Dioxane molecular structure

Fig. 8. Molecular structure of 5-hexyl-2-(4 -bromophenyl)-l,3-dioxane (Reprinted from [71])... 

Figure 23 Schematic representation of the molecular structure of (a) [VO(acac)2(4-phenylpyridine)],537 (b) [VO(acac)2(l, 4-dioxane)]539 (a dioxane molecule bridges two [VO(acac)2] groups) and (c) [VO(OMe)(acac)]2.553 Some...

The nature of multiple bonding between germanium and the heavier chalcogens in the complexes (/74-Megtaa)GeE (E = Se, Te) is best described as an intermediate between the Ge+— E and Ge=E resonance structures. The preparation of these complexes involves the addition of the elemental chalcogen to (/74-Mestaa)Ge, which is synthesized by the metathesis of GeCl2(l,4-dioxane) and Li2[Mestaa] (Mestaa = octamethyldibenzotetraaza[14]annulene dianion). The molecular structures of both complexes are shown in Figures 5 and 610. 

The dipole moment of NMA has been calculated from vapor phase measurements23 to be 3.71 D. This compares reasonably well with 3.82 D as determined from dilute solutions of NMA in benzene23 and with 3.6 D as determined from dilute solutions in carbon tetrachloride24. These values are somewhat lower than the earlier values obtained from more concentrated solutions of NMA in dioxane and carbon tetrachloride by Mizushima et al.2S. The vector moment of NMA is 3.6 D26 based on the molecular structure determined by electron diffraction18. ... 

From the results reported in the literature using low dielectric constant solvents such as dioxane (15), tetrahydrofuran and dimethoxy-ethane (16), or benzene (13, 14), the chemical makeup of the solvent, its molecular structure, or both, might well influence the final results. With the first three solvents the presence of oxygen atoms seems to be... 

Figure 16.1. Molecular structure of some amphiphilic solutes, (a) Dimethyl sulphoxide (DMSO), (b) methanol (MeOH), (c) ethanol (EtOH), (d) tert-butyl alcohol (TEA), (e) acetone. For all these solutes the partial charges are indicated on the corresponding atoms according to the GROMOS-96 force field, (f) Molecular structure of 1,4-dioxane. For 1,4-dioxane the partial charges are indicated on the respective atoms according to / Am. Chem. Soc., 127 (2005), 11019-11028.

A perceptron classifier was used by Hiller et. al. C92, 1071 for the recognition of the anticonvulsi on activity of 1,3-dioxanes. The molecular Structures have been coded by substructuraI entities predictive abilities of 68 - 76 % have been reported. 

Ethers (dioxane, tetrahydrofurane, diethylether), and other 0-containing donor molecules, such as dimethyl sulphoxide, ketones and nitriles give compounds with molecular structures which have been considered as partially ionic in the solid stated . 

Figure 22 Molecular structure of host M [cis-3,3 -bis(diphenylhydrox3raiethyl)stilbene]. Host M is able to undergo irrevCTsible isomerization in its inclusion compounds with the following guests acetone, cyclopentanone, y-butyrolactone, dioxane, dimethylsulfoxide, p3niduie, and Al,lV-dimethl3dbnnamide.

The biscyclooctatetraene complexes have similar properties, are colored, decompose when heated above 160°C under vacuum, and do not sublime even at 1 X 10 mm. However, they are thermally stable when heated to 360 C in sealed tubes under one atmosphere of argon. They are insoluble in CHCI3, CCI4, and hexane, and are moderately soluble in THF and dioxane. The molecular structure of the cerium complex has been determined (Hodgson and Raymond, 1972b) and is shown in fig. 25.24. The important feature is the symmetric coordination of the two CgHi rings in a 7r-fashion. The molecular symmetry is very close to Dgd-... 

Curioni et al.148 studied the protonation of 1,3-dioxane and 1,3,5-trioxane by means of CP molecular dynamics similations. The dynamics of both molecules was continued for few ps following protonation. The simulation provided a detailed picture the evolution of both the geometry and the electronic structure, which helped to rationalize some experimental observations. CP molecular dynamics simulations were applied by Tuckerman et al.149,150 to study the dynamics of hydronium (H30+) and hydroxyl (OH-) ions in liquid water. These ions are involved in charge transfer processes in liquid water H20 H+. .. OH2 - H20. .. H+-OH2, and HOH. . . OH- -> HO-. . . HOH. For the solvatetd H30+ ion, a picture consistent with experiment emerged from the simulation. The simulation showed that the HsO+ ion forms a complex with water molecules, the structure of which oscillates between the ones of H502 and I L/ij clusters as a result of frequent proton transfers. During a consid-... 

Diovan HCT, molecular formula and structure, 5 154t Dioxane... 

As in the case of the 1,2-dioxins, the 1,2-dithiins exist in various states of saturation, oxidation, and benzoannelation (cf. Scheme 1, 17-27) and they have been studied in detail both theoretically and experimentally. Not only were the conformations of the ring and attached substituents investigated, but the valence isomerism of 1,2-dithiin by both NMR and high-level ab initio molecular orbital (MO) calculations and the dithiol/disulfide equilibrium by MP2 calculations were also examined. The latter equilibrium has been applied successfully as a luminescent molecular switch (cf. Section 8.10.2.1). Finally, as a very interesting 1,2-dithiin derivative, the synthesis, structure, and reactivity of the (-l-)-camphor-derived analog 25 and its sulfoxide 26 and sulfone 27 have been reported. Both the synthesis and the antimalarial activity of the 2,3-dioxabicyclo[3.3.1]nonane pharmacophore 28, which contains the 1,2-dioxane moiety, have been reviewed recently <2006BML2991>. 

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