Methyl propyl carbonate

Kinetic stability of lithium and the lithiated carbons results from film formation which yields protective layers on lithium or on the surfaces of carbonaceous materials, able to conduct lithium ions and to prevent the electrolyte from continuously being reduced film formation at the Li/PC interphase by the reductive decomposition of PC or EC/DMC yielding alkyl-carbonates passivates lithium, in contrast to the situation with DEC where lithium is dissolved to form lithium ethylcarbonate [149]. EMC is superior to DMC as a single solvent, due to better surface film properties at the carbon electrode [151]. However, the quality of films can be increased further by using the mixed solvent EMC/EC, in contrast to the recently proposed solvent methyl propyl carbonate (MPC) which may be used as a single sol-... 

Methyl propyl carbonate (MPC) is a structural isomer of DEC. Physical and electrochemical properties of four kinds of partially fluorinated MPC derivatives, 3-fluoro-propyl methyl carbonate (EPMC), methyl 3,3,3-trifluoropropyl carbonate (TrEPMC), methyl 2,2,3,3-tetrafluoropropyl carbonate (TeEPMC), and methyl 2,2,3,3,3-pentaflu-oropropyl carbonate (PeEPMC) in Schane 2.8 were examined [42]. 

Scheme 2.8 Preparation of fluorinated methyl propyl carbonates...

Sasaki, Y. Satake, H. Tsukimori, N. Nanbu, N. Takehara, M. Ue, M., Physical and electrolytic properties of partially fluorinated methyl propyl carbonate and its application to lithium batteries. Electrochemistry 2010, 78,467 70. 

Ein-Eli, Y McDevitt, S. R Aurbach, D. Markovsky, B. Schecheter, A., Methyl propyl carbonate A promising single solvent for Li-ion battery, 7. Electrochem. Soc. 1997, 144, L180-L184. 

DEC = diethyl carbonate, EMC = ethyl metiiyl carbonate, PC = propylene carbonate, DMC = dimethyl carbc ate, EC carbonate, MA = methyl acetate, MPC = methyl propyl carbonate, EA = eAyl acetate. 

An inspection of Tables 17.1 and 17.2 shows that appropriate solvents for lithium batteries mainly belong to classes 6 and 7 and include cyclic (EC, PC) and open-chain (DMC, methyl ethyl carbonate (MEC), diethyl carbonate (DEC), methyl propyl carbonate (MPC) esters and several ethers (dioxolane (DIOX), dimethoxy ethane (DM E), tetrahydrofuran (THE)), as well as inorganic sulfur compounds (SO2, SO2CI2, SOCI2). Sulfur compounds are mainly used as liquid cathode materials. 

Note 1,2-BC 1,2-dunethylethylene carbonate 1,3-DOL 1 -dioxolane AC acetonitrile A.N. acceptor number BC butylene carbonate BEC butyl ethyl carbonate BMC butyl methyl carbonate CF3-EC trifluoromethyl ethylene carbonate QEC chloroethylene carbonate DBC dibutyl carbonate DEC diethyl carbonate DEE 1,2-diethoxyethane DGM diethyleneglycol dimethyl ether DIPC di-isopropyl carbonate DMC dimethyl carbonate DME 1,2-dimethoxyethane DMSO dimethyl sulfoxide D.N. donor number DPC di-n-propyl carbonate EC ethylene carbonate EIPC ethyl isopropyl carbonate EMC ethyl methyl carbonate EPC ethyl propyl carbonate MeTHF 2-methyl tetrahydrofuran MIPC methyl isopropyl carbonate MFC methyl propyl carbonate PC propylene carbonate TEGM tetraethylene glycol dimethyl ether TGM triethylene glycol dimethyl ether TFIF tetrahydrofuran. 

