Piperidinium Cations Research Articles

Supramolecular synthesis based on piperidone derivatives and pharmaceutically acceptable co-formers

The target complexes, bis{(E,E)-3,5-bis[4-(diethylamino)benzylidene]-4-oxopiperidinium} butanedioate, 2C27H36N3O(+)·C4H4O4(2-), (II), and bis{(E,E)-3,5-bis[4-(diethylamino)benzylidene]-4-oxopiperidinium} decanedioate, 2C27H36N3O(+)·C10H16O4(2-), (III), were obtained by solvent-mediated crystallization of the active pharmaceutical ingredient (API) (E,E)-3,5-bis[4-(diethylamino)benzylidene]-4-piperidone and pharmaceutically acceptable dicarboxylic (succinic and sebacic) acids from ethanol solution. They have been characterized by melting point, IR spectroscopy and single-crystal X-ray diffraction. For the sake of comparison, the structure of the starting API, (E,E)-3,5-bis[4-(diethylamino)benzylidene]-4-piperidone methanol monosolvate, C27H35N3O·CH4O, (I), has also been studied. Compounds (II) and (III) represent salts containing H-shaped centrosymmetric hydrogen-bonded synthons, which are built from two parallel piperidinium cations and a bridging dicarboxylate dianion. In both (II) and (III), the dicarboxylate dianion resides on an inversion centre. The two cations and dianion within the H-shaped synthon are linked by two strong intermolecular N(+)-H···(-)OOC hydrogen bonds. The crystal structure of (II) includes two crystallographically independent formula units, A and B. The cation geometries of units A and B are different. The main N-C6H4-C=C-C(=O)-C=C-C6H4-N backbone of cation A has a C-shaped conformation, while that of cation B adopts an S-shaped conformation. The same main backbone of the cation in (III) is practically planar. In the crystal structures of both (II) and (III), intermolecular N(+)-H···O=C hydrogen bonds between different H-shaped synthons further consolidate the crystal packing, forming columns in the [100] and [101] directions, respectively. Salts (II) and (III) possess increased aqueous solubility compared with the original API and thus enhance the bioavailability of the API.

N-Allyl-N-methylpiperidinium bis(trifluoromethanesulfonyl)imide—A film forming ionic liquid for graphite anode of Li-ion batteries

Abstract An ionic liquid, N -allyl- N -methylpiperidinium bis(trifluoromethanesulfonyl)imide PP 13* TFSI has been successfully tested as a solid electrolyte interface (SEI) forming agent for graphite composite anode at elevated temperature of 55 °C in a purely ionic liquid-based electrolyte: 0.5 m LiTFSI in a mixture of PP 13* TFSI–PP 13 TFSI (20–80 wt.%) The reversible discharge capacity was 340–350 mAh g −1 with only a small irreversible capacity loss per cycle. The electrochemical polymerisation of the allylic double bond participates on the SEI formation on the graphite surface. In the absence of unsaturated ionic liquid, the piperidinium cation is co-intercalated into graphite and causes its exfoliation with permanent loss of capacity. The electrolyte is thermally stable up to 320 °C and reasonably conductive (2.4 mS cm −1 at 55 °C).

2-(4-Carboxypiperidinium-1-yl)pyridine-3-carboxylate

The title compound, C12H14N2O4, crystallizes as a zwitterion. A negative charge is delocalized in the deprotonated carboxyl group attached to the pyridine ring. The piperidine N atom accepts a proton and the ring is transformed into a piperidinium cation. There is an intra­molecular N—H⋯O hydrogen bond between the protonated NH and a carboxyl­ate O atom. In the crystal, an O—H⋯O hydrogen bond between the carboxyl group and the carboxyl­ate O atom of another mol­ecule generates a helix along the b axis.

