Presentation is loading. Please wait.

Presentation is loading. Please wait.

CYL 503: Chemistry of the main group elements and solids Shapes of molecules, symmetry and group theory Hypervalency and d orbital participation Space.

Similar presentations


Presentation on theme: "CYL 503: Chemistry of the main group elements and solids Shapes of molecules, symmetry and group theory Hypervalency and d orbital participation Space."— Presentation transcript:

1 CYL 503: Chemistry of the main group elements and solids Shapes of molecules, symmetry and group theory Hypervalency and d orbital participation Space groups Boron group Carbon group Nitrogen group Oxygen group Halogen group Rare gases Instructor : Prof. Anil J. Elias Room: MS 733: IIG1

2 Evaluation and material One quiz on revision of fundamentals (5marks) 10 questions from Minor 1 (25 Marks) (check iitd website for dates) MInor2 ( 25 Marks) Major ( 45 Marks) Material: What the instructor teaches! Lecture Notes/powerpoint slides will be provided from time to time Books: Inorganic chemistry: Huheey, keiter and keiter Inorganic Chemistry: Housecroft and Sykes Your duty: Attend Classes and be punctual ( AM)

3

4

5 IIT Delhi 2014

6

7 Landmark discoveries in the chemistry of p block Elements Instructor: Prof. Anil J. Elias, Room: MS 733: IIG1 An introductory lecture presentation to main group chemistry

8 3000 BC Bronze, an alloy of tin and copper was the first alloy to be used around 3000 BC. After 600 BC pure metallic tin was produced. Zebu Bull from Mohenjo-Daro and Harappa Pure tin candlestick Dancing Girl a bronze statuette dating around 2500 BC, from the Mohenjo- daro site

9 ~1570 BC Tyrian purple, a reddish purple organobromine natural dye was used by ancient Phoenicians. The dye was produced from the secretions of a species of sea snails in the family, Muricidae. The chemical component (main ingredient: 6, 6’- dibromoindigo) was discovered in 1909 by Paul Friedlaender.

10 ~800 BC Fumigating power of sulfur mentioned by Homer. Sulfur is also mentioned in the Bible as brimstone. “ Bring sulfur, old nurse, that cleanses all pollution, and bring me fire that I may purify the house with sulfur” Homers’ Odyssey The three philosophical principles of alchemy: salt, sulfur and mercury

11 940 AD Sulfuric acid and alcohol first prepared by the physician, alchemist and writer from Bagdad, Abu Bekr Zakariya Razi (Rhazes) In 1746 in Birmingham, England, John Roebuck began producing sulfuric acid in lead-lined chambers, which were stronger, less expensive, and could be made much larger than the glass containers which had been used previously.

12 1250 Albertus Magnus, a catholic saint (Albert the Great, 1193–1280) is believed to have been the first to isolate arsenic by heating soap together with arsenic trisulfide (orpiment As 2 S 3 along with realgar, As 4 S 4 ).

13 1669 Hennig Brandt discovers phosphorus from reductive distillation of urine concentrate by evaporating urine to dryness and distilling the residue with sand. The Alchemist Discovering Phosphorus : a painting by Joseph Wright

14 1694 Robert Boyle makes P 4 O 10 by oxidation of yellow phosphorus and H 3 PO 4 by hydrolysis of P 4 O 10. Boyle rejects the Aristotelian theory of the four elements (earth, air, fire, and water) and also the three principles (salt, sulfur, and mercury) proposed by Paracelsus.

15 1772 Daniel Rutherford isolates N 2 gas after he removed oxygen and carbon dioxide from the air mixture. He named the isolated gas as noxious air or phlogisticated air and believed it was exhaled by the mouse which he used in the experiment to remove oxygen by breathing. J. J. Becher proposed the phlogiston theory phlogiston theory is an obsolete scientific theory that postulated a fire-like element called phlogiston, contained within combustible bodies, that is released during combustion.

