Alkylation and Acylation of CyclotriphosphazenesClick to copy article linkArticle link copied!
Abstract

Phosphazenes (RNH)6P3N3 (R = n-propyl, isobutyl, isopropyl, cyclohexyl, tert-butyl, benzyl) are readily alkylated at ring N sites by alkyl halides forming N-alkyl phosphazenium cations. Alkylation of two ring N sites occurred after prolonged heating in the presence of methyl iodide or immediately at room temperature with methyl triflate yielding N,N‘-dimethyl phosphazenium dications. Geminal dichloro derivatives Cl2(RNH)4P3N3 are methylated by methyl iodide at the ring N site adjacent to both P centers carrying four RNH groups. X-ray crystal structures showed that the alkylation of ring N sites leads to substantial elongation of the associated P−N bonds. Both N-alkyl and N,N‘-dialkyl phosphazenium salts form complex supramolecular networks in the solid state via NH···X interactions. Systems carrying less-bulky RNH groups show additional NH···N bonds between N-alkyl phosphazenium ions. N-Alkyl phosphazenium halides form complexes with silver ions upon treatment with silver nitrate. Depending on the steric demand of RNH substituents, either one or both of the vacant ring N sites engage in coordination to silver ions. Treatment of (RNH)6P3N3 (R = isopropyl) with acetyl chloride and benzoyl chloride, respectively, yielded N-acyl phosphazenium ions. X-ray crystal structures revealed that elongation of P−N bonds adjacent to the acylated ring N site is more pronounced than it is in the case of N-alkylated species. Salts containing N-alkyl phosphazenium ions are stable toward water and other mild nucleophiles, while N,N‘-dialkyl and N-acyl phosphazenium salts are readily hydrolyzed. The reaction of (RNH)6P3N3 with bromoacetic acid led to N-alkylation at one ring N site in addition to formation of an amide via condensation of an adjacent RNH substituent with the carboxylic acid group. The resulting bromide salt contains mono cations of composition (RNH)5P3N3CH2CONR in which a CH2−C(O) unit is embedded between a ring N and an exocyclic N site of the phosphazene.
*
To whom correspondence should be addressed. E-mail: a.steiner@ liv.ac.uk.
Cited By
Smart citations by scite.ai include citation statements extracted from the full text of the citing article. The number of the statements may be higher than the number of citations provided by ACS Publications if one paper cites another multiple times or lower if scite has not yet processed some of the citing articles.
This article is cited by 33 publications.
- Cavya Jose, Naniyil Sradha, Ramamoorthy Boomishankar. A Chiral Hexa-amino Cyclotriphosphazene for Enantioselective Recognition of Small Organic Compounds. Inorganic Chemistry 2024, 63
(40)
, 18788-18796. https://doi.org/10.1021/acs.inorgchem.4c02814
- Josefina Jiménez, José Antonio Sanz, José Luis Serrano, Joaquín Barberá, Luis Oriol. Cyclotriphosphazenes as Scaffolds for the Synthesis of Metallomesogens. Inorganic Chemistry 2020, 59
(7)
, 4842-4857. https://doi.org/10.1021/acs.inorgchem.0c00124
- Tapas Senapati, Atanu Dey, Vierandra Kumar, Vadapalli Chandrasekhar. Metalation Studies of Carbophosphazene-Based Coordination Ligands: Metallacages to Polymeric Networks. Crystal Growth & Design 2020, 20
(4)
, 2660-2669. https://doi.org/10.1021/acs.cgd.0c00056
- Elena Gascón, Sara Maisanaba, Isabel Otal, Eva Valero, Guillermo Repetto, Peter G. Jones, Josefina Jiménez. (Amino)cyclophosphazenes as Multisite Ligands for the Synthesis of Antitumoral and Antibacterial Silver(I) Complexes. Inorganic Chemistry 2020, 59
(4)
, 2464-2483. https://doi.org/10.1021/acs.inorgchem.9b03334
- Philip I. Richards, Gavin T. Lawson, Jamie F. Bickley, Craig M. Robertson, Jonathan A. Iggo, Alexander Steiner. Polyanionic Ligand Platforms for Methyl- and Dimethylaluminum Arrays. Inorganic Chemistry 2019, 58
