Summitt 1
Homogeneous Catalysts for Selective Oxidation of Organic
Compounds with N2O
Addie Summitt
Faculty Advisor: Megumi Fujita
University of West Georgia Chemistry Department
Summitt 2
Brief Overview of Project
Nitrous oxide is a very destructive greenhouse gas released in industrial processes such as
nitric acid production. However, in the presence of a well designed metal catalyst, this gas has
the potential to be an oxidation reagent. This potential oxidation by N2O could be exploited in
many industrial oxidation processes as an environmentally friendly alternative because the only
byproduct of the oxidation would be an environmentally benign N2 gas. The use of such a
catalyst in industries would contribute to the reduction of N2O into the environment, which in
turn would help reduce the destruction of the Earth’s ozone layer.
Our research goal is to
develop a transition metal catalyst to activate N2O and mediate in the oxygen atom transfer to an
organic substrate.
The first step in the N2O activation is
n+
LnM
to have a ligand with a metal center (our
CH3OH
catalyst) take the oxygen atom from the N2O.
N2O
n+ = initial oxidation state
L3 = ancillary ligand
The catalyst then acts as the oxidizing agent as
it transfers the oxygen to a gas like CH4. A
initial state
M = Metal
CH4
N2
(n+2)+
good catalyst would be able to repeat this
LnM O
"oxo" species
cycle over and over again.
Hillhouse published a Ni complex that reacted with N2O and activated the O atom.
However, the complex resulted in internal oxidation, and was not catalytic. Nickel was selected
as a central metal ion because of the previous example by Hillhouse that showed N2O activation
by a Ni complex.
The proposed catalyst is made up of a bulky tridentate ligand around a metallic center, in
this case a Ni center. It was proposed that activation of nitrous oxide requires two coordination
Summitt 3
sites next to each other. This ligand allows three available
Br
coordination sites, two of which may be used for N2O
(THF)
1-
2+
N
Ni
N
Br
1-
N
(THF)
activation.
(THF)
Another advantage is the overall -2 ligand charge,
which neutralizes the central metal ion. This will create an
overall neutral metal complex which is compatible with organic reaction media.
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Work Accomplished This Summer
The protonated, neutral form of the ligand (1) was synthesized in four steps (Scheme 1).
The procedures were based on those developed by the lab. Various optimizations of the reaction
and purification conditions have been made, improving the yields at each step.
O
O
H
N
O
1. LiHMDS -78oC
O
NBS/CCl4
N
2.(CH3O)2CO
r.t.
94 %
81%
N
Br
Br
1/2
NH2
N
Br
+ Na2CO3
N O
CH3CN

Br
NH2NH2*HCl + KOH
0oC
O N
N
Br
MeOH
81%
NH
Br
HN
OCH3 OCH3
91%
(1)
Scheme 1. Ligand synthesis
Complexation with Ni(II), still in progress, has been attempeted by the following
procedure (Scheme 2).
2NaH
N
Br
NH
Br
HN
Scheme 2. Ni(II) Complexation
NiCl2
N
Br
N
Br
N
/ THF
"the cataylst"
purple species,
purification and identification
in progress
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Experimental Details
1. N-protection of 2-methylindole (6/6/07, I-1)
O
O
H
N
o
LiHMDS/THF -78 C
N
(CH3O)2CO
Name of
Compound
Formula
Formula
Mass
Amount
Other
Moles
Mole Ratio
2Lithium
methylindole bis(trimethsillyl)amide
C9H9N
((CH3)3Si)2NLi
131.0 g/mol
167.0g/mol
19.654 g
187.5 mL
0.15 mol
1
0.1875 mol
1.25
Dimethyl
carbonate
(CH3O)2CO
90.09 g/mol
C11H11O2N
189.21
g/mol
16.5 mL
d=1.07
g/mL
0.195 mol
1.3
Ref: 1Dhanapoatan Nagarathnam, Synthesis, 1992, 8, 143-5
2
Former Student: Amna Ali’s notebook
Procedure:
In the glove box, 19.654 g of the 2-methylindole and 220 mL of tetrahydrofuran (THF)
were added together in a three neck round bottom flask, and protected from air by a gas adaptor
and septa. The air flow was closed off to all mouths of the flask. Once out of the glove box,
nitrogen was added and vacuumed three times in the hose using the Schlenkline, and then the
mixture was placed under nitrogen. A magnetic stirrer was used to stir the mixture together
while the flask was added to a dry ice bath in a bowl of acetone to lower the temperature to 78oC. Over the next 48 minutes, 48 mL of LiHMDS was added, followed by another 48.5 mL,
followed by another 48 mL, and finished with 43 mL, making a total of 187.5 mL LiHMDS. By
the third LiHMDS addition the color had changed from a yellowish-brown color to a blood-red.
