Single-ring aromatics

Aromatics-single ring, mono and disubstituted by n-paraffins 6 1.91 0.0418 23.5 66.1... 

Aromatics-single ring, mono substituted by isoparaffins 2 2.99 0.0264 37.5 62.6... 

The preseparation utilized a 5 pim cyano column (250 cm X 4.6 mm i.d.) and a 5 p.m silica column (250 cm X 4.6 mm i.d.) in series, followed by GC analysis on an SE-54 column (25 m X 0.2 mm i.d., 0.33 p.m film thickness). The SFC system separated the aviation sample into two peaks, including saturates and single-ring aromatics as the first peak, and two-ring aromatic fractions as the second peak. These fractions were selectively cut and then transferred to the GC unit for further analysis. (Figure 12.20). 

When aromatics, even single-ring compoimds such as benzene, have one substituent already, the introduction of the next also gives rise to regioisomerism. In addition, the first one guides the introduction of the second by steric and electronic effects. 

Organic synthesis 33 [OS 33] Nitration of substituted single-ring aromatics... 

The nitration of several single-ring aromatics with two substituents at various ring positions has been reported [94], The exact nature of these species, however, was not disclosed, probably for intellectual property reasons, as the reactions were performed for an industrial company (BASF). 

OS 33] ]R 16h] [P 25] For the nitration of a single-ring aromatic in a capillary-flow micro reactor, experiments were performed at two temperature levels, 60 and 120 °C [94]. Owing to the assumed increase in conversion rate with higher temperature, attempts were made to compensate for this by decreasing the capillary length at otherwise constant dimensions. For the 60 °C experiment, a very low... 

Single-ring aromatics. Aromatic constituents are characterized by the presence of rings with six carbon atoms and are considered to be the most acutely toxic component of crude oil constituents because of their association with chronic and carcinogenic effects. Many low-molecular-weight aromatics are also soluble in water, increasing the potential for exposure to aquatic resources. 

A comparison of the feed and product compositions achievable by this approach is shown in Figure 16.8, which shows the depletion of multi-ring aromatics from the feed in favor of a variety of single ring aromatics with short alkyl chains. A more challenging approach that leads to a higher-value product involves optimization of the catalyst and process conditions to maximize xylene and toluene production for aromatic complex feeds [60]. 

Soluble in alcohol, ether (Weast, 1986), naphtha, and single-ringed aromatic hydrocarbons. 

---