Enhanced liquid crystal properties in symmetric ethers containing the oxazepine core: synthesis and characterization of seven member heterocyclic dimers

Article abstract of DOI:10.1016/j.tet.2016.05.024

Four new series of symmetric dimers derived from the basic heterocyclic oxazepine core were designed, synthesized, characterized and investigated for liquid crystal properties. The chemical structures of the prepared molecules were characterized by infrared,¹H/¹³C nuclear magnetic resonance spectra and elemental analysis. Thermal properties and mesophase textures were evaluated by using a combination of differential scanning calorimetry and polarized optical microscopy techniques. Most of the compounds exhibited monotropic liquid crystalline phases in cooling processes. The effect of the spacer chain length and terminal alkoxy chain were studied for the influence on the type of mesophase formed by the homologous series of compounds. Lower members possessing the methylene spacer and a terminal alkoxy-chain favoured smectogenic properties; those derived from medium methylene spacer with terminal alkoxy chain favoured nematogenic properties whereas molecules derived with a higher methylene spacer with terminal alkoxy chain members did not favour any liquid crystalline properties.

Full text of DOI:10.1016/j.tet.2016.05.024

Accepted Manuscript
Enhanced liquid crystal properties in symmetric ethers containing the oxazepine core:
synthesis and characterization of seven member heterocyclic dimers
AbdulKarim-Talaq Mohammad, H.T. Srinivasa, S. Hariprasad, Guan-Yeow Yeap
PII:
S0040-4020(16)30409-4
10.1016/j.tet.2016.05.024
TET 27751
DOI:
Reference:
To appear in: Tetrahedron
Received Date: 2 January 2016
Revised Date: 29 April 2016
Accepted Date: 9 May 2016
Please cite this article as: Mohammad A-T, Srinivasa HT, Hariprasad S, Yeap G-Y, Enhanced liquid
crystal properties in symmetric ethers containing the oxazepine core: synthesis and characterization of
seven member heterocyclic dimers, Tetrahedron (2016), doi: 10.1016/j.tet.2016.05.024.
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ACCEPTED MANUSCRIPT
Graphical abstract

ACCEPTED MANUSCRIPT
Enhanced liquid crystal properties in symmetric ethers containing the oxazepine core:
Synthesis and characterization of seven member heterocyclic dimers
AbdulKarim-Talaq Mohammad*1, Srinivasa, H. T2, Hariprasad. S3, Guan-Yeow Yeap4
1Chemistry Department, College of Science, University of Anbar, Ramadi, Iraq
2Raman Research Institute, Soft Condensed Matter Group, Sadashivanagara, Bengaluru-560080,
Karnataka, India
3Department of Chemistry, Central College Campus, Bangalore University, Bengaluru-560001,
Karnataka, India
4Liquid Crystal Research Laboratory, School of Chemical Sciences, Universiti Sains Malaysia,
Minden 11800, Penang, Malaysia
Abstract
Four new series of symmetric dimers derived from the basic heterocyclic oxazepine core were
designed, synthesized, characterized and investigated for liquid crystal properties. The chemical
1
structures of the prepared molecules were characterized by infrared, H/13C nuclear magnetic
resonance spectra and elemental analysis. Thermal properties and mesophase textures were
evaluated by using a combination of differential scanning calorimetry and polarized optical
microscopy techniques. Most of the compounds exhibited monotropic liquid crystalline phases in
cooling processes. The effect of the spacer chain length and terminal alkoxy chain were studied
for the influence on the type of mesophase formed by the homologous series of compounds.
Lower members possessing the methylene spacer and a terminal alkoxy- chain favoured
smectogenic properties; those derived from medium methylene spacer with terminal alkoxy
chain favoured nematogenic properties whereas molecules derived with a higher methylene
spacer with terminal alkoxy chain members did not favour any liquid crystalline properties.
Keywords: mesophase; oxazepine; heterocycle; dimers; smectic; methylene spacers.
_________
*Author for correspondence: AbdulKarim-Talaq Mohammad, Tel; +9647902529959 E-mail
address: drmohamadtalaq@gmail.com
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1. Introduction
The simplest form of oligomer liquid crystal is dimeric, in which the main part of the
molecule contains two rigid mesogenic/non-mesogenic units connected via a flexible spacer.1,2
Several classes of dimeric liquid crystals have been prepared, studied extensively and
documented.3-7 They have attracted enormous attention during the past decade due to their
interesting liquid crystalline properties.8-10 A dramatic increase in the diversity of molecular
architectures comprise rod-, disk- and banana-shaped derived dimeric and oligomeric mesogenic
units. These units are known to exhibit LC behaviour with supramolecular structures.11-17
Imrie’s review illustrates that the structure-property relationship of various dimers/oligomers and
the dimers themselves have attracted attention as they display an unusual interesting
mesomorphism different to that of the corresponding monomers.18 Furthermore, they have the
ability to act as model compounds for semi-flexible, main-chain/side-chain liquid crystalline
oligomers and polymers.19 The majority of the symmetrical dimers possess mesogenic/non-
mesogenic units which assure the mesophase with flexible spacer.
The effects of different spacers on the mesomorphic properties of symmetrical and
unsymmetrical liquid crystalline dimers containing alkoxy-, cyanobiphenyl- and naphthalene
systems are reported.21,22 In connection to dimers, an ether linkage between the mesogenic/non-
mesogenic unit and the central methylene spacer usually produces nematic behaviour, whereas
an ester linkage induces smectic properties in the system.20 It is generally observed that
nematic-isotropic transition temperatures are higher for compounds with an alkoxy chain than for
alkyl chain derivatives with the same total number of carbon atoms. This difference is attributed
to the higher anisotropy of the molecular polarizability expected for an ether linkage in
comparison with a methylene group.23
In this regard, there are few reports which deal with heterocyclic cores held by methylene
spacers.24 To date, a large number of symmetrical and non-symmetrical dimers have been
reported with conventional aromatic cores, but there exists a scarcity of heterocyclic ring derived
dimeric liquid crystals.26-29
There exists one report of molecules that mimic the Archaea
domain which were constructed by tetraether glycolipid analogues. This study inspired us to
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explore the preparation of rigid blunt end derived oxazepine heterocyclic compounds for LC
studies. The idea is a very similar approach to that shown by Plusquellec et al.25
From a heterocyclic chemistry point of view and for their applicability as liquid crystals,
we have studied the oxazepine heterocyclic ring and evaluated it for LC property with exhaustive
chemical structure modifications.30-33 The oxazepine heterocycle by itself hardly exhibits any LC
property in many of its derivatives due to its unconventional size of being a seven membered
polar heterocyclic ring. However, due to the easy synthesis of the oxazepine heterocycle, we
were interested to extend the work to achieve interesting liquid crystals. The liquid crystals
would then possess two oxazepine heterocycles which are connected and terminated by flexible
alkylene spacers to attain low transition temperatures.
In this article, we present a strategy which reports the synthesis and mesomorphic
properties of a new series of heterocyclic oxazepine dione ring derived symmetrical dimeric
molecules in which a flexible spacer ranges from n = 6 - 12 carbon atoms and a terminal alkoxy
chain ranges from n = 6 - 18 carbon atoms.
2. Results and discussion
2.1 Synthesis
The preparative pathway towards obtaining title compounds 7-34 is shown in Scheme 1.
Imines 1a-g were synthesised via a condensation reaction in a similar manner as reported
earlier.34 Compounds 2a-g, 3a-g, 4a-g and 5a-g resulted from Williamson’s etherification
between imines 1a-g and various α,ω-dibromoalkanes ranging from C6H12Br2 to C12H24Br2.30-34
The freshly prepared compounds 2a-g, 3a-g, 4a-g and 5a-g were subsequently reacted with
phthalic anhydride to yield the target compounds 7-34.
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R
N
N R
CHO
OH
O(CH2)nO
Br-(CH2)n-Br
2. R-NH2, EtOH
R N
2a-g. where n = 6, R = 6-18
3a-g. where n = 8, R = 6-18
4a-g. where n = 10, R = 6-18
5a-g. where n = 12, R = 6-18
cat AcOH, reflux
3 h
Cs2CO3, DMF
65 °C, 12 h
OH
1a-g
Compounds 7-13. where n = 6, R = C6H13 - C18H37
14-20. where n = 8, R = C6H13 - C18H37
21-27. where n = 10, R = C6H13 - C18H37
28-34. where n = 12, R = C6H13 - C18H37
O
dry benzene
80 °C, 1 h
O
6
O
O
R
O
O
N
O
N
O(CH2)nO
7 - 34
O
O
R
Scheme 1. Synthetic pathway for symmetric ethers containing the oxazepine core 7-34.
Table 1. Thermotropic behaviours of symmetric oxazepine derivatives 7-34.
No
n/R
Heating scan and Cooling scan (onset 5 °C /min, [°C] /
ꢀ
H [kJ/mol])
7
6/6
6/8
Cr 126.1 (70.10) I
Cr 130.4 (76.13) I
Cr 94.3 (-55.23) I
8
Cr 98.7 (-44.20) SmA 112.3 (-6.22) I
Cr 87 (-83.45) SmA 103.9 (-8.23) I
Cr 84.2 (-70.90) SmA 113.3 (-5.67) I
Cr 89.3 (-42.67) N 117.3 (-7.11) I
Cr1 93.6 (-34.41) N 123.6 (-6.20) I
Cr1 78.1 (-20.22) Cr2 120 (-52.20) I
Cr 89.2 (-44.11) I
9
6/10 Cr 134.8 (59.20) I
10
11
12
13
14
15
16
17
18
19
20
21
22
6/12 Cr 137.1 (62.14) I
6/14 Cr 145.2 (42.67) I
6/16 Cr1 95.2 (20.32) Cr2 151.8 (88.43) I
6/18 Cr1 93.2 (14.60) Cr2 161.4 (48.09) I
8/6
8/8
Cr1 132.5 (25.60) I
Cr 137.6 (48.90) I
Cr 94.3 (-33.43) SmA 118.5 (-5.76) I
Cr1 96.9 (-24.62) SmA 121.6 (-7.20) I
Cr 87.7 (-29.90) N 118.1 (-5.76) I
Cr 84.6 (-23.40) N 111.9 (-7.30) I
Cr1 72.8 (-29.14) Cr2 123.2 (-42.15) I
Cr1 86.2 (-25.46) Cr2 135.1 (-31.83) I
Cr1 86.4 (-28.10) SmA 108.5 (-6.30) I
Cr1 91.8 (-37.41) SmA 116.6 (-3.69) I
8/10 Cr1 82.1 (21.45) Cr2 143.78 (19.00) I
8/12 Cr1 89.4 (37.61) Cr2 147.39 (52.37) I
8/14 Cr1 91.3 (25.51) Cr2 153.40 (72.29) I
8/16 Cr1 94.8 (27.18) Cr2 162.71 (50.35) I
8/18 Cr1 108.9 (50.31) Cr2 167.64 (78.28) I
10/6 Cr 131.4 (48.31) I
10/8 Cr1 136.5 (60.27) I
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23
24
25
26
10/10 Cr1 92.7 (23.49) Cr2 140.6 (32.11) I
Cr 88.6 (-22.60) SmA 109.8 (-3.49) I
Cr1 85.4 (-19.78) SmA 113.7 (-0.86) I
Cr1 94.3 (-14.10) N 118.5 (-4.30) I
Cr1 82.8 (-45.31) Cr2 121.7 (-29.28) N
138.6 (-4.50) I
10/12 Cr1 89.7 (22.10) Cr2 149.4 (21.79) I
10/14 Cr1 98.2 (34.67) Cr2 156.5 (60.19) I
10/16 Cr1 116.3 (18.94)Cr2 163.7 (24.18) I
27
10/18 Cr1 119.3 (48.29) Cr2 171.6 (66.14) I
Cr1 93.6 (-39.76) Cr2 128.6 (-48.25) N
152.6 (-2.89) I
28
29
12/6 Cr1 81.2 (26.50) Cr2 142.5 (19.30) I
12/8 Cr1 84.6 (28.10) Cr2 147.4 (33.20) I
Cr 87.6 (-26.75) SmA 103.2 (-4.55) I
Cr173.2 (-52.18) Cr2 93.9 (-15.64)
SmA 116.5 (-3.78) I
30
31
32
33
34
12/10 Cr1 96.4 (15.45) Cr2 150.5 (17.39) I
12/12 Cr1 112.8 (19.44) Cr2 154.8 (19.78) I
12/14 Cr1 118.4 (14.66) Cr2 163.3 (29.41) I
12/16 Cr1 123.8 (28.76) Cr2 168.6 (31.05) I
12/18 Cr1 128.2 (15.20) Cr2 174.8 (17.52) I
Cr1 82.3 (-67.20) Cr2 103.7 (-18.07)
N 128 (-4.79) I
Cr1 73.5 (-79.20) Cr2 98.7 (-48.85) N
129.4 (-2.82) I
Cr 1 77.3 (-46.30) Cr2 107.4 (-14.55)
N 130.2 (-3.74) I
Cr1 83.4 (-39.76) Cr2 114.3 (-18.90)
N 135.6 (-1.22) I
Cr1 96.3 (-24.89) Cr2 138.8 (-19.33) I
Note: Cr1/Cr2 = crystal to crystal transitions; SmA = smectic A phase; N = nematic phase; I =
isotropic phase
2. 2 Characterization by FT-IR spectroscopy
The diagnostic absorption bands at 2944 and 2870 cm-1 in the FT-IR spectrum of 7 are
assigned to the C-H asymmetric and symmetric stretching of the respective methylene spacers.
At lower frequency, the carbonyl group (C=O) was observed at the frequency 1660 cm-1. The
presence of the aromatic rings was inferred from the absorption bands at 3007, 1600 and 1588
cm-1. The strongest band is observed in the fingerprint region of 1266 cm-1 which can be
attributed to the presence of two ether (O-CH2) groups for every dimeric structure. The FTIR
spectra of compounds 7-34 exhibit similar diagnostic bands as those observed in compound 7.
These values conform with those reported in the FT-IR spectra for various 1,3-oxazepine
compounds reported elsewhere.30-34
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O
9"
6"
3'
5'
2'
6'
O
8"
7"
1"
1'
4'
O
3"
N
5"
O
n
6"
9"
O
3' 2'
N
7"
8"
5"
4'
1'
O
3"
O
1"
6'
5'
O
General structure
2. 3 Characterization by NMR spectroscopy
1
The complete H and 13C NMR assignment of representative compounds 7-34 were
1
1
obtained and substantiated by means of H-1H correlation spectroscopy (COSY), H-13C hetero
1
nuclear multiple quantum correlation (HMQC), and H-13C hetero nuclear multiple bond
correlation (HMBC) spectroscopic measurements, as described in the literature.30-34
The values of the 1H NMR chemical shift for compounds 7-34 in DMSO solution are listed
in the experimental section. A complete assignment for the title compounds can be described
1
based on the representative compounds as shown in Scheme 1.
assignment of compound
A complete H NMR
7
is described as an example. The presence of a singlet at δ = 9.80 ppm
is attributable to the H3′ and 3′′ proton in the heterocyclic ring. This can be further substantiated
by the direct bond hetero nuclear correlation with C3′ and C3′′ within the frequency δ = 90.72
ppm. The aromatic protons H2′ or H6′ can be observed as a doublet at δ = 7.10 ppm. The signals
which appear as a doublet due to H3′ or H5′ are observed at δ = 7.31 ppm and the aromatic
protons (H2′, H3′, H5′ and H6′) are equivalent. The aromatic protons H6′′, H7′′, H8′′ and H9′′ are
found to be non-equivalent. The two doublets in the down-field region at (δ = 8.36 and δ = 7.56
1
ppm) are assigned to aromatic protons H6′′ and H9′′. The H NMR spectrum of compound
7
shows two triplets at (δ = 7.81 and δ = 7.95 ppm) due to aromatic protons H7′′ and H8′′
respectively. This fact suggests that the molecule is symmetric. The triplet attributed to the
methoxy protons of the spacer is evident at slightly higher field (δ = 4.08 ppm), while the two
triplets at δ = 3.80 ppm and δ = 0.95 can be assigned to the methylene proton N-CH2 and CH3 in
6