Extraction of noble metal ions from aqueous solution by ionic liquids

Nine ionic liquids containing pyridinium, pyrrolidinium and piperidinium cations with anion bis(trifluoromethylsulfonyl)imide were synthesized to investigate the ability of ionic liquids to extract silver, palladium, or gold metal ions from water at room temperature. Results are reported for distribution coefficients and extraction percentages with these ionic liquids. Ionic liquids containing a disulfide group or a nitrile group exhibit good extraction properties for silver or palladium ions. Gold ions were efficiently and selectively extracted with these functionalized ionic liquids. The influence of the mass ratio of water to ionic liquid on distribution coefficient or extraction percentage for aqueous gold ions was evaluated.

PEG-functionalized ionic liquids for cellulose dissolution and saccharification

Cellulose-dissolving ionic liquids (ILs) have become powerful neoteric solvents in the pretreatment of cellulosic biomass for ethanol fuel production. There are, however, a number of challenges to using current ionic solvents at large scales (imidazolium-based salts, in particular), including their relatively high costs and viscosities and their sluggish biodegradability. Aiming to overcome these hurdles, we have prepared a new series of poly(ethylene glycol) (PEG)-functionalized ILs comprising inexpensive alkylammonium or piperidinium cations paired with acetate anions. Some of these new ILs are capable of dissolving 8–12 wt% cellulose, while displaying low viscosities and acceptable thermal stabilities at the required process temperature. Our XRD and SEM data further confirm that regenerative pretreatment of cellulose by these PEGylated ILs can effectively transform the cellulose I structure to cellulose II, reducing the crystallinity of cellulose and increasing the structural homogeneity. Most excitingly, cellulose regenerated from these ILs can be rapidly hydrolyzed to glucose, in ∼90% glucose yield after 2 h, using a commercial cellulase supplemented with β-glucosidase.

Solubility of Aliphatic Hydrocarbons in Piperidinium Ionic Liquids: Measurements and Modeling in Terms of Perturbed-Chain Statistical Associating Fluid Theory and Nonrandom Hydrogen-Bonding Theory

Ionic liquids (ILs) reveal many unique properties which make them very interesting for applications in modern "green" technologies. For that reason, detailed knowledge about correlations between the ions' structure, their combinations, and the bulk properties is of great importance. That knowledge can be accessed by reliable measurements and modeling of systems with ILs in terms of various theoretical approaches. In this paper we report new experimental results on liquid-liquid equilibrium (LLE) measurements of 10 binary systems composed of piperidinium ILs [namely, 1-propyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide and 1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide] and aliphatic hydrocarbons (n-hexane, n-heptane, n-octane, cyclohexane, and cycloheptane). Moreover, new results on liquid density of pure 1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide are presented. Upper critical solution temperature type of phase behavior for all studied systems was observed. Decrease of solubility of n-alkane with an increase of its alkyl chain length and increase of solubility when changing linear into cyclic structure of hydrocarbon were detected. LLE modeling of investigated systems was performed in terms of two modern theories, namely, perturbed-chain statistical associating fluid theory (PC-SAFT) and nonrandom hydrogen-bonding theory (NRHB). Pure fluid parameters of the models were obtained from fitting of experimental liquid density and solubility parameter data at ambient pressure and tested against high pressure densities. Then literature values of activity coefficients of n-alkanes and cycloalkanes at infinitely diluted mixtures with ILs were used to optimize binary interaction parameters of the models. Finally, the LLE phase diagrams were calculated with average absolute relative deviations of 4.1% and 3.4% of the IL mole fraction for PC-SAFT and NRHB, respectively. The PC-SAFT and NRHB models were both able to capture phase behavior in a qualitative manner. Both models predict the order in which solubility of hydrocarbon in the IL increases, including the effects of chain length of n-alkane as well as chain length of alkyl substituent in piperidinium cation. Moreover, predicted solubility of cycloalkanes is also higher than that of respective n-alkanes. Our results suggest that the presented approach of PC-SAFT and NRHB modeling can be successfully applied to cross-associating systems as well. In summary, we have shown that relatively good results can be obtained for such complex systems by using quite simple molecular models and combining rules. To the best of our knowledge, this is the very first paper in which such equation-of-state modeling has been adopted for systems with ILs.

