A BRIEF HISTORY OF TIME IN CHEMISTRY Gregory S. Yablonsky Parks College of Engineering, Aviation and Technology, Saint Louis University, St. Louis, Missouri, USA • • “The history of science is the only history which can illustrate the progress of mankind” • (George Sarton) • “The only reason for time is so that everything doesn’t happen at once” • Albert Einstein A. INITIAL STORY • The first step. • There were 500 bricks inside the airplane. One brick was dropped. How many bricks are remained inside the airplane? • Correct! 499! • The second step. How to put an elephant into the refrigerator? Three-stage procedure: (1) To open the refrigerator; (2) To put the elephant into the refrigerator (3) To close the refrigerator • The third step. How to put an reindeer into the refrigerator? Four-stage procedure: (1) To open the refrigerator; (2) To take the elephant out of the refrigerator; (3) To put a reindeer to the refrigerator ; (4) To close the refrigerator lio • The fourth step A lion, the king of animals, has the birthday party. All animals came to this party except one. Who is this one? • Certainly, the reindeer! • The fifth step An old lady crossed the African river with crocodiles. However she survived. Why? • Correct! • All crocodiles attended the lion’s party! • The sixth step, the final one. Unfortunately this old lady died at the same day. Why? • She was hit by the brick which was dropped from the airplane. • The level of complexity of this example is very correspondent to the complexity of chemical reaction. It is the multi-stage process It is the temporal process. It is the cyclic process. There are three conservation laws: • (1) Conservation of the number of all animals • (2) Conservation of the number of bricks • (3) conservation of the space of refrigerator • Also there is a catalyst, the brick. EXAMPLE: 2H2 + O2 = 2H2O B. Time and chemical complexity Pre-history • Many activities of human beings are complex chemical reactions which are occurred in time (1) Combustion as a source of energy since Neanderthal times…(“500, 000 years of combustion technology”); (2) Preparation of food and beverages (bier, wine); (3) Preparation of materials: Bronze from Cu and Sn containing ore (“Bronze age”); Iron using the ferrous metallurgy( “Iron Age”) Etc…Etc… Time and Complexity • What is a meaning of chemical time? • Is it just a scale for presenting the complex reaction, i.e. complex sequence of chemical events(transformation)? • Or it is an exhibition (function) of complex chemical transformations? Three Meanings of Time 1. “Clock” time t (or astronomic, or external time): Change of chemical composition during ∆t 2. “Internal”, or “intrinsic” time: Time scale at which a reaction occurs 3. Residence time: “Transport time” as a measuring stick of the chemical reaction(s) G.B. Marin & G.S. Yablonsky (2011). Kinetics of Chemical 19 Reactions. Decoding Complexity C. Time in Chemistry: Starting Point Discovery of Catalysis Catalysis is the fundamental chemical phenomenon that underlies Life 90% of new chemical processes "Virtually every CO 2 conversion to roses chemical reaction that occurs in living Nontoxic auto-exhaust organisms is Petroleum fuels catalyzed by a specific enzyme." Most important The Living Cell - C. deDuve environmental Ammonia fertilizer technology G. Ertl's 2007 Nobel Chateau Lafite Rothschild (1887) prize involved study Nylon of this catalytic system Sulfuric acid L-dopa Hefty trash bags Anti-freeze Chiral Rh complex Fuel cells creates a chiral product Plastic drain pipe W. Knowles shared Aspartame 2001 Nobel prize for work on this system Makes diet coke Roundup possible and on and on …… Natural Catalytic Phenomena Catalyst Catalyst (enzyme) (enzyme) Regeneration Product Product Reactant Tissue, etc. Reactant (CO 2) (O 2, Carbohydrates) (CO 2) Animal Plant Transformation Reactant Reactant Energy out Energy in work, heat (UV-Vis Light) Story I : Catalysis (Germany: Johann – Wolfgang Doebereiner) Catalysis discovery is more interesting than any Hollywood movie. Main characters of this historical movie are: 1. The chemist Johann-Wolfgang Doebereiner (1780-1856). 2. The great German poet Johann-Wolfgang Goethe (1749-1832), prime-minister of the small Weimar dukedom. 3. August, Duke of the Weimar dukedom 4. Russian Tsar’s sister and Duke’s daughter –in- law, Maria Pavlovna Johann Wolfgang Goethe (1749- 1832) Faust • "Stop time, • thou art so beautiful!