Methane Activation by Diatomic Molybdenum Carbide Cations

Metal carbide species have been proposed as a new type of chemical entity to activate methane in both gas‐phase and condensed‐phase studies. Herein, methane activation by the diatomic cation MoC⁺ is presented. MoC⁺ ions have been prepared and mass‐selected by a quadrupole mass filter and then allowed to interact with methane in a hexapole reaction cell. The reactant and product ions have been detected by a reflectron time‐of‐flight mass spectrometer. Bare metal Mo⁺ and MoC₂H₂⁺ ions have been observed as products, suggesting the occurrence of ethylene elimination and dehydrogenation reactions. The branching ratio of the C₂H₄ elimination channel is much larger than that of the dehydrogenation channel. Density functional theory calculations have been performed to explore in detail the mechanism of the reaction of MoC⁺ with CH₄. The computed results indicate that the ethylene elimination process involves the occurrence of spin conversions in the C?C coupling (doublet→quartet) and hydrogen atom transfer (quartet→sextet) steps. The carbon atom in MoC⁺ plays a key role in methane activation because it becomes sp³ hybridized in the initial stages of the ethylene elimination reaction, which leads to much lower energy barriers and more stable intermediates. This study provides insights into the C?H bond activation and C?C coupling involved in methane transformation over molybdenum carbide‐based catalysts.     

Reaction pathways of Sc+ (3D, 1D) and Fe+ (6D, 4F) with acetone in the gas phase: metal ion oxidation and acetone deethanization

The reactions of Sc⁺ (³D, ¹D) and Fe⁺ (⁶D, ⁴ F) with acetone have been investigated in both high‐ and low‐spin states using density functional theory. Our calculations have indicated that oxidation of Sc⁺ by acetone can take place by (1) metal‐mediated H migration, (2) direct methyl‐H shift and/or (3) C = O insertion. The most energetically favorable pathway is metal‐mediated H migration followed by intramolecular ScO⁺ rotation and dissociation. For the deethanization of acetone mediated by Fe⁺, the reaction occurs on either the quartet or sextet surfaces through five elementary steps, i.e. encounter complexation, C–C bond activation, methyl migration, C–C coupling and non‐reactive dissociation. The rate‐determining step along the quartet‐state potential‐energy surface (PES) is similar to that in the case of Ni⁺ (² F, 3d⁹), namely the methyl‐migration step. For the sextet‐state PES, however, the energy barrier for methyl migration is lower than that for C–C bond activation, and the rate‐determining step is C–C coupling. In general, the low‐spin‐state pathways are lower in energy than the high‐spin‐state pathways; therefore, the reaction pathways for the oxidation of Sc⁺ and the Fe⁺‐mediated deethanization of acetone mostly involve the low‐spin states. Copyright © 2012 John Wiley & Sons, Ltd.     

Chemical and thermal stability of N‐heterocyclic ionic liquids in catalytic C–H activation reactions

¹H‐NMR spectrum analyses are applied to study the chemical and thermal stability of selected N‐heterocyclic ionic liquids within the reaction system that can highly efficiently activate a C–H bond of methane and convert it into the C–O bond in methanol. Our results indicate that under such reaction conditions involving using a powerful Pt‐based catalyst and strong acidic solvent, the aromatic ring of an imidazolium cation becomes unstable generating an ammonium ion (NH₄⁺). Our results also suggest that the instability of the imidazolium ring is more chemically (participation in reactions) than thermally based. Modifications of the aromatic ring structure such as pyrazolium and triazolium cations can increase the chemical/thermal stability of ionic liquids under these reaction conditions. Copyright © 2014 John Wiley & Sons, Ltd.     

Synthesis,crystal structures and spectroscopic properties of dichloroethylphenyltin(IV) and its phenanthroline adduct

The reaction of dichloroethylphenyltin(IV), Ph(Et)SnCl₂, with phenanthroline monohydrate (phen·H₂O) in chloroform, in 1:1 mole ratio, afforded [Ph(Et)SnCl₂(phen)]. The crystal structures of dichloroethylphenyltin(IV) and its phenanthroline adduct were studied by X‐ray diffraction. In Ph(Et)SnCl₂ the tin atom is in a distorted tetrahedral environment, the distortion probably being imposed by weak intermolecular Sn· · ·Cl interactions. In [Ph(Et)SnCl₂(phen)] the tin atom is in an octahedral trans‐C₂, cis‐Cl₂, N₂ environment and weak intermolecular C–H· · ·Cl interactions connect the molecules throughout the lattice. Spectroscopic studies in solution (¹H, ¹³C and ¹¹⁹Sn NMR) were also carried out; the ¹H and ¹³C NMR data in dimethylsulfoxide suggest that [Ph(Et)SnCl₂(phen)] remains at least partially undissociated in this solvent. Copyright © 2003 John Wiley & Sons, Ltd.     

