The water-to-pentyl acetate partition coefficient refers to solute transfer into dry pentyl acetate, and not to the practical partitioning process where water and pentyl acetate would be in direct contact.
From: The Journal of Chemical Thermodynamics, 2018
Related terms:
- Poly(ethylene)
- Methyl
- Methanol
- Partition Coefficient
- Single Crystalline Solid
- Molar Solubility
- Aqueous Solution
- Sorption
Cobalt
Mauro Cataldi, in xPharm: The Comprehensive Pharmacology Reference, 2010
Basic Chemistry
| Chemical Structure | |
| Structure | |
| Comments | Co can occur in four oxidation states (0, +2, +3, +4). |
| Chemical Formula | Co |
| Properties | |
| Physical Properties | The following data are from The Merck Index (8th edition). |
| Elemental cobalt is a hard, silvery grey metal whereas Co sulphate occurs as red to lavender crystals. | |
| Cobalt[II] acetate: mw: 177.03-Ligth pink crystals-Soluble in water, alcohols, diluted acids, pentyl acetate. | |
| Cobalt[II] carbonate: mw: 118.95-Rod powder or rombohedral crystals-Almost insoluble in water, alcohols, methyl acetate. | |
| Cobalt[II] chloride: mw: 129.85-Pale blue hygroscopic leaflets; turns pink upon exposure to most air. | |
| Cobalt[II] chloride hexahydrate: Pink to red slightly deliquescent, monoclinic, prismatic crystals. | |
| Cobalt[II] oxide: mw: 74.94- Powder or cubic exagonal crystals-Color from olive green to red depending on particle size-Insoluble in water, soluble in acids or alkalis. | |
| Cobalt[II] sulfate: Red to lavender dimorphic, orthorhombic crystals. | |
| Molecular Weight | Elemental cobalt 58.933. Cobalt[II] acetate: 177.03-. Cobalt[II] carbonate: 118.95-. Cobalt[II] chloride: 129.85-. Cobalt[II] oxide: 74.94-. Cobalt[II] sulfate: 155 |
| Solubility | Cobalt[II] acetate: - Soluble in water, alcohols, diluted acids, pentyl acetate. Cobalt[II] carbonate: - Almost insoluble in water, alcohols, methyl acetate. Cobalt[II] chloride: soluble in water, alcohols, acetone, ether, pyridine, glycerol. Cobalt[II] chloride hexahydrate: soluble in water, alcohols, acetone, ether, glycerol. Cobalt[II] oxide: Insoluble in water, soluble in acids or alkalis. Cobalt[II] sulfate: monohydrate: dissolves slowly in boiling water; heptahydrate, soluble in water, slightly soluble in ethanol. |
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Physical Organic Chemistry
Charles L. Perrin, in Encyclopedia of Physical Science and Technology (Third Edition), 2003
IV.F Labeling and Crossover Experiments
Labeling experiments are a means to tag a portion of a molecule and follow it through the reaction. The label may be an isotope or it may be a chemical substituent, which opens the risk of changing the mechanism but which is often easier to synthesize and to analyze.
Isotopic labeling shows that ester hydrolysis generally proceeds with cleavage of the acyl–oxygen bond, not the alkyl–oxygen bond. For example, hydrolysis of n-pentyl acetate in alkaline H218O produces acetate containing the 18O and n-pentanol without any 18O:
(44)
This experiment could also be performed with CH3C(
O)18OC5H11 to verify that the 18O
Cpentyl bond does not cleave. However, it is easier to “label” that position with ordinary 16O and run the reaction in H218O. A rare exception to this behavior is with the highly hindered methyl 2,4,6-tri-tert-butylbenzoate, where hydrolysis in H218O produces CH318OH by alkyl–oxygen cleavage.
Reaction of aromatic halides with NaNH2 in liquid ammonia produces the corresponding aromatic amine. However, the conversion of o-iodoanisole (115) to m-anisidine (116) shows that this is not simply a substitution of NH2 for I. Instead it proceeds by proton removal to create 117, which undergoes elimination to a benzyne (118) that preferentially adds NH2− at the meta position to produce 119. The methoxy group is a label to make the rearrangement clear (and to stabilize the anion in 119), and the mechanism was further documented through 14C labeling.
Another example is the rearrangement of 120 to 121. The deuterium labeling shows that the reaction does not proceed simply by opening the four-membered ring at the left. Instead it proceeds by opening the vertical bonds in the middle to form 122, followed by rearrangement as indicated (to 121′, identical with 121).
