction with NO" to form an Fe(CO)2(NO) rotator led to the introduction of a dipole moment, which opens up the possibility of unidirectional rotation. ... 

Rotation of an encapsulated aromatic guest within the covalent capsule 240 as a molecular gyroscope has been controlled in [65] by Scheme 6.37 using changes in its binding geometry with respect to the macropolycyclic host upon the addition and extrusion of co-caged potassium(I) cations. 

Shima T, Hampel F, Gladysz JA (2004) Molecular gyroscopes Fe(CO)3 and (Fe(CO)2(NO) rotaUns encased in three-spoke stators facile assembly by alkene metatheses. Angew Chem Int Ed 43 5537-5540... 

The lower molecular weight PCTFE oils, waxes, and greases are used as inert sealants and lubricants for equipment handling oxygen and other oxidative or corrosive media. Other uses include gyroscope flotation fluids and plasticizers for thermoplastics. 

Brownian Motion of a Rigid Body. Many molecules of interest are extended in three dimensions with three principal moments of inertia of comparable size. Gyroscopic forces complicate the discussion of Brownian motion for such bodies and a number of workers have developed convenient formal treatments without much physical novelty emerging. Steele has given a clear treatment of this problem, but obtains tractable expressions only for spherical-top molecules, which have the same moment of inertia I about all axes through the molecular mass centre, so that the Euler equations of motion fall apart in independent variables. 

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