Experimental and theoretical structural study of ( 3E, 5E)-3,5-bis-(benzylidene)-4-oxopiperidinium mono- and ( 3E, 5E)-3,5-bis-(4- N, N-dialkylammonio)benzylidene)-4-oxopiperidinium trications

( 3E, 5E)-3,5-Bis(benzylidene)-4-oxopiperidinium tetrafluoroborate [C 19H 18NO][BF 4] ( 1), ( 3E, 5E)-3,5-bis[4-(dimethylammonio)benzylidene]-4-oxopiperidinium bearing mixed tetrafluoroborate and bis(hexafluoro(μ-hydroxo)diborate) anions [C 23H 30N 3O][B 2F 6OH] n [BF 4] m · xH 2O ( 2), and ( 3E, 5E)-3,5-bis[4-(diethylammonio)benzylidene]-4-oxopiperidinium tris(tetrafluoroborate) monohydrate [C 27H 38N 3O][BF 4] 3·H 2O ( 3) were obtained via mediated by the boron trifluoride etherate aldol-crotonic condensation of the corresponding aldehyde and piperidin-4-one hydrochloride monohydrate. Their structures were studied by IR and multinuclear NMR spectroscopy, and single crystal X-ray diffraction. The X-ray analysis revealed the presence of monoprotonated piperidinium cation in 1 and triprotonated cations in 2 and 3. The hexafluoro(μ-hydroxo)diborate anion was found in the mixed-anionic salts 2A and 2B which differ by the ratio of the anions. The extended hydrogen-bonded system is registered in all compounds. Static first order hyperpolarizabilities for the neutral ( 3E, 5E)-3,5-bis[4-(dimethylamino)benzylidene]-piperidin-4-one and its positively charged derivatives along with their molecular geometries and binding energy of 1 were calculated using DFT approach.

In silico cytotoxicity estimation of ionic liquids based on their two- and three-dimensional structural descriptors

The cytotoxicity of a series of ionic liquids containing ammonium, pyrrolidinium, imidazolium, pyridinium, and piperidinium cations against leukemia rat cell line IPC-81 was estimated from their structural parameters using quantitative structure–activity relationship methodology. Linear and nonlinear models were developed using genetic algorithm multiple linear regression and multilayer perceptron neural network approaches. Robustness and reliability of the constructed models were evaluated by internal, external, and Y-randomization procedures. Furthermore, the chemical applicability domain was determined via a leverage approach for each model. The results of this study revealed that the contribution of structural characteristics of the anionic parts of the studied ILs were fewer than of the cationic parts.

New functionalized ionic liquids based on pyrrolidinium and piperidinium cations with two ether groups as electrolytes for lithium battery

Four new functionalized ILs based on piperidinium and pyrrolidinium cations with two ether groups and TFSI − anion are synthesized and characterized. Physical and electrochemical properties of these ILs, including melting point, thermal stability, viscosity, conductivity and electrochemical stability, are investigated. All the ILs are liquids at room temperature, and the viscosities of P(2o1) 2-TFSI and P(2o1)(2o2)-TFSI are 55 and 53 mPa s at 25 °C, respectively. Behavior of lithium redox, chemical stability against lithium metal and charge–discharge characteristics of lithium batteries, are also investigated for these IL electrolytes with 0.6 mol kg −1 LiTFSI. Though the cathodic limiting potentials of these ILs are 0.4 V versus Li/Li +, the lithium plating and striping on Ni electrode can be observed for these IL electrolytes, and these IL electrolytes show good chemical stability against lithium metal. Li/LiFePO 4 cells using these IL electrolytes without additives have good capacity and cycle property at the current rate of 0.1 C, and the cell using the P(2o1)(2o2)-TFSI electrolyte owns good rate property.