Access to Silylated Pyrazole Derivatives by Palladium‐Catalyzed C−H Activation of a TMS group

A simple and efficient approach to new silylated heterocycles of potential interest in medicinal chemistry is presented. A set of bromophenyl trimethylsilyl pyrazole intermediates can be transformed by direct organometallic routes into two families of regioisomeric iodoaryl substrates; using either arylzinc or aryllithium chemistry, the TMS group remains on the pyrazole ring or translocates to the aryl moiety. These two families can then be efficiently transformed into benzo silino pyrazoles thanks to a single‐step cyclization relying on the Pd‐catalyzed activation of a non‐activated C(sp³)?H bond alpha to a silicon atom. The experimental conditions used, which are fully compatible with the pyrazole ring, suggest that this reaction evolves through a concerted metalation–deprotonation (CMD) mechanism.     

C–H Activation and Alkyne Annulation via Automatic or Intrinsic Directing Groups: Towards High Step Economy

Direct transformation of carbon–hydrogen bond (C–H) has emerged to be a trend for construction of molecules from building blocks with no or less prefunctionalization, leading high atom and step economy. Directing group (DG) strategy is widely used to achieve higher reactivity and selectivity, but additional steps are usually needed for installation and/or cleavage of DGs, limiting step economy of the overall transformation. To meet this challenge, we proposed a concept of automatic DG (DG^auto), which is auto‐installed and/or auto‐cleavable. Multifunctional oxime and hydrazone DG^auto were designed for C–H activation and alkyne annulation to furnish diverse nitrogen‐containing heterocycles. Imidazole was employed as an intrinsic DG (DGⁱⁿ) to synthesize ring‐fused and π‐extended functional molecules. The alkyne group in the substrates can also be served as DGⁱⁿ for ortho‐C–H activation to afford carbocycles. In this account, we intend to give a review of our progress in this area and brief introduction of other related advances on C–H functionalization using DG^auto or DGⁱⁿ strategies.     

Reaction mechanisms of methanol oxidation by FeIVO biomimetic complex

Density functional theory calculations were carried out to investigate the reaction mechanism of methanol oxidation mediated by [(bpg)Fe^IVO]⁺ ( A ). Two models (CH₃CN‐bound ferryl model B and CH₃OH‐bound ferryl model C ) were also studied in this work to probe ligand effect. Mechanistically, both direct and concerted hydrogen transfer (DHT and CHT) pathways were explored. It is found that the initial step of methanol oxidation by A is C? H bond activation via a DHT pathway. Addition of different equatorial ligands has considerable influence on the reaction mechanisms. Methanol oxidation mediated by B commences via O? H bond activation; in sharp contrast, the oxidation mediated by C stems from C? H bond activation. Frontier molecular orbital analysis showed that the initial C? H bond activation by all these model complexes follows a hydrogen atom transfer (HAT) mechanism, whereas O? H bond activation proceeds via an HAT or proton transfer. © 2016 Wiley Periodicals, Inc.     

Theoretical study of the gas-phase ethane C–H and C–C bonds activation by bare niobium cation

The potential energy surfaces for the reaction of bare niobium cation with ethane, as a prototype of the C–H and C–C bonds activation in alkanes by transition metal cations, have been investigated employing the Density Functional Theory in its B3LYP formulation. All the minima and key transition states have been examined along both high- and low-spin surfaces. For both the C–H and C–C activation pathways the rate determining step is that corresponding to the insertion of the Nb cation into C–H and C–C bond, respectively. However, along the C–H activation reaction coordinate the barrier that is necessary to overcome is 0.13 eV below the energy of the ground state reactants asymptote, while in the C–C activation branch the corresponding barrier is about 0.58 eV above the energy of reactants in their ground state. The overall calculated reaction exothermicities are comparable. Since the spin of the ground state reactants is different from that of both H–Nb⁺–C₂H₅ and CH₃–Nb⁺–CH₃ insertion intermediates and products, spin multiplicity has to change along the reaction paths. All the obtained results, including Nb⁺–R binding energies for R fragments relevant to the examined PESs, have been compared with existing experimental and theoretical data.     

