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Chem 120A Fall 2005

Tuesday & Thursday 8:00 – 9:20 AM Warren Lecture Hall Room 2005

Prof. Karsten Meyer Pacific Hall 4100E 2-4247, [email protected] Office Hours: Mo 10 – 12AM

Handouts http://www.inorganic-chemistry.net/ kmpages/courses.html

Chem 120A

Midterm I: 10/11 (30%) Midterm II: 11/08 (30%)

Final Exam: Dec. 6, 2005 @ 8 – 11 AM (40%)

2 hr Review Session Sunday before Midterm Midterm I: 10/9 location & time tba Midterm II: 11/6 location & time tba

1 Chem 120A Fall 2005

PLEASE:

• Try to be on time

•I know you’re busy,… …but please turn off your phones

• I know it’s early,… …but please don’t fall asleep (if you have to, don’t sit in the first row)

Chem 120A

PLEASE:

• I know you’re in a rush,… …but if you send me an email, please address me and sign your email

• If you do have a question…

…please feel free to interrupt me

…any time!!!

2 Chem 120A

In return, I PROMISE…

• I promise I’ll finish on time

• I promise I’ll help you to understand

• I promise I’ll follow the textbook…

…& Solutions Manual…

…strictly!!!

Chem 120A

3 Miessler & Tarr Brief Contents

9/22 9/27 Mid- Oct. 11 Oct. term I 9/29 + 10/04 10/06 + 10/11 10/18

selected topics 10/20 Mid-

Nov. 08 Nov. 10/25 + 10/27 term II 11/01 + 11/03 11/10 11/15 11/17 11/22 11/24 Thanksgiving

Final Exam 11/29 + 12/01 Dec. 06, 8 – 11AM

Chem 120A

4 1. Contents

1-1 What is ?

• is defined as the chemistry of hydrocarbon compounds and their derivatives

But how about CO, CO2, and HCN…for instance?

• Inorganic chemistry can be described broadly as the chemistry of “everything else”

5 1-1 What is Inorganic Chemistry?

1-1 What is Inorganic Chemistry?

• Organic chemistry is defined as the chemistry of hydrocarbon compounds and their derivatives

• Inorganic chemistry can be described broadly as the chemistry of “everything else”

may be a little too broadly defined…

• bridges both areas; deals with - bonds (incl. La & Ac)

• Bioinorganic chemistry bridges & with inorganic chemistry (think )

Supramolecular~, Phyisical Inorganic ~ etc…

6 1-2 Contrasts with Organic Chemistry?

triple bond!

Figure 1-1. Single- and Multiple Bonds in Organic and Inorganic

1-2 Contrasts with Organic Chemistry?

Figure 1-2. Examples of Bonding Interactions

7 1-1 Contrasts with Organic Chemistry?

Figure 1-3. Examples of Inorganic Compounds Containing H’s & Alkyl

1-2 Contrasts with Organic Chemistry?

Figure 1-4. Geometries of Inorganic Compounds

8 1-2 Contrasts with Organic Chemistry?

Figure 1-5. Organometallic Compounds Containing π-Bonded Aromatics

1-2 Contrasts with Organic Chemistry?

Figure 1-6. Carbon-centered Metal Clusters…5- and 6-bonded C!?

9 1-2 Contrasts with Organic Chemistry?

Figure 1-7. Fullerene Compounds…C60…buckminsterfullerene* “buckyballs”

…but don’t forget C70, C76, C84

*Richard Buckminster Fuller, creator of the “geodesic dome”

1-3 “Big Bang” Genesis of the Elements

t = 0: The matter was not actually matter, but pure energy. It contained infinite mass, infinite density, and no volume: Singularity (like Black Holes) 0 – 10-43 s: Mystery…nobody knows, energy behaved as singularity 10-43 –10-35 s: Energy and matter are indistinguishable @ 10-35 s: Temperature of 1027K (the sun’s surface T is 6000 K) symmetry breaking, forces begin to separate 10-35 –10-32 s: Inflation; universe grows exponentially (1050 in 10-32s)

10 1-3 Big Bang Genesis of the Elements

10-35 –10-32 s: Inflation; universe grows exponentially (1050 in 10-32s) As it cooled, the energy of the universe began to condense. It moved up the list from photons to quarks, neutrinos, electrons, and protons…yippie yeah 1 – 100 s: Era of Nucleosynthesis, almost all of the helium and deuterium nuclei, and some lithium formed @ 100 s: s all of the neutrons and protons had combined to form helium with trace amounts of a few other materials forming with it.

1-3 Big Bang Genesis of the Elements

Then not much happened for about 300,000 years (75% H, 24% He)

mass number 1 proton + neutron 1 4 atomic number 1H nuclear charge 1H 2He

11 1-3 Big Bang Genesis of the Elements

most abundant element heavy water cosmic radiation in in the universe high atmospheres

1 2 3 1H 1H 1H H Deuterium D Tritium T 99.9855% 0.0145% 10-15 %

1-3 Big Bang Genesis of the Elements

Initial Event:

1 1H = p = proton of charge +1 and mass 1.007 mass unit (amu)

0 − -1e = e = electron of charge -1 and mass 1/1823 amu 0 + 1e = e = positron of charge +1 and mass 1/1823 amu 0 1ve = a neutrino with no charge and a very small mass 0 1ve = an antineutrino with no charge and a very small mass 1 0n = a neutron with no charge and a mass 1.009 γ = a gamma ray (high-energy photon ) with zero mass β = a beta particle α = a alpha particle

12 1-3 Big Bang Genesis of the Elements

1 Within minutes T1/2 ( n ) = 11.3 min @ T = 109 K:

Hydrogen-Burning:

