Decane, molecular structure

Figure 5.44 (a) General molecular structure of the porphyrin disulfides, PDSn, described by Ishida and Majima [76]. (b) Changes in the surface plasmon enhanced fluorescence spectra for the exchange reaction of a decane thiol SAM with a 50 mmol dm-31,2-dichloroethane solution of PDS10 (Xem = 725 nm Xex = 425 nm). From A. Ishida and T. Majima, /. Chem. Soc., Chem. Commun., 1299-1300 (1999). Reproduced by permission of The Royal Society of Chemistry... 

Jeffery, S. M., Sutherland, A. G., Pyke, S. M., Powell, A. K., Taylor, R. J. K. Isolation of episulfones from the Ramberg-Backlund rearrangement. Part 2. X-ray molecular structure of 2,3-eplthlo-8,8-dlmethyl-6,10-dloxasplro[4.5]decane S,S-dloxlde and of r-6-benzyl-t-7,t-8-eplthlo-1,4-dloxasplro[4.4]nonane S,S-dloxide. J. Chem. Soc., Perkin Trans. 1 1993, 2317-2327. 

Following are the melting (T ), boiling (Tf,), and critical (T ) temperatures for benzene, cyclohexane, decane, and naphthalene. Explain the trends in terms of molecular structure and forces. Data from [12]. 

Figure 1 Molecular structures of some organic molecules that form the host structures in solid inclusion compounds (these specific host structures are encountered freqnently in this chapter) urea, thiourea, tri-orfto-thymotide (TOT), perhydrotriphenylene (PHTP), deoxycholic acid (DCA) and varions molecules related to deoxycholic acid, host A (l,l,6,6-tetraphenylhexa-2,4-diyne-l,6-diol), host B (frans-2,3-bis(hydroxydiphenylmethyl)-l,4-dioxaspiro[5.4]decane), and host C (irans-2,3-bis(hydroxydiphenylmethyl)-l,4-dioxaspiro[5.4]nonane).

How sharp is the interfacial region between water and an organic liquid and what is its molecular structure Broadly, three possibilities should be considered (1) the interface is sharp and flat, as assumed in continuum models (2) the interfacial region is a mixture of the two liquids and (3) the interface is a locally sharp but rough surface that fluctuates in time. Recent computer simulations of interfaces between water and benzene, " decane, nonane, hexane, dodecane, 1,2-dichloroethane (DCE), CCU, and octanol have dealt with this issue. 

MD simulations also provide an opportunity to detect the structure of molecularly thin films. The most commonly known ordering structure induced by the confinement, the layering, has been revealed that the molecules are packed layer by layer within the film and the atoms would concentrate on several discrete positions. This has been confirmed in the simulations of liquid decane [29]. The density profile of unite atoms obtained from the simulations is given in Fig. 12 where two sharp density peaks appear at the locations near the walls, as a result of adsorption, while in the middle of the film smaller but obvious peaks can be observed on the density profile. The distance between the layers is largely identical to the thickness of the linear chain of decane molecules, which manifests the layered packing of molecules. 

Example The El mass spectmm of -decane is typical for this class of hydrocarbons (Fig. 6.18a). Branching of the aliphatic chain supports cleavage of the bonds adjacent to the branching point, because then secondary or tertiary carbenium ions and/or alkyl radicals are obtained (Fig. 6.18b,c). This allows for the identification of isomers to a certain degree. Unfortunately, hydrocarbon molecular ions may undergo skeletal rearrangements prior to dissociations, thereby obscuring structural information. 

To assist with the MS/MS structure identification, the gross substructure of buspirone is categorized into profile groups (Kerns et al., 1995). Profile groups directly correlate specific product ions and neutral losses with the presence, absence, substitution, and molecular connectivity (Lee et al., 1996) of specific buspirone substructures and their modifications. The profile groups of buspirone are identified with abbreviations that correspond to the three specific substructures azaspirone decane dione (A), butyl piperazine (B), and pyrimidine (P). Substituted substructures are designated with a subscript ( ), and a dash (-) denotes substructure connectivity. Thus, the buspirone molecule is represented by A-B-P. The As-B-P designation... 

Table 6.11 illustrates a representative buspirone metabolite structure database. Information on the structure, molecular weight, UV characteristics, RRT, and product ions of metabolites obtained from rat bile, urine, and liver S9 samples are compiled. Using this format, the predominant buspirone metabolite profile groups, As-B-P, A-B-Ps, and As-B-Ps are easily recognized. These profile groups indicate azaspirone decane dione and pyrimidine as metabolically active sites of attack and the presence of multiple substitution sites on each of these substructures. In many cases, the profile groups indicate the occurrence of metabolic reactions on more than one substructure. 

Physical properties are related to ester-segment structure and concentration in thermoplastic polyether-ester elastomers prepared hy melt transesterification of poly(tetra-methylene ether) glycol with various diols and aromatic diesters. Diols used were 1,4-benzenedimethanol, 1,4-cyclo-hexanedimethanol, and the linear, aliphatic a,m-diols from ethylene glycol to 1,10-decane-diol. Esters used were terephthalate, isophthalate, 4,4 -biphenyldicarboxylate, 2,6-naphthalenedicarboxylate, and m-terphenyl-4,4"-dicarboxyl-ate. Ester-segment structure was found to affect many copolymer properties including ease of synthesis, molecular weight obtained, crystallization rate, elastic recovery, and tensile and tear strengths. 

Isobutane, isopentane, and neopentane are common names or trivial names, meaning historical names arising from common usage. Common names cannot easily describe the larger, more complicated molecules having many isomers, however. The number of isomers for any molecular formula grows rapidly as the number of carbon atoms increases. For example, there are 5 structural isomers of hexane, 18 isomers of octane, and 75 isomers of decane We need a system of nomenclature that enables us to name complicated molecules without having to memorize hundreds of these historical common names. 

Fractionation of an asphaltene by stepwise precipitation with hydrocarbon solvents (heptane to decane) allows separation of the asphaltene by molecular weight. The structural parameters determined using the x-ray method (Table II) show a relationship to the molecular weight (16). For the particular asphaltene in question (Athabasca), the layer diameters (La) increase with molecular weight to a limiting value similar relationships also appear to exist for the interlamellar distance (c/2), micelle height (Lc), and even the number of lamellae (Nc) in the micelle. 

The molecular-interaction parameter can give rise to either positive or negative contributions to the term In y,. If the solvent tends to be self-associated, then the addition of a nonpolar solute disrupts solvent structure. Figure 2-5 indicates that n-decane in water has an activity coefficient of about 100,000. This high activity coefficient in solution is typical of the weak interaction of solute and solvent. On the other hand, where the molecular interaction between solute and solvent is strong, the activity coefficient would be expected to be low, and solute-solvent interactions and association constants may be measurable. ... 

They have a different structure, although they both have the same molecular formula. One is called normal butane, abbreviated to -butane the other may be called isobutane or 2-methylpropane - the latter name describes the structure of the compound, as you will see later. These compounds are isomers of one another. They are not the same compounds and have different melting points, boiling points and solubilities. Isomers are compounds which have the same moiecuiar formuia, but different moiecuiar structures. After butane, the longer the carbon chain of an alkane, the more structurai isomers are possible for a particular molecular formula. For example, there are 75 decanes (C10H22) and over three-hundred-thousand eicosanes (C20H42) ... 

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