OH functional group

It IS convenient m equations such as this to represent generic alcohols and alkyl halides as ROH and RX respectively where R stands for an alkyl group In addition to con venience this notation lets us focus more clearly on the functional group transformation that occurs the OH functional group of an alcohol is replaced as a substituent on car bon by a halogen usually chlorine (X = Cl) or bromine (X = Br)... 

Antioxidants markedly retard the rate of autoxidation throughout the useful life of the polymer. Chain-terminating antioxidants have a reactive —NH or —OH functional group and include compounds such as secondary aryl amines or hindered phenols. They function by transfer of hydrogen to free radicals, principally to peroxy radicals. Butylated hydroxytoluene is a widely used example. 

Strategy An alcohol is a compound that contains the -OH functional group. To make an alcohol chiral, we need to have four different groups bonded to a single carbon atom, sav -H, -OH, -CHj, and -CH9CH3. 

The structure of cellulose reveals the two key components for hydrogen bonding OH functional groups (the X-H unit) and additional oxygen atoms (the Y atom). Hence, water molecules may form intermolecular hydrogen bonds with cellulose in one of two ways ... 

Sorption depends on Sorption Sites. The sorption of alkaline and earth-alkaline cations on expandable three layer clays - smectites (montmorillonites) - can usually be interpreted as stoichiometric exchange of interlayer ions. Heavy metals however are sorbed by surface complex formation to the OH-functional groups of the outer surface (the so-called broken bonds). The non-swellable three-layer silicates, micas such as illite, can usually not exchange their interlayer ions but the outside of these minerals and the weathered crystal edges ("frayed edges") participate in ion exchange reactions. 

Alcohols are organic compounds that contain the OH functional group. In this experiment, you will determine the strength of intermolecular forces of alcohols by determining how fast various alcohols evaporate. The evaporation of a liquid is an endothermic process, absorbing energy from the surroundings. This means that the temperature will decrease as evaporation occurs. 

Both 2-propanol and ethanol contain the same functional group, an —OH (hydroxyl) group, as shown in Figure 1.12. Because ethanol and 2-propanol have the same OH functional group, their behaviour is similar. 

An alcohol is an organic compound that contains the — OH functional group. Depending on the position of the hydroxyl group, an alcohol can be primary, secondary, or tertiary Figure 1.13 gives some examples of alcohols. 

FIG. 6.1 The nitration reaction. Organic compounds containing the -OH functional group are termed "alcohols." These compounds react with nitric acid to produce a class of compounds known as "nitrate esters." Nitroglycerine and nitrocellulose are among the numerous explosive materials produced using this reaction. 

Another important concept from organic chemistry that has an impact on polymer structure is that of isomerism. Recall that structural isomers are molecules that have the same chemical formula, but different molecular architectures. For example, there are two different types of propyl alcohols, both with the same formula, depending on where the —OH functional group is placed on the carbon backbone (see Figure 1.53). Another type of isomerism results in stereoisomers, in which the functional groups are... 

In a typical sol-gel synthesis, the metal or the compounds of main group elements undergo hydrolysis and condensation reactions giving gel materials with extended three-dimensional structures. As shown in Equation 5.32 for silicon, addition of an acid or base catalyst to a solution of an alkoxysilane reagent such as tetrame-thoxysilane (TMOS), water and methanol leads to the hydrolysis of the Si-OMe bonds to form Si-OH functional groups. 

Also shown in Table 1 are differences in pAiR. These are multiplied by 1.364 to give free energies for easier comparison with HIAs. They correspond to intrinsic differences between tertiary, secondary, and primary carbocation centers (CH+, CH2+, and CH3+) and the corresponding values for the carbon bound to an OH functional group (C-OH, CH-OH, and CH2-OH). In principle, carbocation stabilities may be expressed relative to any functional group, but clearly the convenience and prevalence of measurements of pAiR give a special place to the OH group. 

Serine An amino acid with a hydroxyl (-OH) functional group. 

It should be remarked that the plasma surface functionalization by oxygen plasma with and without reduction to monotype OH functional groups yields a lower peel strength compared to the use of the monotype functional groups bearing adhesion-promoting plasmapolymer layers (cf. Fig. 11). 

Esters The product of the reaction between an alcohol or phenol (with the -OH functional group) and a carboxylic acid (with the -COOH functional group). 

Functional group That group of atoms or atom within a molecule that is the most chemically reactive and gives the molecule its chemical characteristics. Compounds are classified and named accordingly, e.g. -OH functional groups in alcohols, named -ol as in linalool. 

Hydroxyl group The -OH functional group found in molecules of alcohols and water. NB Do not confuse it with the hydroxide ion, which has a negative charge OH-. 

In our work NMR has been used mainly to determine structural parameters of the aromatic skeleton. Retcofsky, et al. have used C-13 NMR to determine the C-OH functional groups in phenolic fractions (24). 

The —OH functional group is named as a hydroxy substituent when it appears on a structure with a higher-priority functional group or when the structure is too difficult to name as a simple alcohol. 

---