The Synthesis of a novel tr?ger base polymer of 2,6(7)-Diamino-9,9,10,10-tetramethyl-9,10-dihydroanthracene

Article abstract of DOI:10.13005/ojc/340559

Condensation polymerisation technique has been employed to synthesise a Novel Tr?ger base polymer with thermal stability and microporosity. The synthesis process starts with alkylating anthracene, then nitrating and reducing this to produce the monomer. A Tr?ger base polymer is obtained by polymerising the monomer to afford a white polymer with good solubility into dichloromethane and chloroform, good thermal stability to ~ 377 °C and a good BET surface area of 368.6 m²/g with a total pore volume of 0.4166 ml/g.

Full text of DOI:10.13005/ojc/340559

ISSN: 0970-020 X
CODEN: OJCHEG
018, Vol. 34, No.(5):
Pg. 2661-2666
ORIENTAL JOURNAL OF CHEMISTRY
An International Open Free Access, Peer Reviewed Research Journal
2
www.orientjchem.org
The Synthesis of a Novel Tröger Base Polymer of
2,6(7)-Diamino-9,9,10,10-tetramethyl-9,10-dihydroanthracene
SADIq A. KARIM
Department of Chemistry, College of Science for Women, University of Babylon, Iraq.
*
Corresponding author E-mail: sadiqkarim77@gmail.com
http://dx.doi.org/10.13005/ojc/340559
(Received: April 29, 2018; Accepted: August 27, 2018)
ABSTRACT
Condensation polymerisation technique has been employed to synthesise a Novel Tröger
base polymer with thermal stability and microporosity. The synthesis process starts with alkylating
anthracene, then nitrating and reducing this to produce the monomer. A Tröger base polymer
is obtained by polymerising the monomer to afford a white polymer with good solubility into
o
dichloromethane and chloroform, good thermal stability to ~ 377 C and a good BET surface area
2
of 368.6 m /g with a total pore volume of 0.4166 ml/g.
Keywords: Tröger Base Polymer, Heterocyclic polymer, Tröger Base Polymer of
2,6(7)-Diamino-9,9,10,10-tetramethyl-9,10-dihydroanthracene.
8
-10
INTRODUCTION
V-shape,
besides the two enantiomers of the
1
1-12
Tröger base which exist at room temperature.
The German chemist (Julius Tröger)
Some years ago, a patent application was made
to prepare Tröger base polymers using aromatic
monomers containing diamine with methylene
supplierasdimethoxymethaneintrifluoroaceticacid.
Subsequently, several Tröger bases synthesised as
during his Ph.D., studied, synthesised and isolated
2,8-dimethyl-6H,12H-5,11-methanodibenzo[b,f]
1,5]diazocine) also known as Tröger base 1 from
the condensation of methanal (formaldehyde) with
(
[
13
4
-aminotoluene (p-toluidine) in an acid-catalysed
ladder polymers then tested as potential applications
1
14-20
media. Through a chemical reaction, 2,8-dimethyl-
6
structure was confirmed by M. A. Spielman and
then later by single crystal X-ray diffraction. After
for gas separation membranes
polymers. Furthermore, Tröger base polymers
or as network
2
1
H,12H-5,11-methanodibenzo[b,f][1,5]diazocine
2
are used in various applications as heterogeneous
3
22-24
catalysis.
Recently, Tröger base polymer was
a decade, the Tröger base was described as
synthesised by condensation of 2,8-disubstituted
Tröger base monomers with certain aromatic
compounds. In this work aTröger base is prepared
for an anthracene derivative after alkylation, nitration
4-7
"fascinating molecules'', because their structure in
25
which the chiral 1,5-diazocine bridge locks contains
two stereogenic nitrogen atoms in its rigid twisted
This is an
.0 International License (https://creativecommons.org/licenses/by-nc-sa/4.0/), which permits unrestricted
Non Commercial use, distribution and reproduction in any medium, provided the original work is properly cited.
Open Access article licensed under a Creative Commons Attribution-Non Commercial-Share Alike
4

KARIM., Orient. J. Chem., Vol. 34(5), 2661-2666 (2018)
2662
and reduction to facilitate the monomer, then the
polymerisation of it to form the polymer.This polymer
shows good thermal stability and microporosity.
