Diisopropylnaphthalenes

In more recent times, naphthalene has been used in condensation products from naphthalene sulfonic acids, utili2ing formaldehyde as additives to improve the flow properties of concrete these are referred to as superplastici2ers. Another newer appHcation is the production of diisopropylnaphthalenes. The mutual depression of the melting points in the mixture gives a Hquid which is used as a solvent for dyes in the production of carbonless copy paper. 

The above generalities apply particularly to palladium. Hydrogenation over platinum or rhodium are far less sensitive to the influence of steric crowding. Reduction of 1-t-butylnaphthalene over platinum, rhodium, and palladium resulted in values of /ci//c2 of 0.42, 0.71, and 0.024, respectively. Also, unlike mononuclear aromatics, palladium reduces substituted naphthalenes at substantially higher rates than does either platinum or rhodium. For example, the rate constants, k x 10 in mol sec" g catalyst", in acetic acid at 50 C and 1 atm, were (for 1,8-diisopropylnaphthalene) Pd (142), Pt(l8.4), and Rh(7.1)(25). 

These estimations can be documented by the well-known example with the diisopropylnaphthalene (DIPN) contamination in mixed RCP (RCP grade 1.02). This chemical substance comes from NCR carbonless copy paper and is in this mentioned RCP grade on an average level of 23 mg/kg TS [13], despite the fact that since several years those papers tried to be separated in the RCP grade sorted office paper , coloured letters and carbonless copy paper to reduce the DIPN concentration in mixed papers and board. 

Barder, T. (1991) Separation of 2,7 diisopropylnaphthalene from a feed mixture comprising various diisopropylnaphthalene isomers with a zeolite adsorbent. U.S. Patent 5,012,039. 

CASRN 24157-81-1 molecular formula C10H2O FW 212.33 Photolytic. Fukuda et al. (1988) studied the photolysis of 2,6-diisopropylnaphthalene and other polycyclic aromatic hydrocarbons in distilled water using a high pressure mercury lamp. After 96 h of irradiation, a rate constant of 0.045/h with a half-life of 16.0 h was determined. When the experiment was replicated in the presence of various NaCl concentrations, they found that the rate of photolysis increased proportionately to the concentration of NaCl. The photolysis rates of 2,6-diisopropylnaphthalene at aqueous NaCl concentrations of 0.2, 0.3, 0.4, and 0.5 M following 3 h of irradiation were 33.8, 44.7, 46.4, and 54.6%, respectively. It appeared that the presence of NaCl, the main component in seawater, is the cause for the increased rate of degradation. 

CASRN 40458-98-8 molecular formula C10H2O FW 212.33 Photolytic. Fukuda et al. (1988) studied the photodegradation of 2,6-diisopropylnaphthalene and other polycyclic aromatic hydrocarbons in distilled water and artificial seawater using a high-pressure mercury lamp. Based upon an experimentally rate constant of 0.108/h, the photolytic half-life of 2,7-diisopropylnaphthalene in water is 6.4 h. 

Lewis, M. D., Kleinkopf, G. E., Shetty, K. K. (1997). Dimethylnaphthalene and diisopropylnaphthalene for potato sprout control in storage 1 Application methodology and efficacy. American Potato Journal, 74, 183-197. 

Recently, the synthesis of symmetrically substituted dialkylpolynuclear aromatic hydrocarbons, such as 2,6-diisopropylnaphthalene and 4,4 -diisopropyl-biphenyl has been studied because they are superior candidates of components for advanced materials.4,7 Polynuclear aromatics require larger space for the transition state intermediate composed of reactants and acid sites inside the pores than do mononuclear reactants. For these reasons, twelve-membered ring zeolites, especially HM, are suitable for the formation of the smallest products although the selectivity varies with reactants and zeolites. In this paper, we review the shape-selective alkylation of polynuclear aromatics catalysed by zeolites. 

Catalysis over Typical Zeolites - In the alkylation of naphthalene, a-alkylation occurs in the initial stage because -positions are more reactive than P-positions. However, the (3/a ratio in the product mixture increases with the increase of reaction temperature and time on stream. Figure 8 shows the three reaction paths for producing diisopropylnaphthalene (DIPN) isomers. The reactions are (1) alkylation, (2) isomerization, and (3) transalkylation. Isomerization and transalkylation accompany the rearrangement of isopropyl groups. The zeolite type and reaction conditions, e.g., temperature and time on stream, usually determine the type of reaction path.4... 

Cumene (Isopropylbenzene) -50 Pseudocumene -11 sec-Butvlbenzene -22 tert-Butvlbenzene -32 Diethylbenzene -16 -Cymene (p-Isopropyltoluene) -19 Methyldiethylbenzene 2 sec-Amvlbenzene 11 Ethylisopropylbenzene 2 Triethylbenzene 16 Diisopropylbenzene 20 Methyldiisopropylbenzene 32 Di-sec-butvlbenzene 58 Di-sec-amvlbenzene 82 sec-Amvlnaphthalene 0 Diisopropylnaphthalene 18 Di-sec-amvlnaphthalene 88 Isopropyltetralin 32 Phenylcyclohexane 16 Paraffin wax (m.p. 53) 180 Paraffinic oil 183 Naphthenic oils 148,154 Water <25... 

Di-sec-butylbenzene Di-sec-amylbenzene 1-Methylnaphthalene sec-Amylnaphthalene Diisopropylnaphthalene Di-sec-amylnaphthalene Xsopropyltetralin Limonene (Dipentene)... 

Methyldiethylbenzene sec-Amylbenzene Ethylisopropylbenzene Triethylbenzene D i isopropylbenzene Methyldii sopropylbenzene Hexaethylbenzene sec-Amylnaphthalene Diisopropylnaphthalene Di-sec-amvlnaphthalene IsopropyItetralin... 

JFSSG (1999c) Diisopropylnaphthalenes in food packaging made from recycled paper and board, Food Surveillance Information Sheet 169, available from the Food Standards Agency, Room 303b, P.O. Box 31037, London SW1P 3WG, Tel. No. +44 (0)20 7238 6245/6150, fax +44 (0)20 7238 6330 or email informationcentre foodstandards.gsi.gov.uk... 

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