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both terminal alkyl chains. The subsequent methylene protons of the fragment and those of the
spacer give rise to overlapping multiplets at δ = 1.31-1.94 ppm.
13
After assigning the protons of title compound 7-34, C-NMR spectroscopy was carried
13
out along with DEPT 135. The C NMR spectrum of compounds
7 indicate that the aromatic
carbons give rise to different peaks within the frequency range of δ = 115.43-134.31 ppm. The
aromatic quaternary carbon and its neighboring proton are assigned with the employment of
HMBC experiment. The assignment of C1′ at δ = 159.21 ppm is based on its correlation with H3′
and H5′. The HMBC spectrum also show cross peaks of 1′′ of the carbonyl group (C=O) with
H7′′ atoms at δ = 168.72 ppm and C5′ of the carbonyl group (C=O) with H8′′. Peaks at δ = 90.73
ppm can be assigned to C3′ or C3′′ in the heterocyclic ring. Diagnostic peaks observed at δ =
39.44 ppm indicate the presence of the methylene in (N-CH2) from the alkyl linkage. Signals
attributable to the methylene carbons of the spacer alkyloxy chain and terminal alkyl chains are
observed within the range of δ = 22.14 ppm. Peaks due to the methyl carbons are observed δ =
15.23 ppm.
The results inferred from the IR and NMR spectral data of compounds 7-34 are found to
be in agreement with the proposed structure as shown in Scheme 1.
2. 4 Thermal and optical studies
The transition temperatures and associated enthalpy values were determined using a
differential scanning calorimeter (Elmer Pyris 1 DSC) operating at a scanning rate of ± 5 °C min-
1
on heating and cooling cycles respectively. Texture observation was carried out using Carl
Zeiss Axioskop 40 optical microscope equipped with Linkam LTS350 hot stage and TMS94
temperature controller.
Mesomorphic properties of all the compounds 7-34 were determined by differential
scanning calorimetry (DSC) measurements and polarised optical microscopy (POM). DSC
curves obtained under the same conditions overlapped with each other, indicating that the
reproducibility of the measurements was satisfactory. The phase transition temperatures reported
in this paper were the peak values of the transition on DSC curves. Phase identification was
made by comparing the observed textures with those reported in the literature. The phase
transition temperatures, the associated enthalpy changes and mesophase textures of 7-34 are
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summarized in Table 1. Clear-cut transition temperatures for LC and non-LC molecules and
textures could be obtained from DSC curves and POM observations for all of the compounds.
They were in good agreement with each other for the heating/cooling cycles along with their
enthalpies.
Compounds 7-13 have methylene spacer length n = 6 and terminal alkyl chain varying
from n = 6-18. Compound
7
hardly exhibited any LC property, whereas compounds 8-10
upon heating transformed from a crystalline
showed SmA mesomorphism. The compound
8
state to the isotropic state at 130.4 °C (ꢀH = 76.13). When cooled from the isotropic state, the
compound exhibited focal conics with striped texture with transition bars for the SmC phase.
Since the focal conic stripes did not originate from the isotropic liquid, and were observed after
cooling for some time from the isotropic state, the existence of the SmE phase is ruled out. This
is depicted in Figure 2 (a) at 112.3 °C (ꢀH = - 6.22), before finally re-crystallising at 98.7 °C
(ꢀH = - 44.20). Similar transitions were found for the compounds
9 and 10. The DSC trace of
10 is shown in Figure 1 (a). Notable changes occured in the next members 11 and 12
.
Compound 11 melts at 145.2 °C (ꢀH = 42.67) which went to isotropic state, then it was cooled
from the isotropic state at 117.3 °C (ꢀH = -7.11). It shows mosaic texture for the nematic
phase. Optical photomicrograph of compound 12 upon cooling displaying SmA at 106 °C is
depicted in Figure 2 (b). Interestingly, the compound 13 did not show any LC property.
In the second set of compounds 14-20, having methylene spacer length: n = 8 and
terminal alkyl chain varying from n = 6-18, compound 14 hardly exhibited any LC property,
whereas compounds 15-16 showed SmA mesomorphism. For example, the compound 15 melts
directly to the isotropic state at 137.6 °C (ꢀH = 48.90) without showing any mesophase. When it
was cooled down from the isotropic state, the SmA phase appeared at 118.5 °C (ꢀH = -5.76)
and then crystallised at 94.3 °C (ꢀH = -33.43) respectively. An optical photomicrograph of
compound 15 displaying SmA phase upon cooling at 109 °C is shown in Figure 2(c) with the
observation under POM. Compounds 17 and 18 shows nematic LC property with mosaic texture
monotropically. The representative DSC thermogram of compound 18 as shown in Figure 1(b) in
which two endothermic peaks at 91.3 °C (ꢀH = 25.51) and 153.4 °C (ꢀH = 72.29) and two
exothermic peaks at 84.6 °C (ꢀH = -23.40) and 111.9 °C (ꢀH = -7.30) occurred corresponding to
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Cr1-Cr2-I and I-N-Cr2 transitions. Interestingly, in this set, two compounds 19 and 20 did not
show any LC property.
In the third set of compounds 21-27 having methylene spacer length: n = 10 and terminal
alkyl chain varying from n = 6-18, all the compounds favored monotropic LC property.
Compound 21 and 22 has one crystal-crystal transition on heating scan, while in the cooling scan
the SmA phase appeared at 108.5 °C (ꢀH = -6.30) and 116.6 °C (ꢀH = -3.69), and then
crystallized at 86.4 °C (ꢀH = -28.10) and 91.8 °C (ꢀH = -37.41) respectively. In the case of 23
27, two crystal-crystal transitions appeared on heating cycle as tabulated in Table 1. In this set,
four compounds 21 24 favoured SmA mesomorphism from isotropic states. The DSC
-
-
thermogram of compound 25 during heating run shows two peaks which can be ascribed as Cr1-
Cr2-I at 98.2 °C (ꢀH = 34.67) and 156.5 °C (ꢀH = 60.19) and in the cooling scan, two peaks
appeared at 94.3 °C (ꢀH = -14.10) and 118.5 °C (ꢀH = -4.30) for I-N-Cr2 transitions
respectively. Compound 26 and 27 show the nematic phase with two crystal-crystal transitions
in the cooling scan.
From these observations, it is clear that the length of the alkoxy chain influences not only
the nature of the mesophase, but also the mesomorphic temperature range. Generally, an increase
in terminal length often results in an enhanced induced-dipole-induced-dipole interaction
between the terminal chains, leading to the formation of a more ordered smectic mesophase in
compounds 21-24. Further, an increase in terminal alkyl chain dilutes the order leading to less
ordered nematic mesophase which is proved in the next set of compounds.
In the fourth set of compounds 28-34, having methylene spacer length: n = 12 and
terminal alkyl chain length varying from n = 6-18, all the compounds 28-34 show two crystal-
crystal transitions in both heating and cooling scans as Cr1-Cr2-I and reverse transition as I-N-
Cr2-Cr1 respectively. Only two compounds 28 and 29 exhibit typical focal conic texture of SmA
LC property with similar textural observations. Compound 29 heated to its isotropic state with
Cr1 at 84.6 °C (ꢀH = 28.10) and Cr2-I at 147.4 °C (ꢀH = 33.20) transitions. While in the cooling
cycle I-SmA at 116.5 °C (ꢀH = -3.78), Smectic-Cr2 at 93.9 °C (ꢀH = -15.64) and then Cr2-Cr1 at
73.2 °C (ꢀH = -52.18) transitions respectively, whereas compounds 30-33 shows a nematic
phase. An optical photomicrograph of compound 33 exhibiting nematic mosaic texture upon
cooling at 126 °C is depicted in Figure 2 (d). The last compound 34 did not show any LC
9