Crossover experiments are a form of double-labeling experiment designed to distinguish between intramolecular and intermolecular mechanisms. For example, methyl transfer from oxygen to carbon in o-(p-CH3C6H4SO2) CH−C6H4SO2OCH3 to form o-(p-CH3C6H4SO2)CH (CH3)C6H4SO3− was shown to be intermolecular by using a mixture of this anion (d0) plus (p-CD3C6H4SO2) CH−C6H4SO2OCD3 (d6) and observing that a statistical mixture of d0, d3, and d6 products was formed. The intramolecular methyl transfer would require transition state 123 but with a 180° CH⋯ CH3⋯O angle, to be consistent with inversion of configuration at the methyl, and this geometry is impossible. This reasoning is known as the endocyclic restriction test.
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Abraham model correlations for describing the thermodynamic properties of solute transfer into pentyl acetate based on headspace chromatographic and solubility measurements
Igor A. Sedov, ... Michael H. Abraham, in The Journal of Chemical Thermodynamics, 2018
Abstract
Infinite dilution activity coefficients were measured for 32 liquid organic solutes dissolved in pentyl acetate at 298.15 K. The organic solutes included both saturated (hexane through decane, cyclohexane) and unsaturated hydrocarbons (1-hexene, 1-heptene, cyclohexene, 1-octyne, 1,7-octadiene), several substituted benzene derivatives (benzene, methylbenzene, ethylbenzene, propylbenzene, 1,3-dimethylbenzene, 1-dimethylbenzene, fluorobenzene, bromobenzene), four haloalkanes (trichloromethane, 1-chlorobutane, 1,2-dichloropropane, isopropyl bromide) and three alcohols (ethanol, 1-propanol, 2-propanol), as well six miscellaneous organic compounds (acetonitrile, ethyl acetate, tetrahydrofuran, 1,4-dioxane, propanone, nitromethane). Mole fraction solubilities were also determined for 10 crystalline nonelectrolyte organic solutes dissolved in pentyl acetate. Results of the experimental measurements were used to derive Abraham model correlations for describing thermodynamic properties of solute transfer into pentyl acetate. The derived Abraham model correlations mathematically described the observed data to within 0.12 log units (or less).
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13th European Symposium on Fluorine Chemistry (ESFC-13)
G. Kostov, ... B. Boutevin, in Journal of Fluorine Chemistry, 2002
To improve the relative reactivity of the functional co-monomer to TFE, a 4,5,5-trifluoro-4-ene-pentyl acetate (FAc) was used as a co-monomer in a wide range of monomer compositions (from 95/5 to 10/90) [56]. The MW varied in the range of 3500–5000 and the IP from 1.3 to 1.6. Even in this TFE/FAc copolymerization proceeding with a higher rate than that of TFE/FAl systems, the allyl chain transfer reaction plays a considerable part.
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Organic matrices, ionic liquids, and organic [emailprotected] assisted laser desorption/ionization mass spectrometry
Hani Nasser Abdelhamid, in TrAC Trends in Analytical Chemistry, 2017
6.11 Quinoline-based matrix
The sensitivity, applications, and reaction mechanism of 2-hydrazinoquinoline as a reactive matrix were examined. 2-hydrazinoquinoline was applied for aldehydes (formaldehyde, acetaldehyde, propionaldehyde, and n-butyraldehyde) and ketones (acetone, methyl ethyl ketone, and methyl isobutyl ketone). On the other hand, carboxylic acids (formic acid, acetic acid, propionic acid, and butyric acid) and esters (ethyl acetate, pentyl acetate, isoamyl acetate, and methyl salicylate) could not be detected. 2,4-dinitrophenylhydrazine is a common derivatization reagent for quantitative analysis of carbonyl compounds in gas and liquid chromatography. 2-hydrazinoquinoline solution is acidic solution (trifluoroacetic acid). Thus, it can be used as a reactive matrix for MALDI-MS [239]. 3-aminoquinoline is an excellent matrix for polysaccharides [240]. SBA-15 material modified with quinoline ([SBA-15-8-(3-(triethoxy silyl)propoxy) quinoline, SBA-Q-Si]) was used for the analysis of small molecules [241].
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Metagenomics: Is it a powerful tool to obtain lipases for application in biocatalysis?
