Transition Metal Complexes
- Page ID
- 222047
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Chemical Concept Demonstrated
- Transition metal chemistry
Demonstrations
Nickel
- Dissolve 1-1.5 g NiCl2 in 40 mL concentrated HCL to form the yellow-green NiCl64- complex ion.
- Decant NiCl64- into 500 mL water to produce the blue-green Ni(H2O)62+ complex ion. Divide this solution into two portions: 350 mL and 175 mL.
- Add 1.5 g solid EDTA and about 45 mL 2 M NaOAc to the smaller portion of the Ni(H2O)62+ complex to form the blue Ni(EDTA) complex.
- Add 30 mL concentrated NH3 to the larger portion of the Ni(H2O)62+ complex to form the blue Ni(NH3)62+complex ion. Divide this solution into two equal portions.
- Add a dilute aqueous solution of ethylene diamine to one portion of the Ni(NH3)62+ complex to form a lavender complex for which the formula Ni(en)(NH3)42+ has been proposed.
- Add a solution of dimethyl glyoxime in ethanol to the other portion of the Ni(NH3)62+ complex to form the red Ni(DMG)2 complex.
Cobalt
- Dissolve several grams of CoCl2 in concentrated HCl to form the deep-blue CoCl42- complex ion. Pour some of this solution into water to form the pink Co(H2O)62+ complex. Divide this solution into three equal portions.
- Add a dilute aqueous solution of ethylene diamine to one portion of the CoCl42- solution to form the brown Co(en)32+ complex.
- Add a solution of dimethyl glyoxime in ethanol to another portion of the CoCl42- solution to form the orange-brown Co(DMG)2 complex.
- Add concentrated NH3 to the third portion of the CoCl42- solution to form the blue Co(NH3)62+ complex.
Iron
- Add an aqueous solution of KSCN drop by drop to an aqueous solution of the Fe3+ ion to form a mixture of the Fe(SCN)2+ and Fe(SCN)2+ ions.
Chromium
- Dissolve a few grams of Cr(NO3)3 in 45 mL concentrated HCl and decant the resulting solution into 200 mL of water. Divide the solution into two portions.
- Add a dilute aqueous solution of ethylene diamine to one portion of the Cr3+ solution to form the lavender Cr(en)33+ complex.
- Add concentrated NH3 to the other portion of the Cr3+ solution to form a green solution of the Cr(NH3)63+complex.
- Add a few drops of concentrated HCl to a yellow solution of the CrO42- ion and note the change in the color of the solution to orange as the Cr2O72- ion is formed.
- Add concentrated NH3 to the orange Cr2O72- solution and note the change in the color of the solution as the CrO42- ion is formed.
Copper
- Prepare a saturated solution of the Cu2+ ion in concentrated HCl and note the green color of the solution due to the presence of the CuCl42- ion.
- Pour 20 mL of the CuCl42- ion solution into 200 mL of water and note the formation of the light blue Cu(H2O)62+ complex.
- Add 6 M NH3 drop by drop to a fresh solution of the Cu2+ ion until Cu(OH)2 precipitates.
- Continue adding 6 M NH3 until the solution turns the deep blue color of the Cu(NH3)42+ ion.
Contributors
- Dr. George Bodner (Purdue University)