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property.
DSC thermograms as in Figure 1 (d) of compound 34 show two endothermic
transitions at 128.2°C (ꢀH =15.20) and 174.8 °C (ꢀH = 17.52) with respect to Cr1-Cr2-I
transitions. While in cooling scan, two exothermic transitions appeared at 96.3 °C (ꢀH = -24.89)
and 138.8 °C (ꢀH = -19.33) for I-Cr2 and Cr2-Cr1 respectively. The enthalpy values of I-Cr2 (ꢀH
= -19.33) and Cr2-Cr1 (ꢀH = -24.89) confirms the non-appearance of the mesophase in
compound 34
.
Figure 1. DSC thermograms of compounds (a) for 10, (b) for 18 and (c) for 34
.
It was noted that in the cooling processes, enthalpy values are much lower than those
during heating process (Table 1). This was generally encountered in the case of monotropic
mesophases due to partial vitrification of the samples resulting from the slow kinetics of
crystallization.35 In our case, similar phenomena may be attributed to the slow kinetics of re-
crystallization. However, the clearing points during cooling are much lower than that in the
heating cycle, which may be due to the weak interactions among the LC molecules.
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Figure 2. (a) Optical photomicrograph of compound
9
exhibiting SmA upon cooling at 95 °C (b)
Optical photomicrograph of compound 12 upon cooling displaying SmA at 106 °C (c) Optical
photomicrograph of compound 15 displaying SmA phase upon cooling at 109 °C. (d) Optical
photomicrograph of compound 33 exhibiting nematic texture upon cooling at 126 °C.
The different mesophases were found for lower members (n = 6, 8 and 10) and higher
members (n = 12, 14, 16 and 18) and can be explained by the number of aliphatic chains present
at the periphery and at spacer position of the molecules. In this regard, a smaller aliphatic chain
seems to be co-ordinating in terms of achieving a good packing with less random orientation of
the molecules which may lead to a SmA mesophase. In the case of higher members the
peripheral and spacer alkyl chains do not allow molecules to packing each other due to the bulky
oxazepine heterocycle, and the disturbance may lead to exhibit the nematic phase. Appearance of
a nematic mesophase in higher alkyl chains may be due to the increase in random orientations of
11

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the molecule and least van der Waals attractive forces between the terminal and spacer alkyl
chains.
The phase behaviour shown by the present four set of compounds is unusual. The
conventional behaviour in liquid crystal dimers is smectic behaviour to be favoured on
increasing the spacer length. Since in the present series of compunds nematic phase/non-liquid
crystallinity is favoured in higher methylene spacer containing members, this behaviour is
unexpected.36
A plot of transition temperature as a function of terminal/spacer chain length for the four
sets of compounds 7-34 is shown in Figure 3. Figure 3(a) corresponds to compounds 7-13
,
,
Figure 3(b) corresponds to compounds for 14-20. Figure 3(c) corresponds to compounds 21-27
and Figure 3(d) corresponds to compounds 28-34. Figure 3 indicates that the mesophase ranges
of compounds 13 and 14 20 are better than compounds 21 27 and 28 34 In general, we
7
-
-
-
- .
observed in our target compounds 7-34, the crystal to isotropic temperatures are high for lower
members, low for middle members and again high for higher members. The temperature
decreases in the beginning set of compounds, then increases with the increasing number of
carbons in the methylene spacer and terminal alkyl chains. This behaviour suggests that
increasing the carbon atoms in the methylene spacer serves to dilute the core-core interactions
when compared with the terminal alkyl chain having six carbons. The enhancement nematic
phase was formed when n = 10 and 12, indicating the order parameter is lost due to long alkyl
chains.
The blunt end and relatively large size of the oxazepine heterocycle dimers result in high
transition temperatures. To overcome that, we have extended the length of the spacer and
terminal alkyl chains to attain low temperatures. This strategy works well in the reduction of
transition temperature as we can observe in the plots of Figure 3.
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Figure 3. Plot of monotropic LC transition temperatures verses number of carbon atoms in the
central connecting spaces and terminal alkyl chains: (a) for compounds 8-12, (b) for compounds
15-18, (c) for compounds 21-27 and (d) for compounds 28-33.
Generally, in dimeric compounds, transition temperatures follow a pronounced odd-even effect,
meaning odd number spacer molecules have low melting transition temperatures and even
number spacer molecules have high melting transition temperatures. This behaviour is most
commonly attributed to the pronounced dependence on the molecular shape, length and parity of
the spacer.37 Such behavior has been accounted for by theory, by means of the different shapes
of the conformers having odd or even membered spacers, and their associated conformational
distributions. As a result in the present series of oxazepine dimers the odd-even effect is
eliminated.38
13