Crystal structures and magnetic properties of two molecular solids based on bis(maleonitriledithiolate)nickelate monoanion with substituted piperidinium cations

Two new molecular solids, [1-NaMePid][Ni(mnt) 2] (1) and [2-NaMePid][Ni(mnt) 2] (2) (mnt 2− = maleonitriledithiolate, [1-NaMePid] + = 1-(1′-naphthylmethyl)piperidinium and [2-NaMePid] + = 1-(2′-naphthylmethyl)piperidinium) have been characterized structurally and magnetically. Both [Ni(mnt) 2] − anions and the cations of 1 and 2 form segregated column stacks, and the Ni(III) ions form a 1D zigzig alternating magnetic chain within a [Ni(mnt) 2] − column through Ni···S, S···S, Ni···Ni, or π···π interactions. Some conformational features in two isomeric cations and the geometry of the individual [Ni(mnt) 2] − anion for 1 and 2 remain similar, while the changes of the space filling properties, the packing requirements and the existence of the water molecule in 2 result in the difference of the stacking mode of the [Ni(mnt) 2] − anions. Magnetic susceptibility measurements in the temperature range 2–300 K show that 1 is diamagnetism, while 2 exhibits a novel and interesting spin–gap transition around 16.8 K with antiferromagnetic interaction ( J = −4.6 cm −1) in the high-temperature phase (HT) and the spin–gap (Δ/ k b = 68.5 K) in the low-temperature phase (LT).

Nonapiperidinium monohydrogen decavanadate tetranitrate

The title compound, (C5H12N)9[HV10O28](NO3)4, contains a monoprotonated deca­vanadate polyanion which lies on an inversion center. All the piperidinium cations adopt chair conformations. In the crystal structure, inter­molecular N—H⋯O hydrogen bonds form chains along [001]. As well as half of a polyanion, the asymmetric unit contains one full and two half-occupancy nitrate ions and four full occupancy and one half-occupancy piperidinium cations; the half-occupancy piperidinium cation is disordered over two general sites with occupancies of 0.32 and 0.18, and is, in turn, disordered over an inversion center.

Novel conjugated polymers employing the binding of polyfluorene derivatives and C 60

New polyfluorene (PF)-based conjugated polymers, PClBEHF, PClBEHF- co-PDEHF, PN 3BEHF, PN 3BEHF- co-PDEHF, PEHPBF, PC 60BEHF, PC 60BEHF- co-PDEHF, and PEHPBF +PCBA − containing chloro, azido, piperidine, and fullerene (C 60) groups as pendants, were synthesized. In the case of PC 60BEHF and PC 60BEHF- co-PDEHF, the C 60 moiety was introduced by using covalent bond formation between the azido group and C 60. PEHPBF +PCBA − was synthesized by using ionic bond formation between the piperidinium cation of PEHPBF and carboxylate anion of PCBA. The PL and EL spectra of PClBEHF, PClBEHF- co-PDEHF, PN 3BEHF, PN 3BEHF- co-PDEHF, and PEHPBF exhibited red-shifted and broad peaks caused by the aggregation which was induced by the increasing interchain interaction due to the polar pendants. After binding with C 60, covalently and ionically, the photovoltaic properties of PC 60BEHF, PC 60BEHF- co-PDEHF, and PEHPBF +PCBA − were studied. PL was quenched completely, which indicates photo-induced charge transfer from PF to pendant C 60. Even though photovoltaic effects did not occur in short circuit condition, blending with MEH-PPV as the ratio of 1:1 generated the photovoltaic effects.

Piperidinium bis(2-oxidobenzoato-κ2O1,O2)borate

The asymmetric unit of the title compound, C5H12N+·C14H8BO6 − or [C5H12N][BO4(C7H4O)2], contains two piperidinium cations and two bis­(salicylato)borate anions. The coordination geometries around the B atoms are distorted tetra­hedral. In the two mol­ecules, the aromatic rings are oriented at dihedral angles of 76.27 (3) and 83.86 (3)°. The rings containing B atoms have twist-boat conformations, while the two cations adopt chair conformations. In the crystal, the component species are linked by N—H⋯O hydrogen bonds. In the crystal structure, intra- and inter­molecular N—H⋯O hydrogen bonds link the mol­ecules.

