Chloride potential mapping

The electrophilic site of an acyl cation is its acyl carbon. An electrostatic potential map of the acyl cation from propanoyl chloride (Figure 12.8) illustrates nicely the concentration of positive charge at the acyl carbon, as shown by the blue color. The mechanism of the reaction between this cation and benzene is analogous to that of other electrophilic reagents (Figure 12.9). 

Electrostatic potential map for i-phenyl-l-ethyl cation-chloride anion shows negatively-charged regions (in red) and positi vely-charged regions (in blue). 

Next, examine the structure of 1-phenyl-1-ethyl cation-chloride anion, an ion pair that is initially generated. What evidence is there for cai bon-chlorine bond cleavage Examine the electrostatic potential map for the ion pair. Which face of the cation is more available for attack How could the other enantiomer form ... 

Examine electrostatic potential maps for potassium hydride and hydrogen chloride. How are they similar and how are they different (Focus on whether the molecules are polar or nonpolar (compare dipole moments), and on the electronic character of hydrogen.) Draw the ionic Lewis structure that is most consistent with each electrostatic potential map. Does each atom have a filled valence shell ... 

Compare geometries, atomic charges and electrostatic potential maps of thionyl chloride and phosphorus trichloride. How are they similar How are they different Can you redraw the Lewis structure of SOCI2 so that it gives abetter description of the electrostatic potential map ... 

Alcohol attack generates an unstable intermediate that undergoes nucleophilic attack by CL at carbon. Compare electrostatic potential maps of methanol, thionyl chloride intermediate, and phosphorus trichloride intermediate. What features of these maps are consistent with an electrophilic reactive intermediate ... 

What effect does the solvent have on the structure, charges and reactivity of Grignards Compare geometries, atomic charges and electrostatic potential maps of the diethyl ether complex to that of methylmagnesium chloride itself. How does solvent-magnesium bond formation affect the reactivity of the methyl group Explain. 

Electrostatic interactions can guide alkylation under certain conditions. Examine the electrostatic potential map of the potassium enolate of ethyl acetoacetate. Is carbon or oxygen more electron rich Are electrostatic interactions likely to favor addition of oxygen or carbon Examine atomic charges and electrostatic potential maps for diethylsulfate, ethyl chloride, ethyl bromide and ethyl iodide, pay attention to the backside of the electrophilic carbon. Order the systems from most to least electron poor. Which reaction is most likely to be guided by electrostatics Least likely Can the experimental results be fully explained on this basis ... 

Judging from the following electrostatic potential maps, which kind of carbonyl compound has the more electrophilic carbonyl carbon atom, a ketone or an acid chloride Which has the more nucleophilic carbonyl oxygen atom Explain. 

Electronically, we find that strongly polarized acyl compounds react more readily than less polar ones. Thus, acid chlorides are the most reactive because the electronegative chlorine atom withdraws electrons from the carbonyl carbon, whereas amides are the least reactive. Although subtle, electrostatic potential maps of various carboxylic add derivatives indicate the differences by the relative blueness on the C-O carbons. Acyl phosphates are hard to place on this scale because they are not used in the laboratory, but in biological systems they appear to be somewhat more reactive than thioesters. 

Acid anhydride, amides from, 807 eleclrostatic potential map of, 791 esters from, 807 from acid chlorides, 806 from carboxylic acids, 795 1R spectroscopy of, 822-823 naming, 786... 

Acid chloride, alcohols from, 804 alcoholysis of, 802-803 amides from, 803-804 amines from, 933-935 amjnolysis of, 803-804 carboxylic acids from, 802 electrostatic potential map of, 791... 

DNA sequencing and. 1113 Electrospray ionization (ESI) mass spectrometry, 417-418 Electrostatic potential map, 37 acetaldehyde, 688 acetamide, 791,922 acetate ion. 43. 53, 56, 757 acetic acid. 53. 55 acetic acid dimer, 755 acetic anhydride, 791 acetone, 55, 56. 78 acetone anion, 56 acetyl azide, 830 acetyl chloride, 791 acetylene. 262 acetylide anion, 271 acid anhydride, 791 acid chloride, 791 acyl cation, 558 adenine, 1104 alanine, 1017 alanine zwitterion, 1017 alcohol. 75 alkene, 74, 147 alkyl halide, 75 alkyne. 74... 

Methyllithium, electrostatic potential map of, 37, 143 polar covalent bond in. 37 Methylmagnesium chloride,... 

Trichloroacetic acid, pKa of. 759 Trifluoroacetic acid, pKa of, 756 Trifluoromethylbenzene, electrostatic potential map of, 565 Triglyceride, see Triacylglycerol, 1061 Trimethylamine, bond angles in, 919 bond lengths in, 919 electrostatic potential map of, 921 molecular model of, 919 Trimethylammonium chloride, IR spectrum of, 953 Trimethylsilyl ether, cleavage of, 627-628... 

NaCl The bond in solid sodium chloride is a largely ionic one between Na+ and Cl-. In spite of what we ve said previously, though, experiments show that the NaCl bond is only about 80% ionic and that the electron transferred from Na to Cl still spends some of its time near sodium. A particularly useful way of visualizing this electron transfer is to represent the compound using what is called an electrostatic potential map, which uses color to portray the calculated electron distribution in the molecule. The electron-poor sodium atom is blue, while the electron-rich chlorine is red. 

Figure 2.8 Surface electrostatic potential map of the C1C chloride channel dimer. The channel is sliced in half to show the pore entryways (but not the full extent of their depth) on the extracellular (above) and intracellular (below) sides of the membrane (represented by horizontal lines. The Cl ions are shown as spheres and dashed lines highlight the pore entryways. (reproduced with permission from Reference 3).

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