(18.71 g, 105.0 mmol), LiAlH (10.00 g 270.30 mmol)
4
and diglyme (294.00 ml, 2.07 mol) was prepared in a
1L round-bottom flask.Then the mixture was refluxed
o
at 150 C for 10 h, after which time the reaction was
MATERIALS AND METHOD
Materials and eꢀuipment
cooled to room temperature and the mixture was
poured into 2L (1N) HCl and stirred for 30 minutes.
The organic layer was extract by ethyl acetate and
recrystallization with ethanol to produce 9,9,10,10-
tetramethyl-9,10-dihydroanthracene 7.50 g, 30 %
®
Diglyme, LiAlH4 and Raney -Nickel
were purchased from Sigma-Aldrich. Anthracene,
Hydrazine monohydrate, Dimethoxymethane,
Acetonitrile and Potassium nitrate were purchased
fromAlfaAesar. TrifluoroaceticacidandTrifluoroacetic
anhydride were supplied by Fluorochem.
o
as a white powder; m.p = 166-168 C; FTIR (solid) n
-
1
-1
= 3055 cm (str. aromatic C-H) , 2972 & 2963 cm
-1
(asy.and sy.str.of CH group), 1362 cm (sy.bending
of CH ); H NMR (500 MHz, CDCl ) δ 8.13 (d, J = 8.8
3
1
3
3
Hz, 4H, ArH), 7.70 (d, J = 8.7 Hz, 4H, ArH), 1.76 (s,
1
3
Eꢀuipment used in this research
12H, CH ); C NMR (126 MHz, CDCl ) δ 142.7 (Ar),
3
3
Melting points (Mp) were recorded using
a Sturat Melting Point SMP10 apparatus. Fourier
transform infrared adsorption spectra (FTIR) were
122.4 (Ar), 121.7 (Ar), 38.5 (quadruple carbon), 34.5
(CH ); LRMS (EI, m\z): calculated for C H 236.3,
236.4 (M+) found.
3
18 20
-
1
recorded in the range 4000-400 cm using an FTIR
spectrophotometer as a solid (powder) by Shimadzu
IRAffinity-1S. Nuclear Magnetic Resonance (NMR):
Synthesis of 9,9,10,10-tetramethyl-2,6(7)-Dinitro-
9,10-dihydroanthracene (DNTMA)
1
13
H and C and NMR spectra were recorded in a
A mixture of TMA (5.00 g, 21.15 mmol),
suitable deuterated solvent using Bruker Ascend
TM 500 at the School of Chemistry, University of
Edinburgh. Mass Spectrometry: Low-resolution
mass spectrometric (LRMS) and high-resolution
mass spectrometric results (HRMS) were obtained
using aThermo MAT 900 XP, double focusing sector
at The University of Edinburgh. Gel Permeation
Chromatography (GPC) analyses were performed
potassium nitrate (KNO ) (4.28 g, 42.30 mmol)
3
and Acetonitrile (250.00 ml) was prepared. Then
trifluoroacetic anhydride (TFAA) (35.00 ml, 52.05 g,
and 247.80 mmol) was added drop-wise.The mixture
was then stirred for 24 h, at room temperature, after
which a white precipitate had formed. The solvent
was removed using a vacuum pump and the residue
was stirred with water then extracted with chloroform
to produce a yellow solid. This crude product was
subjected to column chromatography (eluent:
Chloroform) to produce 9,9,10,10-tetramethyl-2,6(7)-
-
1
on chloroform solutions (2 mg ml ) using a GPC
MAX variable loop equipped with two KF-805L
SHODEX columns and a RI(VE3580) detector,
-
1
operating at a flow rate of 1 ml min . Calibration
was achieved usingViscotek polystyrene standards
Dinitro-9,10-dihydroanthracene (DNTMA) 4.20 g,
-
1
(
Mw 1000 – 1,000,000 g mol ). BET Surface Areas:
o
6
=
0 % as an off-white;m.p = 236-238 C;FTIR (solid)n
Low-temperature (77 K) nitrogen adsorption/
desorption isotherms were obtained using Coulter
SA3100 surface area analyser instruments.Thermo-
gravimetric analyses were performed on a Thermal
Analysis SDT Q600 system, heating samples (~10
mg) at a rate of 10°C/min.from 50°C to 800°C under
a nitrogen atmosphere.