16 Scheele isolates oxygen gas by heating manganese dioxide (and later potassium nitrate and mercuric oxide) but did not publish his findings immediately. It was also independently discovered by Joseph Priestly by heating and decomposing mercuric oxide in

17 1774, 1777 Carl Wilhelm Scheele discovers chlorine gas from HCl in He discovered hydrogen sulphide gas when he treated ferrous sulfide or pyrite (fool’s gold) with a mineral acid, which released a gas with the smell of rotten eggs. He referred to this gas as stinkede (stinking) and called it “Schwefelluft” meaning sulfur air. dephlogisticated muriatic acid air Schwefelluft” Carl Wilhelm Scheele

18 1808 Gay Lussac and Thenard discovers PCl 3 and also PCl 5 by passing a slow current of chlorine over heated red phosphorus. Gay Lussac Thenard Red phosphorus

19 1811 Pierre Louis Dulong prepares nitrogen trichloride, NCl 3 and looses two fingers and an eye in two explosions. An NCl 3 explosion also blinded Humphry Davy (famous for Davies Safety lamp) triggering him to hire Michael Faraday as a co-worker. Dulong Nitrogen compounds as explosives

20 1824 Silicon discovered by Berzelius from the reduction of potassium fluorosilicate with metallic potassium: Silicon: a versatile element with myriad aplications

21 1831 Contact process for sulphuric acid patented by the British vinegar merchant Peregrine Phillips. In addition to being a more economical process for concentrated sulfuric acid than the previous lead chamber process, the contact process also produces sulfur trioxide and oleum. Sulfuric acid is the second largest inorganic chemical produced worldwide (200 million tonnes) Contact process for sulphuric acid

22 1834 J. Liebig and F. W ö hler prepares the inorganic heterocycle cyclophosphazene, N 3 P 3 Cl 6 from the reaction of PCl 5 and NH 4 Cl. Friedrich W ö hler Father of Synthetic Organic Chemistry W ö hler statue at G ö ttingen 3 Si + 2 N 2 → Si 3 N 4 (1857)

23 1840 C.F. Schoenbein detects and names ozone from its characteristic odour after a lightning storm Mn 2+

24 1859 The French physicist Gaston Planté discovers the lead–acid battery, the oldest type of rechargeable battery lead–acid battery

25 1886 Henri Moissan prepared fluorine gas, F 2 by the electrolysis of a solution of potassium hydrogen difluoride in liquid hydrogen fluoride. For this discovery he received the Nobel prize in 1906.

26 The Azides: MN 3 and RN 3 Curtius 1890 Wislicenus (1892) The common synthesis method is the "Wislicenus process," which proceeds in two steps from ammonia. In the first step, ammonia is converted to sodium amide: 2 Na + 2 NH 3 → 2 NaNH 2 + H 2 The sodium amide is subsequently combined with nitrous oxide: 2 NaNH 2 + N 2 O → NaN 3 + NaOH + NH 3 Alternatively the salt can be obtained by the reaction of sodium nitrate with sodium amide.

27 1904 F. S. Kipping coins the word "silicone" to describe polydiphenylsiloxane by analogy of its formula, with the formula of benzophenone F. S. Kipping

28 Silicone Polymers Lowest glass transition temperature, Tg = -127 °C In 1937 after 30 years of research, Kipping In the Bakrerian lecture of the Royal Society said “The prospect of any immediate and important advance in this section of organic chemistry does not seem to be very hopeful."

29 1904 Sir William Ramsay discovered neon, krypton, and xenon and received Nobel Prize in He also isolated helium which had been observed in the spectrum of the sun but had not been found on earth till then. In 1910 he also made and characterized radon. (1894 argon with Lord Raleigh) Morris M. Travers ( ) In Ramsay had been asked to advise the Indian government on the founding of a science institute and the institute was established in Bangalore with the help of the Government of Mysore and JN Tata. Ramsay suggested his student Morris Travers as a possible director for this institute and in 1906, Travers was appointed as the director of the new Indian Institute of Science Sir William Ramsay

30 Henry Joseph Round To the Editors of Electrical World: SIRS: – During an investigation of the unsymmetrical passage of current through a contact of carborundum and other substances a curious phenomenon was noted. On applying a potential of 10 volts between two points on a crystal of carborundum, the crystal gave out a yellowish light. Only one or two specimens could be found which gave a bright glow on such a low voltage, but with 110 volts a large number could be found to glow. In some crystals only edges gave the light and others gave instead of a yellow light green, orange or blue. In all cases tested the glow appears to come from the negative pole, a bright blue-green spark appearing at the positive pole. In a single crystal, if contact is made near the center with the negative pole, and the positive pole is put in contact at any other place, only one section of the crystal will glow and that same section wherever the positive pole is placed. There seems to be some connection between the above effect and the e.m.f. produced by a junction of carborundum and another conductor when heated by a direct or alternating current; but the connection may be only secondary as an obvious explanation of the e.m.f. effect is the thermoelectric one. The writer would be glad of references to any published account of an investigation of this or any allied phenomena. New York, N. Y. H. J. Round 1907 The first light emitting diode (LED) made of SiC Gallium arsenide (GaAs) Aluminium gallium arsenide (AlGaAs) Silicon carbide Gallium phosphide Indium gallium nitride etc