“ • (“Faust”, Goethe) Goethe, “Faust” • “Werd ich zum Augenblicke sagen: Verweile doch: du bist zu schoen • Dann magst du mich in Fesseln schlagen, • Dann will ich gern zugrude gehn”. Johann-Wolfgang Dobereiner (1780-1849) CATALYSIS Doebereiner never graduated from any university. Despite that Goethe hired him as a court apothecary. Doebereiner enthusiastically studied the reaction of hydrogen oxidation and found an amazing jump of the reaction rate (“an explosion”) in the presence of platinum Unfortunately, he had no platinum enough because of wars in South America. Grand Duchess Maria Pavlovna (1786-1859) Introducing the concept time • Catalysis = dramatic change in time • A special ‘ catalytic force’, Berzelius (Sweden) • Discovery of catalysis promoted introducing the concept of time into chemistry. • However catalysis as a phenomenon was remaining mysterious until 1880s D. INTRODUCING TIME (1851) Time is introduced into chemistry • Chemical kinetics was born • 1851, Williamson and Wilhelmi • 1851, Williamson (USA), ‘’Some considerations on chemistry dynamics exemplified by the etherification theory” • Williamson seems to have been the first to use the term ‘dynamics’ regarding the non-steady state chemical processes. • “There are many evidences that chemical processes need time, but this commonly accepted fact is not taken into account in treating various phenomena” (Williamson) 1851, Williamson and Wilhelmi • 1851, Wilhelmi (Germany): the first kinetic quantitative relationship in studies of acids on the cane sugar • -(dZ/dT) = MZS, • where Z and S are the amounts of sugar and acid catalyst, respectively; T is the reaction time, and M is the mean amount of sugar which has undergone conversion during an infinitesimal period of time under the effect of unit concentration of the catalyzing agent (Wilhelm )Ostwald about Wilhelmi • “We must consider Wilhelmi as an inventor of the concept of the chemical reaction rate”… • “Wilhelmi’s study had remained absolutely ignored though it has been published in a rather widespread Annals of Physics by Poggendorf… It remained unknown for the later researchers working on similar problems…Only after this field of science had already been so developed that some people began to think about its history, the basic Wilhelmi’s study came to light”… Wilhelm Ostwald (1853-1932) Ostwald’s conceptual breakthrough (1880s-1890s) • Ostwald gave the first essential interpretation of catalysis. • What is catalysis as a phenomenon? • Ostwald’s answer: “CATALYSIS IS JUST KINETICS” Ostwald (1895): “A catalyst accelerates a chemical reaction without affecting the position of the equilibrium.” E. The main law of chemical kinetics The Mass-Action-Law (1860s – 1880s) • The Guldberg-Waage-van’t Hoff’s case story • Guldberg-Waage (Norway) van’t Hoff (Netherlands) Cato Maximilian Guldberg (1836-1902) Peter Waage (1833-1900) Jacobus Henricus van 't Hoff (1852-1911) The Hidden History of Chemical Kinetics, I Gul’dberg and Waage , Norway, 1862-1867 Mass-Action-Law( M.A.L.) Equilibrium formulation “ In chemistry like in mechanics the most natural methods will be to determine forces in the equilibrium states”. Kpq = Kp 'q', where p, q, p' q' are the " action masses" Initially, Guldberg and Waage used an expression Kp αqβ = K(p')α (q')β The Hidden History of Chemical Kinetics, II Gul’dberg and Waage, 1879 Dynamic Formulation of the Mass-Action-Law (M.A.L.) R = K pαααqβββrγγγ The Hidden History of Chemical Kinetics, III Van’t Hoff, Netherlands, the first winner of the Nobel award (1901) on chemistry 1884, “Essays on chemical kinetics” Idea of normal transformation “The process of chemical transformations is characterized solely by the number of molecules whose interaction provides this transformation” (A ⇔B; 2A ⇔ B; A+B ⇔ C; 2A+B ⇔ C) Strong discussion with Gul’dberg and Waage: “As a theoretical foundation I have accepted not the concept of mass action ( I had to leave this concept in the course of my experiment)”. Van’t Hoff tried to eliminate mechanics from chemistry. The Hidden History of Chemical Kinetics, IV Van’t Hoff believed that he found the chemical (not mechanical) LAW OF CHEMICAL KINETICS However, his normal transformation dependences did not fit many real experimental data, e.g. hydrogen oxidation data Van ‘t Hoff’s Revolution Contradictions Van ‘t Hoff introduced the “natural” classification, but at the same time was of the opinion that “normal transformations” occur very rarely He considered the effect of the reaction medium, “disturbing factors”, to be the reason for this Semenov about Van ‘t Hoff’s “Essays”: “…when one is reading this book, one feels as if the author was very interested in the reasons for the abnormal course of reactions and the disturbing factors rather than in further extending his knowledge on normal processes, as he treated them as virtually evident… Van ‘t Hoff’s considerations on the abnormal behavior of reactions is three times as much.” G.B. Marin & G.S. Yablonsky (2011). Kinetics of Chemical 46 Reactions. Decoding Complexity The new idea: “chemical mechanism” (Ostwald? Shoenbein? Christiansen?) It has an obvious “mechanical origin” Maxwell’s metaphor: BELL and MANY ROPES In 1879, a vivid interpretation of complex systems as mechanical systems was given by Maxwell. “In an ordinary chime every bell has a rope that is drawn through a hole in the floor into the bell-ringer room. But let us imagine that every rope instead of putting into motion one bell participates in the motion of many parts of the mechanism and that the motion of every bell is determined not only by the motions of its own rope but the motions of several ropes; then let us assume that all this mechanism is hidden and absolutely unknown for the people standing near the ropes and capable of seeing only the holes ceiling above them”.