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3. Conclusions
In this work we report that oxazepine heterocycle derived dimeric molecules can exhibit
a good range of SmA and nematic mesophases with respect to their middle spacer and terminal
alkyl chain length. We have also found rich polymorphism in most of the compounds, such as
crystal-crystal (Cr1-Cr2), SmA and nematic phases. The mesophase formed in most of the
compounds in the cooling process means that the mesophase is monotropic which was deduced
by the comparison of DSC and POM results. Even though the molecules belong to a
heterocyclic family, the transition temperatures are quite moderate instead of considerably high
transition temperatures. When the terminal and spacer alkyl chain length increases, the nematic
mesophase was favored due to reduction in the order parameter.
4. Experimental
4.1 Chemicals
The series of α,ω-dibromoalkanes, 4-hydroxybenzaldehyde, hexylamine, octylamine,
decylamine, dodecylamine and phthalic anhydride were purchased from Sigma-Aldrich.
Tetradecylamine, hexadecylamine and octadecylamine were procured from Acros Organics. The
chemicals were used directly without further purification. Thin-layer chromatography (TLC) was
performed on pre-coated silica-gel on aluminium plates.
4. 2 Instruments
Elemental (CHN) microanalyses were performed using a Perkin Elmer 2400 LS Series
CHNS/O analyzer. The molecular structure of intermediate and title compounds thus obtained
were characterized using spectroscopic techniques. Fourier transform-infrared (FT-IR) spectra
in the range of 4000-400 cm-1 was recorded using a Perkin Elmer 2000 FT-IR spectrophotometer
1
and H-NMR recorded using a Bruker 400MHz UltrashieldTM spectrometer by dissolving
compounds 1a-g, 2a-e to 5a-e in CDCl3, while the title compounds 7-34 were dissolved in
DMSO with tetramethylsilane (TMS) as the internal standard.
4. 3 General procedure for the synthesis of compounds 7-34
14

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The representative synthetic procedure is described here for compound
7
.
The same
procedure has been followed for the remaining target compounds 8-34
.
4-Hydroxybenzaldehyde was reacted with various amines (n = 6-18) to get intermediates
1a-g and then reacted with series of dibromoalkanes (n = 6-12) to get 2a-e to 5a-e in moderate
yields. Compound 2a (492 mg, 1 mol) was reacted with phthalic anhydride
under reflux conditions in dry benzene at 80 ºC for 1 h. The reaction was monitored by TLC and
the solvent was removed by distillation under reduced pressure. The solid product thus
6 (296 mg, 2 mol)
7
obtained was filtered and recrystallized in absolute ethanol to obtain analytical pure compound.
The analytical data of FT-IR, 1H and 13C NMR for compounds 7-34 are summarized as follows:
1,6-Bis[(1΄-phenyloxy)-
4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-hexyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]hexane (7)
Off white solid; (Yield: 441 mg, 56 %); IR: υmax(KBr, cm-1): 3007, 2944, 2870, 1660, 1600,
1588, 1266. 1HNMR δ (ppm, DMSO): 9.80 (s, 2H, N-CH-Ar), 7.10 (d, 4H, J 8.5 Hz, Ar-H), 7.31
(d, 4H, J 8.2 Hz, Ar-H), 8.36 (d, 2H, J 8.1Hz, Ar-H), 7.81 (t, 2H, J 8.2 Hz, Ar-H), 7.95 (t, 2H, J
8.1 Hz, Ar-H ), 7.56 (d, 2H, J 8.2 Hz, Ar-H), 4.08 (t, 4H, J 6.4 Hz, -OCH2-), 3.80 (t, 4H, J 4.1
Hz, -NCH2-), 1.31-1.94 (m, 24H, -OCH2-CH2-), 0.95 (t, 6H, J 6.7 Hz, -CH3). 13C NMR δ (ppm):
168.70, 169.57 (C=O), 115.40-134.30 (Ar-C), 159.24 (Ar-C-O), 90.70 (C-N), 39.45 (N-CH2),
22.12 (CH2), 15.21 (CH3) ppm. Elemental analysis found for C48H56N2O8 (%): C 73.20, H 7.02,
N 3.31. Calc (%),C 73.07, H 7.15, N 3.55.
1,6-Bis[(1΄-phenyloxy)-
4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-octyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]hexane (8)
Off white solid; (Yield: 465 mg, 55 %); IR: υmax(KBr, cm-1): 3004, 2940, 2873, 1666, 1601,
1588, 1261. 1HNMR δ (ppm, DMSO): 9.81 (s, 2H, N-CH-Ar), 7.10 (d, 4H, J 8.5 Hz, Ar-H), 7.33
(d, 4H, J 8.2 Hz, Ar-H), 8.34 (d, 2H, J 8.2 Hz, Ar-H), 7.80 (t, 2H, J 8.4 Hz, Ar-H), 7.93 (t, 2H, J
8.1 Hz, Ar-H), 7.54 (d, 2H, J 8.1 Hz, Ar-H), 4.05 (t, 4H, J 6.4 Hz, -OCH2-), 3.85 (t, 4H, J 4.1
Hz, -NCH2-), 1.34-1.97 (m, 32H, -OCH2-CH2-), 0.96 (t, 6H, J 6.8 Hz, -CH3). 13C NMR δ (ppm):
168.21, 169.47 (C=O), 115.01-134.57 (Ar-C), 159.90 (Ar-C-O), 90.58 (C-N), 39.17 (N-CH2),
22.50 (CH2), 15.00 (CH3) ppm. Elemental analysis found for C52H64N2O8 (%): C 73.80, H 7.75,
N 3.22. Calc (%), C 73.91, H 7.63, N 3.31 O.
15

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1,6-Bis[(1΄-phenyloxy)-
4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-decyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]hexane (9)
Off white solid; (Yield: 543 mg, 60 %); IR: υmax(KBr, cm-1): 3010, 2956, 2887, 1667, 1600,
1584, 1261. 1HNMR δ (ppm, DMSO): 9.84 (s, 2H, N-CH-Ar), 7.13 (d, 4H, J 8.6 Hz, Ar-H), 7.36
(d, 4H, J 8.2 Hz, Ar-H), 8.35 (d, 2H, J 8.3 Hz, Ar-H), 7.81 (t, 2H, J 8.4 Hz, Ar-H), 7.91 (t, 2H, J
8.1 Hz, Ar-H), 7.51 (d, 2H, J 8.2 Hz, Ar-H), 4.01 (t, 4H, J 6.4 Hz, -OCH2-), 3.84 (t, 4H, J
13
4.1Hz, -NCH2-), 1.37-1.98 (m, 40H, -OCH2-CH2-), 0.98 (t, 6H, J 6.7 Hz, -CH3). C NMR δ
(ppm): 167.89, 169.00 (C=O), 116.23-134.92 (Ar-C), 160.07 (Ar-C-O), 90.45 (C-N), 39.10 (N-
CH2), 22.88 (CH2), 14.67 (CH3) ppm. Elemental analysis found for C56H72N2O8 (%):C 74.50, H
8.19, N 3.22. Calc (%), C 74.64, H 8.05, N 3.11.
1,6-Bis[(1΄-phenyloxy)- 4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-dodecyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]hexane (10)
Off white solid; (Yield: 596 mg, 62 %); IR: υmax(KBr, cm-1): 3009, 2961, 2889, 1660, 1604,
1589, 1259. 1HNMR δ (ppm, DMSO): 9.88 (s, 2H, N-CH-Ar), 7.16 (d, 4H, J 8.5 Hz, Ar-H), 7.37
(d, 4H, J 8.2 Hz, Ar-H), 8.34 (d, 2H, J 8.4 Hz, Ar-H), 7.84 (t, 2H, J 8.4 Hz, Ar-H), 7.90 (t, 2H, J
8.2 Hz, Ar-H), 7.53 (d, 2H, J 8.2 Hz, Ar-H), 4.07 (t, 4H, J 6.4 Hz, -OCH2-), 3.87 (t, 4H, J
13
4.1Hz, -NCH2-), 1.35-1.93 (m, 48H, -OCH2-CH2-), 0.96 (t, 6H, J 6.7 Hz, -CH3). C NMR δ
(ppm): 166.43, 168.87 (C=O), 115.02-134.27 (Ar-C), 160.41 (Ar-C-O), 90.06 (C-N), 39.21 (N-
CH2), 21.24 (CH2), 14.88 (CH3) ppm. Elemental analysis found C60H80N2O8 (%): C 75.07, H
8.60, N 2.81. Calc (%), C 75.28, H 8.42, N 2.93.
1,6-Bis[(1΄-phenyloxy)- 4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-tetradecyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]hexane (11)
Off white solid; (Yield: 673 mg, 66 %); IR: υmax(KBr, cm-1): 3015, 2952, 2880, 1663, 1602,
1585, 1255. 1HNMR δ (ppm, DMSO): 9.90 (s, 2H, N-CH-Ar), 7.13 (d, 4H, J 8.6 Hz, Ar-H), 7.33
(d, 4H, J 8.3 Hz, Ar-H), 8.38 (d, 2H, J 8.5 Hz, Ar-H), 7.80 (t, 2H, J 8.4 Hz, Ar-H), 7.96 (t, 2H, J
8.2 Hz, Ar-H), 7.56 (d, 2H, J 8.4 Hz, Ar-H), 4.04 (t, 4H, J 6.4 Hz, -OCH2-), 3.81 (t, 4H, J
13
4.1Hz, -NCH2-), 1.38-1.96 (m, 56H, -OCH2-CH2-), 0.99 (t, 6H, J 6.7 Hz, -CH3). C NMR δ
(ppm): 166.88, 167.94 (C=O), 116.34-134.00 (Ar-C), 160.23 (Ar-C-O), 90.22 (C-N), 39.04 (N-
16