31 1909 Fritz Haber reports Haber process for the catalytic synthesis of NH 3 which was made into a large scale industrial process along with C. Bosch in Haber received the Nobel Prize in Chemistry in According to an estimate, nearly 80% of nitrogen present in the human tissue has had its origins from Haber process. The worldwide production of ammonia exceeds 140 million tonnes and is the third largest inorganic chemical produced in the world. HaberBosch

32 Alfred Stock- the father of boron hydride chemistry 1912 Alfred Stock prepares a series of boron hydrides including B 2 H 6 and separates them using the first sophisticated vacuum manifold. Due to their very high air and moisture sensitivity and flammability, till then they were not separable. He published his work in 1933.

33 Borazine has the same colligative properties as benzene, however the two are very different chemically. The electron density along the boron-nitrogen bond is not distributed evenly, due to the difference in electro negativities between the two atoms. Therefore, the molecular orbitals of the system are lumpy in appearance. This uneven distribution makes borazine makes it prone to addition reactions. Probability Distributions for borazine (left) and benzene (right) First reported in 1926 by Alfred Stock and Pohland 3 B 2 H NH 3 → 2 B 3 N 3 H H 2 An alternative more efficient route begins with lithium borohydride and ammonium chloride: 3 LiBH NH 4 Cl → B 3 N 3 H LiCl + 9 H 2 Borazine is isostructural with benzene. The six B-N bonds have length of Å. The carbon-carbon bond in benzene is shorter length at 1.42 Å. The boron-nitrogen bond length is between that of the B -N (1.51 Å ) and the B=N (1.31 Å). This suggests partial delocalization of nitrogen lone pair. Borazine: The Inorganic Benzene

34 Aerial view of Chernobyl reactor 1935 H J Taylor

35 1938 Poly tetrafluoroethylene (Teflon) accidentally discovered by Roy J. Plunkett of kinetic chemicals (A subsidiary of DuPont) while attempting to make a new CFC using tetrafluoroethylene. He observed that there was no gas flowing out of a small cylinder of tetrafluoroethylene whose weight indicated no loss of substance. On cutting open the cylinder, he observed a waxy white highly slippery solid on its interior walls whose analysis indicated polymerized tetrafluoroethylene. Roy J. Plunkett

36 Thomas Midgley: A daring inventor 1941 To show that his chlorofluorocarbon (CFC) coolant, Freon, is nontoxic and nonflammable, Thomas Midgley Jr. takes the stage at an ACS national meeting, inhales a lungful of Freon, and blows out a candle. J.R. McNeill an environmental historian remarked that Midgley had more impact on the Earth’s atmosphere than any other living organism due to his inventions: namely, lead gasoline additives and chlorofluorocarbons. However, Midgley wasn’t killed by these inventions which we now know to be exceptionally harmful. He met his maker thanks to a bed that he created after contracting polio and becoming bedridden at the age of 51. The bed featured a complex system of ropes and pulleys to help Midgley’s attendants get him out of bed…ropes which eventually strangled him. In 1941, the American Chemical Society gave Midgley its highest award, the Priestley Medal This was followed by the Willard Gibbs Award in He also held two honorary degrees and was elected to the United States National Academy of Sciences. In 1944, he was elected president and chairman of the American Chemical Society

37 Industrial success of Silicones E.G. Rochow

38 1954 G. Rupprecht reports the semi conducting properties of Indium oxide, In 2 O 3. This was followed by the report by V. A. Williams in 1966 on the potential of tin doped indium oxide (Indium tin oxide, ITO) as a transparent conducting material. ITO is a solid solution of indium(III) oxide and tin(IV) oxide, typically 90% In 2 O 3, 10% SnO 2 by weight. It is the most widely used transparent conducting oxide, especially as films because of its electrical conductivity, optical transparency, as well as the ease of depositing as thin films. Applications include liquid crystal, flat panel and plasma displays, touch screen technology of mobile phones and ATM’s, electronic ink, light-emitting diodes, solar cells, antistatic coatings, defrosting aircraft wind shields and infrared reflecting coatings.indium(III) oxidetin(IV) oxideelectrical conductivityoptical transparency ITO capacitiveresistive

