A Biomimetic O2 Carrier: Cosalen

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A Biomimetic O2 Carrier Co(salen) Synthesis And
Kinetics
Objectives --Synthesize Co(salen)
--Measure kinetics of O2 uptake
--Determine stoichiometry of oxygen complex
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Biomimetic Co(salen)

• Co(salen) can bind oxygen, as does the
  biological heme molecule

versus
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Oxygen Binding in the Body
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Oxygen Binding Co Environment

• As Solid

• Solvated

• --Co(salen) exists with Co in a 4, 5, or 6
  coordinate site

--Solvated Co(salen) will bind O2 when 5 or 6
coordinate
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Synthesis of Co(salen)

--Write all prelab steps correctly and
thoroughly. Check to make sure nothing is left
out. Review well before coming to lab.
--Septum rubber stopper with self-sealing point
in the middle, used with syringe needles.
--Cobalt(II) acetate tetrahydrate 3.0 ml of
water or a little more. Make sure all
Co complex is dissolved.
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Synthesis of Co(salen)
--Few argon stations delays. Synthesize salen
promptly.
--Do not use too much ethanol to dissolve
salen--24 ml or a little less. Make sure all
salen dissolves.
--Addition of 1) ethanol to H2salen, and 2)
Co(acetate) solution to salen solution,
is done through septum on top of reflux
condenser.
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Synthesis of Co(salen)
--Syringes often leak. Use care to transfer
solutions quantitatively.
--Replacement of septum with balloon is done with
TA. One removes septum, other affixes balloon.
--Stir well while refluxing!!!! Prevents
bumping.
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Synthesis of Co(salen)
--Make sure solution is cold before filtering off
product.
--Use only 2 mL cold ethanol to wash product. Add
slowly, dropwise at first.
--Dry product thoroughly on aspirator and on
filter paper.
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Summary
--Bioinorganic chemistry study of a biomimetic
compound that reversibly binds oxygen
--Exacting synthesis of high yield under inert
atmosphere