Temperature was raised to
-22oC as the dry ice bath was removed; as the temperature neared
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room temperature, the mixture was cooled to -71oC again and16.5 mL of dimeythl carbondate
was added over a 15 minute time span. The mixture was allowed to warm to room temperature
over night.
In a 1600 mL separation funnel flask, 12.5 mL of a 12 M HCl solution was added to a
750 mL ice bath in which the mixture from the 3-neck flask was added to the HCl-ice water
mixture. 250 mL of diethyl ether was used to rinse remaining solution from the 3 mouth flask to
the separation funnel. The separation funnel was swirled to reveal two distinct layers: the top
being a dark red ether layer while the bottom was an aqueous layer of light red. In the separation
funnel, the dark red ether layer was extracted from the light red water layer. The ether layer was
placed in a separate flask apart from the water layer. 250 mL of diethyl either was poured into
the separation funnel with the aqueous layer to extract anymore organic substances. The
combined ether layers were washed with brine (120 mL) twice. The remaining ether layer was
emptied into a 1600 mL flask and some sodium sulfate was added to remove trace water in the
solution; let sit for 20 minutes and was filtered afterwards into a pre-weighted pear-shaped flask.
The rotary evaporator was used to evaporate and discard any ether and remaining THF from the
contents of the pear-shaped flask. Using a silica TLC, we tested the reaction against the starting
material in a 1:1 ratio of chloroform:hexanes showing that a reaction had taken place. Another
TLC was taken, but instead of silica, alumina was used in a solution of only chloroform which
showed a better result than the silica TLC that a reaction had taken place. The pear-shaped flask
was hooked up to a vacuum and was left to vacuum over night.
Column 1 test scale:
An alumina (neutral) column (10 cm high, 4 cm wide) was assembled; using only 3.004 g
of the vacuumed product and an eleunt of only chloroform, 6 fractions were taken. Alumina
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TLC was taken with chloroform solvent to show that fractions 1 and 2 contained the product.
Using the evaporation machine, fractions 1 and 2 were evaporated in a pre-weighed round
bottom flask and then vacuumed. The end result was 3.035 g of a clear liquid product after
NMR confirmed the fact that the liquid was pure, free of the starting material, but with residual
solvents. The flask was left under vacuum over the weekend.
Column 2 big scale (unsuccessful):
Another alumina (neutral) column (10 cm high, 5.5 inches wide) was assembled using the
remaining mixture from the vacuumed pear-shaped flask and just a chloroform eleunt. Alumina
TLC with chloroform solvent was used to confirm that fractions 2 and 3 held our product and
were then evaporated in a pre-weighted flask with the evaporator. NMR showed some
impurities so another column was needed to purify the product.
Column 3 small scale basic alumina trial (a) chloroform:
The product was transferred to a pre-weighed 300 mL flask after several washings with
dichloromethane and evaporated. A small column (10 cm high, 2 cm wide) with alumina basic
was set up and only 1.003 g of product was loaded into the column. Alumina TLC with
chloroform solvent was used to determine our product was in fractions 1 and 3; however,
fraction 2 was added to fractions 1 and 3. Fractions 1-3 were evaporated in a pre-weighed flask,
after evaporation .893 g of material was collected.
Column 4 small scale basic alumina trial (b) chloroform:hexanes
Another small column (10 cm high, 2 cm wide) was made with alumina basic with a 1:1
chloroform:hexanes in which the .893 g sample was loaded into. Alumina TLC with chloroform
solvent showed our product in fractions 1, 2, 4, and 5 which were then evaporated in a preweighed flask. After evaporation 1.95 g of pure product was extracted.
Summitt 8
Column 5 big scale neutral alumina hexanes:chloroform
The remaining liquid from the 300 mL flask, 1.95 g pure product, and 3.035 g pure
product was evaporated then loaded into an alumina (neutral) column (14 cm high, 5 cm wide).
Alumina TLC with chloroform solvent confirmed that our product was in fractions 1-7 and was
then evaporated in a pre-weighed flask making 30.028 g of pure product.
