CHEMISTRY 115 HOMEWORK 7 NAME _______________

DUE MAY 23, 01 COMP HMWRK:none

  1. 1.Write the formula, including the correct charge, for a complex that contains Cr+3 ion, two NH3 ligands and four NO2-1 ligands.
  2. [Cr(NO2)4 (NH3)2]-1 following text order of ligands – but this strict anion, neutral ligand order is not necessarily followed by others since the change to name all ligands alphabetically, rather than anion followed by neutral ligands, each alphabetically. (In fact the instructor remembers when the ligand order in the chemical formula was the reverse of the order in the name of the coordination compound.)
  3. 2. Give the systematic names for the following complex compounds.
  4. a) K2 [CuCl4]
  5. Potassium tetrachlorocuprate(II)
  1. [W(NH3)3(H2O)3] (NO3)2

    2. Triamminetriaquatungsten(II) nitrate

  2. Na3 [Fe(CN)5CO]

    3. Sodium carbonylpentacyanoferrate(II)

  3. K2 [Mo(NCS)6]

Potassium hexaisothiocyanatomolybdate(IV) or

Potassium hexathiocyanato-N-molybdate(IV)
  1. Give the chemical formula for each of the following complex ions and compounds.

a) tris(oxalato)ferrate(III) ion

[Fe(C2O4)3]3-

b) dichlorobis(ethlyenediamine)platinum(IV) ion

[PtCl2(en)]2+or [PtCl2(NH2CH2CH2NH2)]2+

c) potassium tetroxochromate(VI)

K2CrO4

  1. d) sodium bromochlorodicyanonickelate(II)

Na2[NiBrCl(CN)2]
  1. The following compound is called diethylenetriamine abr "dien", H2N-CH2-CH2-NH-CH2-CH2-NH2. When it bonds to a metal, it is a ligand with three donor atoms
  1. Which are the most likely donor atoms?

    2. The three nitrogens each have a lone pair that they could donate to the bond

  2. What is the coordination number in the complex Co(dien)2+3 ?

    3. 2 x 3 = 6; each of the two "dien’ occupy three sites.

  3. Sketch the structure of the complex.

    4.  

     

     

    N

     

     

     

     

     

    |

    \

     

     

    N

     

    |

     

    N

     

     

    \

     

    /

     

     

    |

     

    Co

     

    |

     

     

    /

     

    \

     

     

    N

     

    |

     

    N

     

     

    \

    |

     

     

     

     

     

    N

     

     

     

  4. Which compound would be expected to be more stable is aqeuous solution, [Co(dien)2]+3, or [Co(NH3)6]+3?

The chelated [Co(dien)2]+3 would be more stable because of the entropy effect of making more product species when it is formed ([Co(H2O)6 ]3+ + 2 dien = [Co(dien)2]+3 + 6 H2O)

5. Draw and name all the geometric isomers for the following complexes.

A. [Co(en)2Br2] B. [Pt(NH3)2(SCN)2]

 

 

 

Br

 

 

 

 

 

 

 

 

 

 

 

|

 

 

 

 

 

 

 

 

 

N

 

|

 

N

 

H3N

 

 

 

SCN

 

 

\

 

/

 

 

 

\

 

/

 

 

|

 

Co

 

|

 

 

 

Pt

 

 

 

 

/

 

\

 

 

 

/

 

\

 

 

N

 

|

 

N

 

NCS

 

 

  

NH3

 

 

 

|

 

 

 

 

 

 

 

 

 

 

 

Br

 

 

 

 

 

 

 

 

trans-dibromobis(ethylenediamine)cobalt(II) trans-diamminedithiocyanatoplatinum(II)

 

 

 

 

 

N

 

 

 

 

 

 

 

 

 

 

/

|

 

 

 

 

 

 

 

 

 

N

 

|

 

Br

 

H3N

 

 

 

SCN

 

 

\

 

/

 

 

 

\

 

/

 

 

 

 

Co

 

 

 

 

 

Pt

 

 

 

 

/

 

\

 

 

 

/

 

\

 

 

N

 

|

 

Br

 

H3N

 

 

  

SCN

 

 

\

|

 

 

 

 

 

 

 

 

 

 

 

N

 

 

 

 

 

 

 

 

cis-dibromobis(ethylenediamine)cobalt(II) cis-diamminedithiocyanatoplatinum(II)

 

Which, if any, would have an optical isomer? Draw them if present

Which, if any, other type of isomer might be expected for this ion?

 

 

 

 

N

 

 

 

 

 

 

 

 

 

 

 

|

\

 

 

 

 

 

 

 

 

Br

 

|

 

N

 

 

 

 

 

This coordination complex might

 

 

\

 

/

 

 

 

 

 

 

Have a linkage isomer in which

 

 

 

Co

 

 

 

 

 

 

 

The SCN- is bonded through the

 

 

/

 

\

 

 

 

 

 

 

N rather than the S

 

Br

 

|

 

N

 

 

 

 

  

 

 

 

 

|

/

 

 

 

 

 

 

 

 

 

 

N

 

 

 

 

 

 

 

 

cis will have an optical isomer