(5)
, 3355-3363. https://doi.org/10.1021/acs.inorgchem.8b03448
- Dheeraj Kumar, Nem Singh, Anil J. Elias, Pauline Malik, and Christopher W. Allen . Reactions of Alkyne- and Butadiyne-Derived Fluorinated Cyclophosphazenes with Diiron and Dimolybdenum Carbonyls. Inorganic Chemistry 2014, 53
(19)
, 10674-10684. https://doi.org/10.1021/ic501821v
- Serap Beşli, Fatma Yuksel, David B. Davies, and Adem Kılıç . Conversion of a Cyclotriphosphazene to a Cyclohexaphosphazene by Ring Expansion. Inorganic Chemistry 2012, 51
(12)
, 6434-6436. https://doi.org/10.1021/ic300728j
- Chen Chen, Andrew R. Hess, Adam R. Jones, Xiao Liu, Greg D. Barber, Thomas E. Mallouk, and Harry R. Allcock . Synthesis of New Polyelectrolytes via Backbone Quaternization of Poly(aryloxy- and alkoxyphosphazenes) and their Small Molecule Counterparts. Macromolecules 2012, 45
(3)
, 1182-1189. https://doi.org/10.1021/ma202619j
- Arvind K. Gupta, Jennifer Nicholls, Suman Debnath, Ian Rosbottom, Alexander Steiner, and Ramamoorthy Boomishankar . Organoamino Phosphonium Cations as Building Blocks for Hierarchical Supramolecular Assemblies. Crystal Growth & Design 2011, 11
(2)
, 555-564. https://doi.org/10.1021/cg101447q
- Dheeraj Kumar, Nem Singh, Karunesh Keshav, and Anil J. Elias. Ring-Closing Metathesis Reactions of Terminal Alkene-Derived Cyclic Phosphazenes. Inorganic Chemistry 2011, 50
(1)
, 250-260. https://doi.org/10.1021/ic101884s
- Karunesh Keshav, Nem Singh and Anil J. Elias. Synthesis and Reactions of Ethynylferrocene-Derived Fluoro- and Chlorocyclotriphosphazenes. Inorganic Chemistry 2010, 49
(12)
, 5753-5765. https://doi.org/10.1021/ic100703h
- Joanne Ledger, Ramamoorthy Boomishankar and Alexander Steiner . Aqueous Chemistry of Chlorocyclophosphazenes: Phosphates {PO2}, Phosphamides {P(O)NHR}, and the first Phosphites {PHO} and Pyrophosphates {(PO)2O} of These Heterocycles. Inorganic Chemistry 2010, 49
(8)
, 3896-3904. https://doi.org/10.1021/ic100076t
- Muthiah Senthil Kumar, Ram Prakash Gupta and Anil J. Elias. Synthesis and Selectivity in the Formation of Cyclophosphazene-Derived 1,3-Cyclohexadienes from Reactions of RCpCo(COD) [R = MeOC(O)] with Alkynes and Alkenes. Inorganic Chemistry 2008, 47
(8)
, 3433-3441. https://doi.org/10.1021/ic7024507
- Hüseyin Akbaş. (2-Furanylmethyl)spiro(N/N)cyclotriphosphazenes and some quaternized derivatives: syntheses, structural elucidation and free radical scavenging activity studies. Inorganica Chimica Acta 2024, 569 , 122116. https://doi.org/10.1016/j.ica.2024.122116
- Daquan Wang, Xin Xu, Yao Qiu, Jiali Wang, Lingjie Meng. Cyclotriphosphazene based materials: Structure, functionalization and applications. Progress in Materials Science 2024, 142 , 101232. https://doi.org/10.1016/j.pmatsci.2024.101232
- Swati Deswal, Rishukumar Panday, Dipti R. Naphade, Pierre‐Andre Cazade, Sarah Guerin, Jan K. Zaręba, Alexander Steiner, Satishchandra Ogale, Thomas D. Anthopoulos, Ramamoorthy Boomishankar. Design and Piezoelectric Energy Harvesting Properties of a Ferroelectric Cyclophosphazene Salt. Small 2023, 19
(46)
https://doi.org/10.1002/smll.202300792
- Ahmet Karadağ, Hüseyin Akbaş. Phosphazene-Based Ionic Liquids. 2018https://doi.org/10.5772/intechopen.76613
- Hüseyin Akbaş, Aytuğ Okumuş, Ahmet Karadağ, Zeynel Kılıç, Tuncer Hökelek, L. Yasemin Koç, Leyla Açık, Betül Aydın, Mustafa Türk. Phosphorus–nitrogen compounds. Journal of Thermal Analysis and Calorimetry 2016, 123
(2)
, 1627-1641. https://doi.org/10.1007/s10973-015-5001-6
- Michael Craven, Rana Yahya, Elena F. Kozhevnikova, Craig M. Robertson, Alexander Steiner, Ivan V. Kozhevnikov. Alkylaminophosphazenes as Efficient and Tuneable Phase‐Transfer Agents for Polyoxometalate‐Catalysed Biphasic Oxidation with Hydrogen Peroxide. ChemCatChem 2016, 8
