Modem Theories of Chemistry

Lothar Meyer, introduction to the 1864 edition of Modem Theories of Chemistry, 5th ed., trans. Phillips... 

Aqueous electrolyte solutions have been a subject of determined studies for over a century. Numerous attempts were made to construct theories that could link the general properties of solutions to their internal structure and predict properties as yet nnknown. Modem theories of electrolyte solutions are most intimately related to many branches of physics and chemistry. The electrochemistry of electrolyte solutions is a large branch of electrochemistry sometimes regarded as an independent science. 

H. B. Watson, Modem Theories of Organic Chemistry, 2nd ed.. Clarendon Press, Oxford, 1941, p. 241. 

On the whole, historians have tended to identify the beginnings of the "modem" discipline of chemistry with a "Chemical Revolution," with Lavoisier and his circle, and more particularly with pneumatics, the oxygen theory, the balance, and the new chemical nomenclature of the late eighteenth century. This traditional historical interpretation is rooted in nineteenth-century histories of chemistry, particularly those written by the French chemists Dumas, Berthelot, and Wurtz.5... 

It is remarkable that, in the space of less than two decades, the structural theory of organic chemistry should have moved from the first hesitant steps, where the chemical structure was considered to be separate and distinct from the physical structure of the molecule, and represented only the "affinities" of the atoms within the molecule, to the point where those same formulas were now viewed as representations of the actual physical locations of the atoms in the molecule (76). What was left undone at the end of the nineteenth century, by which time three-dimerrsional graphical formitlas for organic compoimds were in routine use, was, of coruse, a description of exactly what the "chemical affinities" of the atoms composing the molecules were. The answer to this problem would have to await the new century, and the development of modem theories of the atom and bonding. 

The concept of steric effects, an extremely important component of the modem theory of organic chemistry, is based upon an oversimplified assumption which considers organic molecules in terms of ball-and-stick models. The latter seem to be absolutely inadequate or even basically incorrect from the point of view of quantum chemistry. Nevertheless, the imaginative and insightful application of this approach enabled organic chemists to start to develop conformational analysis as one of the most fruitful theories of modern organic chemistry, capable not only of explanation but also of prediction of chemical phenomena. 

P.J. Flory, Principles of Polyrrter Chemistry, Cornell University Press, Ithaca NY (1953). H. Yamakawa, Modem Theory of Polymer Solutions. Harper Row, NY (1971). 

Dalton s work marked the beginning of the modem era of chemistry. The hypotheses about the nature of matter on which Dalton s atomic theory is based can be summarized as follows ... 

Goodrich, F.C., "Rheological properties of fluid Interfaces" in Solution Chemistry of Surfactants, Mittal, K.L., (Ed.), Plenum Press, New York, Vol. 1, (1969)738 Goodrich, F.C., "Surface viscosity as a capillary excess transport property" in "The Modem Theory of Capillarity", Akademie-Verlag, Berlin, 1981 Grader, L., PhD Thesis, Leuna-Merseburg, 1985... 

Robert Boyle (1627-1691) is noted for his pioneer experiments on the properties of gases and his espousal of a corpuscular view of matter that was a forerunner of the modem theory of chemical elements and atomic theory. Boyle conducted pioneering experiments in which he demonstrated the physical characteristics of air and the necessity of air for combustion and respiration. In 1661, he described, in the second edition of his work. New Experiments Physio-Mechanical, the relationship, known as Boyle s Law, of the volume of gases and pressure. Attacking the Aristotelian theory of the four elements (earth, air, fire, and water) and the three principles (salt, sulphur and mercury), proposed by Paracelsus, in The Skeptical Chymist, he can be considered as the founder of modem chemistry. " ... 

The application of the modem theory of valency in organic chemistry has led to new remarkable formulations of many compounds, such as ethylene and benzene, two main building blocks of materials used as resist resins in lithography. Today,... 

Finally, in 1787, Lavoisier together with the French chemists, de Morveau, Ber-thollet and de Fourcroy established in Paris a new chemical nomenclature, that has remained valid until today. Lavoisier wrote in 1789 the Trade elementaire de Chimie (Elementary Treatise of Chemistry), the first modem textbook on chemistry, and presented a unified view of new theories of chemistry, containing a clear statement of the law of conservation of mass, and denied the existence of phlogiston. In addition, it contained a list of elements, or substances that could not be broken down further, which included oxygen, nitrogen, hydrogen, phosphoms, mercury, zinc, and sulfur. 

The supersession of the most successful pre-Werner theory of the structure of coordination compounds, the so-called Blomstrand-J0rgensen chain theory, by Alfred Werner s coordination theory constitutes a valuable case study in scientiffc method and the history of chemistry. The highlights of the Werner-J0rgensen controversy and its implications for modem theories of chemical structure are Wretched in this article. 

One of the most striking things about the chemistry of the elements is the periodic repetition of properties. There are several groups of elanents that show great similarities in chemical behavior. As we saw in Chapter 2, these similarities led to the development of the periodic table of the elements. In this chapter we will see that the modem theory of atomic stracture accounts for periodicity in terms of the electron arrangements in atoms. 

In your study of chemistry so far, you ve learned how to name compounds, balance equations, and calculate reaction yields. You ve seen how heat is related to chemical and physical change, how electron configuration influences atomic properties, how elements bond to form compounds, and how the arrangement of bonding and lone pairs accounts for molecular shapes. You ve learned modem theories of bonding and, most recently, seen how atomic-scale properties give rise to the macroscopic properties of gases, liquids, solids, and solutions. 

Graddon DP. Chapter II—Modem theories of co-ordination chemistry. In Graddon DP, editor. An introduction to co-ordination chemistry. 2nd ed. Pergamon 1968. p. 24—54. 

---