ACCEPTED MANUSCRIPT
CH2), 22.56 (CH2), 15.13 (CH3) ppm. Elemental analysis found C64H88N2O8 (%): C 75.98, H
8.85, N 2.90. Calc (%), C 75.85, H 8.75, N 2.76.
1,6-Bis[(1΄-phenyloxy)- 4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-hexadecyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]hexane (12)
Off white solid; (Yield: 646 mg, 60 %); IR: υmax(KBr, cm-1): 3010, 2969, 2872, 1668, 1603,
1580, 1252. 1HNMR δ (ppm, DMSO): 9.88 (s, 2H, N-CH-Ar), 7.11 (d, 4H, J 8.7 Hz, Ar-H), 7.36
(d, 4H, J 8.3 Hz, Ar-H), 8.35 (d, 2H, J 8.5 Hz, Ar-H), 7.85 (t, 2H, J 8.4 Hz, Ar-H), 7.94 (t, 2H, J
8.2Hz, Ar-H), 7.50 (d, 2H, J 8.6 Hz, Ar-H), 4.06 (t, 4H, J 6.4 Hz, -OCH2-), 3.84 (t, 4H, J 4.1
Hz, -NCH2-), 1.33-1.92 (m, 64H, -OCH2-CH2-), 0.90 (t, 6H, J 6.7 Hz, -CH3). 13C NMR δ (ppm):
165.20, 167.14 (C=O), 115.52-134.20 (Ar-C), 159.78 (Ar-C-O), 90.68 (C-N), 39.46 (N-CH2),
21.20 (CH2), 15.80 (CH3) ppm. Elemental analysis found C68H96N2O8 (%): C 76.21, H 9.19, N
2.50. Calc (%), C 76.37, H 9.05, N 2.62.
1,6-Bis[(1΄-phenyloxy)- 4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-octadecyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]hexane (13)
Off white solid; (Yield: 806 mg, 71 %); IR: υmax(KBr, cm-1): 3005, 2960, 2876, 1669, 1601,
1584, 1251. 1HNMR δ (ppm, DMSO): 9.81 (s, 2H, N-CH-Ar), 7.16 (d, 4H, J 8.7 Hz, Ar-H), 7.38
(d, 4H, J 8.2 Hz, Ar-H), 8.36 (d, 2H, J 8.5 Hz, Ar-H), 7.82 (t, 2H, J 8.5 Hz, Ar-H), 7.92 (t, 2H, J
8.2 Hz, Ar-H), 7.56 (d, 2H, J 8.6 Hz, Ar-H), 4.05 (t, 4H, J 6.4 Hz, -OCH2-), 3.86 (t, 4H, J 4.1
Hz, -NCH2-), 1.35-1.98 (m, 72H, -OCH2-CH2-), 0.94 (t, 6H, J 6.7 Hz, -CH3). 13C NMR δ (ppm):
166.82, 169.00 (C=O), 115.77-134.50 (Ar-C), 160.04 (Ar-C-O), 90.47 (C-N), 38.67 (N-CH2),
22.69 (CH2), 16.06 (CH3) ppm. Elemental analysis found C72H104N2O8 (%): C 76.70, H 9.46, N
2.32. Calc (%), C 76.83, H 9.31, N 2.49.
1,8- Bis[(1
΄-phenyloxy)-
4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-hexyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]octane (14)
Off white solid; (Yield 416 mg, 51 %); IR: υmax(KBr, cm-1): 3010, 2949, 2878, 1667, 1604,
1580, 1253. 1HNMR δ (ppm, DMSO): 9.83 (s, 2H, N-CH-Ar), 7.12 (d, 4H, J 8.6 Hz, Ar-H), 7.35
(d, 4H, J 8.2 Hz, Ar-H), 8.32 (d, 2H, J 8.1 Hz, Ar-H), 7.84 (t, 2H, J 8.3 Hz, Ar-H), 7.92 (t, 2H, J
8.1 Hz, Ar-H), 7.53 (d, 2H, J 8.3 Hz, Ar-H), 4.09 (t, 4H, J 6.4 Hz, -OCH2-), 3.85 (t, 4H, J 4.1
17

ACCEPTED MANUSCRIPT
Hz, -NCH2-), 1.39-1.98 (m, 28H, -OCH2-CH2-), 0.99 (t, 6H, J 6.7 Hz, -CH3). 13C NMR δ (ppm):
166.04, 168.33 (C=O), 115.60-134.12 (Ar-C), 160.78 (Ar-C-O), 90.01 (C-N), 39.77 (N-CH2),
22.88 (CH2), 15.90 (CH3) ppm. Elemental analysis found for C50H60N2O8 (%): C 73.32, H 7.59,
N 3.49. Calc (%), C 73.50, H 7.40, N 3.43.
1,8-Bis[(1΄-phenyloxy)-
4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-octyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]octane (15)
Off white solid; (Yield: 480 mg, 55 %); IR: υmax(KBr, cm-1): 3007, 2950, 2872, 1664, 1601,
1583, 1260. 1HNMR δ (ppm, DMSO): 9.82 (s, 2H, N-CH-Ar), 7.10 (d, 4H, J 8.6 Hz, Ar-H), 7.31
(d, 4H, J 8.2 Hz, Ar-H), 8.33 (d, 2H, J 8.1 Hz, Ar-H), 7.82 (t, 2H, J 8.4 Hz, Ar-H), 7.90 (t, 2H, J
8.2 Hz, Ar-H), 7.54 (d, 2H, J 8.7 Hz, Ar-H), 4.05 (t, 4H, J 6.4 Hz, -OCH2-), 3.88 (t, 4H, J 4.1
Hz, -NCH2-), 1.36-1.97 (m, 36H, -OCH2-CH2-), 0.93 (t, 6H, J 6.7 Hz, -CH3). 13C NMR δ (ppm):
164.62, 166.20 (C=O), 116.00-134.77 (Ar-C), 159.47 (Ar-C-O), 90.47 (C-N), 39.20 (N-CH2),
21.37 (CH2), 14.07 (CH3) ppm. Elemental analysis found for C54H68N2O8 (%): C 74.14, H 7.72,
N 3.32. Calc (%), C 74.28, H 7.85, N 3.21.
1,8- Bis[(1
΄-phenyloxy)-
4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-decyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]octane (16)
Off white solid; (Yield: 615 mg, 66 %); IR: υmax(KBr, cm-1): 3012, 2951, 2879, 1666, 1607,
1589, 1253. 1HNMR δ (ppm, DMSO): 9.87 (s, 2H, N-CH-Ar), 7.13 (d, 4H, J 8.8 Hz, Ar-H), 7.37
(d, 4H, J 8.2 Hz, Ar-H), 8.38 (d, 2H, J 8.6 Hz, Ar-H), 7.84 (t, 2H, J 8.6 Hz, Ar-H), 7.94 (t, 2H, J
8.4 Hz, Ar-H), 7.51 (d, 2H, J 8.7 Hz, Ar-H), 4.03 (t, 4H, J 6.4 Hz, -OCH2-), 3.89 (t, 4H, J
13
4.1Hz, -NCH2-), 1.33-1.96 (m, 44H, -OCH2-CH2-), 0.98 (t, 6H, J 6.7 Hz, -CH3). C NMR δ
(ppm): 165.33, 167.40 (C=O), 115.76-134.08 (Ar-C), 160.78 (Ar-C-O), 90.78 (C-N), 39.80 (N-
CH2), 22.66 (CH2), 15.82 (CH3) ppm. Elemental analysis found for C58H76N2O8 (%):C 74.82, H
8.12, N 3.20. Calc (%), C 74.97, H 8.24, N 3.01.
1,8- Bis[(1
΄-phenyloxy)- 4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-dodecyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]octane (17)
Off white solid; (Yield: 732 mg, 74 %); IR: υmax(KBr, cm-1): 3010, 2961, 2880, 1661, 1603,
1583, 1262. 1HNMR δ (ppm, DMSO): 9.85 (s, 2H, N-CH-Ar), 7.16 (d, 4H, J 8.8 Hz, Ar-H), 7.33
18