Combined all pure substances together in a pre-weighed 125 mL flask, evaporated methyl
chloride, then hooked up to vacuum for 3 hours. NMR confirmed that 26.773 g of pure product
had been recovered, making a 94% yield.
2. Double Bromination of N-Protected 2-methylindole (6/14/07, I-15)
O
O
N
O
O
NBS/CCl4
N
r.t.
Br
Br
Name of
compound
Formula
Formula Mass
Amount
Other
Moles
Mole Ratio
C11H11O2N
189.21 g/mol
15.151 g
NBromosuccimide
C4H4BrNO2
177.99 g/mol
31.326 g
0.08 mol
1
0.176 mol
2.2
Carbon
Tetrachloride
CCl4
C11H9O2NBr2
347.006 g/mol
250 mL
Ref: 3Former Student: Amna Ali’s Fall 2006 Research Paper, pg 15
Procedure:
Weighed an empty 1000 mL flask and added 15.151 g of C11H11O2N. Measured out
31.321 g N-Bromosuccimide (NBS). Stirred 250 mL carbon tetrachloride into C11H11O2N.
When NBS was added to the mixture, the mixture turned a lemonade-yellow color and was
stirred over night.
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The next day, the mixture was a cloudy, orange juice color and TLC on alumina with a
2:1 hexanes:chloroform solvent was used to test if the reaction was complete. A sample was
taken from the mixture, evaporated under air, and used for NMR. NMR showed some impurities
so the sample was added back to the original mixture by using methlyene chloride. The mixture
was then filtered and rinsed with carbon tetrachloride. An orange liquid was collected in a flask
and an alumina TLC with was taken the same 2:1 hexanes:chloroform solvent. The orange
liquid was then evaporated in the evaporation machine; as a result, a white powder formed after
evaporation which was then refrigerated over the weekend.
The filtered powder, presumable the byproduct succimide, still contained the product
after doing TLC, therefore was added to the mixture for the first column. A silica column (12
cm high, 7 cm wide) was assembled and a 1:1 chloroform:hexanes eleunt was used as the
refrigerated, filtered white powder was loaded into the column. A silica TLC was taken of the
first 6 fractions with a 1:1 chloroform:hexanes solvent. In a pre-weighed pear-shaped 1000 mL
flask, fractions 1-4 were combined, evaporated, re-weighed (17.583 g pure product), and
refrigerated. Column was continued to fraction 8 where the eleunt was changed to just
chloroform and was continued to fraction 13. The more impure fractions 5-12 were combined,
evaporated, and refrigerated over night.
Fractions 5-12 were taken from the refrigerator and loaded into a silica column with 2:1
hexanes:chloroform eleunt. Silica TLC with 1:1 chloroform:hexanes showed that fractions 3-7
contained the product; fractions were evaporated in a pre-weighed flask. After evaporation,
4.948 g pure product was collected and added to the 17.583 g of pure product from the day
before making a total of 22.531 g of product; a 81.1% yield.
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3. Coupling using n-Butylamine (6/22/07, I-23)
O
O
1/2
N
NH2
Br
+ Na2CO3
Br
Name of
Compound
Formula
Formula
Mass
Amount
Other
Moles
Mole Ratio
CH3CN
68oC
6.007 g
Sodium
Carbonate
Na2CO3
82.999
g/mol
7.179 g
0.0173 mol
0.0865 mol
2
10
C11H9O2NBr2
347.00 g/mol
N
Br
Acetonitrile
CH3CN
41.053
g/mol
500 mL
N O
Br
O N
OCH3 OCH3
NButylamine
C4H11N
C26H27Br2N3O4
73.13 g/mol 605.32 g/mol
0.855 mL
d = 0.74
0.00865
mol
1
Ref: Former Student: Amna Ali’s notebook
2
Procedure:
6.007 g C11H9O2NBr2 and 7.179 g sodium carbonate were mixed with 500 mL
acetonitrile in a 1000 mL flask. Silicon oil bath was heated to 68oC. N-Butylamine was then
added to the flask and placed into the oil bath and the contents was stirred over night.
1
H NMR of a small aliquant, evaporated and dissolved in acetone-d6 showed a very clear
product; however, TLC on silica with 1:1 chloroform:hexanes, showed a little impurity. About
500 mL of distilled water was added to reaction mixture in the separation funnel. 150 mL of
diethyl ether was added (x3) and extracted material. The material was also filtered by a vacuum
filtration to remove excess carbontates. The combined organic layers were a yellow liquid. The
liquid was then dried with sodium sulfate. The organic layer was filtered into a pre-weighed 500
mL flask, evaporated, and refrigerated over night.