Janaina Marques Almeida, ... Nadia Krieger, in Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics, 2020
4.1 Kinetic resolution of optically pure compounds
Most of the metagenomic lipases presented in Table 3 have been evaluated regarding their potential for use in the synthesis of optically active compounds. The majority of these studies involve the kinetic resolution of racemic substrates, such as alcohols, carboxylic acids and esters, products of great relevance to drug development. Three metagenomic lipases gave promising results: LipS, LipG9 and LipR1.
LipS showed high enantioselectivity in the kinetic resolution of carboxylic esters of secondary alcohols (Fig. 2A), giving enantiomeric excesses of the (R)-enantiomer of the alcohol product (i.e. eep values) >99% for the hydrolysis of 1-phenyl-2-butyl acetate and 1-phenyl-2-pentyl acetate [73]. The enantioselectivity of LipS was higher when the chiral center of the substrate (esters of secondary alcohols) was not adjacent to the aromatic ring. LipS also gave 45% conversion in the hydrolysis of the phenyl ester of ibuprofen (Fig. 2B), with an eep >99% for (R)-ibuprofen, and an enantiomeric ratio (E) above 100 [73].
Fig. 2. Kinetic resolution of carboxylic esters (A) and ibuprofen phenyl ester (B) catalyzed by lipase LipS. (R,S)-1: 1-phenylbutan-2-yl acetate; (R,S)-2: 1-phenylpentan-2-yl acetate; (R)-1a: 1-phenylbutan-2-ol; (R)-2a: 1-phenylpentan-2-ol; (R,S)-3: phenyl 2-(4-isobutylphenyl)propanoate; (R)-3a: 2-(4-isobutylphenyl)propanoic acid.
Immobilized LipG9 (denoted “Im-LipG9”) also showed high enantioselectivity in kinetic resolutions. In the transesterification of (R,S)-1-phenylethanol, Im-LipG9 gave an eep >99% for (R)-1-phenylethyl acetate, with E above 200 [67]. In the transesterification of aliphatic secondary alcohols with different sizes of carbon chains, Im-LipG9 gave conversions from 19 to 59%, and enantiomeric excesses of the substrates (ees) from 26 to 88% for alcohols, with E=39 for (R,S)-pentan-2-ol and E=63 for (R,S)-4-methyl-pentan-2-ol (Fig. 3A) [82]. In the kinetic resolution of various secondary benzylic alcohols, Im-LipG9 gave eep values >95%, and E values above 200 (Fig. 3B) [83]. The performance of Im-LipG9 with the secondary benzylic alcohols was similar to that of CALB (Novozym 435) and superior to that of Candida rugosa lipase in the same resolutions. These results show that Im-LipG9 has good potential for the production of chiral intermediaries [83].
Fig. 3. Kinetic resolution of aliphatic sec-alcohols (A) and secondary benzylic alcohols (B), catalyzed by immobilized LipG9. (R,S)-1: pentan-2-ol; (R)-1a: 2-pentyl acetate; (R,S)-2: 4-methyl-pentan-2-ol; (R)-2a: 4-methyl-2-pentyl acetate; (R,S)-3: 1-phenylpropan-1-ol; (R)-3a: 1-phenylpropyl acetate; (R,S)-4: 1-phenylpentan-1-ol; (R)-4a: 1-phenylpentyl acetate; (R,S)-5: 1-(4-nitrophenyl)ethan-1-ol; (R)-5a: 1-(4-nitrophenyl)ethyl acetate; (R,S)-6: 1-(4-methoxyphenyl)ethan-1-ol; (R)-6a: 1-(4-methoxyphenyl)ethyl acetate.
Lyophilized LipR1 was evaluated, in media containing toluene and ionic liquids, in the kinetic resolution of various secondary alcohols: (R,S)-1-indanol, (R,S)-α-methyl-4 pyridine methanol, (R,S)-α-trifluoromethyl benzyl alcohol, (R,S)-1-naphthyl-ethanol and (R,S)-3-benzyloxy-1,2-propanediol [84]. The best results were obtained with 1-naphthyl ethanol, with a conversion of 47% and an eep >99%, a value similar to that reported for the commercial lipases Lipozyme RMIM and Lipozyme TLIM [84].