ACCEPTED MANUSCRIPT
(d, 4H, J 8.2 Hz, Ar-H), 8.32 (d, 2H, J 8.7 Hz, Ar-H), 7.88 (t, 2H, J 8.6 Hz, Ar-H), 7.93 (t, 2H, J
8.4 Hz, Ar-H), 7.58 (d, 2H, J 8.7 Hz, Ar-H), 4.08 (t, 4H, J 6.4 Hz, -OCH2-), 3.84 (t, 4H, J
13
4.1Hz, -NCH2-), 1.36-1.94 (m, 52H, -OCH2-CH2-), 0.99 (t, 6H, J 6.7 Hz, -CH3). C NMR δ
(ppm): 166.43, 168.78 (C=O), 116.02-134.66 (Ar-C), 160.18 (Ar-C-O), 90.00 (C-N), 39.41 (N-
CH2), 21.48 (CH2), 15.08 (CH3) ppm. Elemental analysis found for C62H84N2O8 (%): C 75.41, H
8.72, N 2.93. Calc (%), C 75.57, H 8.59, N 2.84.
1,8- Bis[(1΄-phenyloxy)- 4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-tetradecyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]octane (18
)
Off white solid; (Yield: 754 mg, 72 %); IR: υmax(KBr, cm-1): 3008, 2956, 2874, 1665, 1602,
1586, 1254. 1HNMR δ (ppm, DMSO): 9.88 (s, 2H, N-CH-Ar), 7.14 (d, 4H, J 8.8 Hz, Ar-H), 7.31
(d, 4H, J 8.2 Hz, Ar-H), 8.35 (d, 2H, J 8.7 Hz, Ar-H), 7.86 (t, 2H, J 8.6 Hz, Ar-H), 7.96 (t, 2H, J
8.4 Hz, Ar-H), 7.56 (d, 2H, J 8.7 Hz, Ar-H), 4.01 (t, 4H, J 6.4 Hz, -OCH2-), 3.82 (t, 4H, J 4.1
Hz, -NCH2-), 1.33-1.95 (m, 60H, -OCH2-CH2-), 0.94 (t, 6H, J 6.7 Hz, -CH3). 13C NMR δ (ppm):
166.67, 168.94 (C=O), 115.48-134.02 (Ar-C), 160.58 (Ar-C-O), 90.46 (C-N), 39.05 (N-CH2),
22.43 (CH2), 14.33 (CH3) ppm. Elemental analysis found for C66H92N2O8 (%):C 76.28, H 8.78,
N 2.54. Calc (%), C 76.12, H 8.90, N 2.69.
1,8- Bis[(1΄-phenyloxy)- 4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-hexadecyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]octane (19)
Off white solid; (Yield: 851 mg, 77 %); IR: υmax(KBr, cm-1): 3012, 2954, 2871, 1660, 1606,
1589, 1260. 1HNMR δ (ppm, DMSO): 9.84 (s, 2H, N-CH-Ar), 7.10 (d, 4H, J 8.8 Hz, Ar-H), 7.34
(d, 4H, J 8.2 Hz, Ar-H), 8.32 (d, 2H, J 8.8 Hz, Ar-H), 7.81 (t, 2H, J 8.6 Hz, Ar-H), 7.92 (t, 2H, J
8.4 Hz, Ar-H), 7.54 (d, 2H, J 8.9 Hz, Ar-H), 4.06 (t, 4H, J 6.4 Hz, -OCH2-), 3.86 (t, 4H, J 4.1
Hz, -NCH2-), 1.34-1.98 (m, 68H, -OCH2-CH2-), 0.98 (t, 6H, J 6.7 Hz, -CH3). 13C NMR δ (ppm):
165.40, 167.60 (C=O), 115.08-134.48 (Ar-C), 159.87 (Ar-C-O), 89.70 (C-N), 39.46 (N-CH2),
21.86 (CH2), 15.88 (CH3) ppm. Elemental analysis found for C70H100N2O8 (%): C 76.82, H 9.29,
N 2.41. Calc (%),C 76.60, H 9.18, N 2.55.
1,8- Bis[(1΄-phenyloxy)- 4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-octadecyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]octane (20)
19

ACCEPTED MANUSCRIPT
Off white solid; (Yield: 860 mg, 74 %); IR: υmax(KBr, cm-1): 3018, 2960, 2881, 1664, 1602,
1583, 1262. 1HNMR δ (ppm, DMSO): 9.89 (s, 2H, N-CH-Ar), 7.19 (d, 4H, J 8.7 Hz, Ar-H), 7.38
(d, 4H, J 8.3 Hz, Ar-H), 8.38 (d, 2H, J 8.6 Hz, Ar-H), 7.88 (t, 2H, J 8.6 Hz, Ar-H), 7.95 (t, 2H, J
8.4 Hz, Ar-H), 7.57 (d, 2H, J 8.9 Hz, Ar-H), 4.07 (t, 4H, J 6.4 Hz, -OCH2-), 3.88 (t, 4H, J 4.1
Hz, -NCH2-), 1.36-1.95 (m, 76H, -OCH2-CH2-), 0.94 (t, 6H, J 6.7 Hz, -CH3). 13C NMR δ (ppm):
166.08, 168.31 (C=O), 116.21-134.53 (Ar-C), 160.28 (Ar-C-O), 90.27 (C-N), 38.72 (N-CH2),
22.17 (CH2), 14.39 (CH3) ppm. Elemental analysis found for C74H108N2O8 (%): C 77.28, H 9.31,
N 2.52. Calc (%),C 77.04, H 9.44, N 2.43.
1,10- Bis[(1
΄-phenyloxy)- 4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-hexyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]decane (21)
White solid; (Yield: 439 mg, 52 %); IR: υmax(KBr, cm-1): 3010, 2950, 2873 1664, 1602, 1580,
1262. 1HNMR δ (ppm, DMSO): 9.83 (s, 2H, N-CH-Ar), 7.14 (d, 4H, J 8.7 Hz, Ar-H), 7.33 (d,
4H, J 8.3 Hz, Ar-H), 8.34 (d, 2H, J 8.2 Hz, Ar-H), 7.80 (t, 2H, J 8.6 Hz Ar-H), 7.92 (t, 2H, J
8.4 Hz, Ar-H), 7.52 (d, 2H, J 8.1 Hz, Ar-H), 4.00 (t, 4H, J 6.4 Hz, -OCH2-), 3.82 (t, 4H, J
13
4.1Hz, - NCH2-), 1.36-1.98 (m, 32H, -OCH2-CH2-), 0.99 (t, 6H, J 6.7 Hz, -CH3). C NMR δ
(ppm): 165.24, 167.08 (C=O), 116.11-134.68 (Ar-C), 160.67 (Ar-C-O), 89.40 (C-N), 39.07 (N-
CH2), 21.90 (CH2), 15.68 (CH3) ppm. Elemental analysis found for C52H64N2O8 (%): C 73.80, H
7.54, N 3.43. Calc (%),C 73.91, H 7.63, N 3.31.
1,10- Bis[(1
΄-phenyloxy)-
4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-octyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]decane (22)
White solid; (Yield: 559 mg, 62 %); IR: υmax(KBr, cm-1): 3005, 2956, 2871 1661, 1600, 1583,
1260. 1HNMR δ (ppm, DMSO): 9.86 (s, 2H, N-CH-Ar), 7.11 (d, 4H, J 8.7 Hz, Ar-H), 7.38 (d,
4H, J 8.4 Hz, Ar-H), 8.30 (d, 2H, J 8.2 Hz, Ar-H), 7.86 (t, 2H, J 8.6 Hz, Ar-H), 7.90 (t, 2H, J
8.4 Hz, Ar-H), 7.57 (d, 2H, J 8.1 Hz, Ar-H), 4.06 (t, 4H, J 6.4 Hz, -OCH2-), 3.80 (t, 4H, J 4.1
Hz, -NCH2-), 1.33-1.95 (m, 40H, -OCH2-CH2-), 0.94 (t, 6H, J 6.7 Hz, -CH3). 13C NMR δ (ppm):
166.42, 168.26 (C=O), 116.58-134.08 (Ar-C), 160.31 (Ar-C-O), 89.90 (C-N), 39.56 (N-CH2),
22.67 (CH2), 14.05 (CH3) ppm. Elemental analysis found for C56H72N2O8 (%): C 74.81, H 8.20,
N 3.03. Calc (%), C 74.64, H 8.05, N 3.11.
20

