Problem 64
A platinum-containing compound, known as Magnus's green salt, has the formula \(\left[\mathrm{Pt}\left(\mathrm{NH}_{3}\right)_{4}\right]\left[\mathrm{PtCl}_{4}\right]\) (in which both platinum ions are \(\mathrm{Pt}^{2+}\) ). Name the cation and the anion.
Problem 65
Early in the 20th century, coordination compounds sometimes were given names based on their colors. Two compounds with the formula \(\operatorname{CoCl}_{3} \cdot 4 \mathrm{NH}_{3}\) were named praseo-cobalt chloride (praseo = green ) and violio-cobalt chloride (violet color). We now know that these compounds are octahedral cobalt complexes and that they are cis and trans isomers. Draw the structures of these two compounds, and name them using systematic nomenclature.
Problem 66
Give the formula and name of a square-planar complex of \(\mathrm{Pt}^{2+}\) with one nitrite ion $$\left(\mathrm{NO}_{2}^{-}\right.$$, which binds to \(\mathrm{Pt}^{2+}\) through \(\mathrm{N}\) ), one chloride ion, and two ammonia molecules as ligands. Are isomers possible? If so, draw the structure of each isomer, and tell what type of isomerism is observed.
Problem 67
Give the formula of the coordination complex formed from one \(\mathrm{Co}^{3+}\) ion, two ethylenediamine molecules, one water molecule, and one chloride ion. Is the complex neutral or charged? If charged, give the net charge on the ion.
Problem 68
How many geometric isomers of the complex ion \(\left[\mathrm{Cr}(\text { dmen })_{3}\right]^{3+}\) can exist? (dmen is the bidentate ligand \(1,1-\) dimethylethy-lenediamine. $$\left(\mathrm{CH}_{3}\right)_{2} \mathrm{NCH}_{2} \mathrm{CH}_{2} \mathrm{NH}_{2}$$
Problem 70
From experiment, we know that \(\left[\mathrm{CoF}_{6}\right]^{3-}\) is paramagnetic and \(\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{6}\right]^{3+}\) is diamagnetic. Using the ligand field model, depict the electron configuration for each ion, and use this model to explain the magnetic property. What can you conclude about the effect of these ligands on the magnitude of \(\Delta_{0} ?\)
Problem 71
Three geometric isomers are possible for \(\left[\mathrm{Co (\mathrm{en})\left(\mathrm{NH}_{3}\right)_{2}\left(\mathrm{H}_{2} \mathrm{O}\right)_{2}\right]^{3+} .\) One of the three is chiral; that is, it has a non-superimposable mirror image. Draw the structures of the three isomers. Which one is chiral?
Problem 73
The complex \(\left[\mathrm{Mn}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}\) has five unpaired electrons, whereas \(\left[\mathrm{Mn}(\mathrm{CN})_{6}\right]^{4-}\) has only one. Using the ligand field model, depict the electron configuration for each ion. What can you conclude about the effects of the different ligands on the magnitude of \(\Delta_{0} ?\)
Problem 74
Experiments show that \(\mathrm{K}_{4}\left[\mathrm{Cr}(\mathrm{CN})_{6}\right]\) is paramagnetic and has two unpaired electrons. The related complex \(\mathrm{K}_{4}\left[\mathrm{Cr}(\mathrm{SCN})_{6}\right]\) is paramagnetic and has four unpaired electrons. Account for the magnetism of each compound using the ligand field model. Predict where the SCN - ion occurs in the spectrochemical series relative to CN \(^{-}\).
Problem 75
Give a systematic name or the formula for the following: (a) \(\left(\mathrm{NH}_{4}\right)_{2}\left[\mathrm{CuCl}_{4}\right]\) (b) tetraaquadichlorochromium(III) chloride (c) aquabis(ethylenediamine) thiocyanatocobalt(III) nitrate
