Big Chemical Encyclopedia

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

Articles Figures Tables About

Symmetrical function

Other Access Routes for Symmetrical and Unsymmetrical Thiazolo Ds-es. Other functionally symmetrical reagents such as diethoxymethylacetate (method C), ethoxymethylenediethylmalonate (method D), diphenyl formamidine, and ethylisoformanilide condense with 2-methylthiazoliura to give the trimethine thiazolo dyes. [Pg.55]

To treat the reagents and products as indistinguishable, one must make the total (electronic + nuclear) wave function symmetric under a cyclic exchange of nuclei, which is equivalent to making it symmetric under rotations 2n/3, 4n/3. about the threefold axis of symmetry. Mead showed that, because the electronic wave function >]> is antisymmetric under 2ti/3> must be symmetrized... [Pg.32]

An ACF is always an even function, symmetrical with respect to =0. The fast decreasing ACF of a very fast fluctuating stochastic signal can be considered as an impulse. [Pg.104]

Y, and Z are connected by bonds of fixed length joined at fixed valence angles, that atoms W, X, and Y are confined to fixed positions in the plane of the paper, and that torsional rotation 0 occurs about the X-Y bond which allows Z to move on the circular path depicted. If the rotation 0 is "free such that the potential energy is constant for all values of 0, then all points on the circular locus are equally probable, and the mean position of Z, i.e., the terminus of , lies at point z. The mean vector would terminate at z for any potential function symmetric in 0 for any potential function at all, except one that allows absolutely no rotational motion, the vector will terminate at a point that is not on the circle. Thus, the mean position of Z as seen from W is not any one of the positions that Z can actually adopt, and, while the magnitude ll may correspond to some separation that W and Z can in fact achieve, it is incorrect to attribute the separation to any real conformation of the entity W-X-Y-Z. Mean conformations tiiat would place Z at a position z relative to the fixed positions of W, X, and Y have been called "virtual" conformations.i9,20it is clear that such conformations can never be identified with any conformation that the molecule can actually adopt... [Pg.51]

Separating the even and odd components of the function F, by means of the projection operators F- and F produces functions that transform according to irreducible representations Ag and A of the group Ci, which consists of symmetry elements E and i. An analogous technique could be used to con-stmct functions symmetric and antisymmetric with respect to a mirror plane or a dyad. [Pg.112]

Problem 11-24. Write the function of problem 11-22, F x,y,z) = +y z +xz as the sum of two functions symmetric and antisymmetric with respect to (reflection in the x-z plane). Write a projection operator that would project out the component of a function symmetric with respect to ... [Pg.113]

S-S Sip Sop SALC SCF SO SOMO T tds tdt tfd TP UV xo 9m 9l 9 P Dithiolene or dithiolate chelate In-plane dithiolene S p orbital Out-of-plane dithiolene S p orbital Symmetry adapted linear combination Self-consistent held Sulfite oxidase Singly occupied molecular orbital Tesla (Trihuoromethyl)ethylenediselenato Toluene-2,3-dithiolate Bis(trihuoromethyl)-1,2-dithiete Trigonal prismatic Ultraviolet Xanthine oxidase Metal-based function Ligand-based function Symmetric in-plane dithiolene molecular orbital... [Pg.198]

For the H system and its isotopomers after separating the CM motion from the Schrodinger equation, the problem is reduced to a two pseudo-particle problem. In the basis functions defined in eqn.40 r = (r[, r 2) is the 6x1 vector of relative coordinates defined above. The ground state spatial wave function (symmetric with respect to exchange of electrons) is then given as the symmetry projected linear combination of the 0, ... [Pg.38]

Several methods can be potentially used for the synthesis of functionalized symmetric stars. The chlorosilane method has been applied for the synthesis of three-arm PBd stars carrying one or two end-functional groups,70 as shown in Scheme 30. The dimethylamino end groups were later transformed to sulfozwitterions by reaction with 1,3-propane sultone. [Pg.578]

The irradiation of functionalized symmetrical diphosphiranes (2d-h) gave largely 1,3-diphos-phapropenes in the cis and tram configurations in 50-80% yield <90JOC5750>. Their 3IP NMR... [Pg.482]

Like the normal distribution, the Lorentzian distribution is a continuous function, symmetric about its mean, p., with a spread characterized by the... [Pg.14]

Another useful technique for the preparation of dialkyl 2-oxo-(o-(alkoxycarbonyl)alkylphos-phonates is based on the reaction of dimethyl 1-lithiomethylphosphonate with appropriately protected and functionalized symmetric or disymmetric carboxylic esters. ° For example, treatment of methyl tert-butyl glutarate with dimethyl 1-lithiomethylphosphonate (4 eq) produces dimethyl 2-oxo-5-(tert-butoxycarbonyl)pentylphosphonate in 28% yield. ... [Pg.458]

