Lithium charge distribution

Problem 1.8 concerned the charge distribution in methane (CH4), chloromethane (CH3CI), and methyllithium (CH3Li). Inspect molecular models of each of these compounds, and compare them with respect to how charge is distributed among the various atoms (carbon, hydrogen, chlorine, and lithium). Compare their electrostatic potential maps. 

We have also performed the calculation of hyperfine coupling constants the electric quadrupole constant B and magnetic dipole constant A, with inclusion of nuclear finiteness and the Uehling potential for Li-like ions. Analogous calculations of the constant A for ns states of hydrogen-, lithium- and sodiumlike ions were made in refs [11, 22]. In those papers other bases were used for the relativistic orbitals, another model was adopted for the charge distribution in the nuclei, and another method of numerical calculation was used for the Uehling potential. 

A tetraanion salt (84 )/4M has been formed by stepwise four-electron transfer from 4,7,12,15-tetrastyryl[2.2]paracyclophane (8) to lithium, sodium, and potassium metals in [2Hx]THF at 220 K a strong effect of the cyclophane hub on the charge distribution has been demonstrated and the influence of o1, o2, o3, o4-tetramethyl and px, p2,pi,pA-tetramethoxy substituents on the ease of reduction has been tested.9... 

The reduction of several annelated corannulene derivatives has been performed using lithium and potassium metals.7 It has been found that annelation affects the annulenic character of corannulene by changing its charge distribution the dianions of derivatives that are annelated with six-membered rings have less annulenic character and are less paratropic than corannulene dianion. 

Figure 2.3 la) Methanol, CH3OH, has a polar covalent C-0 bond, arid b) methyl-lithium, CH3Li, has a polar covalent C—Li bond. The computer-generated representations, called electrostatic potential maps, use color to show calculated charge distributions, ranging from red lelectron-rich 5 ) to blue (electron-poor 5 + ),... 

UV-Vis, H and NMR study of monometallic salts of 9,10-dihydroan-thracene and its 9,10-disubstituted derivatives in THE, showed lithium 9-phenyl-9,10-dihydroanthracene-9-ide, lithium 9,10-dimethyl-9,10-dihydroanthracenide and lithium 9,10-diphenyl-9,10-dihydroanthracenide exist as a solvent separated ion pair (SSIP). Sodium, potassium, rubidium and cesium 9,10-dihydroanthracenides, 9-methyl-9,10-dihydroanthracene-10-ides and 9-cyano-9,10-dihydroanthracenides exist as contact ion pairs (CIP) in solution. A model, taking into account the geometry and charge distribution, for the transition of CIP of alkali metal salts of 9,10-dihy-droanthracene and its derivatives into SSIP is proposed [283]. 

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