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Permeability of block copolymers to vapors and liquids
Anne JonquièresRobert ClémentPierre Lochon, in Progress in Polymer Science, 2002
Systematic studies of sorption, diffusion and permeation using the commercial PU Vibrathane B600 (Uniroyal) were also reported by Aminabhavi et al. for series of organic solvents (i.e. aromatic solvents [129], aliphatic esters [130] and halogenated solvents [131]). Moreover, all of the experimental data were compiled and thoroughly discussed in the review by Aithal et al. [125]. Therefore, only the key results will be analyzed thereafter, stressing out the main observations about qualitative or quantitative structure/property relationships. For apolar aromatic solvents (i.e. benzene, toluene, p-xylene, mesitylene), the molar swelling Gm (expressed in mmoles of sorbed species/g of dry polymer membrane) decreased linearly with the solvent molecular weight [125,129]. However, such a QSPR could not be extended to aromatics bearing ether, nitro or halogenated groups [125]. The average diffusion coefficients of the former apolar aromatics also decreased with the solvent molecular weight, thus leading to a global decrease in permeability. The esters chosen by the same team using the same PU material included acetate esters obtained from simple linear alcohols (i.e. MeOH, EtOH, n-PrOH, n-BuOH) and the branched iso-pentanol, and more complex esters (i.e. methyl acetoacetate, ethyl acetoacetate and methyl salicylate) for which no clear effect of molecular structure on permeation properties was observed [130]. However, for the former five esters, the molar swelling and diffusion coefficients decreased systematically from methyl acetate to iso-pentyl acetate, corresponding to a significant decrease in permeability (almost −70 and −80% for n-butyl acetate and iso-pentyl acetate, respectively, as compared to methyl acetate at 25°C). Extending their former analysis to a series of halogenated solvents (1,2-dichloroethane, 1,2-dibromoethane, bromoform, trichloroethylene, carbon tetrachloride, 1,3-dibromopropane, tetrachloroethylene, 1,1,2,2-tetrachloroethane and 1,4-dichlorobutane), Aminabhavi and coworkers found high to extremely high sorption values, reflecting the very strong sensitivity of the polyetherurethane Vibrathane B600 to halogenated solvents [131]. As way of examples, sorption coefficients for 1,1,2,2-tetrachloroethane and bromoform reached extremely high values of 520 and 560%, respectively, at 25°C. A systematic analysis of sorption based on the Flory–Rehner theory led to unrealistic values for the interaction parameter χ (i.e. a negative value of −2.15 was even obtained for trichloroethylene) whereas the value for the molar mass between cross-links Mc strongly depended upon the nature of the halogenated solvent. Typically, Mc values varied in the range 300–5050, the extreme values being obtained for tetrachloroethylene and 1,1,2,2-tetrachloroethane. A detailed analysis of the sorption transient regime also showed a systematic deviation from the Fickian behavior. Such a deviation was ascribed to the contribution of the hard segments to the sorption phenomenon, inducing special relaxation effects and affecting the polymer ability to sorb organic species. Most likely owing to the particular role of the hard segments in these highly swollen systems, no correlation was found between the size and permeation features (i.e. sorption, diffusion coefficients, and permeability) of the different halogenated solvents. In the same order of idea, Schneider et al. investigated the swelling of the commercial PU Estane 2714 (Goodrich) (PTMO1000/MDI/1,4-BD with a soft block content WSB=0.52) in non-hydrogen bonding solvents of increasing polarity [132]. Their main purpose was to use solvents capable of interacting with the soft segments and also with the PU hard blocks, depending on the solvent power of the penetrant (i.e. n-heptane, 1-chloroheptane, 1,7-dichloroheptane, 1,6-dichlorohexane, 1,5-dichloroheptane and o-dichlorobenzene). The sorption was strongly dependent on the solvent polarity. The n-heptane led to the lowest sorption coefficient (G=6.5%) at 20°C. Substituting heptane terminal hydrogen atoms for chlorine atoms gave a very significant increase in sorption (i.e. G=41% for 1-chloroheptane, and G=78% for 1,7-dichloroheptane at the same temperature). Moreover, the PU swelling in 1,6-dichlorohexane was 2.7 times higher than that observed in 1,7-dichloroheptane, to be compared to the swelling induced by the C6 aromatic species o-dichlorobenzene which exceeded 200%. Similarly as what would be described later for other related systems by Aminabhavi and coworkers [131], the values of molar mass between cross-links Mc calculated from the Flory–Rehner theory were strongly dependent on the nature of the halogenated solvent. Worthy of mention, they were found to increase very sharply with the solvent power of the interacting species (i.e. Mc=250, 1120 and 3860, for n-heptane, 1,7-dichloroheptane and 1,6-dichlorohexane, respectively). To take into account the imperfectly segregated microstructure of the PU material, the model was modified to allow 30% mixing of hard blocks with the soft segments. The modified model enabled to calculate fairly realistic Mc values which were much less dependent on the nature of the interacting solvent for all the solvents inducing a moderate swelling (i.e. Mc in the range 840–1350, to be compared with the molecular weight of the PPO precursor MPPO=1000). However, the solvents (e.g. 1,6-dichlorohexane and o-dichlorobenzene) that were responsible for the highest sorption values (G>200%) still led to unrealistic Mc values (Mc>3000, corresponding to almost three times the molecular weight of the PTMO precursor). Such an obvious discrepancy was ascribed to the interaction of these highly solvating species with the PU hard segments. An analysis of the sorption transient regime also confirmed the very particular behavior of these extremely swollen systems with various anomalies that might be related to the solvent induced relaxation of the PU hard segments.