In this example we have augmented VDM-SL with conventional matrix notation. In addition, we have made use of two auxiliary functions to hide the lower level details of the specification. For example, the auxiliary function Symmetric may be expressed as... [Pg.348]

Rowan, Mather et al. [63—65] have examined the use of complementary nu-cleobase interactions to allow the formation of supramolecular LC materials of the main type shown in Fig. 3a and b. In these cases, a rod-like mesogen-bis(phenylethynyl)benzene-was functionalized symmetrically (homoditopi-cally) with thymine (T) or N6-anisoyl protected adenine (AAn) using alkoxy spacers of varying length to yield molecules of the type Bp-1-Bp, where Bp depicts the variable nucleobase moiety, AAn or T (Fig. 5). [Pg.126]

Particles obeying M.-B. It is applied to those It is applied to those Statistics are called particles which have particles which have a Maxwellons or symmetric wave functions symmetric wave functions Boltzmannons. like photons or atoms and like electrons, protons or... [Pg.219]

Certain half-reactions imply a regiospecificity which is often not warranted when applied to particular synthon skeletons. All s =l half-reactions are of course regiospecific as involving only one carbon and most s =3 half-reactions are clearly directive owing to functional asymmetry, but s =2 half-reactions with symmetrical substrate functionality are not. These are essentially those with substrate /-lists of 11, 11, or 22, t.e., 12,52,12,12. 2 and with minimum /-lists. A major synthetic problem of regiospecificity is the A2 reaction when either CH adjacent to ketone may act as enolate, and the A3 reaction, also with tauto-merically equivalent a- and y-carbons, has the same problem. In many such functionally symmetrical cases it is skeletal asymmetry which offers regiospecificity, and this is simply expressed in the different or-values of the two carbons competing for the construction. [Pg.87]

Like the normal distribution, the Lorentzian distribution is a continuous function, symmetric about its mean, p, with a spread characterized by the half-width, c0 /2. The standard deviation is not defined for the Lorentzian distribution because of its slowly decreasing behaviour at large deviations from the mean. Instead, the spread is denoted by o>i/2, defined as the full-width at half maximum height. Figure 1.7 illustrates the comparison between the normal and Lorentzian shapes. We shall meet the Lorentzian function in subsequent chapters. [Pg.16]

To further demonstrate that the spin factor does not affect the energy, we shall assume we are doing a variational calculation for the He ground state using the trial function (j) = /(ri, t-2, ri2)2 / [a(l)/3(2) - /3(l)a(2)], where / is a normalized function symmetric in the coordinates of the two electrons. The variational integral is... [Pg.290]

Since bosons require a wave function symmetric with respect to interchange, there is no restriction on the number of bosons in a given state. [Pg.295]

There are other particles, called bosons, which satisfy other quantum statistics, the Bose-Einstein statistics, and that are described by wave functions symmetric with respect to the exchange, for which the Pauli principle is not valid. We may dispense with a further consideration of bosons in this chapter. [Pg.429]

The mean bead size distribution curves obtained by plotting the relative frequencies versus bead diameter, typically resulted in a continuous function symmetrical about the mean value (Figure 31.11a ... [Pg.879]


See other pages where Symmetrical function is mentioned: [Pg.54]    [Pg.34]    [Pg.279]    [Pg.748]    [Pg.116]    [Pg.372]    [Pg.147]    [Pg.264]    [Pg.451]    [Pg.300]    [Pg.112]    [Pg.372]    [Pg.279]    [Pg.336]    [Pg.300]    [Pg.350]    [Pg.391]    [Pg.397]    [Pg.460]    [Pg.254]    [Pg.204]    [Pg.487]    [Pg.428]    [Pg.31]   
See also in sourсe #XX -- [ Pg.126 ]




SEARCH



Anti-symmetric function

Anti-symmetric nuclear spin function

Anti-symmetrical function

Dirac function symmetric states

Eigen symmetrical and antisymmetric functions of non-localized objects

Elementary symmetric function

Even functions Symmetric

Fluorescence symmetrically functionalized

Mixing functions symmetric

Spherically symmetric function

Strength function symmetrical

Symmetric Function and Newton Identities

Symmetric function

Symmetric properties electronic wave function

Symmetric properties energy functional form

Symmetric properties nuclear spin function

Symmetric properties rotational wave function

Symmetric properties total molecular wave function

Symmetric properties vibrational wave function

Symmetric relaxation function

Symmetric spin functions

Symmetric top wave functions

Symmetric wave function

Symmetric wave function, definition

Symmetrical Potential Functions

Symmetrized autocorrelation function

Symmetrized correlation function

Symmetrized correlation function classical limit

Symmetrized function

© 2024 chempedia.info