Monoses, configuration

Source Station Magnet Xc or Ec Station or mono horizontal acceptance (mrad) Mirror configuration Mono configuration... 

A great many polymers appear to form films having a flat molecular configuration. Thus various polyesters [7] gave extrapolated areas of about 2.5 m /mg corresponding to about the calculated 60-70 area per segment, or mono-layer Sickness of 3-5 A. A similar behavior was noted for poly(vinyl acetate)... 

The isotopic purity of the product is usually about 48-62%, the rest of the material being mainly undeuterated. (An alternate preparation of a-mono-deuterio ketones of high configurational and isotopic purity is the mild oxidation of cis- or tra 5-deuterated alcohols under Jones conditions, see sections V-D and VII-A.) Treatment with zinc in acetic acid-OD has also been applied to the deiodination of 2a-iodoandrost-4-ene-3,17-dione. In a slightly modified version the iodine in 19-iodocholesterol acetate has been replaced with tritium by using tritium oxide as the isotope source/... 

Studies by Levisalles and Tkatchenko on the mechanism and stereochemistry of the steroidal benzilic rearrangement have demonstrated that the configuration of the product obtained in about 85 % yield from 5a-cholestane-3,4-dione (27) is as shown (28). When redistilled ethylene glycol mono-... 

Salts of mono-alkylated or arylated sulfur diimide anion [RNSN] (R = aryl, Bu, SiMcs) are prepared by Si-N cleavage of RNSNSiMcs with [(Me2N)3S][Mc3SiF2]. ° ° These anions adopt cis configurations with very short terminal S-N bond lengths (1.44 - 1.49 A) indicative of a thiazylamide anion, [RNS N] (5.21). ... 

As shovm above, the attachment of the aromatic ring to the carbon chain bearing the basic nitrogen may be accomplished through an ester or an amide configured in either direction. A simple ether linkage fulfills this function in yet another compound that exhibits local anesthetic activity. Thus, alkylation of the mono potassium salt of hydroquinone with butyl bromide affords the ether (77) alkylation of this with w-C3-chloropropyl)morpholine affords pramoxine (78)... 

The all-d.v benzamide 12, readily obtainable from 8 at low temperature with methyllithium,16 is cleanly transformed to the mono-trans isomer 13 above O C. Both anions 12, 13 can be trapped at low temperature with methyl chloroformate to yield the corresponding methyl azepinc-A -carboxylates 14 and 15, respectively, with retention of the configuration.17... 

Mono- and cis-di-substituted thiirane oxides can theoretically exist in the syn- (s) and anti- (a) configurations shown below ... 

There have a number of computational studies of hypothetical RMMR species [10-13, 40, 411. The simplest compounds are the hydrides HMMH. Some calculated structural parameters and energies of the linear and trans-bent metal-metal bonded forms of the hydrides are given in Table 1. It can be seen that in each case the frans-bent structure is lower in energy than the linear configuration. However, these structures represent stationary points on the potential energy surface, and are not the most stable forms. There also exist mono-bridged, vinylidene or doubly bridged isomers as shown in Fig. 2... 

Preferential addition to one end or the other of a vinyl (CH2=CHX) or substituted vinyl (CH2=CXY) monomer seems to be the rule to which exceptions are rare. This generalization appears to apply to ionic as well as to free radical polymerizations. The polymers of mono-unsaturated compounds consequently are characterized by a high degree of head-to-tail regularity in the arrangement of successive units. Little is known concerning the sequence of d and I configurations of the asym-... 

Formation of the mono- and dinitrosyl complexes is a thermodynamically favorable process, which distinctly depends on the electronic configuration of the metal center. The adsorption energy, defined as A=. Eaddukt - ( mzsm-5+ no)> is shown in the form of a histogram in Figure 2.16. Formation of mononitrosyl complexes is exothermic... 

Consider the case where the interaction between the molecules A and B is not yet very strong. The magnitude of Hq>P is almost linear with So,p, so that the second-order term in Eq. (3.9) is proportional to the square of So,p. The order of magnitude of So,p is equal to the rth power of an overlap integral s of an MO a of the molecule A and an MO b of the molecule B, where y is the minimum number of electron transfers between A and B required to shift the electron configuration from 0 to p. Therefore, the terms from monotransferred configurations in Eq. (3.9) have magnitudes of the order of Sab, while the monoex. and the ditr. terms are of Sob, and the monoex.-monotr. term s , the diex. term s , and so on. If the interaction is weak and s0 is small, the mono-transferred terms are important in comparison with the others. 

Surfactant molecules can be considered as building blocks for certain forms of geometry in colloidal chemistry. Various forms of association molecules can be obtained as the concentration of surfactant in water is increased and/or physicochemical conditions are changed (e.g. CMC, Craft-point, etc.). Figure 2 schematically shows the most likely structural configurations and assemblages of surfactants association in an aqueous system (26). Upon addition of oil and a short-chain alcohol, for example, one can convert the oil-in-water micelles into water-in-oil microemulsions. It is therefore possible to induce a transition from one structure to another by changing the physicochemical conditions such as temperature, pH and addition of mono or di-valent cations to the surfactant solution. It should be also noted that the sur-... 

Nenajdenko et al. described the first example of addition of a 1,2-dication to C-C mutiple bonds. The only S-S dication found to participate in this reaction was the highly strained dication 115 derived from 1,4-dithiane. The reaction with alkenes 119 proceeded under mild conditions and led to derivatives of dithioniabicyclo[2.2.2]octane 120 as shown in Equation (33) and Table 21 <1998JOC2168>. This reaction was sensitive to steric factors and proceeded only with mono and 1,2-disubstituted ethylenes. Only alkenes conjugated with aromatic or cyclopropane moieties underwent this reaction. For the 1,2-disubstituted alkenes used in this study, the relative configuration of substitutents at the double bond was preserved and only one diastereomer was formed (see entries 2 and 3). 

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