Latent polarity

Recalled in Arthur Lapworth, "Latent Polarities of Atoms and Mechanism of Reaction, with Special Reference to Carbonyl Compounds," Mem.Manchester LPS 64, no. 3 (191920) 15. 

Arthur Lapworth. "Latent Polarities of Atoms," 116 Robert Robinson, "The Conjugation of Partial Valencies," ibid., no. 4 (1920) 114. This paper is reproduced in Robinson s Memoirs. 

The question of how one chooses appropriate carbon-carbon bond disconnections is related to functional group manipulations since the distribution of formal charges in the carbon skeleton is determined by the functional group(s) present. The presence of a heteroatom in a molecule imparts a pattern of electrophilicity and nucleophilicity to the atoms of the molecule. The concept of alternating polarities or latent polarities... 

Sea Salts - Most of the Na and Cl in both Greenland and Antarctica is of marine origin [1,13,21]. Near the ocean, sea salts may also account for most of the Mg, K, Ca, and S042-. Concentrations of Na and Cl display a maximum in winter Greenland precipitation which is coincident with the minimum oxygen isotope delta values [1,13,18]. The seasonal maximum in sea salt concentrations may be due to increased storminess, over the ocean in winter or to an increased poleward latent heat flux during the polar night [13]. 

Clearly equality between the two stages in the process of evaporation from the interior of the Hquid should only obtain for perfectly symmetrical molecules with increasing asymmetry, the second step or the detachment of the polar end of the molecule should become more important and the energy associated with this rupture will be a larger fraction of the total eiiergy of vaporisation. An examination of the surface energy and latent heats of evaporation for a series of compounds at corresponding... 

It has already been observed in the case of pure liquids such as substituted hydrocarbons that the surface tension was, if not completely defined by the non-polar portions of the molecule, at least not so markedly affected by substituent groups as we should anticipate if no orientation existed. Again, although vaporisation and condensation at a liquid surface such as water at high temperatures takes place with great speed, yet the life of a molecule on the surface is probably long enough to permit of such adjustment as orientation requires. Even more conclusive in favour of the hjq)othesis of at least partial orientation is the evidence derived from a consideration of the latent heats of evaporation and the... 

Physical properties of the solvent are used to describe polarity scales. These include both bulk properties, such as dielectric constant (relative permittivity), refractive index, latent heat of fusion, and vaporization, and molecular properties, such as dipole moment. A second set of polarity assessments has used measures of the chemical interactions between solvents and convenient reference solutes (see table 3.2). Polarity is a subjective phenomenon. (To a synthetic organic chemist, dichloromethane may be a polar solvent, whereas to an inorganic chemist, who is used to water, liquid ammonia, and concentrated sulfuric acid, dichloromethane has low polarity.)... 

Where a negative image is required, e.g., when printing from a microform negative, then the toner has the same polarity as the corona in Step 1. Electrostatic lines of force drive the toner particles away from the latent image toward the uncharged area, which is the area exposed from the negative. 

In a liquid consisting of polar molecules this mutual attraction will give rise to an increase in the latent heat of evaporation. 

Another interpretation for the meta sequence is conceivable. Polarization of the aromatic by an electrophilic reagent (Z+) may induce the latent resonance effects of the m-fluoro substituent ... 

Development. This is obtained through the electrical attraction of a toner (thermoplastic pigment mixed with carbon black), whose fine particles carry electrical charges that are opposite in polarity to the latent electrostatic image charges. 

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