Summitt 11
NMR was taken and 4.787 g of pure product was recorded making a 91.4% yield.
4. Deprotection (small scale) (6/29/07, I-28)
N
Br
N O
Br
O N
NH2NH2*HCl + KOH
0oC
N
Br
Br
MeOH
NH
HN
OCH3 OCH3
Name of
Compound
Formula
Formula Mass
Amount
Other
Moles
Mole Ratio
C26H27Br2N3O4
605.32 g/mol
0.5 g
Hydrazinium
Chloride
N2H5Cl
68.5061 g/mol
0.908 g
Potassium
Hydroxide
KOH
56.108 g/mol
1.856 g
0.826 mmol
1
13.21 mmol
16
33.04 mmol
40
C22H23Br2N3
489.25 g/mol
Procedure:
In a pre-weighed 100 mL round bottom flask, 0.5 C26H27Br2N3O4, 0.908 g hydrazinium
chloride, and 10 mL methanol were combined and set in an ice bath of 0oC. 1.856 g potassium
hydroxide was dissolved in 10 mL methanol and added drop wise to the ice-bath mixture while
stirring. The mixture was then taken off the ice bath and continued to stir at room temperature.
An hour later, a silica TLC with 1:1 chloroform:hexanes solvent confirmed that the reaction was
making progress. The mixture continued to stir over the weekend.
Reaction mixture was poured into 70 mL brine in a separation funnel which was then
rinsed with 40 mL methylene chloride. The funnel was shaken and the two layers were
separated, the bottom methylene chloride layer (a peach color) was collected and saved.
Separation was repeated two more times using fresh 40 mL methylene chloride everytime. The
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methylene chloride layer was dried with sodium sulfate for 15 minutes, filtered into a preweighed 125 mL flask, and evaporated. The result was an amber colored oil. NMR showed
some impurities, so an alumina (basic) column was assembled with a chloroform eleunt and
fractions 1-9 were collected and tested on alumina TLC with chloroform solvent. Fractions 2-7
were combined and evaporated in a pre-weighed 1000 mL flask. The brown oil was vacuumed
for 4 hours; NMR confirmed that 0.354 g of pure product was collected making a 87.6% yield.
5. Deprotection (large scale) (7/3/07, I-33)
N
Br
N O
Br
O N
NH2NH2*HCl + KOH
0oC
N
Br
Br
MeOH
NH
HN
OCH3 OCH3
Name of
Compound
Formula
Formula Mass
Amount
Other
Moles
Mole Ratio
C26H27Br2N3O4
605.32 g/mol
2.501 g
Hydrazinium
Chloride
N2H5Cl
68.5061 g/mol
4.527 g
Potassium
Hydroxide
KOH
56.108 g/mol
9.268 g
4.13 mmol
1
66.08 mmol
16
165.2 mmol
40
C22H23Br2N3
489.25 g/mol
Procedure:
In a pre-weighed round bottom flask, 2.501 g of C26H27Br2N3O4, 4.527 g of hydrazinium
chloride, and 50 mL methanol were combined and cooled by an ice bath to 0oC. 9.268 g of
potassium hydroxide was dissolved in 50 mL methanol and added drop wise to the ice bath
mixture while stirring. After all potassium hydroxide/methanol mixture was added, ice bath was
removed, and mixture was allowed to stir at room temperature for 24 hours.
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TLC was done on alumina with 1:1 chloroform:hexanes to show that the reaction was
complete. In a 1000 mL separation funnel, 350 mL brine was added to reaction mixture. The
flask rinsed with 200 mL methylene chloride, shaken, and drained methylene chloride layer. 50
mL of distilled water was added to the flask to dissolve the white-powdery substance. Fresh 200
mL methylene chloride was added to the flask, shaken, and the methylene chloride layer was
drained; repeated a second time. All methylene chloride layers were combined and dried over
sodium sulfate. In a pre-weighed 500 mL flask, the methylene chloride layer was evaporated
and hooked up to vacuum for two hours.
The column chromatography was carried out by Amna Ali. An alumina (neutral) column
(11.5 inches high, 4.5 cm wide) was assembled; the following eleunts were used:
Fractions
Eleunt
1-11
1:1 chloroform:hexanes
12-15
2:1 chloroform:hexanes
16-35
Pure chloroform
36-43
98% chloroform 2% ethyl acetate
44-51
95% chloroform 5% ethyl acetate
52-59
90% chloroform 10% ethyl acetate
60-63
80% chloroform 20% ethyl acetate
64-71
1:1 chloroform: ethyl acetate
Alumina TLC with pure chloroform solvent showed that fractions 52-70 contained the
pure products. Fractions 52-70 were combined in a pre-weighed flask, evaporated, vacuumed,
and re-weighed. NMR showed that 1.665 g of pure product was collected, making a 81.89 %
yield.
