Crystallization of from benzene solution below 30 °C (when solubility is maximum) yields a triclinic solid solvate ·4. Above 30 °C one obtains solvate-free fcc .
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H-bond donor ability is classified on a scale (α). Protic solvents can solvate solutes that can accept hydrogen bonds. Similarly, solvents that can accept a hydrogen bond can solvate H-bond-donating solutes. The hydrogen bond acceptor ability of a solvent is classified on a scale (β).
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In other solvents, the concentration of the respective solvonium/solvate ions should be used, such as pCl in POCl3.
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Typically NaH is used as a suspension in THF, a solvent that resists attack by strong bases but can solvate many reactive sodium compounds.
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Thus, it takes less energy to solvate the molecules in amorphous phase. The effect of amorphous phase on solubility is widely used to make drugs more soluble.
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Fluoroboric acid or tetrafluoroboric acid (archaically, fluoboric acid) is an inorganic compound with the chemical formula [H+][BF4−], where H+ represents the solvated proton. The solvent can be any suitably Lewis basic entity. For instance, in water, it can be represented by (oxonium tetrafluoroborate), although more realistically, several water molecules solvate the proton: [H(H2O)n+][BF4−]. The ethyl ether solvate is also commercially available: [H(Et2O)n+][BF4−], where n is most likely 2.
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Disodium tetracarbonylferrate is the organoiron compound with the formula Na2[Fe(CO)4]. It is always used as a solvate, e.g., with tetrahydrofuran or dimethoxyethane,. which bind to the sodium cation.
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Anhydrous copper(II) nitrate has been crystallized in two solvate- free polymorphs. α- and β-Cu(NO3)2 are fully 3D coordination polymer networks. The alpha form has only one Cu environment, with [4+1] coordination, but the beta form has two different copper centers, one with [4+1] and one that is square planar. The nitromethane solvate also features "[4+ 1] coordination", with four short Cu-O bonds of approximately 200 pm and one longer bond at 240 pm.
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Small band gap fullerenes are highly reactive and bind to other fullerenes or to soot particles. Solubility of in some solvents shows unusual behaviour due to existence of solvate phases (analogues of crystallohydrates). For example, solubility of in benzene solution shows maximum at about 313 K. Crystallization from benzene solution at temperatures below maximum results in formation of triclinic solid solvate with four benzene molecules ·4H6 which is rather unstable in air. Out of solution, this structure decomposes into usual face-centered cubic (fcc) in few minutes' time.
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Solvents with a dielectric constant (more accurately, relative static permittivity) greater than 15 (i.e. polar or polarizable) can be further divided into protic and aprotic. Protic solvents solvate anions (negatively charged solutes) strongly via hydrogen bonding. Water is a protic solvent.
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FeBr2 is synthesized using a methanol solution of concentrated hydrobromic acid and iron powder. It adds the methanol solvate [Fe(MeOH)6]Br2 together with hydrogen gas. Heating the methanol complex in a vacuum gives pure FeBr2. FeBr2 reacts with two equivalents of tetraethylammonium bromide to give [(C2H5)4N]2FeBr4.
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Further, vapor sorption experiments can be used to study hydrate F.G. Vogt, J. Brum, L.M. Katrincic, A. Flach, J.M. Socha, R.M. Goodman, and R.C. Haltiwanger, Crystal Growth & Design. 6 (2006) 2333-2354. and solvate D.J. Burnett, F. Thielmann, and T. Sokoloski, Journal of Thermal Analysis and Calorimetry. 89 (2007). 693-698. formation.
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At temperatures above solubility maximum the solvate is not stable even when immersed in saturated solution and melts with formation of fcc . Crystallization at temperatures above the solubility maximum results in formation of pure fcc . Millimeter-sized crystals of and can be grown from solution both for solvates and for pure fullerenes.
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Coordinating solvents such as ether or THF, are required to solvate (complex) the magnesium(II) center. The solvent must be aprotic since alcohols and water contain an acidic proton and thus react with phenylmagnesium bromide to give benzene. Carbonyl-containing solvents, such as acetone and ethyl acetate, are also incompatible with the reagent.
