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Curnow OJ, Senthooran R, Somers AE. Tris(dialkylamino)cyclopropenium dialkylphosphate ionic liquids as lubricants. Phys Chem Chem Phys 2023; 25:2401-2410. [PMID: 36598037 DOI: 10.1039/d2cp05109e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Six new tris(dialkylamino)cyclopropenium dialkylphosphate ionic liquids (ILs), [C3(NR2)3]BEHP (NR2 = NEt2, NBuMe, NPr2, NBu2, NHex2, NDec2; BEHP = bis(2-ethylhexyl)phosphate), were prepared and characterised as potential lubricants. Thermophysical and thermochemical properties of these ILs were investigated, namely: viscosity, density, conductivity, miscibility, thermal stability and phase transitions. Miscibility studies indicated that [C3(NEt2)3]BEHP would not be suitable due to its water solubility and hexane immiscibility. [C3(NDec2)3]BEHP was not investigated as a lubricant due to its low purity (the chloride salt of this cation is also hexane miscible). Of the other four, [C3(NHex2)3]BEHP was found to exhibit significantly less wear for pin-on-disk test conditions than the standard phosphonium [P6,6,6,14]BEHP IL. The amount of wear was found to generally decrease with increasing molecular weight.
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Affiliation(s)
- Owen J Curnow
- School of Physical and Chemical Sciences, University of Canterbury, Private Bag 4800, Christchurch 8041, New Zealand.
| | - Rathiga Senthooran
- School of Physical and Chemical Sciences, University of Canterbury, Private Bag 4800, Christchurch 8041, New Zealand.
| | - Anthony E Somers
- Institute for Frontier Materials, Deakin University, Geelong, Victoria 3220, Australia
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Muñoz Sánchez GM, Zdilla MJ. Crystal structure of N-butyl-2,3-bis-(di-cyclo-hexyl-amino)-cyclo-propeniminium chloride benzene monosolvate. Acta Crystallogr E Crystallogr Commun 2022; 78:936-941. [PMID: 36072514 PMCID: PMC9443799 DOI: 10.1107/s2056989022008076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Accepted: 08/11/2022] [Indexed: 11/16/2022]
Abstract
N-Butyl-2,3-bis-(di-cyclo-hexyl-amino)-cyclo-propenimine (1) crystallizes from benzene and hexa-nes in the presence of HCl as a mono-benzene solvate of the hydro-chloride salt, [1H]Cl·C6H6 or C31H54N3 +·Cl-·C6H6, in the P21/n space group. The protonation of 1 results in the generation of an aromatic structure based upon the delocalization of the cyclo-propene double bond around the cyclo-propene ring, giving three inter-mediate C-C bond lengths of ∼1.41 Å, and the delocalization of the imine-type C-N double bond, giving three inter-mediate C-N bond lengths of ∼1.32 Å. Ion-ion and ion-benzene packing inter-actions are described and illustrated.
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Affiliation(s)
- Gaby M. Muñoz Sánchez
- Department of Chemistry, Temple University, 1901 N. 13th Street, Philadelphia, PA 19122, USA
| | - Michael J. Zdilla
- Department of Chemistry, Temple University, 1901 N. 13th Street, Philadelphia, PA 19122, USA
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Curnow OJ, Senthooran R. Highly-fluorinated Triaminocyclopropenium Ionic Liquids. Chem Asian J 2022; 17:e202200139. [PMID: 35239986 PMCID: PMC9314049 DOI: 10.1002/asia.202200139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/02/2022] [Indexed: 11/27/2022]
Abstract
A series of highly-fluorinated triaminocyclopropenium salts, with up to six fluorous groups, were prepared and their properties as ionic liquids investigated. Reaction of pentachlorocyclopropane or tetrachlorocyclopropene with bis(2,2,2-trifluoroethyl)amine, HN(CH2 CF3 )2 , occurs in the presence of a trialkylamine, NR3 , to give cations with two fluorinated amino groups, [C3 (N(CH2 CF3 )2 )2 (NR2 )]+ (R=Et, Pr, Bu, Hex), with traces of [C3 (N(CH2 CF3 )2 )3 ]+ . Use of appropriate reagent ratios and reaction times and subsequent addition of a dialkylamine, HNR'R", gives cations with one fluorinated amino group, [C3 (N(CH2 CF3 )2 )(NR2 )(NR'R")]+ ((NR2 )(NR'R")=(NBu2 )2 , (NEt2 )(NPr2 ), (NBu2 )(NBuMe)). These cations were isolated as chloride salts and some of these were converted to bistriflamide, dicyanamide and triflate salts to provide ionic liquids. These salts were characterised by thermal (DSC and TGA) measurements and miscibility/solubility properties (determined in a range of solvents). Ionic liquids (ILs) were also characterised by density, viscosity and conductivity measurements where possible. X-ray diffraction studies of chloride salts showed the formation of fluorous regions and more hydrophilic ionic regions in the solid state.
