700-12-9

Usage

Uses

Used in Chemical Industry:
Pentamethylbenzene is used as a high-temperature solvent for its ability to withstand extreme temperatures without decomposing, making it suitable for various chemical processes.
Used in Polymer and Resin Production:
It serves as a precursor to certain types of polymers and resins, contributing to the formation of these materials due to its chemical structure and properties.
Used in Dye Production:
Pentamethylbenzene is used in the production of dyes, where its aromatic nature plays a role in the color characteristics and stability of the dyes.
Used in Fragrance Industry:
It is utilized in the creation of fragrances, leveraging its aromatic properties to contribute to the scent profiles of various products.
Used as a Chemical Intermediate:
Pentamethylbenzene is employed as a chemical intermediate in the synthesis of various other compounds, highlighting its versatility in organic chemistry.
It is important to handle and store Pentamethylbenzene with caution to prevent potential health risks associated with its vapors.

InChI:InChI=1/C11H16/c1-7-6-8(2)10(4)11(5)9(7)3/h6H,1-5H3

Upstream product

• 74-87-3 methylene chloride 
• 95-63-6 1,2,4-Trimethylbenzene 
• 527-53-7 1,2,3,5-Tetramethylbenzene 
• 115-10-6 Dimethyl ether 
• 106-42-3 para-xylene 
• 526-73-8 1,2,3-trimethylbenzene 
• 1585-17-7 2,4-bis(chloromethyl)mesitylene 
• 60-29-7 diethyl ether 
• 75-36-5 acetyl chloride 
• 67-64-1 acetone 
• 108-67-8 1,3,5-trimethyl-benzene 
• 67-56-1 methanol 
• 110-62-3 pentanal 
• 3853-91-6 2,3,4,5,6-pentamethyliodobenzene 

Downstream Products

• 1080-50-8 pentamethyl-trichloromethyl-benzene 
• 2243-32-5 pentamethylbenzoic acid 
• 87-85-4 Hexamethylbenzene 
• 34875-59-7 pentamethylbenzamide 
• 5082-88-2 2,2',3,3',4,4',5,5',6,6'-decamethyldiphenylmethane 
• 19936-85-7 1-acetoxymethyl-2,3,4,5,6-pentamethylbenzene 
• 110051-39-3 2,3,4,5,6,2'-hexamethyl-benzophenone 
• 95-47-6 o-xylene 
• 1839-64-1 1,2,3,4,5-pentamethyl-cyclohexane 
• 5153-40-2 2,3,4,5,6-pentamethylbromobenzene 
• 3853-91-6 2,3,4,5,6-pentamethyliodobenzene 
• 106-42-3 para-xylene 
• 488-23-3 1,2,3,4-Tetramethylbenzene 
• 4681-79-2 2,3,4,5-tetramethylbenzene-1-sulfonic acid 

Relevant academic research and scientific papers

Direct observation of hexamethylbenzenium radical cations generated during zeolite methanol-to-olefin catalysis: An ESR study

The generation of hexamethylbenzenium radical cations as the key reaction intermediate in chabazite-type molecular sieve acids (i.e., H-SAPO-34 and H-SSZ-13) during the methanol-to-olefin process has been directly evidenced by ESR spectroscopy.

Contact and Solvent-Separated Geminate Radical Ion Pairs in Electron-Transfer Photochemistry

