Advanced Inorganic Chemistry

1. Advanced Inorganic Chemistry

2. Textbooks 2 Required texts: d-Block Chemistry (book 1) by Mark J. Winter (Oxford Primers) Introduction to Molecular Symmetry (book 2) by J. S. Ogden (Oxford Primers) The Mechanisms of Reactions at Transition Metal Sites (book 3) by Richard A. Henderson (Oxford Primers) Recommended: Basic Inorganic Chemistry by F. Albert Cotton et G. Wilkinson, Wiley; not in the library Advanced Inorganic Chemistry by F. Albert Cotton et al., Wiley; 6th edition � 1999; on hold Inorganic Chemistry by Gary L. Miessler and Donald A. Tarr, Prentice Hall, Inc., 2004 Chemical Applications of Group Theory by F. Albert Cotton et al., Wiley; 3rd edition � 1990; in the library Inorganic Chemistry by D. F. Shriver et al., Freeman; 3rd edition � 1999; permanent reserves

3. Grading Test (April 7): 10% Midterm: 25% Final : 40% Quizzes : 15% Homework : 10% Extra credit: 5% 10-15 students: critical study of a paper / DFT calculations Presentation to a high school on inorganic chemistry: letter from instructor Personal choice if approved 3

4. Course content Coordination Chemistry (book 1) Structures and Isomers Simple bonding theory Acid-Base Chemistry (book 1) Hard and soft acids and bases Introduction to Molecular Symmetry (book 2) Symmetry elements and point groups Representations Molecular vibrations and vibrational spectroscopy Chemical bonding 4

5. Course content Coordination Chemistry (book 1 and 2) Bonding Electronic Spectra Inorganic Reaction Mechanisms (book 3) Substitution reactions Electron transfer reactions Ligand-based reactions 5

6. VSEPR model 6

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11. The d-block elements: transition metals Nature: as active sites of enzymes � hemoglobin (oxygen transport), nitrogenases (nitrogen fixation), hydrogenases, etc. 11

12. Nitrogen fixation Heterogeneous catalysis: Haber-Bosch process Homogeneous catalysis: 12

13. Vitamin B12 13

14. Gemstones 14

15. Coordination chemistry 15

16. Coordination chemistry: Definitions A coordination compound, sometimes called a coordination complex, contains a central metal atom or ion surrounded by a number of oppositely charged ions or neutral molecules (possessing lone pairs of electrons) which are known as ligands. If a ligand is capable of forming more than one bond with the central metal atom or ion, then ring structures are produced which are known as metal chelates, the ring forming groups are described as chelating agents or polydentate ligands. The coordination number of the central metal atom or ion is the total number of sites occupied by ligands. Note: a bidentate ligand uses two sites, a tridentate three sites etc. 16

17. Examples of complexes derived from common ligands 17

18. Examples of complexes derived from common ligands 18

19. Complexes of common ligands 19

20. Nomenclature rules: Formulae In a coordination formula, the central atom is listed first. The formally anionic ligands appear next, listed in alphabetical order according to the first symbols of their formula. The neutral ligands follow, also in alphabetical order, according to the same principle. The formula of the entire coordination entity, whether charged or not, is enclosed in square brackets. If the coordination entity is negatively charged, the formula is preceded by the cation formula. When ligands are polyatomic, their formulae are enclosed in parentheses. Ligand abbreviations are also enclosed in parentheses. 20

21. Nomenclature rules: Names 1. In naming the entire complex, the name of the cation is given first and the anion second (just as for sodium chloride), no matter whether the cation or the anion is the complex species. 2. In the complex ion, the name of the ligand or ligands precedes that of the central metal atom. (This procedure is reversed from writing formulae.) 3. Ligand names generally end with 'o' if the ligand is negative ('chloro' for Cl-, 'cyano' for CN-, 'hydro' for H-) and unmodified if the ligand is neutral ('methanamine' for MeNH2). Special ligand names are 'aqua' for water, 'ammine' for ammonia, 'carbonyl' for CO, 'nitrosyl' for NO. 21

22. Nomenclature rules: Names 4. A Greek prefix (mono, di, tri, tetra, penta, hexa, etc.) indicates the number of each ligand (mono is usually omitted for a single ligand of a given type). If the name of the ligand itself contains the terms mono, di, tri, eg triphenylphosphine, then the ligand name is enclosed in parentheses and its number is given with the alternate prefixes bis, tris, tetrakis instead.  Again, one would use diammine, for (NH3)2, but bis(methylamine), for (NH2Me)2, to make a distinction from dimethylamine. (Note that this ambiguity does not arise if the preferred IUPAC name, methanamine, is used instead of methylamine). There is no elision of vowels or use of a hyphen, e.g. in tetraammine and similar names. Some texts suggest that if a ligand is "complicated" then use the bis, tris multipliers. What constitutes "complicated" is not spelled out however, so a simpler approach is to use them if the name of the ligand is three or more syllables long!  22

23. Nomenclature rules: Names 5. A Roman numeral or a zero in parentheses is used to indicate the oxidation state of the central metal atom. 6. If the complex ion is negative, the name of the metal ends in 'ATE' for example, ferrate, cuprate, nickelate, cobaltate, etc. 7. If more than one ligand is present in the species, then the ligands are named in alphabetical order regardless of the number of each. For example, NH3 (ammine) would be considered an 'a' ligand and come before Cl- (chloro). 23

24. Some additional notes Some metals in anions have special names B - Borate Au - Aurate Ag - Argentate Fe - Ferrate Pb - Plumbate Sn - Stannate Cu - Cuprate Use of brackets or enclosing marksSquare brackets are used to enclose a complex ion or neutral coordination species.  Examples: [Co(en)3]Cl3 [Co(NH3)3(NO2)3] K2[CoCl4]  note that it is not necessary to enclose the halogens in brackets. Note that in 2004 it was recommended that anionic ligands will end with -ido so that chloro would become chlorido, etc. 24

25. Stability and lability It is necessary to distinguish between thermodynamic and kinetic stability. Terms: stable and unstable refer to thermodynamic stability inert and labile refer to kinetic stability if a reaction takes longer than 1 minute under the conditions of concentration 0.1 M, temperature 25�C, then compound X is INERT; if under the same conditions the reaction time < 1 minute, then it is LABILE. 25

26. Stability of a complex in solution It refers to the degree of association between the two species involved in the state of equilibrium. Qualitatively, the greater the association, the greater the stability of the compound. The magnitude of the (stability or formation) equilibrium constant for the association, quantitatively expresses the stability. 26

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