(1)
, 200-208. https://doi.org/10.1002/cctc.201500922
- Dheeraj Kumar, Anil J. Elias. Reduction reactions of alkyne and butadiyne derived fluorinated cyclophosphazenes. Journal of Fluorine Chemistry 2014, 166 , 69-77. https://doi.org/10.1016/j.jfluchem.2014.07.022
- Ranit Biswas, Karunesh Keshav, Dheeraj Kumar, Anil J. Elias. Reactions of allylzinc bromide with ethynylferrocene derived fluorinated cyclophosphazenes. Journal of Organometallic Chemistry 2014, 768 , 157-162. https://doi.org/10.1016/j.jorganchem.2014.06.025
- Serap Beşli, Ceylan Mutlu, Fatma Yuksel, Adem Kılıç. Reactions of ansa fluorodioxy cyclotriphosphazene derivatives with phenol. Polyhedron 2014, 81 , 777-787. https://doi.org/10.1016/j.poly.2014.07.043
- Dheeraj Kumar, Jatinder Singh, Anil J. Elias. Chiral multidentate oxazoline ligands based on cyclophosphazene cores: synthesis, characterization and complexation studies. Dalton Trans. 2014, 43
(37)
, 13899-13912. https://doi.org/10.1039/C4DT01741B
- Michael Craven, Rana Yahya, Elena Kozhevnikova, Ramamoorthy Boomishankar, Craig M. Robertson, Alexander Steiner, Ivan Kozhevnikov. Novel polyoxometalate–phosphazene aggregates and their use as catalysts for biphasic oxidations with hydrogen peroxide. Chem. Commun. 2013, 49
(4)
, 349-351. https://doi.org/10.1039/C2CC36793A
- Eric W. Ainscough, Andrew M. Brodie, Ross J. Davidson, Geoffrey B. Jameson, Carl A. Otter. Flexible pyridyloxy-substituted cyclotetraphosphazene platforms linked by silver(i). CrystEngComm 2013, 15
(21)
, 4379. https://doi.org/10.1039/c3ce40395e
- Serap Beşli, Ceylan Mutlu, Fatma Yuksel. Nucleophilic substitution reactions of 10- and 11-membered fluorodioxy ansa cyclotriphosphazene derivatives. Dalton Transactions 2013, 42
(48)
, 16709. https://doi.org/10.1039/c3dt52461b
- Muthiah Senthil Kumar, Dheeraj Kumar, Anil J. Elias. Synthesis of (β-phenylethynyl)-gem-diphenyltrifluorocyclotriphosphazene and its reaction with RCpCo(PPh3)2 [R=MeOC(O)]. Inorganica Chimica Acta 2011, 372
(1)
, 175-182. https://doi.org/10.1016/j.ica.2011.01.064
- Katrin Veldboer, Thomas Schürmann, Martin Vogel, Hans‐Dieter Wiemhöfer, Uwe Karst. Liquid chromatography/electrospray time‐of‐flight mass spectrometry for the characterisation of cyclic phosphazenes. Rapid Communications in Mass Spectrometry 2011, 25
(1)
, 147-154. https://doi.org/10.1002/rcm.4837
- Josefina Jiménez, Antonio Laguna, Mohamed Benouazzane, Jose Antonio Sanz, Carlos Díaz, María Luisa Valenzuela, Peter G. Jones. Metallocyclo‐ and Polyphosphazenes Containing Gold or Silver: Thermolytic Transformation into Nanostructured Materials. Chemistry – A European Journal 2009, 15
(48)
, 13509-13520. https://doi.org/10.1002/chem.200902180
- Alexander Steiner. Supramolecular Structures of Cyclotriphosphazenes. 2009, 411-453. https://doi.org/10.1002/9780470478882.ch20
- Ivan I. Vorontsov, Dzidra R. Tur, Vladimir S. Papkov, Mikhail Yu. Antipin. X-ray crystal structures and DFT calculations of differently charged aminocyclophosphazenes. Journal of Molecular Structure 2009, 928
(1-3)
, 1-11. https://doi.org/10.1016/j.molstruc.2009.03.002
- Katrin Veldboer, Yunus Karatas, Torsten Vielhaber, Uwe Karst, Hans‐Dieter Wiemhöfer. Cyclic Phosphazenes for the Surface Modification of Lanthanide Phosphate‐based Nanoparticles. Zeitschrift für anorganische und allgemeine Chemie 2008, 634
(12-13)
, 2175-2180. https://doi.org/10.1002/zaac.200800297
- Mark A. Benson, Joanne Ledger, Alexander Steiner. Zwitterionic phosphazenium phosphazenate ligands. Chemical Communications 2007, 182
(37)
, 3823. https://doi.org/10.1039/b708993g
Article Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.
Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.
The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated.