Synthesis and characterization of new (dimethylsilyl)phenoxy and (dimethyl(vinyl)silyl)phenoxy substituted cyclotriphosphazenes

Article abstract of DOI:10.1016/j.jorganchem.2017.10.030

The routes of synthesis, as well as, spectroscopic and X-ray diffraction characterization of a new group of bis- or hexakis-4-(dimethyl(vinyl)silyl)phenoxy and 4-(dimethylsilyl)phenoxy-substituted cyclotriphosphazenes as a versatile starting substrates for the synthesis of a variety of organic cyclophosphazene derivatives, via catalytic hydrosilylation or silylative coupling processes, is presented.

Full text of DOI:10.1016/j.jorganchem.2017.10.030

Accepted Manuscript
Synthesis and characterization of new (dimethylsilyl)phenoxy and
(dimethyl(vinyl)silyl)phenoxy substituted cyclotriphosphazenes
Rafał Januszewski, Michał Dutkiewicz, Maciej Kubicki, Grzegorz Dutkiewicz, Hieronim
Maciejewski, Bogdan Marciniec
PII:
S0022-328X(17)30617-4
10.1016/j.jorganchem.2017.10.030
JOM 20150
DOI:
Reference:
To appear in: Journal of Organometallic Chemistry
Received Date: 21 August 2017
Revised Date: 12 October 2017
Accepted Date: 19 October 2017
Please cite this article as: Rafał. Januszewski, Michał. Dutkiewicz, M. Kubicki, G. Dutkiewicz,
H. Maciejewski, B. Marciniec, Synthesis and characterization of new (dimethylsilyl)phenoxy and
(dimethyl(vinyl)silyl)phenoxy substituted cyclotriphosphazenes, Journal of Organometallic Chemistry
(2017), doi: 10.1016/j.jorganchem.2017.10.030.
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to
our customers we are providing this early version of the manuscript. The manuscript will undergo
copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please
note that during the production process errors may be discovered which could affect the content, and all
legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
Synthesis and Characterization of New (dimethylsilyl)phenoxy and
(dimethyl(vinyl)silyl)phenoxy Substituted Cyclotriphosphazenes.
Rafał Januszewski,1 Michał Dutkiewicz,*2,3 Maciej Kubicki,1 Grzegorz Dutkiewicz,1
Hieronim Maciejewski,1 Bogdan Marciniec2
1Faculty of Chemistry, Adam Mickiewicz University in Poznań,
Umultowska 89b, 61-614 Poznań, Poland
2Centre for Advanced Technologies, Adam Mickiewicz University in Poznań,
Umultowska 89c, 61-614 Poznań, Poland
3Adam Mickiewicz University Foundation,
Rubież 46, 61-612 Poznań, Poland
*Corresponding author:
Michał Dutkiewicz - midu@amu.edu.pl
Centre for Advanced Technologies, Adam Mickiewicz University in Poznań,
Umultowska 89c, 61-614 Poznań, Poland
Abstract
The routes of synthesis, as well as, spectroscopic and X-ray diffraction characterization of a
new group of bis- or hexakis-4-(dimethyl(vinyl)silyl)phenoxy and 4-(dimethylsilyl)phenoxy-
substituted cyclotriphosphazenes as a versatile starting substrates for the synthesis of a variety
of organic cyclophosphazene derivatives, via catalytic hydrosilylation or silylative coupling
processes, is presented.
Keywords
Cyclophosphazene, nucleophilic substitution, dimethylsilylphenoxy
Introduction
Cyclotriphosphazenes, are considered as one of the most interesting and oldest group of
inorganic phosphorus and nitrogen heterocyclic compounds with general formula N3P3R6,
1

ACCEPTED MANUSCRIPT
where R can be a chlorine atom or an organic group bonded to the phosphorus1. The origins of
research on the synthesis, properties and applications of this group of compounds dates back
to the mid-nineteenth century when Liebig and Rose used phosphorus pentachloride and
ammonia to obtain the first known cyclic phosphazene trimer2. Since then
hexachlorocyclotriphosphazene, because of the excellent reactivity of the P-Cl bond, was used
over the decades as a versatile starting material for the synthesis of cyclotriphosphazene
derivatives mainly by nucleophilic substitution reactions, in which chlorine atoms can be
exchanged to a variety of functional groups1,3 influencing, together with the nature of
inorganic –P=N– skeleton the unique properties of cyclophosphazene derivatives4. Due to the
mentioned varied properties cyclophosphazenes have been studied among others as flame
retardant additives5, high temperature fluids6, clathrates7, photostabilizers, or antioxidants in
organic polymers8. They have also been used as phase transfer catalysts, as polypodants and
cryptands9. Cyclophosphazenes have also been successfully used as biologically active
agents10. Moreover cyclotriphosphazenes, were used for polymer functionalization and
synthesis, as pendant groups or monomers for polyphosphazene synthesis, especially those
bearing six chlorine atoms or phenoxy groups3,11
.
The literature on the synthesis and applications of cyclophosphazenes is very diverse, mainly
because of mentioned above reactivity of P-Cl bond and functional groups substituted to the
cyclotriphosphazene rings, which make them versatile precursors for synthesis of new
derivatives and materials easily modifiable by many organic transformations. However, there
are a limited number of examples describing their combinations with silicon substrates12.
Moreover the information about the use of transition metal catalyzed processes (like
hydrosilylation13 or silylative coupling14) for the synthesis of functional cyclophosphazenes is
even more scant. This is caused mainly by the lack of proper starting substrates for such
transformations. Taking into account the lack of silyl cyclophosphazene derivatives having
reactive dimethylsilyl or dimethyl(vinyl)silyl groups capable for functionalization via
hydrosilylation or silylative coupling processes we decided to undertake attempts to
synthesize mentioned above derivatives which can in our opinion affect the research
development on the synthesis and possible applications of this group of compounds.
Results and Discussion
Synthetic procedures applied were based on nucleophilic substitution processes of Cl atom
present in hexachlorocyclotriphosphazene substrate with 4-bromophenol and 2,2’-biphenol
2

ACCEPTED MANUSCRIPT
and subsequent reaction of obtained 4-bromophenoxycyclotriphosphazenes with
chlorodimethyl
silanes
to
yield
the
final
products.
While
hexakis(4-
(dimethyl(vinyl)silyl)phenoxy) and hexakis(4-(dimethylsilyl)phenoxy) cyclotriphosphazenes
were obtained in two step synthesis, to prepare bis(biphenyl-2,2’-diyl)bis(4-
(dimethylsilyl)phenoxy) and bis(biphenyl-2,2’-diyl)bis(4-(dimethyl(vinyl)silyl)phenoxy)
bisspirocyclic derivatives three step synthesis were applied.
Scheme
(dimethylsilyl)phenoxycyclotriphosphazenes
(dimethyl(vinyl)silyl)phenoxycyclotriphosphazenes.
1.
General
scheme
of
synthesis
of
bis-
and
and
hexakis-
4-
4-
Path
to
synthesis
of
hexakis(4-(dimethylsilyl)phenoxy)
and
hexakis(4-
(dimethyl(vinyl)silyl)phenoxy) cyclotriphosphazenes (3) and (4) is presented on Scheme 1. A
and B. In the first step (Scheme 1. A) via nucleophilic substitution of Cl atoms in the substrate
(1) with 4-bromophenol in the presence of potassium carbonate hexakis(4-
bromophenoxy)cyclotriphosphazene (2) has been synthesized with high 98% yield as a white
crystalline powder. Compound 2 was obtained at first by H.R. Allcock et al. using sodium
hydride in anhydrous THF.15 However, employing K2CO3 as a base in acetone as solvent
resulted in significant reduction in reaction time. Subsequently, in the second stage (Scheme
1. B) obtained intermediate (2) has been reacted with chlorodimethyl- or
chlorodimethylvinylsilane in the presence of n-butyllithium to yield hexakis(4-
3

