Planar extension

Case 1 Mn < M. The structure of uniaxially aligned LMW PF2/6 has been recently studied by combination of optical spectroscopy, NEXAFS and GIXRD, Fig. 22 exhibits a representative NEXAFS data and the subsequent analysis. These data support a structural model in which there is a graded morphology such that the top and bottom surfaces exhibit extensive planar, uniaxial alignment while the film interior is less well oriented and includes both planar and tilted (i.e., non-planar) PF2/6 chains [114]. 

More recently, Marks and coworkers developed a totally different approach for obtaining very high fi values. Their strategy does not focus on extensive planar 7r-conjugation, which is prone to chemical, thermal, and photochemical instabilities [58], but on twisted 7r-electron system chromophores. These unconventional twisted % zwitterionic structures (TM and TMC) exhibit unprecedented hyperpolarizabilities as large as 15 times greater than those reported previously (fj.fi as high as -488,000 x 10 48 esu) [59,60],... 

Simple shear Uniaxial extension Planar extension... 

Marmur [12] has presented a guide to the appropriate choice of approximate solution to the Poisson-Boltzmann equation (Eq. V-5) for planar surfaces in an asymmetrical electrolyte. The solution to the Poisson-Boltzmann equation around a spherical charged particle is very important to colloid science. Explicit solutions cannot be obtained but there are extensive tabulations, known as the LOW tables [13]. For small values of o, an approximate equation is [9, 14]... 

Until recently, naphthalene was something of an outpost Cor the ah initio method. Most calculations were carried out on molecules far smaller than naphthalene, which lends itself to more extensive calculation only because of its simple planar sti uctui e atid its symmetry (hydi ogens not shown)... 

The ally carbocation is an example of an intermediate whose structure has been extensively investigated by MO methods. The hybridization/resonance approach discussed earlier readily rationalizes some of the most prominent features of the allyl carbocation. The resonance structures suggest a significant stabilization and imply that the molecule would be planar in order to maximize the overlap of the n system. 

Hiickel s calculations on planar conjugated systems were extensively exploited, and I refer you once again to Streitwieser s classic book. Molecular Orbital Theory for Organic Chemists. What few calculations that had been done at that time on the (T framework had used the method of linear combination of bond orbitals. 

As first shown by Hladky and Haydon 7,8), it is possible to observe the current due to a single transmembrane channel by using extensions of the planar lipid hilaver approach of Mueller and Rudin 9). The basic system is shown in Fig. 2 and is commonly referred to as the black lipid membrane (BLM) method. This is because, as the lipid in the hole between the two chambers thins, the areas that have become planar bilayers are seen as black. Additional terms are bilayer lipid membranes or planar lipid bilayer membranes. These lipid bilayer membranes, particularly those which are solvent free, have capacitances which are very close to those of biological membranes. 

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