ACCEPTED MANUSCRIPT
1,10- Bis[(1
΄-phenyloxy)- 4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-decyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]decane (23)
White solid; (Yield: 943 mg, 67 %); IR: υmax(KBr, cm-1): 3011, 2960, 2878 1668, 1604, 1588,
1254. 1HNMR δ (ppm, DMSO): 9.82 (s, 2H, N-CH-Ar), 7.19 (d, 4H, J 8.7 Hz, Ar-H), 7.36 (d,
4H, J 8.4 Hz, Ar-H), 8.38 (d, 2H, J 8.2 Hz, Ar-H), 7.89 (t, 2H, J 8.6 Hz, Ar-H), 7.96 (t, 2H, J
8.4 Hz, Ar-H), 7.56 (d, 2H, J 8.1 Hz, Ar-H), 4.03 (t, 4H, J 6.4 Hz, -OCH2-), 3.88 (t, 4H, J 4.1
Hz, -NCH2-), 1.39-1.98 (m, 48H, -OCH2-CH2-), 0.97 (t, 6H, J 6.7 Hz, -CH3). 13C NMR δ (ppm):
166.27, 168.70 (C=O), 115.58-134.31 (Ar-C), 159.79 (Ar-C-O), 90.24 (C-N), 39.15 (N-CH2),
21.00 (CH2), 14.60 (CH3) ppm. Elemental analysis found for C60H80N2O8 (%): C 75.13, H 8.57,
N 2.81. Calc (%), C 75.28, H 8.42, N 2.93.
1,10- Bis[(1΄-phenyloxy)- 4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-dodecyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]decane (24)
White solid; (Yield: 748 mg, 77 %); IR: υmax(KBr, cm-1): 3014, 2958, 2872 1660, 1602, 1584,
1251. 1HNMR δ (ppm, DMSO): 9.88 (s, 2H, N-CH-Ar), 7.17 (d, 4H, J 8.7 Hz, Ar-H), 7.39 (d,
4H, J 8.3 Hz, Ar-H), 8.32 (d, 2H, J 8.2 Hz, Ar-H), 7.88 (t, 2H, J 8.4 Hz, Ar-H), 7.98 (t, 2H, J
8.4 Hz, Ar-H), 7.52 (d, 2H, J 8.1 Hz, Ar-H), 4.08 (t, 4H, J 6.4 Hz, -OCH2-), 3.86 (t, 4H, J 4.1
Hz, -NCH2-), 1.38-1.96 (m, 56H, -OCH2-CH2-), 0.93 (t, 6H, J 6.7 Hz, -CH3). 13C NMR δ (ppm):
165.00, 167.29 (C=O), 116.20-133.87 (Ar-C), 160.25 (Ar-C-O), 90.68 (C-N), 38.70 (N-CH2),
22.24 (CH2), 15.07 (CH3) ppm. Elemental analysis found for C64H88N2O8 (%): C 75.69, H 8.84,
N 2.70. Calc (%), C 75.85, H 8.75, N 2.76.
1,10-
Bis[(1
΄-phenyloxy)-
4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-tetradecyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-
2
΄΄,4΄΄-benzoxazepinyl))]decane (25)
White solid; (Yield: 824 mg, 76 %); IR: υmax(KBr, cm-1): 3010, 2953, 2878 1669, 1605, 1588,
1263. 1HNMR δ (ppm, DMSO): 9.88 (s, 2H, N-CH-Ar), 7.12 (d, 4H, J 8.7 Hz, Ar-H), 7.33 (d,
4H, J 8.4 Hz, Ar-H), 8.38 (d, 2H, J 8.2 Hz, Ar-H), 7.82 (t, 2H, J 8.6 Hz, Ar-H), 7.95 (t, 2H, J
8.6 Hz, Ar-H), 7.51 (d, 2H, J 8.1 Hz, Ar-H), 4.02 (t, 4H, J 6.4 Hz, -OCH2-), 3.87 (t, 4H, J 4.1
Hz, -NCH2-), 1.35-1.94 (m, 64H, -OCH2-CH2-), 0.90 (t, 6H, J 6.7 Hz, -CH3). 13C NMR δ (ppm):
165.48, 167.05 (C=O), 115.18-134.35 (Ar-C), 160.05 (Ar-C-O), 90.92 (C-N), 38.46 (N-CH2),
21

ACCEPTED MANUSCRIPT
22.80 (CH2), 15.14 (CH3) ppm. Elemental analysis found for C68H96N2O8 (%): C 76.53, H 9.23,
N 2.68. Calc (%), C 76.37, H 9.05, N 2.62.
1,10-Bis[(1
΄-phenyloxy)-
4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-hexadecyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-
2
΄΄,4΄΄-benzoxazepinyl))]decane (26)
White solid; (Yield: 850 mg, 75 %); IR: υmax(KBr, cm-1): 3019, 2960, 2873 1664, 1602, 1581,
1255. 1HNMR δ (ppm, DMSO): 9.83 (s, 2H, N-CH-Ar), 7.16 (d, 4H, J 8.6 Hz, Ar-H), 7.36 (d,
4H, J 8.4 Hz, Ar-H), 8.33 (d, 2H, J 8.8 Hz, Ar-H), 7.80 (t, 2H, J 8.6 Hz, Ar-H), 7.98 (t, 2H, J
8.6 Hz, Ar-H), 7.54 (d, 2H, J 8.1 Hz, Ar-H), 4.05 (t, 4H, J 6.4 Hz, -OCH2-), 3.87 (t, 4H, J
4.1Hz, -NCH2-), 1.37-1.99 (m, 72H, -OCH2-CH2-), 0.96 (t, 6H, J = 6.76 Hz, -CH3). 13C NMR δ
(ppm): 166.48, 169.21 (C=O), 116.31-134.89 (Ar-C), 160.24 (Ar-C-O), 90.42 (C-N), 39.33 (N-
CH2), 21.50 (CH2), 14.27 (CH3) ppm. Elemental analysis found for C72H104N2O (%): C 76.94, H
9.20, N 2.44. Calc (%),C 76.83, H 9.31, N 2.49.
1,10-
Bis[(1
΄
-phenyloxy)-
4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-octadecyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-
2
΄΄,4΄΄-benzoxazepinyl))]decane (27)
White solid; (Yield: 930 mg, 78 %); IR: υmax(KBr, cm-1): 3012, 2959, 2878 1661, 1601, 1584,
1260. 1HNMR δ (ppm, DMSO): 9.82 (s, 2H, N-CH-Ar), 7.12 (d, 4H, J 8.7 Hz, Ar-H), 7.31 (d,
4H, J 8.5 Hz, Ar-H), 8.30 (d, 2H, J 8.8 Hz, Ar-H), 7.82 (t, 2H, J 8.5 Hz, Ar-H), 7.92 (t, 2H, J
8.6 Hz, Ar-H), 7.50 (d, 2H, J 8.2 Hz, Ar-H), 4.07 (t, 4H, J 6.4 Hz, -OCH2-), 3.88 (t, 4H, J
4.1Hz, -NCH2-), 1.34-1.97 (m, 80H, -OCH2-CH2-), 0.96 (t, 6H, J = 6.76 Hz, -CH3). 13C NMR δ
(ppm): 166.87, 168.70 (C=O), 115.01-134.20 (Ar-C), 160.58 (Ar-C-O), 90.20 (C-N), 39.69 (N-
CH2), 22.46 (CH2), 15.38 (CH3) ppm. Elemental analysis found for C76H112N2O8 (%): C 77.12, H
9.68, N 2.30. Calc (%), C 77.25, H 9.55, N 2.37.
1,12- Bis[(1
΄-phenyloxy)- 4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-hexyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]dodecane (28)
White solid; (Yield: 611 mg, 70 %); IR: υmax(KBr, cm-1): 3014, 2956, 2870 1670, 1601, 1589,
1255. 1HNMR δ (ppm, DMSO): 9.82 (s, 2H, N-CH-Ar), 7.10 (d, 4H, J 8.9 Hz, Ar-H), 7.35 (d,
4H, J 8.2 Hz, Ar-H), 8.32 (d, 2H, J 8.3 Hz, Ar-H), 7.84 (t, 2H, J 8.5 Hz, Ar-H), 7.91 (t, 2H, J
8.6 Hz, Ar-H), 7.57 (d, 2H, J 8.0 Hz, Ar-H), 4.04 (t, 4H, J 6.4 Hz, -OCH2-), 3.85 (t, 4H, J
22

