Inorganic-organic hybrids based on cyclotetraphosphazenes

Article abstract of DOI:10.1080/15421400390193459

Organic cyclic and oligoaminoacid derivatives of cyclotetraphosphazenes were synthesized and characterized. WAXS and DSC methods were applied to the bulk and LB-films study, being different crystalline structures are shown both for initial cyclotetraphosp

Full text of DOI:10.1080/15421400390193459

This article was downloaded by: [University of Otago]
On: 12 July 2015, At: 13:44
Publisher: Taylor & Francis
Informa Ltd Registered in England and Wales Registered Number: 1072954
Registered office: 5 Howick Place, London, SW1P 1WG
Molecular Crystals and Liquid
Crystals
Publication details, including instructions for
authors and subscription information:
http://www.tandfonline.com/loi/gmcl20
Inorganic-Organic
Hybrids Basedon
Cyclotetraphosphazenes
Galina Popova a , Vjacheslav Kireev a , Alexander
Spitsyn a , Hirotaka Ihara b , Maxim Scherbina c &
Sergei Chvalun c
a Research Laboratory "Molecular Materials" ,
Mendeleyev Univ. Chem. Technology , Miusskaya sq.,
9, Moscow , 125190 , Russia
b Dept. Applied Chemistry & Biochemistry , 2-39-1,
Kumamoto , 860-8555 , Japan
c State Research Centre , Karpov Inst. of Physical
Chemistry , Vorontzovo pole, 10, Moscow , 103064 ,
Russia
Published online: 18 Oct 2010.
To cite this article: Galina Popova , Vjacheslav Kireev , Alexander Spitsyn , Hirotaka
Ihara , Maxim Scherbina & Sergei Chvalun (2003) Inorganic-Organic Hybrids Basedon
Cyclotetraphosphazenes, Molecular Crystals and Liquid Crystals, 390:1, 91-96, DOI:
10.1080/15421400390193459
To link to this article: http://dx.doi.org/10.1080/15421400390193459
PLEASE SCROLL DOWN FOR ARTICLE
Taylor & Francis makes every effort to ensure the accuracy of all the
information (the “Content”) contained in the publications on our platform.
However, Taylor & Francis, our agents, and our licensors make no
representations or warranties whatsoever as to the accuracy, completeness,
or suitability for any purpose of the Content. Any opinions and views

expressed in this publication are the opinions and views of the authors, and
are not the views of or endorsed by Taylor & Francis. The accuracy of the
Content should not be relied upon and should be independently verified with
primary sources of information. Taylor and Francis shall not be liable for any
losses, actions, claims, proceedings, demands, costs, expenses, damages,
and other liabilities whatsoever or howsoever caused arising directly or
indirectly in connection with, in relation to or arising out of the use of the
Content.
This article may be used for research, teaching, and private study purposes.
Any substantial or systematic reproduction, redistribution, reselling, loan,
sub-licensing, systematic supply, or distribution in any form to anyone is
expressly forbidden. Terms & Conditions of access and use can be found at
http://www.tandfonline.com/page/terms-and-conditions

Mol. Cryst. Liq. Cryst., Vol. 390, pp. 91–96
Copyright # 2003 Taylor & Francis
1542-1406/03 $12.00+.00
DOI: 10.1080/15421400390193459
INORGANIC-ORGANIC HYBRIDS BASED
ON CYCLOTETRAPHOSPHAZENES
Galina Popova, Vjacheslav Kireev, and Alexander Spitsyn
Research Laboratory ‘‘Molecular Materials’’,
Mendeleyev Univ. Chem. Technology, Miusskaya sq., 9,
Moscow 125190, Russia
Hirotaka Ihara
Dept. Applied Chemistry & Biochemistry, 2-39-1,
Kumamoto 860-8555, Japan
Maxim Scherbina and Sergei Chvalun
State Research Centre, Karpov Inst. of Physical Chemistry,
Vorontzovo pole, 10, Moscow 103064, Russia
Organic cyclic and oligoaminoacid derivatives of cyclotetraphosphazenes were
synthesized and characterized. WAXS and DSC methods were applied to the
bulk and LB-films study, being different crystalline structures are shown both
for initial cyclotetraphosphazenes and for their organic hybrids.
Keywords: cyclotetraphosphazenes; oligoaminoacids; crystalline structure
INTRODUCTION
Cyclophosphazenes and their derivatives are attractive subjects for current
chemical, physical and biological study. Structures of the unique polymers,
such as dendrimers and arborols can be obtained on the cyclophosphazene
basis [1]. On the other hand, the unusual low molecular compounds (f. ex.
adamantane and triptamines derivatives) were prepared by chlorine atoms
substitution in cyclophosphazenes [2,3]. These Research permit to inves-
tigate different properties, thermal and oxidative stability, lipophilicity,
bioactivity and biocompability. Taking in account great amount of papers
concerning cyclotriphosphazene modification, we concentrated attention
This work was supported by Russian Fond of Basic Research (grants 00-03125 and 01-03-
32652) and JSPS Grants (Japan).
91

92
G. Popova et al.
on octachlorocyclotetraphosphazene (OCTP) transformation. It was
necessary to prepare pure crystalline OCTP and substituted CTP as initial
reagents. We described as well 5-methoxytryptamine containing
cyclotetraphosphazene, olygoalanyl- and olygoglutamyl- derivatives of
cyclotetraphosphazene. WAXS data shown discotic-like structures for few
compounds, the loss of crystalinity is noticed for olygomeric forms of CTP,
although their LB-films can contain some crystalline domains.
SUBSTITUTION IN OCTACHLOROCYCLOTETRA-
PHOSPHAZENE BY LOW MOLECULAR COMPOUNDS
General conversion of cyclotetraphosphazenes and synthesis of inorganic
low molecular synthons are represented by Scheme 1.
We could use two ways at least for our purposes: the substitution of
chlorine atoms in OCTP directly or in defined non-geminal intermediate
compounds for variant isomers decreasing.
Early we have described OCTP preparation by cyclo-widening reaction
in fusion [4]. The yield of tetramer is depended upon purity and ideal
crystallinity of initial cyclophosphazenes (mixture of tri- and tetra-)
strongly. Analysis of publications and own results on morphological and
optical investigations confirmed symmetry of OCTP as tetragonic syngony,
trimer possess rhombic syngony, both compounds relate to planexial type
with D4R (4/mmm). Optical constants are different, being OCTP has bright
interference, Figure 1.
Using of non-geminal tetraphenyltetrachlorocyclotetraphosphazene
(TPTCP) is more suitable, than OCTP, so we can carry out easy two next
SCHEME 1 Conversion of cyclotetraphosphazenes. Synthons preparation.

Inorganic-Organic Hybrids Based on Cyclotetraphosphazenes
93
FIGURE 1 1a. Microphotography of crystalline piece of hexachlorocyclotripho-
sphazene with octochlorocyclotetraphosphazene inclusion (500x increasing
polarization microscope). 1b. Ideal monocrystal of high-pure hexachloro-
cyclotriphosphazene.
reactions: tetraamine - and tetrraisocyanate - functional cyclophosphazene
preparation, Scheme 1, Table 1.
Aminolysis of TPTCP by 5-methoxytriptamine and 1-pyrenylbutirylhy-
drazide result to di- and tetrasubstituted tetraphenylcyclotetrapho-
sphazene, Figure 2.
OLIGOAMINOACID DERIVATIVES OF CYCLOTETRA-
PHOSPHAZENE
N-Carboxyanhydrides of g-methylglutamate (g-Me-Gly-NCA) and Alanine
were polymerizated by action with tetraphenyltetraaminocyclotetrapho-
TABLE 1 Properties of Synthesized Synthons
Yield,
%
M.p.,
ꢀC
IR, cmꢁ1
31P NMR
1H NMR
8.2 (Ph)
(P¼N)4Ph4(NCS)4
(P¼N)4Ph4(NH2)4
85–90
154
1990–2000 (NCS)
1440 (P-Ph)
1300 (P¼N)
3400 (NH2)
ꢁ12.1
(singl.)
30–50
225
ꢁ3
8.8 (NH2)
6.5–7.1 (Ph)
3380 (NH2)
1440 (P-Ph)
1300 (P¼N)
(singl.)

94
G. Popova et al.
FIGURE 2 Chemical structures of the cyclotetraphosphazenes.
sphazene (TATP) as initiator, Figure 2. Reaction is existed in dimethyl-
formamide at room temperature under an atmosphere of dry argon and at
different molar rations of NCA/TATP. The molecular weight of olygomers
calculated from the NMR-1H data and gel-permittion chromatography
measurement, n ¼ 40, MM ¼ 6000, n ¼ 20, MM ¼ 3100. Symmetric replace-
ment of olygoaminoacid chains on the inorganic plate could result to
induction of a-helical conformation (4-helix bundle) that was noticed for
porphirine and pyridine – functionalized templates [5]. This event is
achieved when metallocompounds taked place inside cycliophosphazene.
STRUCTURAL PROPERTIES
We compared initial tetrasubstituted and olygoaminoacid derivatives of
cyclotetraphosphazene. As it was shown by X-ray method the synthesized
species are crystalline with different degree of crystallinity. Aminosub-
stituted cyclotetraphosphazene is powder with large grain morphology. Its
WAXS pattern contains up to 18 reflection, Figure 3, Table 2.
Isocyanate derivatives is rather crystalline also (about 7 distinct
reflections). Olygoaminoacid derivatives (polymerization degree ꢀ 40)
have broad diffuse reflections, that is in accordance with loss of crystal-
linity. The ratio of d-spacing is approximately 1:2:3:4 pointing to the
˚
layered structure. The layer width is 7.8A which is conistent with voluemn

Inorganic-Organic Hybrids Based on Cyclotetraphosphazenes
95
FIGURE 3 The scattering profile of (P¼N)4Ph4(NH2)4.
of cyclic tetraphosphazene fragment. It was proposed the discotic shape of
cyclotetraphosphazene derivatives.
DSC study is agreed with X-ray data. On the DSC curve of the most
crystalline NH2-substituted there are three endothermic peaks at 208, 236,
250ꢀC. Polyaminoacid chains (n ꢂ 40) lead to the less of crystallinity there
is one very weak peak only, at 55ꢀC, Figure 4.
Polyalanylderivatives have bad solubility in common solvents, however
form monolayers. Polyglutamylcyclotetraphosphazene form stable mono-
layers and LB-films (ꢃ40 monolayers). Character p/A isotherm is not
simple, Figure 4b. Perhaps, it demonstrates crystallization domains on the
surface [6], that was noticed for polyglutamic derivatives [7].
TABLE 2 D-Spacing, A
ꢁNH2 10.5 7.6 5.5 5.2 4.6 4.4 3.7 3.4 3.1 2.9 2.7 2.5 2.3 2.2 2.1 2.0 1.9
ꢁNCS
7.8 4.9 4.6 4.2 3.9
ꢁn-Ala 7.5 5.3 4.5 3.7
D8Advance Bruker, expose 4–5 h.

96
G. Popova et al.
FIGURE 4 1a. DSC Data: 1 - NH2-derivative has 3 endothermic peaks at 208, 236
and 250ꢀC. 2 - n-Ala (n ¼ 20) has 1 very weak peak at 55ꢀC. Mettler 1000, Scan rate
of 20ꢀC/min at of (ꢁ50) ꢁ300ꢀC. 1b. Langmuir isotherm of (P¼N)4Ph4(Glu)n,
n ¼ 20; 40.
REFERENCES
[1] Majoral, J.-P. & Caminade, M. (1999). Chem. Rev., 99, 3, 858–880.
[2] Krause, W., Parvez, M., Visscher, K., & Allcock, H. (1996). Inorg. Chem., 35, 6337–6338.
[3] Alapishvili, M., Popova, G., Vorontzov, E., Kireev, V., & Suvorov, N. (1983). Zorn. Obz.
Chem. (Rus), 53, 5, 1040–1044.
[4] Melashvili, I., Kireev, V., & Goldin, J. (1983). Rus. Pat. 1018914.
[5] Schneider, J. & Kelly, J. W. (1995). Chem. Rev., 95, 2169–2187.
[6] Chi, L. F., Anders, M., Fuchs, H., Johnston, R. R., & Ringsdorf, H. Jan. 8. (1993). Science,
259.
[7] Sohn, D., Kitaev, V., & Kumacheva, E. (1999). Langmiur, 15, 1968–1702.