*Crystallization*
After scraping out as much pure product from the deprotection (large scale) and
refrigerated, we did a crystallization test with the remaining material. In four separate vials
eleunts hexanes, diethyl ether, ether, and acetonitrile were tested on .001 g of product. After
adding heat, hexanes appeared to have low solubility at room temperature, but higher at near
Summitt 14
boiling point, so did ethyl acetate. In an empty pre-weighed flask, transferred remaining solid
from the hexanes crystallization to a beaker by washing with hexanes and heating. The hot plate
was used to heat the mixture in the beaker and filtered into a separate vial. Removed the vial
from heating plate and let cool with top slightly open; after a few hours, nothing happened, so
mixture was put in the freezer over night.
The next morning, crystals still had not formed so air was blown on hexanes until dry,
then added a few drops ethyl acetate and, immediately, crystals formed! The excess liquid was
removed, then cooled crystals and some ethyl acetate in an ice bath. Crystals were then washed
with the cool ethyl acetate. The excess liquid also grew crystals, so it was put in the ice bath as
well and air was blown on it and let crystals grow in the ice bath. Crystals were washed with cool
ethyl acetate three times to remove red liquid and leave white crystals, then dried carefully. The
elemental analysis of the crystals showed the good match to a 1:1 co-crystal of the product with
ethyl acetate.
6. Nickel Complexation (small scale) (7/10/07, I-40)
2NaH
N
Br
NH
Name of
Compound
Formula
Formula
Mass
Amount
Other
Moles
Mole Ratio
Br
1 day
HN
C22H23Br2N3
489.253
g/mol
0.0306 g
0.0625
mmol
1
N
Sodium
Hydride
NaH
23.998
g/mol
0.0030 g
0.125 mmol
2
NiCl2
N
Br
Acetonitrile
CH3CH
41.053
g/mol
Br
/ THF
"the catalyst"
“brown species”
1 day
N
Nickel
Chloride
NiCl2
129.596
g/mol
0.0081 g
0.0625
mmol
1
?
Summitt 15
Procedure: (In the glove box)
In a pre-weighed flask 0.0306 g of C22H23Br2N3 and in a separate vial 0.0030 g sodium
hydride were weighed. About 5 mL acetonitrile was added to C22H23Br2N3, then transferred to
sodium hydride and stirred the pale yellow liquid. About an hour later, the color changed to a
brown color; left stirring over night.
Using about 5 mL acetonnitrile, 0.0081 g nickel chloride was added to the mixture, and
continued to stir over night, a cloudier brown color appeared.
Mixture was heated and turned black. Heat was removed and color changed back to
brown color. Stir was stopped and a white precipitate appeared at the bottom of the brown
liquid. Liquid was filtered and vacuumed. 1H NMR CD3CN showed something that looked like
a mixture of two species, one of which seemed like the sodium salt.
7. Nickel Complexation (attempt 2) (small scale) (7/12/07, I-42)
2NaH
N
Br
NH
Name of
Compound
Formula
Formula
Mass
Amount
Other
Moles
Mole Ratio
Br
NiCl2
N
Br
Br
1 day
HN
N
C22H23Br2N3
489.253
g/mol
0.0306 g
0.0625
mmol
1
Sodium
Hydride
NaH
23.998
g/mol
0.0030 g
0.125 mmol
2
Acetonitrile
CH3CH
41.053
g/mol
/ THF
"the catalyst"
“purple species”
3 days
N
Nickel
Chloride
NiCl2
129.596
g/mol
0.0081 g
0.0625
mmol
1
?
Summitt 16
Procedure: (In the glove box)
In a pre-weighed flask 0.0306 g of C22H23Br2N3 and in a separate vial 0.0030 g sodium
hydride were weighed. About 5 mL acetonitrile was added to C22H23Br2N3, then transferred to
sodium hydride and stirred the pale yellow liquid over night.
The color changed to a dark brownish color. A small sample was taken, evaporated, and
did NMR in CD3CN to record the spectrum of the sodium salt. NMR mixture was added back to
the original mixture. Using about 5 mL acetonitrile, 0.0081 g nickel chloride was added to the
mixture, and let stir over the weekend.
