Inductive pull

This effect is even more pronounced in meta trifluoro aniline, as the fluorine results in a greater inductive pull... 

This greater inductive pull results in a greater positive charge at C, and hence a greater repulsion between the carbon and the nitrogen. 

This should not be confused with the lower pK value that results upon halogenation of phenol (see Table 2.1), for this again represents inductive pull. Nonetheless, resonance effects can extend themselves to other important examples as is noted by a comparison of the basicity of cyclohexylamine and aniline. The former has a pK typical of an organic amine (Table 2.1), but the latter is considerably more acidic. That is because at any given time the electron density of the amino function of aniline is much less than that of cyclohexylamine. The nonbonding electrons are smeared into the aromatic ring via resonance ... 

Another potent group of alkylators are the a-haloketones. The classic example is the alkylator TPCK (tosyl-L-phenylalanylchloromethyl ketone) which interacts specifically with one imidazole ring (histidine residue) in the enzyme a-chymotrypsin (see Section 7.2.3). These compounds are significantly more reactive in Sn2 displacements than alkyl halides. For example, nucleophilic attack by iodide will proceed 33,000 times as quickly on chlo-roacetone as on n-propyl chloride (acetone solvent, 50°C). Inductive pull of the carbonyl function would be expected to both increase the electrophilicity of the methylene function, and stabilize the approaching anionic nucleophile. a-Haloacids and amides will exhibit a similar effect, and both iodoacetic acid and iodoacetamide have found use as biochemical probes for the alkylation of purified enzymes. 

Remember, in nonaqueous solvents (e.g., tetrahydrofuran) fluoride is a good nucleophile. The inductive pull of the three chlorine atoms makes the trichlo-roethyl function the preferred leaving group. The highly reactive phosphoro-fluoridate intermediate decomposes on chromatographic workup. Cleavage has also been undertaken with sodium hydroxide. 

NEMA, in its publication MG-1 for induction Motors, has prescribed four rotor designs. A, B, C, and D, covering almost all sizes of LT motors, to possess a prescribed minimum 77, Tp and pull-up torques. These torques are generally as drawn in Figure 2..3 to meet all normal industrial, agricultural or domestic needs. (Refer to the said publication or lEC 60034-12 for values of these torques. lEC 60034-12 has also provided similar stipulations.)... 

Since the presumed cytosolic pathway interfaces directly with the network of secondary metabolism, the observed induction of DS-Co and CM-2 isozymes in response to wounding was expected. However, the even greater response of plastidic isozymes was unexpected. Perhaps the increased pull on carbohydrate metabolism in the cytosol affects the balance of substrates feeding into the aromatic pathway of the plastid. If so, a tendency to starvation for pathway endproducts may trigger derepression of the plastidic-pathway isozymes. 

The most common methods of growing crystals involve solidification from the melt (in the case of one-component systems) or crystallization from solution. Some of the methods for growing crystals from melt are described schematically in Fig. 3.6. In the Czochralski method, commonly known as the pulling technique, the material is melted by induction or resistance heating in a suitable nonreactive crucible. The melt temperature is adjusted to slightly above the melting point and a seed crystal is dipped into the melt. After thermal equilibration is attained, the seed is slowly lifted from the... 

Fluorine in organic compounds is associated with a set of electronic effects inductive and mesomeric, stabilizing and destabilizing, pulling or pushing electrons, which are convincingly... 

The Czochralski Technique. Pulling from the melt is known as the Czochralski technique. Purified material is held just above the melting point in a cmcible, usually of Pt or Ir, most often powered by radio-frequency induction heating coupled into the wall of the crucible. The temperature is controlled by a thermocouple or a radiation pyrometer. A rotating seed crystal is touched to the melt surface and is slowly withdrawn as the molten material solidifies onto the seed. Temperature control is used to widen the crystal to the desired diameter. A typical rotation rate is 30 rpm and a typical withdrawal rate, 1—3 cm/h. Very large, eg, kilogram-sized crystals can be grown. 

The chlorine atom is an electron-pulling substituent with a strong -I-effect overcoming a weak +M-effect therefore the electron density of the aromatic system is reduced. This results in a blue-shifted fluorescence compared to the parent p4P. The fact that the spectrum of CLP4 shows well-resolved vibronic structures indicates that the lone pairs of the chlorine atoms are not directly involved in the aromatic system that is, the fluorescence relevant transition has no charge transfer character. The blueshift is clearly due to an inductive effect, since the... 

ER(i. (A) GST pull-down experiments. The purified fusion proteins were incubated with labeled SRC-1 in the absence (lanes 3 and 7) or presence of 5 nM E2 (lanes 4 to 6 and 8 to 10) in addition to a 100-fold excess of EM-652 (lanes 5 and 9) and ICI 182,780 (lanes 6 and 10). The input lane (lane 1) represents 20% of the total amount of labeled SRC-1 used in each binding reaction. An equivalent amount of protein was used in the sample containing only GST (lane 2). (B) COS-1 cells were cotransfected with 1 pg vitAaERETKLuc and 500 ng pCMX-ERa in the presence or absence of 1 pg SRC-1 expression plasmid. Cells were incubated with or without 10 nM E2 or 100 nM antagonist as indicated. Results are expressed as the factor by which response exceeds basal levels set arbitrarily at 1.0. (C) Same as in (B), except that ERP expression vector was used. (D) and (E) Same as in (B) and (C), respectively, except that pS2Luc reporter and HeLa cells were used in transfections. (F) Dose response of EM-652 (filled squares) and ICI 182,780 (open squares) in the presence of 10 nM E2 on ERa activity in COS-1 cells transfected with vitA2ERETKLuc reporter and SRC-1 expression plasmid. The maximal induction by E2 alone was set arbitrarily at 100%. (G) Same as in (F), except that ERP expression vector was used (Tremblay et al., 1998a). 

The changes in the pAia values associated with different carboxylic acids are the result of inductive effects. Inductive effects occur when electronegative groups pull electron density away from acidic centers, rendering these centers more acidic. Conversely, inductive effects... 

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