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FAQs
Pentyl Acetate - an overview? ›
Applications Pentyl Acetate is a good solvent for numerous synthetic and natural resins, e. g. acrylics and cellulose derivatives. Thus it can be used in the coatings industry for cellulose nitrate lacquers or acrylic paints.
What does pentyl acetate smell like? ›Colorless liquid with a persistent banana-like odor.
What does pentyl acetate taste like? ›Pentyl acetate is a banana, ethereal, and fruity tasting compound.
What is another name for pentyl acetate? ›Pentyl acetate, also known as amyl acetic ester or amyl acetic acid, belongs to the class of organic compounds known as carboxylic acid esters.
What are the side effects of amyl acetate? ›* Exposure to high concentrations of n-Amyl Acetate can cause headache, drowsiness, weakness, dizziness and even unconsciousness. * Prolonged or repeated skin contact can cause irritation, dryness and cracking. * n-Amyl Acetate may damage the liver. * n-Amyl Acetate is a FLAMMABLE LIQUID and a FIRE HAZARD.
What ester smells like banana? ›Isoamyl acetate is naturally produced by ripening fruit. It creates a strong, fruity banana or pear odor that is widely used to flavor foods, attract bees, and improve the smell of everything from perfumes to shoe polish.
What are the properties of pentyl acetate? ›Amyl acetate (pentyl acetate) is an organic compound and an ester with the chemical formula CH3COO[CH2]4CH3 and the molecular weight 130.19 g/mol. It is colorless and has a scent similar to bananas and apples. The compound is the condensation product of acetic acid and 1-pentanol.
What is pentyl used for? ›WHAT IS PENTYL PROPIONATE? n-Pentyl Propionate is a solvent used in various applications, such as floor cleaners. It is a Non-HAP (Hazardous Air Pollutant) Solvent and has good solvency in coatings applications, particularly in automotive coatings and Inks. It has a slow evaporation rate and a high boiling point.
What does Pentanol smell like? ›The ester formed from 1-pentanol and acetic acid is amyl acetate (also called pentyl acetate), which smells like banana.
What is another name for pentyl? ›amyl alcohol, also called Pentyl Alcohol, any of eight organic compounds having the same molecular formula, C5H11OH, but different structures.
Is pentyl acetate flammable? ›
Hazard class: Flammable liquids (Category 3). Flammable liquid and vapor (H226). Keep away from heat, sparks, open flames, and hot surfaces.
What is the new name for acetate? ›Although its systematic name is ethanoate (/ɪˈθænoʊ. eɪt/), the common acetate remains the preferred IUPAC name.
What is the old name for acetate? ›Acetate, or the IUPAC name of ethanoate, having a negative charge, will commonly form salts with cations and can be called acetate salts or ethanoates.
What does acetate smell like? ›Ethyl acetate is one of the simplest carboxylate esters. (Former Molecule of the Week methyl formate is the simplest.) The colorless liquid has a sweet, fruity odor that most people find pleasant.
What does pentyl alcohol smell like? ›The ester formed from acetic acid and 1-pentanol, amyl acetate (pentyl acetate), smells like banana.
What is the odor of acetate? ›Isoamyl Acetate is a clear, colorless liquid with a banana-like odor. It is used as a solvent, in perfumes, and in artificial fruit flavorings.