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Affiliation(s)
- Owen J. Curnow
- School of Physical and Chemical SciencesUniversity of CanterburyPrivate Bag 4800Christchurch8140New Zealand
| | - Rathiga Senthooran
- School of Physical and Chemical SciencesUniversity of CanterburyPrivate Bag 4800Christchurch8140New Zealand
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Ranga PK, Ahmad F, Singh G, Tyagi A, Vijaya Anand R. Recent advances in the organocatalytic applications of cyclopropene- and cyclopropenium-based small molecules. Org Biomol Chem 2021; 19:9541-9564. [PMID: 34704583 DOI: 10.1039/d1ob01549d] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The development of novel small molecule-based catalysts for organic transformations has increased noticeably in the last two decades. A very recent addition to this particular research area is cyclopropene- and cyclopropenium-based catalysts. At one point in time, particularly in the mid-20th century, much attention was focused on the structural aspects and physical properties of cyclopropene-based compounds. However, a paradigm shift was observed in the late 20th century, and the focus shifted to the synthetic utility of these compounds. In fact, a wide range of cyclopropene derivatives have been found serving as valuable synthons for the construction of carbocycles, heterocycles and other useful organic compounds. In the last few years, the catalytic applications of cyclopropene/cyclopropenium-based compounds have been uncovered and many synthetic protocols have been developed using cyclopropene-based compounds as organocatalysts. Therefore, the main objective of this review is to highlight recent developments in the catalytic applications of cyclopropene-based small molecules in different areas of organocatalysis such as phase-transfer catalysis (PTC), Brønsted base catalysis, hydrogen-bond donor catalysis, nucleophilic carbene catalysis, and electrophotocatalysis developed within the past two decades.
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Affiliation(s)
- Pavit K Ranga
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Knowledge City, S.A.S Nagar, Manauli (PO), Punjab - 140306, India.
| | - Feroz Ahmad
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Knowledge City, S.A.S Nagar, Manauli (PO), Punjab - 140306, India.
| | - Gurdeep Singh
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Knowledge City, S.A.S Nagar, Manauli (PO), Punjab - 140306, India.
| | - Akshi Tyagi
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Knowledge City, S.A.S Nagar, Manauli (PO), Punjab - 140306, India.
| | - Ramasamy Vijaya Anand
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Knowledge City, S.A.S Nagar, Manauli (PO), Punjab - 140306, India.
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Ranga PK, Ahmad F, Nager P, Rana PS, Vijaya Anand R. Bis(amino)cyclopropenium Ion as a Hydrogen-Bond Donor Catalyst for 1,6-Conjugate Addition Reactions. J Org Chem 2021; 86:4994-5010. [PMID: 33721500 DOI: 10.1021/acs.joc.0c02940] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The catalytic application of the bis(amino)cyclopropenium ion has been investigated in conjugate addition reactions. The hydrogen atom, which is attached to the cyclopropene ring of bis(amino)cyclopropenium salts, is moderately acidic and can potentially serve as a hydrogen-bond donor catalyst in some organic transformations. This hypothesis has been successfully realized in the 1,6-conjugate addition reactions of p-quinone methides with various nucleophiles such as indole, 2-naphthol, thiols, phenols, and so forth. The spectroscopic studies (NMR and UV-vis) as well as the deuterium isotope labeling studies clearly revealed that the hydrogen atom (C-H) that is present in the cyclopropene ring of the catalyst is indeed solely responsible for catalyzing these transformations. In addition, these studies also strongly indicate that the C-H hydrogen of the cyclopropene ring activates the carbonyl group of the p-quinone methide through hydrogen bonding.
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Affiliation(s)
- Pavit Kumar Ranga
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Knowledge City, Manauli (P.O.), S. A. S. Nagar, Punjab 140306, India
| | - Feroz Ahmad
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Knowledge City, Manauli (P.O.), S. A. S. Nagar, Punjab 140306, India
| | - Prashant Nager
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Knowledge City, Manauli (P.O.), S. A. S. Nagar, Punjab 140306, India
| | - Prabhat Singh Rana
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Knowledge City, Manauli (P.O.), S. A. S. Nagar, Punjab 140306, India
| | - Ramasamy Vijaya Anand
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Knowledge City, Manauli (P.O.), S. A. S. Nagar, Punjab 140306, India
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Al-Masri D, Yunis R, Hollenkamp AF, Doherty CM, Pringle JM. The influence of alkyl chain branching on the properties of pyrrolidinium-based ionic electrolytes. Phys Chem Chem Phys 2020; 22:18102-18113. [PMID: 32760990 DOI: 10.1039/d0cp03046e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ionic liquids and plastic crystals based on pyrrolidinium cations are recognised for their advantageous properties such as high conductivity, low viscosity, and good electrochemical and thermal stability. The pyrrolidinium ring can be substituted with symmetric or asymmetric alkyl chain substituents to form a range of ionic liquids or plastic crystals depending on the anion. However, reports into the use of branched alkyl chains and how this influences the material properties are limited. Here, we report the synthesis of six salts - ionic liquids and organic ionic plastic crystals - where the typically used linear propyl chain substituent is replaced by the branched alternative, isopropyl, to form the cation [C(i3)mpyr]+, in combination with six different anions: dicyanamide, (fluorosulfonyl)(trifluoromethanesulfonyl)imide, bis(trifluoromethanesulfonyl)imide, bis(fluorosulfonyl)imide, tetrafluoroborate and hexafluorophosphate. The thermal and transport properties of these salts are compared to those of the analogous N-propyl-N-methylpyrrolidinium and N,N-diethylpyrrolidinium-based salts. Finally, a high lithium salt content ionic liquid electrolyte based on the bis(fluorosulfonyl)imide salt was developed. This electrolyte showed high coulombic efficiencies of lithium plating/stripping and high lithium ion transference number, making it a strong candidate for use in lithium metal batteries.