The two primary intermediates that play a major role in determining the efficiencies of bimolecular photoinduced electron-transfer reactions are the contact (A.-D.+) and the solvent-separated (A.-(S)D.+) radical ion pairs, CRIP and SSRIP, respectively.These two species are distinguished by differences in electronic coupling, which is much smaller for the SSRIP compared to the CRIP, and solvation, which is much larger for the SSRIP compared to CRIP.The present work addresses the quantitative aspects of these and other factors that influence the rates of energy-wasting return electron transfer within the ion-pair intermediates.The electron acceptor tetracyanoanthracene (TCA) forms ground-state charge-transfer complexes with alkyl-substituted benzene donors.By a change of the excitation wavelength and/or donor concentration, either the free TCA or the CT complex can be excited.Quenching of free lTCA* by the alkylbenzene donors that have low oxidation potentials, such as pentamethylbenzene and hexamethylbenzene, in acetonitrile solution leads to the direct formation of geminate SSRIP.Excitation of the corresponding charge-transfer complexes leads to the formation of geminate CRIP.Rates of return electron transfer within the two types of ion pair are determined from quantum yields for formation of free radical ions together with the CRIP fluorescence decay lifetimes.The rates of return electron transfer within both sets of radical ion pairs depend upon the reaction exothermicity in a manner consistent with the Marcus inverted region.The data are analyzed by using a golden rule model in which the rate is given as a function of an electronic coupling matrix element, reorganization energies for the rearranged high-frequency (skeletal vibration) and low-frequency (mainly solvent and libration) motions, and an averaged frequency for the skeletal modes.Estimates for the reorganization energies and the skeletal frequency for the CRIP are obtained independently by analysis of the spectral distribution of the CRIP (exciplex) emission spectrum.A good fit to the return electron-transfer rate data for the CRIP is obtained by using the values for these parameters obtained from the emission spectrum.It is found that the electronic coupling in the CRIP is ca. 2 orders of magnitude higher than in the SSRIP and that the intermolecular (mainly solvent) reorganization energy for the contact pair is ca. 1 eV lower than that of the solvent-separated pair.The relevance of these observations to the photophysical and photochemical properties of contact radical ion pairs is discussed.

Coupling of Methanol and Carbon Monoxide over H-ZSM-5 to Form Aromatics

The conversion of methanol into aromatics over unmodified H-ZSM-5 zeolite is generally not high because the hydrogen transfer reaction results in alkane formation. Now circa 80 % aromatics selectivity for the coupling reaction of methanol and carbon monoxide over H-ZSM-5 is reported. Carbonyl compounds and methyl-2-cyclopenten-1-ones (MCPOs), which were detected in the products and catalysts, respectively, are considered as intermediates. The latter species can be synthesized from the former species and olefins. 13C isotope tracing and 13C liquid-state NMR results confirmed that the carbon atoms of CO molecules were incorporated into MCPOs and aromatic rings. A new aromatization mechanism that involves the formation of the above intermediates and co-occurs with a dramatically decreased hydrogen transfer reaction is proposed. A portion of the carbons in CO molecules are incorporated into aromatic, which is of great significance for industrial applications.

Methylbenzene hydrocarbon pool in methanol-to-olefins conversion over zeolite H-ZSM-5

The formation and reactivity of a methylbenzenes (MBs) hydrocarbon pool in the induction period of the methanol-to-olefins (MTO) reaction over zeolite H-ZSM-5 was investigated and the mechanistic link of MBs to ethene and propene was revealed. Time evolution analysis of the formed MBs and 12C/13C methanol-switching experiments indicate that in the induction period bulkier compounds such as tetraMB and pentaMB have higher reactivity than their lighter counterparts such as p/m-diMB and triMB. By correlating the distribution of MBs trapped on H-ZSM-5 with ethene and propene, we found that tetraMB and pentaMB favor the formation of propene, while p/m-diMB and triMB mainly contribute to the formation of ethene. On the basis of this relationship, the olefin (ethene and propene) selectivity can be controlled by regulating the distribution of trapped MBs by varying the silicon-to-aluminum ratio of ZSM-5, reaction temperature, and space velocity. The reactivity of MBs and the correlation of MBs with olefins were also verified under steady-state conditions. By observation of key cyclopentenyl and pentamethylbenzenium cation intermediates using in situ solid-state NMR spectroscopy, a paring mechanism was proposed to link MBs with ethene and propene. P/M-diMB and triMB produce ethylcyclopentenyl cations followed by splitting off of ethene, while tetraMB and pentaMB generate propyl-attached intermediates, which eventually produce propene. This work provides new insight into the MBs hydrocarbon pool in MTO chemistry.

K-promoted Mo/Co- and Mo/Ni-catalyzed Fischer-Tropsch synthesis of aromatic hydrocarbons with and without a Cu water gas shift catalyst

The catalyst systems Mo/Co/K/ZSM-5 and Mo/Ni/K/ZSM-5, alone and with the added copper-based water gas shift catalyst, were used for the conversion of two CO/H2 ratios in a batch reactor. GC analysis of the gas phase was used to determine CO conversion while GCMS and NMR studies were used to characterize the liquid products formed and liquid product selectivities. The liquids were hydrocarbons consisting mainly of alkyl substituted benzenes. Methyl substitution in the alkyl benzenes in the product liquid ranged from an average of 1.3 to 4.5 methyls per ring depending on reaction conditions and reactant gas mole ratios. The additional presence of the WGS catalyst significantly increased CO conversion in the reactions taking place at 280 °C from ～25% to ～90% while increasing selectivity toward higher average methyl substitution. Similar conversions and selectivities were observed with both a bio-syngas and a 50/50 mixture of H2 and CO.

Block copolymers for stable micelles

The present invention relates to the field of polymer chemistry and more particularly to multiblock copolymers and micelles comprising the same. Compositions herein are useful for drug-delivery applications.

Direct observation of cyclic carbenium ions and their role in the catalytic cycle of the methanol-to-olefin reaction over chabazite zeolites

Carbenium ions in zeolites: Two important carbenium ions have been observed for the first time under working conditions of the methanol-to-olefins (MTO) reaction over chabazite zeolites using 13C NMR spectroscopy. Their crucial roles in the MTO

Influence of (2,3,4,5,6-pentamethyl/phenyl)phenyl scaffold: Stereoelectronic control of the persistence of o-quinonoid reactive intermediates of photochromic chromenes

Regioisomeric photochromic chromenes 1Ch-6Ch substituted with the (2,3,4,5,6-pentamethyl/phenyl)phenyl scaffold were designed to delve into stereoelectronic effects on the spectrokinetic properties of photogenerated o-quinonoid reactive intermediates. While the latter derived from 1Ch, 2Ch, 4Ch, and 5Ch were found to exhibit notable persistence, those from 3Ch and 6Ch were found to revert rapidly at room temperature to preclude visible coloration. The intermediates of 1Ch and 2Ch were found to be marginally more stable than those of 4Ch and 5Ch, respectively, attesting to the possibility of toroidal conjugation via Cipso-π orbitals in the former. The rapid reversion of the intermediates of 3Ch and 6Ch is attributed to unfavorable electronic repulsion between the phenyl ring of the (pentamethyl/phenyl)phenyl scaffold and one of the lone-pairs of the o-quinonoid oxygen. Thus, the regioisomerically substituted photochromic chromenes are shown to permit control of the reversion, very rapidly as well as slowly, of the colored o-quinonoid intermediates through operation of stereoelectronic effects differently.

PROCESS FOR THE PRODUCTION OF A HYDROCARBON

A method of alkane homologation is provided, comprising contacting: a reactive alkane; a methylating agent; an optional diamondoid modifier; and an activating catalyst, thereby generating a hydrocarbon product having a greater number of carbon atoms than the reactive alkane.

Selective methylative homologation: An alternate route to alkane upgrading

InI3 catalyzes the reaction of branched alkanes with methanol to produce heavier and more highly branched alkanes, which are more valuable fuels. The reaction of 2,3-dimethylbutane with methanol in the presence of InI3 at 180-200°C affords the maximally branched C7 alkane, 2,2,3-trimethylbutane (triptane). With the addition of catalytic amounts of adamantane the selectivity of this transformation can be increased up to 60%. The lighter branched alkanes isobutane and isopentane also react with methanol to generate triptane, while 2-methylpentane is converted into 2,3-dimethylpentane and other more highly branched species. Observations implicate a chain mechanism in which InI3 activates branched alkanes to produce tertiary carbocations which are in equilibrium with olefins. The latter react with a methylating species generated from methanol and InI 3 to give the next-higher carbocation, which accepts a hydride from the starting alkane to form the homologated alkane and regenerate the original carbocation. Adamantane functions as a hydride transfer agent and thus helps to minimize competing side reactions, such as isomerization and cracking, that are detrimental to selectivity.