The reaction had turned a dark purple, almost black. After filtering and vacuuming, a 1H
NMR in CD3CN was taken; the results showed a mixture of at least two, one of them was very
similar to the original ligand, which was not a good thing (where did the protons come from?).
The mixture was filtered again using a filtering aid after returning the sample used for NMR and
vacuumed. The filtrate was condensed to half volume to do a preliminary crystallization test.
Diethyl ether was added; the solubility of the purple species did not seem to drop by ether
addition, thus not suitable for re-crystallization medium). The mixture was then evaporated and
left a little bit wet; 1.5 mL of toluene was added and put in the refrigerator.
*Crystallization Test*
The purple compound was tested with different solvents for the best conditions during the
crystallization test. At room temperature, toluene seemed to dissolve well, while diethyl ether
proved to be fairly soluble, and hexanes was a very poor solvent at both low and high
temperatures. Therefore, crystallization was done with toluene and hexanes. The mixture was
dissolved in toluene and then filtered to remove the undissolved solid. Hexanes was added to the
top and allowed for a slow diffusion. After a couple of hours, there were some solids observed
Summitt 17
but they were not crystalline. The mother liquor was transferred to another vial and the
remaining solid was dried under vacuum. An NMR was done of the evaporated solid in CD3CN.
NMR showed a very dilute sample, but when the picture was blown up, the results showed that
crystallization seemed to have gotten rid of any of the starting ligand.
8. Drying of Nickel Chloride
As anhydrous NiCl2 was suspected as the proton source, we decided to further dry under
vacuum and heat. A round bottom flask and stopcock was heated in the oven and then pumped
into the glove box. Poured a small amount of nickel chloride was added to the round bottom
flask and heated in a heating mantle while hooked up to the vacuum for 3 hours. The nickel
chloride was occasionally stirred to open up power and evaporated any excess liquid. The color
changed from yellow to orange which showed that there may have been a presence of water in
the nickel chloride.
9. Nickel Complexation (attempt 3) (small scale) (7/18/07, I-45)
2NaH
N
Br
NH
Br
1 day
HN
Name of
Compound
Formula
Formula
Mass
Amount
Other
Moles
Mole Ratio
C22H23Br2N3
489.253
g/mol
0.0306 g
0.0625
mmol
1
N
Sodium
Hydride
NaH
23.998
g/mol
0.0030 g
0.125 mmol
2
NiCl2
N
Br
Br
N
Acetonitrile
CH3CH
41.053
g/mol
/ THF
"the catalyst"
“purple species”
4 days
Nickel
Chloride
NiCl2
129.596
g/mol
0.0081 g
0.0625
mmol
1
?
Summitt 18
Procedure: (In the glove box)
In a pre-weighed flask 0.0306 g of C22H23Br2N3 and in a separate vial 0.0030 g sodium
hydride were weighed. About 5 mL acetonitrile was added to C22H23Br2N3, then transferred to
sodium hydride and stirred the pale yellow liquid over night.
The color had once again changed to a dark brown color; using about 5 mL acetonitrile,
0.0081 g nickel chloride was added to the mixture, and let stir over the weekend. After
evaporation of the purple mixture, the 1H NMR showed no peaks resembly the original ligand,
but showed different peaks from the attempt 2 purple species.
10. Nickel Complexation (large scale)
2NaH
N
Br
NH
Br
Name of
Compound
Formula
Formula
Mass
Amount
Other
Moles
Mole Ratio
Br
1 day
HN
C22H23Br2N3
489.253
g/mol
0.0918 g
0.1875
mmol
1
Procedure: (In the glove box)
N
Sodium
Hydride
NaH
23.998
g/mol
0.0090 g
0.375 mmol
2
NiCl2
N
Br
N
Acetonitrile
CH3CH
41.053
g/mol
/ THF
"the catalyst"
“purple species”
2 days
Nickel
Chloride
NiCl2
129.596
g/mol
0.2430 g
0.1875
mmol
1
?
Summitt 19
Conclusion
The yield of each step has been improved by optimizing the reaction, workup, and
purification conditions. This is the first time our lab produced this ligand in a large (2 g) scale,
which allows us to explore metal complexation chemistry.
The synthesis reactions conducted thus far have been very successful. Future work
includes having a successful reaction between the tridentate ligand and nickel chloride, and then
testing the catalyst for catalytic behavior.