W-Undecane

The first tetramine we will discuss is the acyclic AfW -bis-(2-aminoethyl)propane-1,3-diamine (36) with an accompanying gas-phase enthalpy of formation58 of 0.0 3.3 kJmol-1. In the absence of intramolecular hydrogen bonding and any vie- and more distant diamine effects, this value could be estimated by summing the enthalpy of formation of w-undecane, 2- 4 and 2-85. The calculated value is —17 kJmol-1. Because the calculated enthalpy of formation is more negative than the experimentally measured... 

Mixture of Equal Parts of w-Undecane, n-Pentacosane, n-Hexatriacontane... 

Crompton and co-workers [1,2] have applied the gas chromatographic technique to the determination in PS of styrene and a wide range of other aromatic volatiles in amounts down to the 10 ppm level. In this method a weighed portion of the sample is dissolved in propylene oxide containing a known concentration of pure w-undecane as an internal standard. After allowing any insolubles to settle an approximately measured volume of the solution is injected into the chromatographic column which contains 10% Chromasorb 15-20 M supported on 60-70 BS Celite. 

Figure 5.2 Gas chromatography of aromatics in polystyrene, (a) synthetic mixture (b) propylene oxide solution of polymer in propylene oxide. Column Carbowax 15-20 M at 90 glass liner on injection port internal standard w-undecane concentrations as percentage polymer. Source Author s own files)...

FIGURE 4.7 Plot of resolution versus average carrier gas linear velocity. The lines represent resolution calculated from theory, and the points represent the measured values for the following pairs of peaks A = w-undecane, 2,4-DMA B = 1-octanol, n-undecane C = 2,4-DMA, n-dodecane D = n-dodecane, naphthalene. For conditions, see Figure 4.5. [Reprinted from LC/GC Magazine with permission of Advanstar Publications (7).]... 

Payne and Finn 364) have recently studied the pheromone receptor system of females of the greater wax moth. Galleria mellonella. The male produces -nonanal and -undecanal in its wing glands. Using the differential adaptation technique on female antennal preparations, the authors concluded that -nonanal reacts with both acceptors (receptor sites), whereas w-undecanal reacts with only one acceptor (receptor site). 

Figure 1.11 Plot of the logarltha of the adjusted retention tine against the reciprocal of coluan tesperature for two honologous series of n-alkane and n-alkylbensenes (and ortho-xylene) on a 2 seter 20% (H/H) colunn of tetrahutylaanoniua 4-toluenesulfonate coated onto Chronosorb (W-AH). Solute identification, 1 decane, 2 - undecane, 3 - dodecane, 4 trideceme, 5 tetradecane, 6 -pentadecane, 7 > benzene, 8 - toluene, 9 - ethylbenzene, 10 -propylbenzene, 11 - ortho-xylene, and 12 - butylbenzene.

Polybia occidentalis W-VG Alarm (2S,6R,8S)-2,8-Dimethyl-1,7-dioxaspiro-[5.5] undecane 142 [188]... 

W, 6.S,+,87 +)-6-Methyl-2,tl-dioxatricyclo[6.3.0.01-6 undecan-3-one Typical Procedure using 3-Chloroper-oxybenzoic Acid 26... 

The progress of the reaction may be conveniently followed by g.l.c. Remove samples (c. 2-3 ml) from the reaction mixture by means of a hypodermic syringe and submit them to a small-scale hydrolysis and extraction procedure similar to that described for the main reaction mixture. Analyse the organic layer on a 10 per cent squalane on Chromosorb W column held at 140 °C. Under these conditions 1-iodoheptane has a slightly longer retention time than undecane. 

MacDougall, J. M. Santora, V. J. Verma, S. K. Turnbull, P. Hernandez, C. R. Moore, H. W. Cydobutenone-based syntheses of polyqui-nanes and bicydo[6.3.0]undecanes by tandem anionic oxy-Cope reactions. Total synthesis of ( )-precapnelladiene. J. Org. Chem. 1998, 63, 6905-6913. 

Internal Standard w-Decane and either n-undecane or n-dodecane according to the requirement of the System Suitability Test. 

To a stirred mixture of 5 mass equiv of W-Rancy nickel in 2 mL of Et20 under hydrogen at 20CC, 0.46 g (1.1 mmol) of ( ,Z)-2-phenyl-8-[(phenylseleno)methyl]-l,7-dioxaspiro[5.5]undecan-4-one (20) are added. After 5 h the mixture is filtered through a pad of silica gel and the solvent is removed under reduced pressure yield 0.27 g (94%). 

This method w as used in a synthesis of m-jasmone to eifect removal of a dithiokelal group.Thus oxidation of (1) with ceric ammonium nitrate gave undecane-2,5-dione (2) in 80% yield. In this case use of chloramine-T (this volume) gave (2) in 67.3 % yield. 

Baldwin, S. W., Doll, R. J. Synthesis of the 2-aza-7-oxatricyclo[4.3.2.04,8]undecane nucleus of some gelsemium alkaloids. Tetrahedron Lett. 1979, 3275-3278. 

G. Schneider, Z. Alwani, W. Heim, E. Horvath, and E. U. Pranck (1967) Phase equilibria and critical phenomena in binary mixtures (CO2 with N-octane N-undecane N-tridecane and N-hexadecane up to 1500 bar). Chem. Ing. Techn. 39, p. 649... 

Fig. 3 GCxGC-ECNI-TOF-MS chromatograms of polychlorinated (a) decanes, (b) undecanes, (c) dodecanes, (d) tridecanes and (e) C10-C13 technical mixture, all with 55% (w/w) Cl content, obtained on DB-lx007-65HT column combination. Lines indicate the positions of apices within the bands [50]...

Analysis. Heavy Products. High molecular weight hydrocarbons were analyzed by gas-liquid chromatography. A known volume of undecane was added to the irradiated sample as internal standard. The stationary phase was silicone oil on Chromosorb W. The column was 1.50 meters long its diameter was 3 mm. A flame ionization detector was used. 

Figure 2.12. A plot of Vn / Vl against 1 / Vl for several compounds on Carbowax 20M and the poly(dicyanoalkylsiloxane) OV-275 on Chromosorb W-AW at 80.8°C. Identification 1 = dodecane 2 = nitromethane 3 = undecane 4 = dioxane 5 = decane 6 = ethanol 7 = tridecane and 8 = tetradecane.

As noted already, the detergency of the quaternary mixtures for lipophilic polyester fabric wjk 30 C is lower than for cotton fabrics. Besides, Fig. 14 shows that it is affected much more by the composition of the cleaning medium. After being cleaned with bicontinuous microemulsions or two-phase systems with an all l polyglycol ether content Cy = 20 wt% and n-undecane concentrations of 30 wt%test fabrics show a maximum in the reflectance difference of A/ =5 ll%. If the all l polyglycol ether content is decreased or the -undecane concentration is changed to - <20 wt% or c >60 wt%, the detergency decreases. The lowest values are found for oil-rich W/O microemulsions of samples 10, 15 and 20 (see Table 2). 

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