Latin rotatable

A substance that rotates plane-polarized light in the clockwise direction is said to be dextrorotatory, and one that rotates plane-polarized light in a counterclockwise direction is said to be levorotatory (Latin dexter, right and laevus, left). 

As the story goes, a wine production batch gone bad provided fairly large amounts of a new organic compound, the study of which was deemed of practical importance for the French wine industry. The new material had the same molecular formula as tartaric acid, which to some experts of the time meant it had to be the same as tartaric acid. Solutions of salts of the new material, however, did not rotate the plane of polarization of plane-polarized light, as solutions of salts of tartaric acid were known to do. The new material was named para tartaric acid, or racemic acid (the name racemic acid being derived from the Latin racemus bunch of grapes). 

In the above cited example [/ (a)] the rotation of the plane of polarization is to the right (clockwise), the lactic acid is dextrorotatory (Latin dexter = right) designated by d if the rotation is to the left (counterclockwise), the lactic acid [/ (h) is levorotatoiy (Latin laevus = left) designated by 7 . In the same vein, the example [ii (h) represents 1-2 methyl-1-butanol a product derived from fusel oil. 

We might want to increase a> to generate larger limiting currents in order to increase the precision. Improving the precision by this means is valid at low to medium rotation rates (that is, up to about 100 cycles per second) because the motion of solution over the face of the electrode is smooth and reproducible. We say that the flow is laminar. (The word laminar comes from the Latin root lami, meaning thin layer or plate .) We can then see how laminar flow implies that solution readily flows over itself in a smooth and reproducible way. 

One special type of diastereomer is called a geometric isomer. Geometric isomers exist due to hindered rotation about a bond. Rotation may be hindered due to a ring structure or a double or triple bond. Since mtation is hindered, similar substituents on opposing carbons may exist on the same-side or opposite sides of the hindered bond. Molecules with same side substituents are called cis-isomers those with opposite-side substituents are called trans-isomers (Latin cis on the same side tram on the other side). 

View the molecule so that the bond from the chirality center to group number 4 is pointed directly away from you. Now determine whether the direction of the cycle proceeding from group I to 2 to 3 and back to I is clockwise or counterclockwise. If this rotation is clockwise, the configuration is R (from the Latin word for right, rectus). If the rotation is counterclockwise, the configuration is S (from the Latin word for left, sinister). 

Compounds that rotate the plane toward the left (counterclockwise) are called levorotatory, from the Latin word laevus, meaning toward the left. These terms are sometimes abbreviated by a lowercase d or Z. Using IUPAC notation, the direction of rotation is specified by the (+) or (—) sign of the rotation ... 

Let us at first consider an absohUely rigid dipole (dumb-bell) molecule [i.e. a molecule without electronic or oscillation states). Then the probability Ppjg that the Greek molecule is in the pure rotation state p and the Latin one in the pure rotation state k is given by... 

Statistical manipulations on the USDA database (cluster analysis, principal component analysis with varimax rotation e.g., Everitt, 1980) revealed subsets of represent ve species, as idealized in Fig 2b, but with dif ent variables (orthogonal principal components) than traditional fractions as measured by USDA. A set cf species from each orthogonal subset appears in Table 1. The Latin names, and where available, the common names of the biomass species are given. The extractives ranges are ash content, 4 to 17% protein content, 5 to 14% polyphenol, 3 to 11% and oil content, 1 to 4%. However no species contains extremes of all 4 variables. Nor can species be found, retaining native compositions, at extremes of just one extractive composition, while the other fractions are present at constant levels. Thus we use orthogonal but non-intuitive compositions in this work, then rank pyrolysis effects in terms of traditional extractives content to get an understanding of their impact on biomass pyrolysis. 

One enantiomer rotated polarised li t to the right or clockwise, and it was referred to as (+)-glyceraldehyde. The other rotated polarised light to the left or counterclockwise and was referred to as (-)-glyceraldehyde. The two enantiomers of glyceraldehyde were, according to their Fischer projections called D and L, from the Latin word dexter (right) and laevus (left). 

To understand the consequences of this inability to rotate, compare the two possible structures of 2-butene shown in Figure 22-12. The arrangement in which the two methyl groups are on the same side of the molecule is indicated by the prefix cis-. The arrangement in which the two methyl groups are on opposite sides of the molecule is indicated by the prefix trans-. These terms derive from Latin cis means on the same side, and trans means across from. Because the double-bonded carbons cannot rotate, the cis- form caimot easily change into the trans- form. 

Enantiomers can be represented by the letters D and L according to their geometry. If the rotation of the plane (see below) is to the right the substance is dextrorotatory (Latin dexter, means right) if the rotation is to the left, the substance is laevorotatory (Latin laevus, means left). For example, the enantiomer of lactic acid formed in sour milk is D-lactic acid, the other, which is found in muscles and produced in high amounts after performing heavy exercise, causing cramps, is L-lactic acid. 

If an optically active compound rotates the plane of polarization clockwise, it is called dextrorotatory, indicated by (+). If an optically active compound rotates the plane of polarization counterclockwise, it is called levorotatory, indicated by (—). Dextro and levo are Latin prefixes for to the right and to the left, respectively. Sometimes lowercase d and I are used instead of (+) and (—). 

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