GENERAL CHEMISTRY WORKSHOP

COORDINATION CHEMISTRY

1. Name the following coordination compounds. (Do not attempt to distinguish among

isomers). a) [Co(OH)(H2O)4(NH3)]+2; b) [Co(ONO)3(NH3)3]; c) [Al(OH)(H2O)5]+2; d) [Pt(H2O)4][PtCl6]; e) [Fe(ox)2(H2O)2]-1; f) Ag2[HgI4]; g) [CoCl(NO2)(NH3)4]+;

h) [Cr(NH3)6][Co(CN)6]; i) [CoSO4(NH3)5]Br; j) [Co(ox)3]-4.

2. Write appropriate formulæ for the following species. (Do not attempt to distinguish among isomers). a) potassium hexacyanoferrate(III); b) bis(ethylenediamine)copper(II) ion; c) pentaaquahydroxoaluminum(III) chloride; d) trioxalatocobaltate(III) ion;

e) amminechlorobis(ethylenediamine)chromium(III) sulfate; f) dicyanoargentate(I) ion; g) tris(ethylenediamine)iron(III) hexacyanoferrate(II); h) sodium hexacyanochromate(II);

i) hexaaquanickel(II) ion; j) pentaaquachlorochromium(III) iodide. 3. If A, B, C, and D are four different ligands, a) How many geometric isomers will be

found for square planar [PtABCD]+2? b) Will tetrahedral [ZnABCD]+2 display optical isomerism?

4. How many isomers are there of the complex ion [CoCl2(en)(NH3)2]+? Sketch their

structures. 5. The structures of four complex ions are given below. Each has Co+3 as the central ion.

The ligands are H2O, NH3, and oxalate ion, C2O4-2. Determine which, if any, of these

complex ions are isomers, which are identical, and which are distinctly different.

6. Indicate the coordination number and the oxidation state of the central metal in each of the following complexes: a) [Co(NH3)6]+2; b) [AlF6]-3; c) [Co(ox)3]-4;

d) [CrBr2(NH3)4][Cr(OH)3(NH3)3]; e) [Al(OH)(H2O)5][Zn(CN)4]. Name each complex.

7. Cyano complexes of transition metal ions (such as Fe+2 and Cu+2) are often yellow,

whereas aqua complexes are often green or blue. Give a reasonable explanation for this difference in color.

8. Predict which of the following complex ions is diamagnetic or paramagnetic: a) [MoCl6]-3; b) [Co(en)3]+3; c) [Cu(CN)4]-2 (this is a square planar complex ion); d) [Fe(H2O)6]+2; e) [Fe(CN)6]-4. 9. Indicate the number of unpaired electrons expected for: a) the tetrahedral complex ion

[CoCl4]-2; b) the octahedral [Mn(CN)6]-3; c) the tetrahedral [FeCl4]-1 10. Shown below is the absorption spectrum of [Ti(H2O)6]+3 in aqueous solution. a) Describe the color of light that [Ti(H2O)6]+3 absorbs most strongly and the color of

the solution. b) Describe the electron transition responsible for the absorption peak, and determine the energy associated with this transition. c) Explain how you expect the absorption peak to shift if the ligand water is replaced by nitrite.