Synthesis of Hyperbranched Dendrimers Capable of Temperature
Controlled Fe(II) Complexation via RAFT Polymerization
Adam Dyer, Christian A. Tooley, Lea Nyiranshuti, John R. Csoros, Dr. Roy Planalp
amn275@wildcats.unh.edu; Parsons Hall, 23 Academic Way, Durham NH 03824
Introduction
Conclusions
The presence of heavy metal ions in water has been a long time issue. The purpose of this experiment was the development
•Diphenylammonium triflate (DPAT) (1) was successfully
of a polymer bound ligand capable of the complexation metal ions in an aqueous environment. The synthesis of the polymer was
isolated as a white powder (1.340 g, 4.2 mmol, 84%) with a
1
4
done in a dendrimer-like fashion , the core in this case being a metal ion complexed by ligands . The polymer was then grown
melting point of 179-181 ℃ (lit3 178-183℃ ).
from the complex with crosslinkage between branches
to createTrend
a molecular
Temperature
Reportimprint of the metal ion.
v2.0
•The outcome of the subsequent reactions were difficult to
Results and Discussions
interpret because several preferred analysis methods were
• Diphenylammonium triflate (DPAT) (1) was successfully synthesized in
unavailable.
reaction A and characterized by melting point determination.
•The
red-brown
precipitate
was
used
as
qualitative
Sample Details
• In reaction B, DPAT was implemented as a catalyst forSample
the esterification
of
Name: diluted Hot 4-25-13
determination that complexation had taken place.
SOP Name: mansettings.nano
4,7-dihydroxy-1,10-phenanthroline and 2-(dodecylthiocarbonothioylthio)-2General Notes: 11.25 g/L
methylpropionic acid to form 2 followed by was characterization by 1H NMR
(fig. 1).
File Name: Undiluted Hot 4-24-13.dts
Dispersant Name: Water
Record Number: 50
Dispersant RI: 1.330
• The polymer chosen for reaction C was poly(N-isopropylacrylamide)
due toMeasurement
its
Material RI: 1.59
Date and Time: Thursday, April 25, 2013 2:1...
Material Absorbtion: 0.01
unique thermal phase transition. The phase transition
occurs at the lower
critical solution temperature, or LCST2. This phase
System transition was used to
Temperature Start (°C): 20.0
Cell Description: Disposable sizing cuvette
dissociate and associate the metal ion. DLS was used
to determine the LCST of
Temperature End (°C): 65.0
5 after 24 hours of dialysis (fig. 2). Red-brown precipitate was formed in
Results
solution above the LCST but below the LCST, the precipitate would disappear.
Malvern Instruments Ltd - © Copyright 2008
Trend Graph
320
400000
300
280
Number Mean (d.nm)
240
220
200000
200
180
160
Derived Count Rate (kcps)
300000
260
100000
140
120
100
10
20
30
40
50
60
0
70
Temperature
Number Mean
Figure 1: 1H NMR data for compound 2
Derived Count Rate
Figure 2: Temperature trend graph for polymer 5
Future Work
The next step is to further analyze the polymer to quantify its ability to complex. This will
be done with gel permeation chromatography and further test with dynamic light scattering.
Acknowledgments
Malvern Instruments Ltd
www.malvern.com
Zetasizer Ver. 6.12
Serial Number : MAL500553
Funding from the Department of Chemistry, UNH, is gratefully acknowledged.
References
1.
2.
D. Tzalis, Y. Tor.; Tetrahedron Letters. 1996,
37, 46.
J. Zeng et al.; Journal of Colloid and
Interface Science. 2009, 322, 654.
3.
4.
K. Wakasugi, T. Misaki, K. Yamade.;
Tetrahedron Letters. 2000, 41, 5249.
G. R. Newkome, E. He, C. N. Mooreffield.;
Chem. Rev. 1999, 99, 1689.
# Temp
°C
50
51 20.0
52 21.0
53 22.0
54 23.0
55 24.0
56 25.0
57 25.9
58 27.0
59 28.0
60 29.0
61 30.1
62 31.1
63 31.9
64 33.0
65 34.0
66 35.0
67 36.0
68 37.0
69 38.0
70 39.0
71 40.0
72 41.0
73 42.0
74 43.0
75 44.0
76 45.0
77 46.0
78 47.0
79 48.0
80 49.0
81 50.0
DCR
kcps
8685.2
8521.2
8676.5
9082.2
8565.4
9417.2
8619.9
9098.3
8835.7
9328.7
8829.0
9074.8
8498.2
8569.3
8842.6
103233.1
86901.1
209025.7
206955.1
222532.6
241846.6
258450.5
260526.4
288589.4
302523.4
319079.5
328949.6
334158.7
334280.9
331853.7
334087.6
Z-Avg
d.nm
487.7
461.8
531.4
554.6
474.9
544.7
431.5
515.7
469.2
521.1
463.0
504.9
438.2
387.0
396.1
212.1
249.9
269.7
283.5
296.0
310.5
318.5
322.1
324.9
335.9
340.3
343.1
350.5
345.9
File name: Undiluted Hot 4-24-13
349.1
Record Number: 50
30 Apr 2013 1:16:10 PM
352.2