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This motif is mediated with halogen bonds and halogen-π interactions. Solvent interactions are also noted in the formation of the hexagonal structures, especially in pyridine and chloroform. Initially, crystals that form these solutions form channeled structures. Over time, new needle-like solvate-free structures form are packed tighter together, and these needles are actually the thermodynamically favored crystal.
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Hexahydroxybenzene triscarbonate is a chemical compound, an oxide of carbon with formula . Its molecular structure consists of a benzene core with the six hydrogen atoms replaced by three carbonate groups. It can be seen as a sixfold ester of hexahydroxybenzene (benzenehexol) and carbonic acid. The compound was obtained by C. Nallaiah in 1984, as a tetrahydrofuran solvate.
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It was obtained by reacting tetrahydroxy-1,4-benzoquinone with oxalyl chloride in tetrahydrofuran. It is a yellow solid that can be crystallized as a tetrahydrofuran solvate, but could not be prepared in pure form. H. S. Verter, H. Porter, and R. Dominic (Verter, Porter and Dominic, 1968), A new carbon oxide: synthesis of tetrahydroxybenzoquinone bisoxalate. Chemical Communications (London), p. 973b–974.
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Tetrahydroxy-1,4-benzoquinone biscarbonate is a chemical compound, an oxide of carbon with formula . Its molecule consists of a 1,4-benzoquinone core with the four hydrogen atoms replaced by two carbonate groups. It can be seen as a fourfold ester of tetrahydroxy-1,4-benzoquinone and carbonic acid. The compound was obtained by C. Nallaiah in 1984, as a tetrahydrofuran solvate.
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Mechanistically this is because there are insufficient water molecules to effectively solvate the ions. This can result in ion-dipole interactions between the salts and hydrogen bonding species which are more favorable than normal hydrogen bonds. Common chaotropic agents used include n-butanol, ethanol, guanidinium chloride, lithium perchlorate, lithium acetate, magnesium chloride, phenol, 2-propanol, sodium dodecyl sulfate, thiourea, and urea.
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The diameter of the selectivity filter is ideal for the potassium cation, but too big for the smaller sodium cation. Hence the potassium cations are well "solvated" by the protein carbonyl groups, but these same carbonyl groups are too far apart to adequately solvate the sodium cation. Hence, the passage of potassium cations through this selectivity filter is strongly favored over sodium cations.
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Initiation of styrene polymerization with sodium naphthalene proceeds by electron transfer from the naphthalene radical anion to the monomer. The resulting radical dimerizes to give a dilithio compound, which then functions as the initiator. Polar solvents are necessary for this type of initiation both for stability of the anion-radical and to solvate the cation species formed. The anion-radical can then transfer an electron to the monomer.
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Structural isomerism occurs when the bonds are themselves different. Four types of structural isomerism are recognized: ionisation isomerism, solvate or hydrate isomerism, linkage isomerism and coordination isomerism. # Ionisation isomerism – the isomers give different ions in solution although they have the same composition. This type of isomerism occurs when the counter ion of the complex is also a potential ligand. For example, pentaamminebromocobalt(III) sulphate [Co(NH3)5Br]SO4 is red violet and in solution gives a precipitate with barium chloride, confirming the presence of sulphate ion, while pentaamminesulphatecobalt(III) bromide [Co(NH3)5SO4]Br is red and tests negative for sulphate ion in solution, but instead gives a precipitate of AgBr with silver nitrate.Huheey, James E., Inorganic Chemistry (3rd ed., Harper & Row 1983), p.524–5 # Solvate or hydrate isomerism – the isomers have the same composition but differ with respect to the number of molecules of solvent that serve as ligand vs simply occupying sites in the crystal. Examples: [Cr(H2O)6]Cl3 is violet colored, [CrCl(H2O)5]Cl2·H2O is blue-green, and [CrCl2(H2O)4]Cl·2H2O is dark green.
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The conductivity of a solution depends on the solvation of its ions. Nonpolar solvents cannot solvate ions, and ions will be found as ion pairs. Hydrogen bonding among solvent and solute molecules depends on the ability of each to accept H-bonds, donate H-bonds, or both. Solvents that can donate H-bonds are referred to as protic, while solvents that do not contain a polarized bond to a hydrogen atom and cannot donate a hydrogen bond are called aprotic.