ACCEPTED MANUSCRIPT
(dimethylsilyl)phenoxy)cyclotriphosphazene
(3)
or
hexakis(4-
(dimethyl(vinyl)silyl)phenoxy)cyclotriphosphazene (4) as yellowish oils with 92 and 94%
yield respectively.
It should be noted that functionalization of compound (2) with organolithium reagents was
studied by Allcock et al. They established a condition enabling complete substitution of
bromine atoms by lithium. Moreover, obtained organolithium cyclotriphoshazene derivative
was reacted with CO2, Ph2PCl, Ph2CO, C4H9Br, Ph3SnCl, Ph3PAuCl and D2O15. These results
definitely have broadened the knowledge of the reactivity of cyclophosphazenes, however, in
our point of view incorporation of reactive organosilicon moieties to the cyclophosphazene
rings should also have a similar impact on the field of cyclophosphazene chemistry.
Path
to
the
synthesis
of
bis(biphenyl-2,2’-diyl)bis(4-
bis(biphenyl-2,2’-diyl)bis(4-
(dimethylsilyl)phenoxy)cyclotriphosphazene
(7)
and
(dimethyl(vinyl)silyl)phenoxy) cyclotriphosphazene (8) is presented on Scheme 1. C, D and
E. In this case the first step (Scheme 1. C) based on nucleophilic substitution of Cl atoms in
substrate (1) with two equimolar amounts of 2,2’-biphenol in the presence of potassium
carbonate bis(biphenyl-2,2’-diyl)bischlorocyclotriphosphazene (5) has been synthesized with
92% yield as a white solid according to the published method16. Next in the second stage
(Scheme 1. D) obtained intermediate (5) has been reacted with 4-bromophenol to yield
bis(biphenyl-2,2’-diyl)bis(4-bromophenoxy)cyclotriphosphazene (6) with 95% yield also as a
white solid. Finally, in the third step (Scheme 1. E) intermediate (6) has been reacted with
chlorodimethyl or chlorodimethylvinylsilane in the presence of n-butyllithium to prepare
respectively bis(biphenyl-2,2’-diyl)bis(4-(dimethylsilyl)phenoxy)cyclotriphosphazene (7) and
bis(biphenyl-2,2’-diyl)bis(4-(dimethyl(vinyl)silyl)phenoxy)cyclotriphosphazene (8) with 94
and 96% yield as a white crystals.
Structures of all obtained intermediates and final products were confirmed with NMR
spectroscopy. The 1H and 13C NMR spectra were recorded using Bruker Ultrashield 300 MHz
29
31
spectrometer while Si and P ones were recorded using Bruker Ascend 400 spectrometer.
All spectra were collected at room temperature in CDCl3 or toluene-d8 as solvents. Detailed
analytical results, as well as, spectra recorded are available in Electronic Supplementary
Information (ESI). Additionally because intermediate (6), as well as, products (7) and (8)
formed white, crystalline solids, after recrystallization from diethyl ether or methylene
chloride, X-ray structure analysis was performed.
4

ACCEPTED MANUSCRIPT
Diffraction data were collected at 100(1) K, by the ω-scan technique on Agilent Technologies
Xcalibur four-circle diffractometer with Eos CCD detector and graphite-monochromated
MoKα radiation (λ=0.71069 Å). The data were corrected for Lorentz-polarization, as well as,
for absorption effects17. Precise unit-cell parameters were determined by a least-squares fit of
973 (6), 7203 (7), and 13517 (8) reflections of the highest intensity, chosen from the whole
experiment. The structures were solved with SIR9218 and refined with the full-matrix least-
squares procedure on F2 by SHELXL-201319. All non-hydrogen atoms were refined
anisotropically, Si-H hydrogen atoms in (7) were found in the difference Fourier map and
their position was further refined. All other hydrogen atoms were placed in idealized positions
and refined as ‘riding model’ with isotropic displacement parameters set at 1.2 (1.5 for methyl
groups) times Ueq of appropriate carrier atoms. In structure of (7) large voids filled with
diffused electron density were found; and as the modelling of solvent molecules was
unsuccessful, the SQUEEZE procedure20 was applied. Some soft restraints were applied for
the shape and size of thermal ellipsoids in this structure. The relevant experimental data and
refinement details are listed in ESI. Perspective views of the molecules are shown on Figure
1. and selected geometrical characteristics are listed in Table 1. In all structures, the P3N3
rings are almost flat and P-O bonds are directed above and below the mean ring plane. It
might be noted that NPN bond angles are systematically smaller than PNP ones.
Figure 1. A perspective view of molecules of (6) (7) and one of the symmetry-independent
molecule of (8); ellipsoids are drawn at the 50% probability level, hydrogen atoms are shown
as spheres of arbitrary radii.
Dihedral angles in biphenyl fragments (substituents at P2 and P3) are similar in all structures
while the disposition of the substituents at P1 - dihedral angles between two phenyl rings -
5