Figure 3 shows a typical FUR analysis of the surface films formed on graphite electrodes in a methyl-propyl carbonate (MPC) solution, which is based on FUR spectra of a higher resolution obtained from lithium electrodes treated in the same solution and some reference solutions (external reflectance mode) [60]. Spectmm 3a relates to surface films on a graphite electrode cycled in an MPC solution. Spectmm 3b relates to surface films formed on lithium in the... 

Ether carbon atoms also exhibit a downfield shift in the 13C NMR spectrum, where they usually absorb in the 50 to 80 5 range. For example, the carbon atoms next to oxygen in methyl propyl ether absorb at 58.5 and 74.8 8. Similarly, the methyl carbon in anisole absorbs at 54.8 8. 

Numerous research activities have focused on the improvement of the protective films and the suppression of solvent cointercalation. Beside ethylene carbonate, significant improvements have been achieved with other film-forming electrolyte components such as C02 [156, 169-177], N20 [170, 177], S02 [155, 169, 177-179], S/ [170, 177, 180, 181], ethyl propyl carbonate [182], ethyl methyl carbonate [183, 184], and other asymmetric alkyl methyl carbonates [185], vinylpropylene carbonate [186], ethylene sulfite [187], S,S-dialkyl dithiocarbonates [188], vinylene carbonate [189], and chloroethylene carbonate [190-194] (which evolves C02 during reduction [195]). In many cases the suppression of solvent co-intercalation is due to the fact that the electrolyte components form effective SEI films already at potential which are positive relative to the potentials of solvent co-intercalation. An excess of DMC or DEC in the electrolyte inhibits PC co-intercalation into graphite, too [183]. 

Carbonate (2-Fluoro-2-methyl-propyl) TrilHioromethyl- ElOa. 257 (tert.-H -> F)... 

Acetone 1-Methoxy-l-(2,2,2-triflnoro-ctlioxy)- ElOb,. 578 [OH -> CH(OR)-CO-R) Carbonate (2-Methyl-propyl) Irifliioromethyl- ElOa. 257 (Educt)... 

Carbons I, 4, 5, and 6 are all bonded to two or more hydrogens, so they are not chirality centers. Carbon 2 is bonded to two methyl groups, so it is not a chirality center either. However, carbon 3 is bonded to four different groups (hydrogen, methyl, propyl, isopropyl) and is a chirality center. Because the molecule has one chirality center, it is chiral. Chirality centers are sometimes marked with an asterisk ( ). 

Isocyano-2-methyl)-propyl-l-carbonic acid methyl ester... 

By reacting the product of Step 1 with benzyl amine and then introducing co-reagents, the product, 2-(N-benzyl-N-acyl-3-methyl-butylamido)-2-methyl-propyl-1-carbonic acid, methyl ester, (I), was also prepared by the author as illustrated in Eq. 4 ... 

Thus, if we consider a reaction in which ethyl acetate dissolved in diethyl carbonate is allowed to react with methyl propyl ketone (2-pentanone). to give a ketonic ester, in the presence of sodium hydride, we have a set of affairs which can be expressed algebraically as... 

By replacing acetone with methyl, ethyl, propyl, butyl or benzyl alcohol as a solvent, the reaction of j>, S methyl cyanodithioimido-carbonate (5) with potassium hydroxide furnished the unexpected key intermediates, -alkyl and benzyl -potassium cyanoimidocarbonates (30-34, Table IV). 

On the basis of the metabolic products identified and their relative amounts formed during incubation, a degradative pathway involving hydroxylation and sulfoxidation mechanisms is proposed (Figure 7). EPTC is first hydroxylated at the a-propyl carbon to form a-hydroxy-propyl EPTC. This compound is unstable and breaks down to form N-depropyl EPTC and propionaldehyde. The N-depropyl EPTC is further metabolized to s-ethyl formic acid and propylamine. The s-ethylcarboxylic acid is then demethylated to s-methyl formic acid. This product is hypothesized to degrade to form C02 and methyl mercaptan. 

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