Matarial gathers together into galactic clusters

Helium-Burning @ T = 107 –108 K:

1-3 Big Bang Genesis of the Elements

In more massive Stars T > 6 108K:

Carbon- Cycles

@ still higher T:

I guess, you got the idea…

13 1-3 Big Bang Genesis of the Elements

And last but not least…Cosmic Abundance of the Elements

nuclear stability log10/ V most stable near Z = 26

have a close look at what is considered “rare” & “precious”

see what we are made off

atomic number / Z

1-4 Nuclear Reactions & Reactivity

Stable Isotopes 1 2 3 1H 1H 1H F only has one stable isotope: 19F

Cl has two stable isotopes: 35Cl (nat. abd.: 75.77%), 37Cl (24.23%)

3H and 14C are constantly formed (cosmic rays, low conc.)

Z = 26 “stable zone”, heavier elements (Z>=40) may have isotopes with long half-lifes, e.g., 40K 1.25 x 109y β− (1.32 MeV) or 234, 235,238U

man-made elements (Transuranics) such as Np and Pu via “Bombardment” of one element with nuclei of another, e.g., n + U folowed by release of β−

14 1-4 Nuclear Reactions & Reactivity

α = a alpha particle (He nucleus)

Alpha particles (Ernest Rutherford, England 1899) are a type of ionizing radiation ejected by the nuclei of some unstable . They are large , heavy subatomic 4 fragments consisting of 2 protons and 2 neutrons ( 2He).

Why? With increasing atomic mass, ratio of neutrons to protons 238 increases from 1:1 to 1.6:1 for 92U. When the ratio of neutrons to protons in the nucleus is too low, certain atoms restore the balance by emitting alpha particles.

Relative Abundance of Uranium Isotopes Isotope 238-U 235-U 234-U Nat. Abundance (%) 99.27 0.72 0.0055 Half-life (years) 4.47 billion 700 million 246,000

1-4 Nuclear Reactions & Reactivity

β = a beta particle (e −)

Beta Particles (Henri Becquerel , 1900) are equivalent to electrons. The difference is that beta particles originate in the nucleus and electrons originate outside the nucleus.

Why? Beta particle emission occurs when the ratio of neutrons to protons in the nucleus is too high: an excess neutron transforms into a proton and an electron. The proton stays in the nucleus and the electron is ejected energetically. -> a new element is born!

Beta emitters are: 99Tc (99Ru) or 60Co (60Ni) or 3H (3He)

15 1-4 Nuclear Reactions & Reactivity

γ = a gamma ray (high-energy photon ) with zero mass

Gamma Rays (Henri Becquerel 1896) have no mass and no electrical charge; they are pure electromagnetic energy (10,000 times as much energy as the photons in the visible) gamma photons travel at the speed of light and can cover hundreds to thousands of meters in air before spending their energy

Why? Gamma radiation emission occurs when the nucleus of a radioactive has too much energy (often follows the emission of a beta particle).

E.g.: 137Cs β + (137Ba)* γ + 137Ba

1-6 History of Inorganic Chemistry

3000 BC

silver tin antimony lead

1500 BC colored glasses & ceramic glazes

made from SiO2 and MOx

http://www.chemsoc.org/timeline/pages/timeline.html

16 1-6 History of Inorganic Chemistry

Anno Domini

Alchemy

Simplified, the aims of the alchemists were threefold: to find the Stone of Knowledge (The Philosophers' Stone), to discover the medium of Eternal Youth and Health, and to discover the transmutation of . To the medieval alchemist’s mind the different elements were but the same original substance in varying degrees of purity. Gold was the purest of all and silver followed closely.

1-6 History of Inorganic Chemistry

Anno Domini Various alchemical symbols used to denote elements until the 18th Century

antimony arsenic bismuth copper gold iron lead

mercury phosphorous platinum silver

tin

17 1-6 History of Inorganic Chemistry

Anno Domini In the 18th century scientists tried to pry loose the real achievements in chemistry, and from this confusing cornucopia of science and magic.

Discovery of Hydrogen (1766)

Henry Cavendish A. L. de Lavoisier 1731 – 1810 1743 – 1794

1-6 History of Inorganic Chemistry

By 1869 Concepts of atoms & molecules are well-established:

“I began to look about and write down the elements with their atomic weights and typical properties, analogous elements and like atomic weights on separate cards, and this soon convinced me that the properties of elements are in periodic dependence upon their atomic weights.”

--Mendeleev, Principles of Chemistry, 1905, Vol. II

Dmitri I. Mendeleev (Born in Siberia 1834, 17 Feb. 1869 )

18 1-6 History of Inorganic Chemistry

By 1869 Concepts of atoms & molecules are well-established:

Dmitri I. Mendeleev’s of the Elements (17 Feb. 1869 )

1-6 History of Inorganic Chemistry

By 1869 I.I. Mendeleev, Concepts of atoms & molecules J. Russ. Phys. Chem., 1869, I,60. are well-established:

Dmitri I. Mendeleev’s Periodic Table of the Elements (17 Feb. 1869 )

19 1-6 History of Inorganic Chemistry

In 1913

In 1913 British physicist Henry Moseley confirmed earlier suggestions that an element's chemical properties are only roughly related to its atomic weight (now known to be roughly equal to the number of protons plus neutrons in the nucleus). What really matters is the element's atomic number - the number of electrons its atom carries, which Moseley could measure with X-rays.

Ever since, elements have been arranged on the periodic table according to their atomic numbers.

1-6 History of Inorganic Chemistry

20