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Affiliation(s)
- Danah Al-Masri
- Institute for Frontier Materials, Deakin University, Melbourne, Victoria 3125, Australia.
| | - Ruhamah Yunis
- Institute for Frontier Materials, Deakin University, Melbourne, Victoria 3125, Australia.
| | - Anthony F Hollenkamp
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Energy, Clayton, 3168, VIC, Australia
| | - Cara M Doherty
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Manufacturing, Clayton, 3168, VIC, Australia
| | - Jennifer M Pringle
- Institute for Frontier Materials, Deakin University, Melbourne, Victoria 3125, Australia.
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8
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Litterscheidt J, Bandar JS, Ebert M, Forschner R, Bader K, Lambert TH, Frey W, Bühlmeyer A, Brändle M, Schulz F, Laschat S. Self-Assembly of Aminocyclopropenium Salts: En Route to Deltic Ionic Liquid Crystals. Angew Chem Int Ed Engl 2020; 59:10557-10565. [PMID: 32119178 PMCID: PMC7317216 DOI: 10.1002/anie.202000824] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/25/2020] [Indexed: 01/27/2023]
Abstract
Aminocyclopropenium ions have raised much attention as organocatalysts and redox active polymers. However, the self-assembly of amphiphilic aminocyclopropenium ions remains challenging. The first deltic ionic liquid crystals based on aminocyclopropenium ions have been developed. Differential scanning calorimetry, polarizing optical microscopy and X-ray diffraction provided insight into the unique self-assembly and nanosegregation of these liquid crystals. While the combination of small headgroups with linear p-alkoxyphenyl units led to bilayer-type smectic mesophases, wedge-shaped units resulted in columnar mesophases. Upon increasing the size and polyphilicity of the aminocyclopropenium headgroup, a lamellar phase was formed.
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Affiliation(s)
- Juri Litterscheidt
- Institute of Organic ChemistryUniversity of StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Jeffrey S. Bandar
- Department of ChemistryColorado State UniversityFort CollinsCO80523USA
| | - Max Ebert
- Institute of Organic ChemistryUniversity of StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Robert Forschner
- Institute of Organic ChemistryUniversity of StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Korinna Bader
- Institute of Organic ChemistryUniversity of StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Tristan H. Lambert
- Department of Chemistry & Chemical BiologyCornell University122 Baker LaboratoryIttacaNY14853USA
- Department of ChemistryColumbia UniversityNew YorkNY10027USA
| | - Wolfgang Frey
- Institute of Organic ChemistryUniversity of StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Andrea Bühlmeyer
- Institute of Organic ChemistryUniversity of StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Marcus Brändle
- Institute of Organic ChemistryUniversity of StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Finn Schulz
- Institute of Organic ChemistryUniversity of StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Sabine Laschat
- Institute of Organic ChemistryUniversity of StuttgartPfaffenwaldring 5570569StuttgartGermany
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Litterscheidt J, Bandar JS, Ebert M, Forschner R, Bader K, Lambert TH, Frey W, Bühlmeyer A, Brändle M, Schulz F, Laschat S. Self‐Assembly of Aminocyclopropenium Salts: En Route to Deltic Ionic Liquid Crystals. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202000824] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Juri Litterscheidt
- Institute of Organic Chemistry University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Jeffrey S. Bandar
- Department of Chemistry Colorado State University Fort Collins CO 80523 USA
| | - Max Ebert
- Institute of Organic Chemistry University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Robert Forschner
- Institute of Organic Chemistry University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Korinna Bader
- Institute of Organic Chemistry University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Tristan H. Lambert
- Department of Chemistry & Chemical Biology Cornell University 122 Baker Laboratory Ittaca NY 14853 USA
- Department of Chemistry Columbia University New York NY 10027 USA
| | - Wolfgang Frey
- Institute of Organic Chemistry University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Andrea Bühlmeyer
- Institute of Organic Chemistry University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Marcus Brändle
- Institute of Organic Chemistry University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Finn Schulz
- Institute of Organic Chemistry University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Sabine Laschat
- Institute of Organic Chemistry University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
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Steinman NY, Starr RL, Brucks SD, Belay C, Meir R, Golenser J, Campos LM, Domb AJ. Cyclopropenium-Based Biodegradable Polymers. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b00430] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
| | - Rachel L. Starr
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Spencer D. Brucks
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | | | - Rinat Meir
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | | | - Luis M. Campos
- Department of Chemistry, Columbia University, New York, New York 10027, United States
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