Isomers are different organic compounds with the same molecular formula but differ in their properties. Isomers are divided into structural and stereoisomers. Structural isomers are isomers that have the same molecular formula but differ in structural formula, that is, in the order in which the different atoms are linked in the molecules. They have different IUPAC names, the same or different functional groups, different physical properties and different chemical properties. Structural isomers are further divided into chain isomerism, position isomerism, functional isomerism, metamerism and tautomerism. 
Chain isomerism is isomers that have the same molecular formula but differ in which the carbon atoms are bonded to each other. For example, …show more content…
This isomerism is caused by migration of H-atom from one group to another. For example, ethyl acetoacetate is in equilibrium mixture of the following two forms:
Conformational isomers differ in the relative position of some of the atoms in the molecule in 3Dimensional-space due to the rotation about sigma bonds.
Configurational isomers are those isomers which arise due to some kind of rigidity in the molecule, and these are inter converted only by bond breaking or making. Configurational isomerism has been further classified in two types, geometric isomers and optical isomers.
Geometric isomers (or cis-trans isomers) are molecules with a double bond that form cis and trans isomers. Square planar molecules can also display geometric isomerism. Cis and trans refer to the orientation of functional groups within a molecule and mostly occur in alkenes. In alkenes, C=C bonds have restricted rotation so the groups on either end of the bond are ‘frozen’ in one position; it isn’t easy to flip between the two. This produces two possibilities. The two structures cannot interchange easily so the atoms in the two molecules occupy different positions in
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Formulas for compounds can be written as empirical or molecular formulas where empirical formulas are the simplest formula of a compound and a molecular formula is the actual, or true, formula of a compound. These are the same form in ionic compounds, but may differ in covalent. For example, in Benzene, a covalent
Hydrogens, alkyls, or aryls bonded to carboxyl groups—made up of a carbonyl group and a hydroxyl group—are known as carboxylic acids. Derivatives of carboxylic acids include acid chlorides, esters, anhydrides, amides, and generally nitriles. These derivatives are formed by the replacement of the hydroxyl group with a different electronegative heteroatom substituent, which can be a single atom, such as a chlorine atom, or a group of atoms, such as in the formation of
isotopes have the same chemical properties as their elements but different chemical properties. This is because isotopes of an element have the same number of electrons as an atom of that particular element. The electron arrangement is what affects chemical properties, and isotopes have the same electron arrangement , so they have the same chemical properties. However the have a different number of neutrons which changes the mass number. The mass number is what determines the physical properties , such as boiling point and
- The C-H bonds in this structure are shown at 1444 and 1368cm-1. These two bands indicate the two different types of C-H bends that occur on the molecule. One is that of the alkene and the other is that of the several alkanes on the molecule.
Ans. Chair conformer of cyclohexane has negligible dipole moment due to symmetry and equal charge distribution. On the other hand Boat conformation of cyclohexane has dipole moment due to the shape of the conformer making it polar due to charge distribution and steric effects.
Two different reactions had been performed and formed the cis and trans products. Isomers that are cis are defined as molecules that have higher priority groups both on same sides of a molecule. Molecules that have higher priority groups both on opposing sides are trans isomers. The compound 1,2-cyclohexanediol is formed using methydioxirane. This is a compound prepared using acetone as well as oxone.
The basic building blocks of proteins are amino acids, the biuret reaction tests for protein. A solution of sodium hydroxide is added to a sample then a few drops of copper sulphate solution, if positive – the solution will turn mauve. There are 20 different amino acids and they can be joined in any order. Therefore there can be many different functions. A protein consists of one or more polypeptide chains (a polypeptide chain being multiple amino acids joined together via condensation, producing a peptide bond). Different proteins have different shapes as the shapes are determined by the sequence of amino acids.
There may also be sections where the secondary structure is neither helix nor sheet. Then the structure is called a random structure, indicating that it folds in random directions. The amino acids in an alpha helix are arranged in a right-handed helical structure resembling a spring. The alpha helix is the most common form of regular secondary structure in proteins. The beta-sheet is the second form of regular secondary structure in proteins consisting of beta strands connected laterally by three or more hydrogen bonds, forming a generally twisted, pleated sheet. The beta-sheet is sometimes called the beta pleated sheet since sequential neighboring atoms are alternately above and below the plane of the sheet giving a pleated appearance. Turns are the third of the three "classical" secondary structures that serve to reverse the direction of the polypeptide chain. They are located primarily on the protein surface and accordingly contain polar and charged residues. However, they are not very common in discussions of protein structure today.
For the acetic acid spectrum, the broad peak ranging from 3300 cm-1 indicate the presence of a carboxylic O-H bond. The little bump at just under 3000 cm-1 indicates the presence of sp3 carbon hydrogen bonds. The peak at 1704.3 cm-1 shows the presence of a carbon oxygen double bond. For the isopentanol spectrum, the peaks located just under 3000 cm-1 indicate carbon hydrogen bonds. The broad peak ranging from 3300 cm-1 to 3200 cm-1 indicate the presence of an oxygen hydrogen alcohol bond present. For the product, the peaks located just under 3000 cm-1 indicate carbon hydrogen bonds. The peak located at 1739.58 cm-1 indicate the presence of a carbon oxygen double bond, more specifically an ester carbon oxygen double bond, because it falls in the typical range of 1735 cm-1 to 1750 cm-1. In this spectra however, there is no peak located in the region for an alcohol O-H bond or a carboxylic acid O-H bond. Based on these spectra, the data indicates that the that the esterification has occurred
One of fundamental concept in addressing the impact of excipients on proteins is their preferential interactions in the system[12-16]. The interactions of additives can be attractive or repellent to proteins, resulting the concentration of cosolvents in the local domain near proteins differs from that in the bulk solution. Such a discrete population of cosolvents influences the thermodynamic properties of the protein inducing a significant change in conformational or colloidal stability. A key parameter to quantify the preferential behavior of excipients is the