-1
1516 and 1346 cm for asymmetric and symmetric
for NO group; H NMR (500 MHz, CDCl ) δ 8.13
1
2
3
(
d, J = 8.8 Hz, 2H, ArH), 7.71 (d, J = 8.8 Hz, 2H,
13
ArH), 7.69 (s, 2H, ArH), 1.76 (s, 12H, CH ) ; C NMR
3
(
126 MHz, CDCl ) δ 148.0 (Ar), 147.0 (Ar), 128.4 (Ar),
3
126.8 (Ar), 122.4 (Ar), 121.6 (Ar), 38.5 (quadruple
carbon), 34.7 (CH ); HRMs (EI, m\z): Calculated for
3
C H N O 326.40: 326.2950 (M+) found.
19
22
2
4
Procedures
Synthesis route of 2,6(7)-diamino-9, 9,10,10-
tetramethyl-9,10-dihydroanthracene-Tröger base
polymer (DATMA-TB)
Synthesis of 2,6(7)-Diamino-9,9,10,10-tetramethyl
-9,10-dihydroanthracene (DATMA)
A suspension of 2,6(7)-Diamino-9,9,10,10-
Synthesis of 9, 9,10,10-tetramethyl-9,10-
dihydroanthracene (TMA)
According to relevant literature , in
a nitrogen atmosphere, a mixture of Anthracene
tetramethyl-9,10-dihydroanthracene (DNTMA) (5.00
g, 15.32 mmol) in THF (200 ml) was stirred for
30 min. in a nitrogen atmosphere. Then Raney
Nickel (40 mg) was added to the mixture. Hydrazine
2
6

KARIM., Orient. J. Chem., Vol. 34(5), 2661-2666 (2018)
2663
monohydrate (13.00 g, 259.69 mmol) was added
drop-wise and the mixture was refluxed for 24 hours.
The colourless mixture was cooled in an ice bath and
filtered in nitrogen. The organic layer was extracted
with diethyl ether and the solvent was removed
washed with water and methanol until the washed
liquids ran clear.The resulting powder was dissolved
in chloroform and re-precipitated with methanol
three times and then dissolved in chloroform. The
solution was added drop-wise into hexane with
vigorous stirring. The polymer was collected by
filtration, as a fine powder. The polymer was dried
in a vacuum oven at 120°C for 5 h, to produce
0.84 g, 70% as an off-white powder; FTIR (solid)
o
in a vacuum at 25 C to produce 2,6(7)-Diamino-
9
3
,9,10,10-tetramethyl-9,10-dihydroanthracene
o
.1 g, 90% as a white powder; m.p = 202-205 C;
-
1
FTIR solid n = 3340 & 3309 cm for asy. & sy. of NH
2
-
1
-1
-1
group, 1620 cm bending vibration of NH group;
(Fig. 1) n = 3055 cm (Ar-H), 2943 cm (asy.
2
1
-1
H NMR (500 MHz, CDCl ) δ 7.31 (d, J = 3.2 Hz,
str. CH ), 2963 cm (asy. & sy. str. of CH & CH3
3
3
2
-
1
2
H, Ar), 7.29 (d, J = 3.2 Hz, 2H, Ar), 6.80 (s, 2H,
groups), 2860 cm (sy. str. of CH group), 1680,
2
13
-1
-1
Ar), 3.59 (s, 4H, NH ), 2.17 (s, 12H, CH ); C NMR
1597 and 1489 cm (C=C of Ar), 1325 cm (Ar-N),
2
3
-
1
1
(
126 MHz, CDCl ) 145.3 (Ar), 143.1 (Ar), 128.2 (Ar),
1215 cm (Caliphatic-N); H NMR (500 MHz, CDCl )
3
3
1
19.0 (Ar), 114.8 (Ar), 113.0 (Ar), 37.1 (quadruple
(Fig. 2). δ 7.89 (br. m, 4H, Ar), 4.48 (br. d, J = 17.0
Hz, 2H, aliphatic), 4.27 (br. s, 2H, aliphatic), 3.90
(br. d, J = 17.0 Hz, 2H, aliphatic), 1.73 (br. s, 12H,
carbon), 35.4 (CH ); HRMs (EI, m\z): Calculated for
C H N 282.4300: 266.2987 (M+) found.
