Explore chapters and articles related to this topic
Introduction to Nanosensors
Published in Vinod Kumar Khanna, Nanosensors, 2021
An alkyl group (symbol R) is a group formed from an alkane by removal of a single atom of hydrogen (–CH3, methyl group; –CH3CH2, ethyl group, etc.). An aryl group is a group formed from an aromatic compound by removing a single hydrogen atom, such as the C6H5– group from benzene.
An Overview of Catalytic Bio-oil Upgrading, Part 1:
Published in Ozcan Konur, Biodiesel Fuels, 2021
Jianghao Zhang, Junming Sun, Yong Wang
Other C–C bond formation reactions, such as alkylation and hydroalkylation, also build up larger compounds. Alkylation is the introduction of an alkyl group into an organic compound by substitution or addition. Similar to alkylation, hydroalkylation reactions also increase the carbon number of furans and phenols. Corma et al. (2011) converted 2-methylfuran with a consecutive hydroxyalkylation, alkylation, and hydrodeoxygenation. By hydroalkylation reaction, 2-methylfuran firstly reacted with aldehyde forming the furanic alcohol. Further alkylation with the second 2-methyl furan followed by HDO formed 6-alkyl undecane. Readers are referred to the literature for detailed discussion (Corma et al., 2011; Li et al., 2014; Wu et al., 2016; Zhao et al., 2012).
Feedstock Composition
Published in James G. Speight, Refinery Feedstocks, 2020
By definition, the saturate fraction consists of paraffins and cycloparaffin derivatives (naphthene derivatives). The single-ring naphthene derivatives, or cycloparaffin derivatives, present in crude oil are primarily alkyl-substituted cyclopentane and cyclohexane rings. The alkyl groups are usually quite short, with methyl, ethyl, and isopropyl groups the predominant substituents. As the molecular weight of the naphthenes increases, the naphthene fraction contains more condensed rings with six-membered rings predominating. However, five-membered rings are still present in the complex higher-molecular-weight molecules.
Investigation of Aviation Lubricant Aging under Engine Representative Conditions
Published in Tribology Transactions, 2021
Abdolkarim Sheikhansari, Ehsan Alborzi, Christopher Parks, Spiridon Siouris, Simon Blakey
To understand the nature of the observed differences in reactivity, we next probed the steric and electronic properties of the antioxidant molecules. As can be seen in the space-filling structures in Fig. 13, the steric environment around the N-H hydrogen is very similar in both antioxidants. The hydrogen is pointing out into an open face and the approach of the radical oil species should not be impeded in either structure. The marginal difference in reactivity must therefore be attributed to an electronic effect. The radical that is forming on the nitrogen atom is immediately bound to two aryl rings. The difference arises in the DODPA structure, which has an octyl group on each ring in a para position relative to the nitrogen atom. Alkyl groups are electron donating and their presence will act to stabilize the generated nitrogen radical.
A kinetic model and parameters estimate for the synthesis of 2-phenyloctane: a starting material of bio-degradable surfactant
Published in Indian Chemical Engineer, 2023
Sudip Banerjee, Md Aurangzeb, Amit Kumar
Alkylation reaction involves transferring an alkyl group into a molecule. The alkyl group is shared as carbocation, free radical, carbanion or carbene. Alkylation is used industrially to produce basic building blocks to synthesise more elaborate materials. In this connection, a few classic examples are the production of anti-knock gasoline, alkylation of phenol with 1-octene to produce alkyl phenol and synthesis of styrene and xylene from alkylation of toluene with methanol [1].