INORGANIC CHEMISTRY 2 CHEM 251 Dr Violeta Jevtovic

1.1. Introduction Textbook: “Inorganic Chemistry” by C. E. Housecroft and A. G. Sharpe, Prentice Hall (1st ed., 2001; 2nd ed., 2005) Other suggested readings: Chemistry of elements by Greenwood & Earnshav, Butterwort- Heinemann, 1997 Advance Inorganic Chemistry, 6rd ed., by F. A. Cotton et al., Wiley (1999) 2nd ed. Inorganic Chemistry, 3rd ed., by G.L. Miessler and D.A. Tarr, Prentice Hall (2004)

Inorganic chemistry II Inorganic chemistry I and II is the study of the synthesis and behavior of inorganic and organometallic compounds. This field covers all chemical compounds except the myriad organic compounds (carbon based compounds, usually containing C-H bonds), which are the subjects of organic chemistry. The difference between the two disciplines is far from absolute, and there is much overlap, most importantly in the sub-discipline of organometallic chemistry. It has applications in every aspect of the chemical industry –including catalysis, materials science, pigments, coatings, medicine, fuel, and agriculture.

Course objectives: ..is to fully understand the chemistry of the transition metals, will be given a systematic study of Coordination chemistry … will be introduced modern and clasical treatmens of bonding (crystal and ligand field theory) in coordination compounds and the application of these models in the interpretation of spectroscopic and magnetic properties.

1.2. Important application of complex compound

1.3. Transition Metals and Coordination Chemistry coordination chemistry is the chemistry of d- block or transition metals d block elements have d sublevel and have d electrons necessary for the construction of coordination links

Multiple Oxidation States

1.4. Complexes early work Each complex has an inner and outer sphere. The outer sphere makes ligan, ligand environment, which is wrapped around the metal ions like as crab pliers. Therefore, it is another name for this type of compounds is chelates ... from the Greek word for cancer pliers. Inner sphere A central metal atom bonded to a group of molecules or ions is a metal complex. Compounds containing complexes are coordination compounds. outer sphere Central metal

Complex Ions . . . species where the transition metal ion is surrounded by a certain number of ligands (Lewis bases). Co(NH3)63+ Pt(NH3)3Br+ Most compounds are colored, because the transition metal ion in the complex ion can absorb visible light of specific wavelengths. Many compounds are paramagnetic or diamagnetic.

LIGANDS The molecules or ions coordinating to the metal are the ligands. They are usually anions or polar molecules. ligands have a free pair of electrons to create connections with metal

But, if you have more electron pairs we call them: Polydentate Ligands Ethylenediaminetetraacetat , abbreviated EDTA, has six donor atoms.

Coordination Number Some metals, such as chromium(III) and cobalt(III), consistently have the same coordination number (6 in the case of these two metals). The most complexes usually have numbers are 4 and 6, and 2.

Geometries There are two common geometries for metals with a coordination number of four: Tetrahedral Square planar

Examples of discrete (finite) complex Coordination number Geometry Examples of discrete (finite) complex Examples in crystals 2 linear Ag(CN)2− in KAg(CN)2 [3] Ag in silver cyanide, Au in AuI [2] 3 trigonal planar Cu(CN)32− in Na2Cu(CN)3.3H2O[2] O in TiO2 rutile structure[3] 4 tetrahedral CoCl42−[2] Zn and S in zinc sulfide, Si in silicon dioxide[3] square planar AgF4−[2] CuO[3] 5 trigonal bipyramidal SnCl5−[3] square pyramidal InCl52− in (NEt4)2InCl5[2] 6 octahedral Fe(H2O)62+[2] Na and Cl in NaCl[3]

Oxidation Numbers -2 X if you know the charge on a complex ion and the charge on each ligand, one can determine the oxidation number for the metal.

The central metal and the ligands directly bonded to it make up the coordination sphere of the complex. In CoCl3 ∙ 6 NH3, all six of the ligands are NH3 and the 3 chloride ions are outside the coordination sphere.

Werner proposed putting all molecules and ions within the sphere in brackets and those “free” anions (that dissociate from the complex ion when dissolved in water) outside the brackets.

1.5. Formulas of Coordination Compounds Nomenclature 1. Cation then anion 2. Total charges must balance to zero 3. Complex ion in brackets K2[Co(NH3)2Cl4] [Co(NH3)4Cl2]Cl

Names of Coordination Compounds 1. Cation then anion 2. Ligands in alphabetical order before metal ion neutral: molecule name* anionic: -ide  -o prefix indicates number of each 3. Oxidation state of metal ion in () only if more than one possible 4. If complex ion = anion, metal ending  -ate

Examples K2[Co(NH3)2Cl4] potassium diamminetetrachlorocobaltate(II) [Co(NH3)4Cl2]Cl tetraamminedichlorocobalt(III) chloride