3
1
9
26
2
13
CH ); C NMR (126 MHz, CDCl ) (Fig. 3). δ 146.9
3
3
Synthesisof2,6(7)-Diamino-9,9,10,10-tetramethyl
(
Ar), 144.5 (Ar), 141.2 (Ar), 132.5 (Ar), 131.4 (Ar),
27.9 (Ar), 126.6 (Ar), 126.4 (Ar), 125.9 (Ar), 67.4
-
(
9,10-dihydroanthracene-Tröger base polymer
DATMA-TB)
1
(
(
aliphatic), 64.24 (aliphatic), 55.0 (aliphatic), 17.4
9,9,10,10-Tetramethyl-2,6(7)-diamino-9,10-
CH ). On a BET surface area (Fig. 4), the sample
3
dihydroanthracene (DATMA) (1 g, 3.76 mmol) was
dissolved in dimethoxymethane (DMM) (2 ml, 1.72 g,
was degassed overnight before analysis to give
a value of 368.6 m2/g with a total pore volume =
23.24 mmol).The solution was cooled in an ice bath
0.4166 ml/g;Gel permeation chromatography (GPC)
and trifluoroacetic acid (10 ml) was added drop-wise
for 10 min. and the mixture was stirred for 7 days at
room temperature. The viscous mixture was slowly
poured into 25 ml of aqueous ammonium hydroxide
solution and stirred vigorously for 2 h, during which a
solid was formed.The solid was collected by filtration,
(
Fig. 5), polystyrene standards (Mw 1000–1000000
g mol-1): Mn=11400, Mw=19400 g/mol. The TGA
analysis (Fig. 6) of that polymer was the initial
weight loss due to thermal degradation commencing
at ~ 377.53°C with an 1.28 % loss of mass.
Scheme 1: synthesis of 2, 6(7)-Diamino-9,9,10,10-tetramethyl-9,10-dihydroanthracene-Tröger base polymer (DATMA-TB)
RESULTS AND DISCUSSION
synthesised by nitration of TMA, which forms mixed
compounds of the 2,6 and 2,7 dinitro position.
Potassium nitrate and the trifluoroacetic anhydride
were used to form the nitrating agent trifluoroacetyl
nitrate, potassium nitrate being chosen because it is
the least hydroscopic compared with other common
nitrates while the nitric acid produces nitro compound
multiproducts. This method affords a good product
yield with small quantities of impurities which were
easily separated. The nitration was carried out in
A TMA is synthesised by alkylation of
anthracene, with a lower yield. This low yield can
be attributed to several products of alkyl anthracene
which were formed, 30% of which was tetramethyl.
This alkylation process occurs with LiAlH as a
4
reducing agent to react with diglyme to form an
intermediate from a methyl carbonium ion to attack
the active positions of anthracene. A DNTMA is

KARIM., Orient. J. Chem., Vol. 34(5), 2661-2666 (2018)
2664
acetonitrile solvent because of the greater solubility
of the inorganic salts. The reaction was processed
at room temperature because increased heating will
result in a higher ratio of impurity.The crude product
was subjected to column chromatography (eluent:
Chloroform) to produce as an off-white powder.
The FTIR of DNTMA appears as asymmetric and
mixture is stirred at room temperature under a
constant inert atmosphere until the solution realises
the required viscosity. The colour of the solution
will change to dark red. Tröger base polymerisation
exhibits the rate of acid addition and changes in
concentration. To quench it, the mixture is slowly
poured into aqueous ammonium hydroxide solution
to precipitate the polymer as an amorphous solid.