Piperidinium 3-hydroxy-2-naphthoate

The crystals of the title salt, C5H12N+·C11H7O3 −, were obtained from a methanol/water solution of 3-hydr­oxy-2-naphthoic acid and piperidine at room temperature. In the crystal structure, the piperidinium cations display a chair conformation and link with hydroxy­naphthoate anions via N—H⋯O and C—H⋯O hydrogen bonds. An intra­molecular O—H⋯O inter­action is also present.

Reactions of solvated electrons with imidazolium cations in ionic liquids

We examined formation of solvated electrons in several ionic liquids composed of ammonium, pyrrolidinium and piperidinium cations by observing absorption spectra in the visible and near-infrared regions using pulse radiolysi. We also examined reactions of the solvated electrons with imidazolium cations in the ionic liquids. The reaction rate constants were an order of magnitude faster than the diffusion-limited rate calculated from the viscosity. The electrons before full solvation (dry electrons) reacted efficiently with the imidazolium cations. These observations suggest that the electrons in the ionic liquids can move easily before solvation. The scavenging of the dry electron by the imidazolium cation was also examined using C2-alkylated-imidazolium cations. It is found that the alkylation of imidazolium suppresses the reactivity with the dry electron.

Piperidinium 3-carboxy-4-hydroxybenzenesulfonate monohydrate

The asymmetric unit of the title compound, C5H12N+·C7H5O6S−·H2O, contains a piperidinium cation, one 3-carb­oxy-4-hydroxy­benzene­sulfonate anion and one water mol­ecule. Inter­molecular O—H⋯O, O—H⋯S and N—H⋯O hydrogen bonds generate a three-dimensional hydrogen-bonded framework.

Novel cyclic tetraphosphetanes: Molecular and crystal structures of diethylammonium and piperidinium salts of 1,2,3,4-tetramercapto-1,2,3,4-tetrathioxotetraphosphetane

Crystal structures of novel tetrakis(diethylammonium) and tetra(piperidinium) salts of 1,2,3,4-tetramercapto-1,2,3,4-tetrathioxotetraphosphetane are determined by single crystal X-ray diffraction. It is found that the substitution of the piperidinium cation for the diethylammonium one results in a change in the nature of charge distribution in crystals of the compounds, but the nature of supramolecular structures originating from intermolecular hydrogen bonding is preserved. Stoichiometry of the composition and phosphorus-containing anions turn out to be identical in both cases.

A novel dianionic seven-coordinate complex of tungsten(II), [WCl 3(GeCl 3)(CO) 3] 2−: Synthesis, spectroscopic properties and X-ray crystal structure

A new dianionic complex of tungsten(II), [(WCl 3(GeCl 3)(CO) 3] 2− ( 1 2−), containing the piperidinium cations [Hpip] + as the counter ions, has been obtained from the reaction between [W(CO) 4(pip) 2] and GeCl 4 in dichloromethane solution, and its molecular structure has been elucidated by single-crystal X-ray diffraction studies. The chemical properties of complex 1 were investigated by IR and NMR spectroscopy in solution.

Reaction between Diiodide Anion Radicals in Ionic Liquids

Photodetachment of electrons from iodide ions produced diiodide anion radicals in ionic liquids containing ammonium, pyrrolidinium, and piperidinium cations. The rates of reaction between diiodide anion radicals in molecular solvents such as H2O, methanol, and ethanol could be estimated by the Debye-Smoluchowski equation, which accounts for electrostatic interactions using dielectric constants for the molecular solvents. In contrast, the rates of reaction between diiodide anion radicals in the ionic liquids were close to the diffusion-limited rates for the neutral molecules, suggesting that electrostatic repulsion between the diiodide anion radicals is weakened by Coulombic shielding in the ionic liquids.

An Efficient One‐Pot Synthesis of 6‐Aryl‐5‐cyano‐2‐thiopyrimidinone Derivatives and Their Piperidinium Ionic Forms, X‐Ray Crystal Structures.

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