39 The discovery of the first noble gas reaction In March of 1962, Bartlett set up a glass apparatus containing PtF 6, a red gas in one container and xenon, a colorless gas in an adjoining container, separated by a seal. Here's his recollection of the ensuing experiment, which he conducted while working alone in his laboratory: "Because my co-workers at that time (March 23, 1962) were still not sufficiently experienced to help me with the glassblowing and the preparation and purification of PtF 6 [platinum hexafluoride] necessary for the experiment, I was not ready to carry it out until about 7 p.m. on that Friday. When I broke the seal between the red PtF 6 gas and the colorless xenon gas, there was an immediate interaction, causing an orange- yellow solid to precipitate. At once I tried to find someone with whom to share the exciting finding, but it appeared that everyone had left for dinner!" The reaction took place at room temperature "in the twinkling of an eye" and was "extraordinarily exhilarating," recalls Bartlett. He was certain that the orange-yellow solid was the world's first noble gas compound. But convincing others would prove somewhat difficult. The prevailing attitude was that no scientist could violate one of the basic tenets of chemistry: the inertness of noble gases. That orange-yellow solid was subsequently identified in laboratory studies as xenon hexafluoroplatinate (XePtF 6 ), the world's first noble gas compound. 1962

40 Metalla Carboranes “olla” metallacarborane M. F Hawthorne 1965

41 Allen K. Breed uses sodium azide, NaN 3 along with a collision sensor in automobile airbags (instead of compressed air) and achieves inflation of the airbag under 30 milliseconds required for collision safety Allen K. Breed 1967 One azido group contributes about 335 kj/mol ( 80 kcal/mol) of endothermicity to a compound

42 Wade’s Rules Ken Wade, Durham For borane and carborane clusters, the structures are based on deltahedra, which are polyhedra in which every face is triangular. The clusters are classified as closo-, nido-, arachno- or hypho-, based on whether they represent a complete (closo-) deltahedron, or a deltahedron that is missing one (nido-), two (arachno-) or three (hypho) vertices. Boron hydrideNameNo. of skeletal electron pairs Examples [B n H n ] 2- or B n H n+2 Closon+1B 6 H 6 2-, B 12 H B n H n+4 Nidon+2B 2 H 6,B 5 H 9, B 10 H 14 B n H n+6 Arachnon+3B 4 H 10 B n H n+8 Hyphon+4B 5 H 12  Each BH unit furnishes 2 skeletal bonding electrons Each additional H· furnishes 1 skeletal bonding electron Ionic charges must be included in the electron count 1971

43 Earl R. Stadtman (b. 1919) and Theresa C. Stadtman (b. 1920) Selenocysteine is the 21st proteinogenic amino acid. It exists naturally in all kingdoms of life as a building block of selenoproteins. Selenocysteine is a cysteine analogue with a selenium-containing selenol group in place of the sulfur-containing thiol group. It is present in severalenzymes (for example glutathione peroxidases, tetraiodothyronine 5' deiodinases, thioredoxin reductases, formate dehydrogenases, glycine reductases etc). Selenocysteine was discovered by biochemist Theresa Stadtman, wife of Earl R. Stadtman, at the National Institutes of Health. 1976

44 ROBERT WEST Å Robert West makes the first stable silicon–silicon double bonded compound “Why do you want to climb mount Everest”? “Because it‘s there” George Mallory :British mountaineer,

45 Anthony J. Arduengo, III Carbene Is Genie In A Bottle Chemists are particularly drawn to molecules that behave like ferocious cats, reacting rapidly and often violently and hence cannot seem to resist the temptation to control them. One such species is the carbene which is imperative for an entire framework of organic reactions thereby leading to an altogether a separate branch named---Carbene Chemistry Anthony J Arduengo III prepares the first stable carbene now well known as the NHC or N-Heterocyclic Carbene

46 1999 First N 5 + (pentazenium) compound, N 5 + AsF 6 - discovered by Karl O. Christe. N 5 + cation is a highly energetic ion with a calculated endothermicity of kJ/mol. Pentazenium, N 5 + Karl O. Christe One azido group contributes about 335 kj/mol (80 kcal/mol) of endothermicity to a compound

