Synthesis of a Copper Complex

1
Synthesis of a Copper Complex
2
Overview

• Synthesis of a Cu(en)2SO4
• Do not synthesize the Manganese Complex
• CuSO45H2O(aq) 2H2NCH2CH2NH2(l)?
  Cu(H2NCH2CH2NH2)2SO4(s) 5H2O(l)
• Reactants
• Solution of copper sulfate from copper sulfate
  pentahydrate
• Liquid ethylenediamine
• Products
• Solid Copper complex

3
Reactants

• Copper sulfate pentahydrate
• CuSO4 5H2O(s)
• 249.68 g/mole
• Approximately 5.0 g dissolve in 15 mL deionized
  water
• Record actual mass to four decimal places
• Use graduated cylinder to dispense DI water
• Ethylenediamine
• H2NCH2CH2NH2(l)
• 0.90 g/ml
• 60.10 g/mole
• 3.00 mL from buret into 50 mL beaker

4
Product Copper Complex

• Cu(H2NCH2CH2NH2)2SO4(s)
• Coordination Complex
• 279.81 g/mole

5
Coordination Complex

• Coordinate covalent bonds - Bonds in which one
  atom supplies both electrons
• Ligand atoms, molecules, or ions bonded to a
  central atom such as the central metal ion of a
  coordiantion complex
• Coordination number The number of coordinate
  covalent bonds between ligands and a central
  metal ion.

6
Copper Coordination Complex

• Coordination number of complex is six.
• Molecular geometry of complex is octahedral
• Ligands
• Two ethylenediamines
• bidentate
• two coordination covalent bonds per molecule
• Two sulfates

7
Crystallization Basic Techniques

• Lower temperature
• Solubility of solid in liquid tends to decrease
  at lower temperature
• Remove solvent
• Evaporation of solvent results in higher
  concentration of solute
• Change the nature of the solvent
• Solubility of solute varies with solvent
• Copper complex soluble in water
• Copper complex insoluble in ethanol
• Seed
• Provide surface for nucleation
• Scratch the glass
• Provide surface for nucleation
• Techniques utilized for Copper Complex
  crystallization

8
Filtration Buchner Funnel

• Dampen filter paper with ethanol
• Attach vacuum hose to house vacuum (NOT faucet
  aspirator)
• Stabilize buchner funnel
• Transfer and rinse ALL crystals
• USE chilled ethanol NOT water crystals will
  dissolve in water
• Keep crystals suspended while transferring
• Have vacuum on only while filtering

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Procedure Notes

• Record all masses to 4 decimal places, include
  units.
• Add ethylenediamine carefully with dropper for
  best crystal formation.
• Transfer and wash crystal with cold ethanol only
  to maximize yield.
• Put ethanol on ice at start of procedure.
• Record the mass of the dry filter paper and watch
  glass prior to filtration for ease of
  calculation.
• Store crystals in lab drawer, on watch glass,
  until next week.

10
Waste Disposal

• Dispose of all waste in designated liquid waste
  container.
• DO NOT overflow the waste container.
• DO NOT dispose of crystals.

11
Safety Reminders

• Cuts or burns
• First - Flush with cold water
• Second - Ask neighboring student to inform
  instructor
• Always wear safety glasses
• Long pants, closed-toe shoes

12
Data Analysis Theoretical Yield

• Determine moles used of both reactants

13
Data Analysis Theoretical Yield cont.

• Determine moles of product possible from each
  reactant
• CuSO45H2O(aq) 2H2NCH2CH2NH2(l)?
  Cu(H2NCH2CH2NH2)2SO4(s) 5H2O(l)

Actual theoretical yield is the LOWER amount of
the two!!!!!
14
Data Analysis Percent Yield
Experimental yield will be determined next week
after drying is complete.
15
NEXT WEEK

• Gas Law Investigation Using LabWorks Page 167
  of manual.
• Note Your syllabus incorrectly indicates this
  procedure is a handout.