The FT-IR of polymer (Fig. 1) shows disappearing
-
1
symmetric stretching of NO 1516 and 1346 cm ,
2
1
3
respectively. The C NMR of DNTMA refers to
Caromatic-NO at δ 148.0 and 147.0. The reduction of
vibration stretching and bending of –NH and the
2
2
DNTMA to DATMA using hydrazine monohydrate
and a catalytic quantity of Raney nickel produced
amines with the highest purity. The reduction was
carried out under reflux to decrease the reaction
time. The reduction must be conducted under an
inert atmosphere using solvents that have been
thoroughly deoxygenated. The FTIR of DATMA
appears as asymmetric and symmetric stretching
appearance of a new vibration of Caliphatic-N forTröger-
1
base cyclic. H NMR (Fig. 2) clearly refers to Ar-N-
CH for Tröger-base cyclic at δ 4.48 and 3.90 ppm
2
13
beside to N-CH -N at δ 4.27 ppm. C NMR (Fig. 3)
2
of polymer refers to Caromatic-N at δ 146.9 and 144.5
ppm and Caliphatic-N at δ 67.4 and 64.24 ppm. The
solubility of that polymer is shown as good in DMSO,
DMAC, NMP, DMF, DCM and CHCl but insoluble
3
in Toluene, Xylene, THF, ethanol and acetone
(Table 1). The BET surface area calculated from
nitrogen isotherms shows microporosity of DATMA-
TB polymer where the BET surface area is 368.6
-
1
of the NH group at 3340 & 3309 cm , respectively,
2
-1
with bending vibration of the NH group at 1620 cm .
The H NMR of DATMA refers to the NH group at δ
.59 ppm.The C NMR of DATMA refers to Caromatic
2
1
2
13
2
3
-
m /g, the total pore volume = 0.4166 ml/g, which is
attributed to methyl groups besides the heterocyclic
V shape of the Tröger base BET surface area
NH at 145.3 and 143.1 ppm.The DATMA monomer
2
was polymerised using dimethoxymethane (DMM)
which is a "methylene" source in a strongly acidic
solvent, and a catalyst such as trifluoroacetic acid
(
(
Fig. 4). Gel permeation chromatography (GPC)
Fig. 5) polystyrene standards (Mw 1000–1000000
-
1
g mol ) Mn=11400, Mw=19400 g/mol. Thermal
gravimetric analysis (TGA) of the DATMA-TB
polymer showed an initial weight loss due to thermal
degradation commencing at ~ 377 °C with a 1.28 %
loss of mass, then a decrease in mass until a loss of
~ 47% at ~ 631°C where complete decomposition
took place (Fig. 6).
(
TFA). A typical procedure of polymerisation is one
equivalent of a pure aromatic diamine mixed with
five equivalents of dimethoxymethane (excess) and
cooled to the temperature of ice. TFA (8-10 ml per
gram of monomer) is then slowly added drop-wise
over a period of 10 to 30 minutes.The polymerisation
Table 1: Solubility of DATMA-TB in common organic solvents
I,II
Solvents
DMSO DMAC NMP DMF Toluene Xylene THF Acetone DCM CHCl3 EtOH
DATMA-TB
+
+
+
+
-
-
-
-
+
+
-
I
II
-1
Solubility guide: (+) soluble, (-) insoluble. All solvents tested had a concentration of 0.01 g ml at
room temperature
1
Fig. 1. FTIR of DATMA-TB
Fig. 2. H NMR of DATMA-TB

KARIM., Orient. J. Chem., Vol. 34(5), 2661-2666 (2018)
2665
Fig. 3. 13C NMR of DATMA-TB
Fig. 4. Nitrogen adsorption isotherms at 77 K for DATMA-TB
Fig. 5. GPC (based on polystyrene standards) for DATMA-TB
Fig. 6. Thermal gravimetric analysis for DATMA-TB
CONCLUSION
produced as white by condensation polymerisation of
DATMA with DMM inTFA.TMA, DNTMA and DAMTA
In summary, TMA synthesis by alkylating
anthracene took place with a 30% yield following
nitration to produce DNTMA 60%, the DATMA
resulting in 90%. DATMA-Tröger base polymer was
1
compounds are characterised by FT-IR, H-NMR,
13
C-NMR besides TGA and the BET surface area
of polymer.
REFERENCES
Tröger, J. J. für Praktische Chemie., 1887, 2.