ACCEPTED MANUSCRIPT
strongly depending on the size and kind of substitution at this ring. In the crystal structure of
(6) characteristic triangular motifs created by halogen Br···Br interactions can be observed
(see ESI Fig. 30).19 Additionally, in this structure the disordered (across the threefold axis)
solvent CH2Cl2 molecule is present, which fills the voids in the crystal structure (see ESI Fig.
31). Structures (7) and (8) are almost solely defined by van der Waals dispersive interactions,
with no hydrogen bonding involved in the crystal architecture determination. Additionally in
the structure of (8) there are two symmetry-independent molecules in the crystal structure,
very similar in geometry.
Table 1. Selected geometrical parameters (Å, °) with s.u.’s in parentheses.
(6)
(7)
(8)A
(8)B
NPN angles 117.79(19) 117.64(12
116.8(2)
117.3(2)
118.5(2)
118.3(2)
121.5(3)
120.3(3)
121.6(3)
85.35(17)
44.23(18)
118.83(19) 118.29(12) 118.0(2)
118.17(19) 118.48(12) 118.3(2)
PNP angles
121.2(2)
121.6(2)
122.1(2)
29.14(13)
42.76(13)
42.31(11)
0.038(2)
122.11(14) 122.1(3)
121.29(15) 122.0(3)
121.46(14) 120.8(3)
d1
79.64(8)
41.65(10)
41.98(9)
84.4(2)
41.4(3)
d2
d3
42.51(18) 42.4(3)
0.106(3)
dev
0.0518(12) 0.101(3)
d1, d2 and d3 denote the dihedral angles between the planes of phenyl rings at P1 and biphenyl
rings at P2 and P3, respectively, and dev is maximal deviation from P3N3 plane.
Conclusions
Presented methodologies enabled us to obtain with high yield a group of versatile starting
substrates for the synthesis of a variety of organic cyclophosphazene derivatives via catalytic
transformations. Potentially they can also be useful alternatives for tetramethyldisiloxanes or
tetramethylcyclotetrasiloxanes, commonly used as silicone rubber crosslinkers. Moreover
they can also play the role of co-monomers or seeds in linear or star shaped polymer and
hybrid materials synthesis.
6

ACCEPTED MANUSCRIPT
Supporting Information
Detailed experimental procedures; Spectroscopic analysis of isolated compounds;
Crystallographic data. This material is available free of charge via the Internet at
Funding Sources
Research financed by the National Science Centre, Poland within the project granted on the
basis of the decision number DEC-2012/05/D/ST5/03580.
References
[1] Gleria, M.; De Jeager, R, Phosphazenes - A worldwide insight; Gleria, M.; De Jeager, R,
Eds.; Nova Science, 2004
[2] Rose, H. Ueber eine Verbindung des Phosphors mit dem Stickstoff Ann. Chem., 1834,
11, 129.
[3] Allcock, H. R, Chemistry and Applications of Polyphosphazenes, Wiley, New York,
2003.
[4] (a) Allen, C. W. Regio- and stereochemical control in substitution reactions of
cyclophosphazenes. Chem. Rev. 1991, 91, 119; (b) Allcock, H. R.; Connolly, M. S.;
Sisko, J. T.; Al-Shali, S. Effects of organic side group structures on the properties of
poly(organophosphazenes). Macromolecules, 1988, 21, 323.
[5] (a) Allen, C. W, The Chemistry of Inorganic Homo- and Hetero-Cycles; Haiduc, I.;
Sowerby, D. B, Eds.; Academic Press, London, Vol. 2, 1987; (b) Allen, C. W. The use of
phosphazenes as fire resistant materials. J. Fire. Sci., 1993, 11, 320. (c) Li, J.; Pan, F.;
Zeng, X.; Xu, H.; Zhang, L.; Zhong, Y.; Sui, X.; Mao, Z.; The flame-retardant properties
and mechanisms of poly(ethylene terephthalate)/hexakis (para-allyloxyphenoxy)
cyclotriphosphazene systems, J. Appl. Polym. Sci., 2015, 132, 42711. (d) Krishnadevi,
K.; Selvaraj, V., Development of halogen-free flame retardant phosphazene and rice
husk ash incorporated benzoxazine blended epoxy composites for microelectronic
applications, New J. Chem., 2015, 39, 6555. (e) Byczyński, Ł.; Dutkiewicz, M.;
Januszewski, R.; Thermal behaviour and flame retardancy of polyurethane high-solid
coatings modified with hexakis(2,3-epoxypropyl)cyclotriphosphazene, Prog. Org.
Coat., 2017, 108, 51.
7

ACCEPTED MANUSCRIPT
[6] (a) Singler, R. E.; Bieberich, M. J. Synthetic Lubricants and High Performance
Functional Fluids; Shubkin, R. L, Ed.; Marcel Dekker, New York, 1992; (b) Singler, R.
E.; Deome, A. J.; Dunn, D. A.; Bieberich, M. J. Preparation and properties of
phosphazene fire-resistant fluids. Ind. Eng. Chem. Prod. Res. Dev., 1986, 25, 46.
[7] (a) Allcock, H. R.; Silverberg, E. N.; Dudley, G. K.; Pucher, S. R. Inclusion
Polymerization within a Tris(2,3-naphthylenedioxy)cyclotriphosphazene Clathrate.
Macromolecules, 1994, 27, 7550.; (b) Allcock, H.R.; Dudley, G. K.; Silverberg, E. N.
Stereocontrolled Polymerization of Diene Monomers within
a
Tris(o-
phenylenedioxy)cyclotriphosphazene Tunnel Clathrate. Macromolecules, 1994, 27,
1039.
[8] (a) Bortolus, P.; Gleria, M.
Photochemistry and photophysics of
poly(organophosphazenes) and related compounds: A review. III. Applicative aspects. J.
Inorg. Organomet. Polym., 1994, 4, 205.; (b) Goins, D. E.; Li, H. M. US Patent
5105001, 1992. (c) Singh, R.K.; Kukrety, A.; Saxena, R.C.; Chouhan, A.; Jain, S.L.;
Ray, S.S. Phosphazene-based novel organo-inorganic hybrid salt: synthesis,
characterization and performance evaluation as multifunctional additive in polyol, RSC
Adv., 2017, 7, 13390.
[9] (a) Valter, B.; Masar, B.; Janout, V.; Hrudkova, H.; Cefelin, P.; Tur, D. R.; Vinogradova,
S. V. Polymers with sulfinyl and oxyethylene constitutional units as catalysts of
nucleophilic substitution reactions. Makromol. Chem., 1991, 192, 1549; (b) Zanin, B.;
Scheidecker, S.; Soumies, F.; Labarre, J. F. Crystal and molecular structure of the
monobino dicyclophosphazene N3P3Cl5 [HN(CH2)3O(CH2)6O(CH2)3NH] Cl5P3N3. J.
Mol. Struct., 1991, 246, 133; (c) Valerio, C.; Labarre, M. C.; Labarre, J. F. Lariat-
bearing cyclophosphazenes: potential molecular sepulchers for magnetic resonance
imaging agents. J. Mol. Struct., 1993, 299, 171. (d) Çirali, D.E.; Dayan, O.; Özdemir,
N.; Hacioglu, N. A new phosphazene derivative, spiro-N3P3[(O2C12H8)2(OC6H6N-3)2],
and its Ru(II) complex: Syntheses, crystal structure, catalytic activity and antimicrobial
activity studies, Polyhedron, 2015, 88, 170. (e) Zhang, H.; Hu, S.; Zhao, J.; Zhang, G.
Phosphazene-Catalyzed Alternating Copolymerization of Dihydrocoumarin and
Ethylene Oxide: Weaker is Better, Macromolecules, 2017, 50, 4198.
[10] (a) Bare, D.; Black, C. A. Foliar Application of P. I. Screening of Various Inorganic and
Organic P Compounds Agron. I., 1979, 71, 15; (b) Brandt, K.; Jedlinski, Z. New
monospirocyclic tetrakis (aziridinyl) cyclotriphosphazene derivatives as potential
antitumor drugs, Makromol. Chem. Suppl., 1985, 9, 169. (c) Krishnadevi, K.; Selvaraj,
8