47 Konrad Seppelt discovers the first metal-xenon compound where xenon acts as a ligand achieved by reduction of AuF 3 with xenon. The AuXe 4 2+ (Sb 2 F 11 - ) 2 complex had a square planar gold with a Au-Xe bond distance of 274 pm Konrad Seppelt first metal-xenon compound where xenon acts as a ligand

48 Jemmis’ rules E.D. Jemmis, I.I.Sc, Bangalore Jemmis draws together a number of corollaries to Wade's rules into a single, easily employed general rule," Thomas P. Fehlner Jemmis’ mno rule states that m + n + o skeletal electron pairs are necessary for a closed macropolyhedral system to be stable [or (m + n + o + p) for systems having open polyhedra as well]. Here m = number of condensed polyhedra n = number of vertices o = number of single atom bridges between two polyhedra p = number of vertices missing for open polyhedra if present. For example, for nido clusters p = 1 and for arachno clusters p = 2. For a benzene ring or cyclopentadienyl ring as such p = 2 and if it is already in an  6 or  5 mode, p= 1. For transition metals, the oxidation state of the metal should be known and the number of electrons for the electron count should be taken as the same as the number of electrons lost by the neutral metal atom to reach that oxidation state; for example, Fe3+ gives 3 electrons. The uniqueness of Jemmis’ mno rules is that they are not only applicable to macropolyhedral clusters but also applied to polyhedra, metallocenes, and even unsaturated cyclic organic compounds. Interestingly, Jemmis’ rules get reduced to Wade’s rules when m = 1 and o = 0 (one polyhedron). 2001

49 Akiro Sekiguchi prepares the first silicon-silicon triple bonded compound 2004 Akiro Sekiguchi first silicon-silicon triple bond

50 2004 Sir Andre Geim Graphene consists of one-atom-thick layers of carbon atoms arranged in two-dimensional hexagons, and is the thinnest material in the world, as well as one of the strongest and hardest.The material has many potential applications and is considered a superior alternative to silicon. Geim's achievements include the discovery of a simple method for isolating single atomic layers of graphite, known as graphene. The team published their findings in October 2004 in Science Geim was awarded the 2010 Nobel Prize in Physics jointly with Novoselov "for groundbreaking experiments regarding the two-dimensional material graphene". Stronger than steel: 200 times Thinner than hair: 1 million times Worlds most conductive material Stretchable, transparent, flexible permeable Worlds first 2D material Graphene

51 2006 Douglas W. Stephan discovers the first example of a frustrated Lewis acid base pair based on boron and phosphorus. Due to their unquenched reactivity such molecules are able to heterolytically cleave dihydrogen molecule making them potential metal free hydrogenation catalysts. Douglas Stephan

52 GREG ROBINSON B=B Si=Si (0 state) G.M Robinson proposed the first gallium–gallium triple bonded compound in 1997 which evoked the famous comment from F.A Cotton that, "That's no more a triple bond than I'm the Dalai Lama!" Å

53 K Tamao prepares a stable germanone molecule having a Ge=O bond. This is the first example of a heavier element ketone analogue 2012 K Tamao

54 First example of a stable diboryne having a B  B and stabilized by N-heterocyclic carbenes prepared by Holger Braunschweig 2012 Holger Braunschweig

55 2014 Lai-Sheng Wang at Brown University in Providence, Rhode Island, and his colleagues have made a cage-like molecule with 40 boron atoms by vaporizing a chunk of boron with a laser then freezing it with helium, creating boron clusters. The team analyzed the energy spectra of these clusters and compared them with computer models of 10,000 possible arrangements of boron atoms. The matching configuration revealed they had created the boron ball. Unlike carbon buckyballs, in which the faces are made of hexagons and pentagons, the boron buckyball is made from triangles, hexagons and heptagons. As a result, it is less spherical but still an enclosed structure. Wang has dubbed the molecule "borospherene". The team is now hunting for a boron analogue of graphene – a strong sheet of carbon just one atom thick that is often touted as a "wonder" material because of its unique electrical properties. ( july 12, 2014 Nature Chemistry ) Borospherene Lai-Sheng Wang


Download ppt "CYL 503: Chemistry of the main group elements and solids Shapes of molecules, symmetry and group theory Hypervalency and d orbital participation Space."

Similar presentations


Ads by Google