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One Cp ligand can be removed from Cp2TiCl2 to give tetrahedral CpTiCl3. This conversion can be effected with TiCl4 or by reaction with SOCl2. Titanocene itself, TiCp2, is so highly reactive that it rearranges into a TiIII hydride dimer and has been the subject of much investigation. This dimer can be trapped by conducting the reduction of titanocene dichloride in the presence of ligands; in the presence of benzene, a fulvalene complex, can be prepared and the resulting solvate structurally characterised by X-ray crystallography.
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Penne alla vodka Along with the penne pasta, this dish generally contains cream sauce mixed with marinara sauce or tomato paste, which are a combination unusual in Italian cooking because the acidity of the tomatoes tends to make the oil in the cream separate. The ethanol (vodka) serves as an emulsifier, allowing the water and lipids to remain mixed together.Stella Culinary: What Is An Emulsion? A Cook's Guide Ethanol is also thought to solvate certain flavors from the tomato that would otherwise be inaccessible in water.
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Aprotic solvents such as acetone or dichloromethane tend to have large dipole moments (separation of partial positive and partial negative charges within the same molecule) and solvate positively charged species via their negative dipole.Lowery and Richardson, p. 183. In chemical reactions the use of polar protic solvents favors the SN1 reaction mechanism, while polar aprotic solvents favor the SN2 reaction mechanism. These polar solvents are capable of forming hydrogen bonds with water to dissolve in water whereas non-polar solvents are not capable of strong hydrogen bonds.
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Ferrous chloride is prepared by addition of iron powder to a solution of hydrochloric acid in methanol. This reaction gives the methanol solvate of the dichloride, which upon heating in a vacuum at about 160 °C converts to anhydrous FeCl2. The net reaction is shown: : Fe + 2 HCl → FeCl2 \+ H2 FeBr2 and FeI2 can be prepared analogously. An alternative synthesis of anhydrous ferrous chloride is the reduction of FeCl3 with chlorobenzene: :2 FeCl3 \+ C6H5Cl → 2 FeCl2 \+ C6H4Cl2 \+ HCl In one of two classic syntheses of ferrocene, Wilkinson generated FeCl2 in situ by comproportionation of FeCl3 with iron powder in THF.
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Photographer: Armin Kübelbeck, CC-BY-SA, Wikimedia Commons Solvent polarity is the most important factor in determining how well it solvates a particular solute. Polar solvents have molecular dipoles, meaning that part of the solvent molecule has more electron density than another part of the molecule. The part with more electron density will experience a partial negative charge while the part with less electron density will experience a partial positive charge. Polar solvent molecules can solvate polar solutes and ions because they can orient the appropriate partially charged portion of the molecule towards the solute through electrostatic attraction.
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The limiting acid in a given solvent is the solvonium ion, such as H3O+ (hydronium) ion in water. An acid which has more of a tendency to donate a hydrogen ion than the limiting acid will be a strong acid in the solvent considered, and will exist mostly or entirely in its dissociated form. Likewise, the limiting base in a given solvent is the solvate ion, such as OH− (hydroxide) ion, in water. A base which has more affinity for protons than the limiting base cannot exist in solution, as it will react with the solvent.
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This compound is prepared by a modified Williamson ether synthesis in the presence of a templating cation: It can be also prepared by the oligomerization of ethylene oxide: :(CH2OCH2CH2Cl)2 \+ (CH2OCH2CH2OH)2 \+ 2 KOH → (CH2CH2O)6 \+ 2 KCl + 2 H2O It can be purified by distillation, where its tendency to supercool becomes evident. 18-Crown-6 can also be purified by recrystallisation from hot acetonitrile. It initially forms an insoluble solvate. Rigorously dry material can be made by dissolving the compound in THF followed by the addition of NaK to give [K(18-crown-6)]Na, an alkalide salt.
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Most effort involved aprotic materials, which consist of a lithium metal anode, a liquid organic electrolyte and a porous carbon cathode. The electrolyte can be made of any organic liquid able to solvate lithium salts such as , , , and ), but typically consisted of carbonates, ethers and esters. The carbon cathode is usually made of a high- surface-area carbon material with a nanostructured metal oxide catalyst (commonly or ). A major advantage is the spontaneous formation of a barrier between anode and electrolyte (analogous to the barrier formed between electrolyte and carbon–lithium anodes in conventional Li-ion batteries) that protects the lithium metal from further reaction with the electrolyte.
