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The inductive effect acts like that for the carboxylate anion but in the opposite direction (i.e. it produces small positive charges on the ortho and para positions but not on the meta position and it destabilises the Wheland intermediate.) Hence these groups are deactivating and meta directing:
In organic chemistry, a directing group (DG) is a substituent on a molecule or ion that facilitates reactions by interacting with a reagent.The term is usually applied to C–H activation of hydrocarbons, where it is defined as a "coordinating moiety (an 'internal ligand'), which directs a metal catalyst into the proximity of a certain C–H bond."
Groups with unshared pairs of electrons, such as the amino group of aniline, are strongly activating (some time deactivating also in case of halides) and ortho/para-directing by resonance. Such activating groups donate those unshared electrons to the pi system, creating a negative charge on the ortho and para positions.
Musical expression is the art of playing or singing with a personal response to the music. [1] At a practical level, this means making appropriate use of dynamics, phrasing, timbre and articulation to bring the music to life. [2] Composers may specify these aspects of expression to a greater or lesser extent in the notation of their musical score.
An acetate is a salt formed by the combination of acetic acid with a base (e.g. alkaline, earthy, metallic, nonmetallic or radical base). "Acetate" also describes the conjugate base or ion (specifically, the negatively charged ion called an anion) typically found in aqueous solution and written with the chemical formula C 2 H 3 O − 2.
The ortho effect also occurs when a meta-directing group is positioned in a meta arrangement relative to an ortho–para-directing group, a new substituent introduced into the molecule tends to preferentially occupy the ortho position relative to the meta-directing group rather than the para position.
Directed metallation is not limited to lithium intermediates or even to an ortho preference. In one study [13] it is found that the reaction product of N,N-dimethylaniline with a complex of TMEDA, sodium salt of TMP and di-tert-butylzinc is a meta zincated complex as a stable crystalline compound.
In bowed string music, an indication to discontinue extended techniques such as sul ponticello, sul tasto or col legno, and return to normal playing. The same as "naturale". organ trio In jazz or rock, a group of three musicians which includes a Hammond organ player and two other instruments, often an electric guitar player and a drummer.