6, 225-245.
1.
Spielman, M. A.; J. Am. Chem. Soc., 1935,
57, 583-585.
3

KARIM., Orient. J. Chem., Vol. 34(5), 2661-2666 (2018)
2666
3
4
5
6
7
.
.
.
.
.
Larson, S. B.; Wilcox; C. S., Acta Cryst.
Section C., 1986, 42, 224-227.
K. ; McKeown N. B. Adv. Mater., 2014, 26,
3526-3531.
Rose I.; Carta M.; Malpass-Evans R.; Ferrari
M.; Bernardo P.; Clarizia G.; Jansen J. C.;
McKeown, N. B. ACS Macro Letters., 2015,
4, 912-915.
Vögtle, F., Fascinating Molecules in Organic
Chemistry; Wiley and Sons., 1992, 237-249.
Becker D. P.; Finnegan P. M.; Collins P. W.;
Tetrahedron Letter., 1993, 34, 1889-1892.
Adrian, J.C.;Wilcox C.S.; J.Am.Chem.Soc.,
16.
17.
18.
Z. G. Wang, X. Liu, D. Wang and J. Jin, Poly.
Chem., 2014, 5, 2793-2800.
1992, 114, 1398-1403.
Weber , E.; Müller, U.; Worsch, D.; Vögtle,
F.; Will, G.; Kirfel, A. ; J. Chem. Soc. Chem.
Comm., 1985, 1578-1580.
ZhuangY.;Seong,J.G.;Do,Y.S.;Lee,W.H.;Lee,
M.J.;Cui, Z.;Lozano, A.E.;Guiver, M.D.;Lee,Y.
M. Chem. Comm., 2016, 52, 3817-3820.
Ghanem, B.; Alaslai N.; Miao, X.; Pinnau I.;
Polymer., 2016, 96, 13-19.
KarimS.A.;BraihiA.J. JGPT., 2017, 12(9), 30-35.
Carta M.; Croad; M.; Bugler K.; Masyib, K.
J; McKeown N. B. Polym. Chem., 2014, 5,
5262-5266.
Rong Y.; Malpass-Evans R.; Carta M.;
McKeown, N. B.; Attard G. A.; Marken, F.
Electroanalysis., 2014, 26, 904-909.
Cabrero-Antonino J. R.; Garcia T.; Rubio-
Marqués P.; Vidal-Moya J. A.; Leyva-Pérez
A.; Al-Deyab S. S.; Al-Resayes S. I.; Diaz U.;
Corma A. ACS Catal., 2011, 1, 147-158.
Poli E.; Merino E.; Diaz U.; Brunel, D.; Corma
A. J. Phys. Chem. C., 2011, 115, 7573-7585.
Li W.; Michinobu T. Macromol. Chem. and
Phys., 2016, 217, 863-870.
8
9
1
1
.
Sergeyev, S. Helv. Chim. Acta., 2009, 92,
19.
415-444.
.
Adrian, J. C. , Wilcox, C. S. ; J. Am. Chem.
Soc., 1989, 111, 8055-8057.
Wilcox, C.S.; Cowart, M. D. ; Tetrahedron
Letters., 1986, 27, 5563-5566.
Didier, D.; Tylleman, B.; Lambert N.; Velde,
C.; Blockhuys F.; Collas A.; Sergeyev S.
Tetrahedron., 2008, 64, 6252-6262.
20.
21.
0.
1.
22.
23.
1
1
1
2.
3.
4.
Trapp, O.;SchurigV.J.Am.Chem.Soc., 2000,
122, 1424-1430.
Carta, M.; Croad M.; McKeown N. B., 2010,
WO2012/035328 A1.
Carta, M.; Malpass-Evans, R.; Croad,
M.; Rogan, Y.; Jansen J. C.; Bernardo P.;
Bazzarelli, F;McKeown N.B.Science., 2013,
24.
25.
26.
339, 303-307.
1
5.
Carta M.; Croad M.; Malpass-Evans R.;
Jansen J. C.; Bernardo P.; Clarizia,G.; Lanc,
Kamatani J.;TakiguchiT.;Okada S.US Patent
Application., 2008, 20080007161.