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Cocrystal engineering has become of such great importance in the field of pharmaceuticals that a particular subdivision of multicomponent cocrystals has been given the term pharmaceutical cocrystals to refer to a solid cocrystal former component and a molecular or ionic API (active pharmaceutical ingredient). However, other classifications also exist when one or more of the components are not in solid form under ambient conditions. For example, if one component is a liquid under ambient conditions, the cocrystal might actually be deemed a cocrystal solvate as discussed previously. The physical states of the individual components under ambient conditions is the only source of division among these classifications.
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Keepers are substances (typically solvents, but sometimes adsorbent solids) added in relatively small quantities during an evaporative procedure in analytical chemistry, such as concentration of an analyte-solvent mixture by rotary evaporation. The purpose of a keeper is to reduce losses of a target analyte during the procedure. Keepers typically have reduced volatility and are added to a more volatile solvent. In the case of volatile target analytes, it is difficult to totally avoid loss of the analyte in an evaporative procedure, but the presence of a keeper solvent or solid is intended to preferentially solvate or adsorb the analyte, so that the volatility of the analyte is reduced as the evaporative procedure continues.
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In molecular mechanics, several ways exist to define the environment surrounding a molecule or molecules of interest. A system can be simulated in vacuum (termed a gas-phase simulation) with no surrounding environment, but this is usually undesirable because it introduces artifacts in the molecular geometry, especially in charged molecules. Surface charges that would ordinarily interact with solvent molecules instead interact with each other, producing molecular conformations that are unlikely to be present in any other environment. The best way to solvate a system is to place explicit water molecules in the simulation box with the molecules of interest and treat the water molecules as interacting particles like those in the molecule.
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Anhydrous chromium(III) chloride may be prepared by chlorination of chromium metal directly, or indirectly by carbothermic chlorination of chromium(III) oxide at 650–800 °CD. Nicholls, Complexes and First-Row Transition Elements, Macmillan Press, London, 1973. :Cr2O3 \+ 3 C + 3 Cl2 → 2 CrCl3 \+ 3 CO Dehydration with trimethylsilyl chloride in THF gives the solvate: :CrCl3 \+ 12 Me3SiCl → CrCl3(THF)3 \+ 6 (Me3Si)2O + 12 HCl It may also be prepared by treating the hexahydrate with thionyl chloride:Pray, A. P. "Anhydrous Metal Chlorides" Inorganic Syntheses, 1990, vol 28, 321–2. :CrCl3 \+ 6 SOCl2 → CrCl3 \+ 6 SO2 \+ 12 HCl The hydrated chlorides are prepared by treatment of chromate with hydrochloric acid and methanol.
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They found that basic amino alcohols are ideally suited for this purpose, probably because amino groups effectively solvate phospholipids and basicity helps to preserve fluorescence signal. Amino alcohols have also beneficial effect when used for clearing of other tissues, which are mostly highly vascularized, and their opacity is given by absorption of light by hemoglobin on top of light scattering. Amino alcohols reduce pigmentation of those tissues very effectively by eluting the hem from hemoglobin. The original protocol is two- step incubation of fixed tissue in two different aqueous based clearing solutions, altogether taking one to two weeks. First solution, referred as ScaleCUBIC-1, CUBIC-1 or just reagent-1, is composed of N,N,N’,N’-tetrakis(2-hydroxypropyl)ethylenediamine (commercially under name Quadrol), urea and Triton X-100 in water.
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Researchers have yet to fully characterize the solvation of hydronium ion in water, in part because many different meanings of solvation exist. A freezing-point depression study determined that the mean hydration ion in cold water is approximately : on average, each hydronium ion is solvated by 6 water molecules which are unable to solvate other solute molecules. Some hydration structures are quite large: the magic ion number structure (called magic because of its increased stability with respect to hydration structures involving a comparable number of water molecules – this is a similar usage of the word magic as in nuclear physics) might place the hydronium inside a dodecahedral cage. However, more recent ab initio method molecular dynamics simulations have shown that, on average, the hydrated proton resides on the surface of the cluster.
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