ACCEPTED MANUSCRIPT
V.; Prasanna, D. Thermal, mechanical and antibacterial properties of cyclophosphazene
incorporated benzoxazine blended bismaleimide composites, RSC Adv., 2015, 5, 913.
(d) Krishnamoorthy, V.; Rajiv, S. Potential Seed Coatings Fabricated from
Electrospinning Hexaaminocyclotriphosphazene and Cobalt Nanoparticles Incorporated
Polyvinylpyrrolidone for Sustainable Agriculture, ACS Sustainable Chem. Eng., 2017,
5, 146. (e) Görgülü, A. O.; Koran, K.; Özen, F.; Tekin, S.; Sandal, S. Synthesis,
structural characterization and anti-carcinogenic activity of new cyclotriphosphazenes
containing dioxybiphenyl and chalcone groups., J. Mol. Struct., 2015, 1087, 5, 1.
[11] (a) Chandrasekhar, V. Inorganic and Organometallic Polymers, Springer Berlin
Heidelberg, 2005; Cho, Y.; Baek, H.; Sohn, Y. S. Thermal Polymerization of
Hexakis(pyridinoxy)cyclotriphosphazenes:ꢀ Ring-Opening Polymerization of Ring-
Strain-Free Cyclic Trimers Fully Substituted by Organic Groups. Macromolecules,
1999, 32, 2167. (b) Fu, J.; Xu, Q. Green Manufacturing and the Application of High-
Temperature Polymer-Polyphosphazenes, Green and Sustainable Manufacturing of
Advanced Materials, Elsevier Inc., 2015, 603. (c) Carter, K. R.; Allen, C. W. Mixed
substituent poly[(vinyloxy)cyclotriphosphazenes], J. Polym. Sci. A, 2013, 51, 2288.
[12] (a) Allcock, H. R.; Coggio, W. D. Organosiloxyphosphazene polymers: synthesis via
aminosiloxane reagents. Macromolecules, 1990, 23, 1626; (b) Boscoletto, A. B.; Gleria,
M.; Milani, R.; Meda, L.; Bertani, R. Surface functionalization with phosphazene
substrates
-
part
VII.
Silicon-based
materials
functionalized
with
hexachlorocyclophosphazene. Surf. Interface Anal., 2009, 41, 27; (c) Wang S., Sui, X.;
Li, Y.; Li, J.; Xu, H.; Zhong, Y.; Zhang, L.; Mao, Z. Durable flame retardant finishing of
cotton fabrics with organosilicon functionalized cyclotriphosphazene. Polymer
Degradation and Stability, 2016, 128, 22.; (d) Díaz, C.; Valenzuela, M. L.; Bravo, D.;
Lavayen, V.; O’Dwyer, C. Synthesis and Characterization of Cyclotriphosphazenes
Containing Silicon as Single Solid-State Precursors for the Formation of
Silicon/Phosphorus Nanostructured Materials. Inorg. Chem., 2008, 47, 11561.
[13] Hydrosilylation: A Comprehensive Review on Recent Advances, Marciniec, B. Ed.,
Springer, Berlin, 2009
[14] Pawluć, P.; Prukała, W.; Marciniec, B. Silylative Coupling of Olefins with Vinylsilanes
in the Synthesis of π-Conjugated Double Bond Systems. Eur. J. Org. Chem., 2010, 2,
219.
9

ACCEPTED MANUSCRIPT
[15] Allcock, H. R.; Evans, T. L.; Fuller, T. J. Small-Molecule Cyclic Models for the
Synthesis of New Polyphosphazenes: Side-Group Construction via Lithio-Phenoxy
Derivatives. Inorg. Chem., 1980, 19, 1026.
[16] Cil, E.; Tanyildizi, M. A.; Ozen, F.; Boybay, M.; Arslan, M.; Gorgulu. A. O. Synthesis,
Characterization, and Biological–Pharmacological Evaluation of New Phosphazenes
Bearing Dioxybiphenyl and Schiff Base Groups. Arch. Pharm. Chem. Life Sci. 2012,
345, 476.
[17] Agilent Technologies, CrysAlis PRO (Version 1.171.33.36d), Agilent Technologies Ltd,
2011.
[18] Altomare, A.; Cascarano, G.; Giacovazzo, C.; Gualardi, A. Completion and refinement
of crystal structures with SIR92. J. Appl. Crystallogr., 1993, 26, 343.
[19] Sheldrick, G. M. Crystal structure refinement with SHELXL. Acta Crystallogr., 2015,
C71, 3.
[20] Spek, A. L. PLATON SQUEEZE: a tool for the calculation of the disordered solvent
contribution to the calculated structure factors. Acta Crystallogr., 2015, C71, 9.
10

ACCEPTED MANUSCRIPT
Highlights
• Path of synthesis of dimethylsilylphenoxy substituted cyclophosphazenes is presented
• Spectral and x-ray characteristic of new derivatives is given
• Obtained compounds are useful substrates for their further catalytic transformations
• These compounds can be alternatives for conventional silicone rubber cross-linkers