The Microscale Universe: Atoms and Molecules

1. The Microscale Universe:Atoms and Molecules

2. Star:  massive gaseous body in outer space (ex. Sun);  generates energy through nuclear fusion and emits visible light;  Nuclear energy, from the rearrangement of protons and neutrons, power the star and given “birth” to the elements stars ~ 109 m

3. Putting Atoms in various arrangement (making Molecules): Preparative Chemistry

4. A Defining Feature of Chemistry: the ability to create something new Dmitri Mendeleev, father of the Periodic Table, 1869

5. Periodic Table of Elements (Atoms): The Ultimate Lego Set Inside of the Atom Covalent: share e- Ionic: transfer e-

6. Activity:Atoms vs. Legos Legos Grains of Sand H2O molecules # 100 ~ 4 minutes # 106 ~ 23 days # 1026 ~ 1019 years Sense of Scale: Atoms are Significantly Smaller Atomic Architectures are Functional Taxol: Anticancer Drug

8. Periodic Table of Elements (Atoms): The Ultimate Lego Set

9. ? Hindenburg disaster, 1937

11. Although we now know that his hypothesis was correct, van’t Hoff has received harsh criticism from renowned chemist and editor of Journal of Practical Chemistry, Adolph Kolbe. Here is an excerpt of his criticism: “A Dr. H. van ’t Hoff of the Veterinary School at Utrecht has no liking, apparently, for exact chemical investigation. He has considered it more comfortable to mount Pegasus (apparently borrowed from the Veterinary School) and to proclaim in his “The arrangement of atoms in Space” how the atoms appear to him to be arranged in space, when he is on the chemical Mt. Parnassus which he has reached by bold flight.”

13. methane

17. Polypropylene • Isotactic melting points M.P. = 130 ° C • Syndiotactic M.P. = 160 °C • Atactic M.P. < 0 ° C • Symmetry & Arrangement of atoms in space matters

18. Working with models allows us to predict physical properties of materials • Isotactic • Syndiotactic • Atactic The strands of syndiotactic pack the closest (intercalated packing), followed by isotactic and then atactic. Syndiotactic would be harder and more plasticky then isotactic and especially then atactic. Symmetry arrangement of atoms and consequent packing of atomic chains explains why: syndiotactic has higher melting temperature (Tm=160ºC) than isotactic (Tm= 130 ºC), which then has a higher melting temperature than atactic (Tm <0 ºC).

20. Asymmetry on a Molecular Scale:Chirality

21. Symmetry and Asymmetry: on a Microscopic Scale Z A The Unifying Principle

22. Symmetry and Asymmetry: on a Microscopic Scale Assembly of atoms into Symmetric & Asymmetric molecular architectures & consequences of molecular asymmetry.

23. Carbon with 4 different atoms bond to it creates an Asymmetric Molecule (Chiral Molecule) (R), D (S), L Enantiomers non-superimposable mirror images Chiral Molecules  rotate plane polarized light

24. Demonstration:Building a simple polarimeter light source 2 polarizers cup NaOCl3 crystals material: demystifying the instrument

25. Demonstration:Building a simple polarimeter

26. Chirality: Smells Differently in the Mirror limonene (S)-(–)-limonene smells like turpentine (pine) (R)-(+)-limonene has the odor of oranges The binding specificity of a chiral receptor site for a chiral molecule is usually only favorable in one way *

27. 2-methylbutanoic acid carvone R-(‒) Cheesy Sweaty Smell S-(+) Fruity Sweet Smell (S)-(+)-carvone smells like caraway (R)-(–)-carvone smells like spearmint * * * *

28. Chirality Governs Drug Action ? • When chiral compounds are introduced into the body, physiological processes show a high degree of chiral distinction; • Essential physiological process are homochiral; Biomolecules are made of units that have the same sense of chirality: PROTEINS L-centered amino acids NUCLEIC ACIDS (DNA & RNA) D-centered sugar units right/left handed helical twist left-handed DNA (atypical)

29. Influence of Chirality on Drug Action Thalidomide horror, late 1950s * thalidomide Friedman, L.. et al. Science. 1971, 172(3987), 1044-1046. (R) vs. (S) (S) Thalidomide, a drug once used to suppress morning sickness

30. Influence of Chirality on Drug Action Illegal as the Mirror-image form Methamphetamine * * non-stimulant stimulant Chirality Matters !!!

31. a) The Origin of Symmetry & Asymmetry on a Microscopic (Molecular) Scale • Murchison meteorite, which fell about 60 miles north of Adelaide, Australia in 1969. • One of the first reports stated that the amino acids that were found were equally right and left handed. • Subsequent reports have been controversial… We have something to eagerly look forward to: Perhaps the answer to the questions regarding the origin of molecular asymmetry on Earth will come in year 2014 ! This is when the robotic lander Philae will detach itself from the orbiter of the Rosetta space craft and land on the comet 67P/Churyumov-Gerasimenko.

32. b) from Microscopic to Macroscopic Scale, Asymmetry Prevails In 1857, Pasteur has noticed that molds had grown in a dish containing an optically inactive solution, one that did not rotate plane polarized light. Instead of simply throwing away the "contaminated" solution, having curious nature he checked its effect on a light beam. The contaminated solution rotated light! Pasteur viewed handedness as one of the clearest distinctions between living and dead matter and ultimately proclaimed it to be a profound fact of nature that went far beyond the chemistry of life. He wrote the following: "Life as manifested to us is a function of the asymmetry of the universe and of the consequences of this fact." later, before the French Academy of Sciences, he made the grand conjecture, "L'universestdissymetrique."

33. c) Symmetry & Asymmetry in Living Organisms

34. Symmetry & Asymmetry  the parallel between Science & Art

35. Artwork of M. C. Escher Drawing Hands, 1948 Still Life with Spherical Mirror, 1934 Balcony, 1945 Eric J. Heller Gallery Where science inspires art and art informs science... While a sidelight, Heller said his artwork serves an important purpose. It doesn't just educate the public about physics, it engages them and interests them in what's going on at the atomic level.