ACCEPTED MANUSCRIPT
13
4.1Hz, -NCH2-), 1.39-1.99 (m, 36H, -OCH2-CH2-), 0.91 (t, 6H, J 6.7 Hz, -CH3). C NMR δ
(ppm): 166.71, 169.00 (C=O), 115.36-134.26 (Ar-C), 159.11 (Ar-C-O), 90.76 (C-N), 39.19 (N-
CH2), 22.83 (CH2), 14.27 (CH3) ppm. Elemental analysis found for C54H68N2O8 (%): C 74.40, H
7.66, N 3.15. Calc (%), C 74.28, H 7.85, N 3.21.
1,12- Bis[(1
΄-phenyloxy)-
4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-octyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]dodecane (29)
White solid; (Yield: 633 mg, 68 %); IR: υmax(KBr, cm-1): 3012, 2950, 2879 1675, 1600, 1584,
1254. 1HNMR δ (ppm, DMSO): 9.81 (s, 2H, N-CH-Ar), 7.10 (d, 4H, J 8.9 Hz, Ar-H), 7.32 (d,
4H, J 8.3 Hz, Ar-H), 8.39 (d, 2H, J 8.4 Hz, Ar-H), 7.82 (t, 2H, J 8.6 Hz, Ar-H), 7.96 (t, 2H, J
8.2 Hz, Ar-H), 7.58 (d, 2H, J 8.1 Hz, Ar-H), 4.01 (t, 4H, J 6.4 Hz, -OCH2-), 3.88 (t, 4H, J
13
4.1Hz, -NCH2-), 1.37-1.96 (m, 44H, -OCH2-CH2-), 0.97 (t, 6H, J 6.7 Hz, -CH3). C NMR δ
(ppm): 165.90, 167.33 (C=O), 116.41-134.63 (Ar-C), 160.40 (Ar-C-O), 90.76 (C-N), 38.33 (N-
CH2), 21.00 (CH2), 14.88 (CH3) ppm. Elemental analysis found for C58H76N2O8 (%):C 74.86, H
8.17, N 3.09. Calc (%), C 74.97, H 8.24, N 3.01.
1,12-Bis[(1
΄-phenyloxy)-
4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-decyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]dodecane (30)
White solid; (Yield: 603 mg, 61 %); IR: υmax(KBr, cm-1): 3010, 2956, 2878 1673, 1603, 1580,
1261. 1HNMR δ (ppm, DMSO): 9.88 (s, 2H, N-CH-Ar), 7.16 (d, 4H, J 8.8 Hz, Ar-H), 7.36 (d,
4H, J 8.4 Hz, Ar-H), 8.36 (d, 2H, J 8.5 Hz, Ar-H), 7.84 (t, 2H, J 8.6 Hz, Ar-H), 7.94 (t, 2H, J
8.3 Hz, Ar-H), 7.53 (d, 2H, J 8.1 Hz, Ar-H), 4.08 (t, 4H, J 6.4 Hz, -OCH2-), 3.84 (t, 4H, J 4.1
Hz, -NCH2-), 1.36-1.98 (m, 52H, -OCH2-CH2-), 0.99 (t, 6H, J 6.7 Hz, -CH3). 13C NMR δ (ppm):
164.16, 166.40 (C=O), 115.01-134.19 (Ar-C), 160.68 (Ar-C-O), 90.14 (C-N), 38.81 (N-CH2),
22.33 (CH2), 14.79 (CH3) ppm. Elemental analysis found for C62H84N2O8 (%): C 75.39, H 8.64,
N 2.78. Calc (%),C 75.57, H 8.59, N 2.84.
1,12-Bis[(1
΄-phenyloxy)- 4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-dodecyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-2΄΄,4΄΄-
benzoxazepinyl))]dodecane (31)
White solid; (Yield: 753 mg, 72 %); IR: υmax(KBr, cm-1): 3005, 2952, 2872 1671, 1601, 1583,
1257. 1HNMR δ (ppm, DMSO): 9.80 (s, 2H, N-CH-Ar), 7.13 (d, 4H, J 8.8 Hz, Ar-H), 7.34 (d,
23

ACCEPTED MANUSCRIPT
4H, J 8.5 Hz, Ar-H), 8.32 (d, 2H, J 8.6 Hz, Ar-H), 7.82 (t, 2H, J 8.7 Hz, Ar-H), 7.96 (t, 2H, J
8.3 Hz, Ar-H), 7.52 (d, 2H, J 8.3 Hz, Ar-H), 4.00 (t, 4H, J 6.4 Hz, -OCH2-), 3.81 (t, 4H, J 4.1
Hz, -NCH2-), 1.33-1.96 (m, 60H, -OCH2-CH2-), 0.92 (t, 6H, J 6.7 Hz, -CH3). 13C NMR δ (ppm):
164.39, 166.75 (C=O), 115.61-134.57 (Ar-C), 160.03 (Ar-C-O), 89.63 (C-N), 38.16 (N-CH2),
21.14 (CH2), 14.96 (CH3) ppm. Elemental analysis found for C66H92N2O8 (%): C 76.28, H 8.76,
N 2.58. Calc (%), C 76.12, H 8.90, N 2.69.
1,12-
Bis[(1
΄-phenyloxy)-
4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-tetradecyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-
2
΄΄,4΄΄-benzoxazepinyl))]dodecane (32)
White solid; (Yield: 817 mg, 74 %); IR: υmax(KBr, cm-1): 3010, 2951, 2863 1668, 1603, 1584,
1262. 1HNMR δ (ppm, DMSO): 9.88 (s, 2H, N-CH-Ar), 7.15 (d, 4H, J 8.8 Hz, Ar-H), 7.33 (d,
4H, J 8.5 Hz, Ar-H), 8.34 (d, 2H, J 8.6 Hz, Ar-H), 7.86 (t, 2H, J 8.6 Hz, Ar-H), 7.94 (t, 2H, J
8.3 Hz, Ar-H), 7.59 (d, 2H, J 8.1 Hz, Ar-H), 4.07 (t, 4H, J 6.4 Hz, -OCH2-), 3.85 (t, 4H, J
13
4.1Hz, -NCH2-), 1.37-1.99 (m, 68H, -OCH2-CH2-), 0.95 (t, 6H, J 6.7 Hz, -CH3). C NMR δ
(ppm): 165.20, 167.14 (C=O), 116.39-134.07 (Ar-C), 159.67 (Ar-C-O), 90.03 (C-N), 38.55 (N-
CH2), 22.68 (CH2), 14.00 (CH3) ppm. Elemental analysis found for C70H100N2O8 (%): C 76.52, H
9.10, N 2.61. Calc (%), C 76.60, H 9.18, N 2.55.
1,12-
Bis[(1
΄-phenyloxy)-
4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-hexadecyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-
2
΄΄,4΄΄-benzoxazepinyl))]dodecane (33)
White solid; (Yield: 848 mg, 73 %); IR: υmax(KBr, cm-1): 3019, 2954, 2860 1670, 1601, 1589,
1257. 1HNMR δ (ppm, DMSO): 9.89 (s, 2H, N-CH-Ar), 7.17 (4H, d, J 8.8 Hz, Ar-H), 7.39 (4H,
d, J 8.5 Hz, Ar-H), 8.38 (2H, d, J 8.5 Hz, Ar-H), 7.85 (2H, t, J 8.7 Hz, Ar-H), 7.90 (2H, t, J 8.3
Hz, Ar-H), 7.54 (2H, d, J 8.1 Hz, Ar-H), 4.07 (t, 4H, J 6.4 Hz, -OCH2-), 3.89 (t, 4H, J 4.1Hz, -
NCH2-), 1.39-1.98 (m, 76H, -OCH2-CH2-), 0.98 (t, 6H, J 6.7 Hz, -CH3). 13C NMR δ (ppm):
166.36, 168.05 (C=O), 115.31-134.20 (Ar-C), 160.52 (Ar-C-O), 90.01 (C-N), 38.03 (N-CH2),
21.25 (CH2), 15.80 (CH3) ppm. Elemental analysis found for C74H108N2O8 (%): C 77.18, H 9.32,
N 2.40. Calc (%), C 77.04, H 9.44, N 2.43.
1,12-
Bis[(1
΄
-phenyloxy)-
4΄-(3΄΄-(1΄΄,5΄΄-dioxo-4΄΄-octadecyl-1΄΄,3΄΄,4΄΄,5΄΄-tetrahydro-
2
΄΄,4΄΄-benzoxazepinyl))]dodecane (34)
24

ACCEPTED MANUSCRIPT
White solid; (Yield: 853 mg, 70 %); IR: υmax(KBr, cm-1): 3009, 2958, 2853 1673, 1600, 1582,
1261. 1HNMR δ (ppm, DMSO): 9.87 (s, 2H, N-CH-Ar), 7.11 (d, 4H, J 8.8 Hz, Ar-H), 7.33 (d,
4H, J 8.5 Hz, Ar-H), 8.34 (d, 2H, J 8.6 Hz, Ar-H), 7.80 (t, 2H, J 8.9 Hz, Ar-H), 7.94 (t, 2H, J 8.2
Hz, Ar-H), 7.58 (d, 2H, J 8.1 Hz, Ar-H), 4.09 (t, 4H, J 6.4 Hz, -OCH2-), 3.84 (t, 4H, J 4.1Hz, -
NCH2-), 1.32-1.95 (m, 84H, -OCH2-CH2-), 0.99 (t, 6H, J 6.7 Hz, -CH3). 13C NMR δ (ppm):
166.07, 168.46 (C=O), 116.19-134.85 (Ar-C), 160.06 (Ar-C-O), 90.67 (C-N), 38.27 (N-CH2),
22.08 (CH2), 14.24 (CH3) ppm. Elemental analysis found for C78H116N2O8 (%): C 77.44, H 9.66,
N 2.32. Calc (%), C 77.49, H 9.73, N 2.38.
Acknowledgement
AK-T M extends grateful thanks to Prof. John West and Liquid Crystal Institute at the Kent
State University, for performing molecular model calculations and their hospitality. Authors
thank the University Sains Malaysia and the Malaysian Government for financing this project
through the short term Grant (304/PKIMIA/6312051) and FRGS Grant (203/ PKIMIA/671119).
Corresponding author thanks Department of Chemistry, College of Sciences, University of
Anbar.
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25

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