New Hexanuclear Niobium Cluster Compounds with Perfluorinated Ligands Made Using Ionic Liquids

Three new hexanuclear niobium cluster compounds, which carry trifluoroacetate ligands on the exo sites of the metal atom octahedra, were synthesized and characterized. For the syntheses, the ionic liquid 1,1,3,3‐tetramethylguanidinium‐trifluoroacetat, (TMG‐H)TFA, was used as solvent as well as source for the ligands and cations. All three cluster compounds consist of the [Nb₆Cl₁₂(TFA)₆]^4– anion and (TMG‐H)⁺, (TMG‐H)⁺ + (TMGTFAA‐H)⁺, or (TMGTFAA‐H)⁺ cations [(TMGTFAA‐H)⁺ = 1,1,3,3‐tetramethylguanidine‐trifluoroacetamidinium]. TMGTFAA and the corresponding cation are obtained by either heating and/or by addition of TFA‐anhydrate to (TMG‐H)TFA in a slow chemical reaction. (TMGTFAA‐H)TFA comprises a second ionic liquid in this reaction system, which provides cations for two of the three characterized niobium cluster compounds. Structural details of the three new cluster compounds as well as of TMGTFAA were obtained by X‐ray diffraction experiments. With a melting point of approx. 145 °C the cluster compound with the (TMG‐H)⁺ cations almost can be called a “cluster ionic liquid“.     

A DFT Study on the Mechanism of Rh2II,II‐Catalyzed Intramolecular Amidation of Carbamates

The potential‐energy surfaces of the reactions of dirhodium tetracarboxylate (Rh₂^II,II) catalyzed nitrene (NR) insertion into C H bonds were examined by a DFT computational study. A pure Becke exchange functional (B88) rather than a hybrid exchange functional (B3, BHandH) was found to be appropriate for the calculation of the energy difference between the singlet and triplet Rh₂^II,II–NH nitrene species. Rh₂^II,II–NR¹ (R¹=(S)‐2‐methyl‐1‐butylformyl) is thermodynamically more favorable with a free energy lower than that of Rh₂^II,II–N(PhI)R¹. The singlet and triplet states of Rh₂^II,II–NR¹ have similar stability. Singlet Rh₂^II,II–NR¹ undergoes a concerted NR insertion into the C H bond with simultaneous formation of the N H and N C bonds during C H bond cleavage; triplet Rh₂^II,II–NR¹ undergoes H atom abstraction to produce a diradical, followed by subsequent bond formation by diradical recombination. The singlet pathway is favored over the triplet in the context of the free energy of activation and leads to the retention of the chirality of the C atom in the NR insertion product. The reactivities of the C H bonds toward the nitrene‐insertion reaction follow the order tertiary>secondary>primary. Relative reaction rates were calculated for the six reaction pathways examined in this work.     

Chloro­(hist­amine)(1,10‐phenanthro­line)copper(II) chloride monohydrate

In the cationic complex present in the title compound, chloro­[2‐(4‐imidazolyl‐κN¹)­ethyl­amine‐κN](1,10‐phenanthroline‐κ²N,N′)copper(II) chloride monohydrate, [CuCl(C₅H₉­N₃)­(C₁₂H₈N₂)]Cl·H₂O, the metal centre adopts a five‐coordinate geometry, ligated by the two phenanthroline N atoms, two amine N atoms of the hist­amine ligand (one aliphatic and one from the imidazole ring) and a chloro ligand. The geometry around the Cu atom is a distorted compressed trigonal bipyramid, with one phenanthroline N and one imidazole N atom in the axial positions, and the other phenanthroline N atom, the histamine amine N atom and the chloro ligand in the equatorial positions. The structure includes an uncoordinated water mol­ecule, and a Cl⁻ ion to complete the charge. The water mol­ecule is hydrogen bonded to both Cl⁻ ions (coordinated and uncoordinated), and exhibits a close Cu⋯H contact in the equatorial plane of the bipyramid.     

Ab initio study of C4H3 potential energy surface and reaction of ground‐state carbon atom with propargyl radical

The potential energy surface for the reaction of the ground‐state carbon atom [C(³P_j)] with the propargyl radical [HCCCH₂(X²B₁)] is investigated using the G2M(RCC,MP2) method. Numerous local minima and transition states for various isomerization and dissociation pathways of doublet C₄H₃ are studied. The results show that C(³P_j) attacks the π system of the propargyl radical at the acetylenic carbon atom and yields the n‐C₄H₃(²A′) isomer i3 after an 1,2‐H atom shift. This intermediate either splits a hydrogen atom and produces singlet diacetylene, [HCCCCH ( p1 )+H] or undergoes (to a minor amount) a 1,2‐H migration to i‐C₄H₃(²A′) i5 , which in turn dissociates to p1 plus an H atom. Alternatively, atomic carbon adds to the triple C?C bond of the propargyl radical to form a three‐member ring C₄H₃ isomer i1 , which ring opens to i3 . Diacetylene is concluded to be a nearly exclusive product of the C(³P_j)+HCCCH₂ reaction. At the internal energy of 10.0 kcal/mol above the reactant level, Rice–Ramsperger–Kassel–Marcus calculations show about 91.7% of HCCCCH comes from fragmentation of i3 and 8.3% from i5 . The other possible minor channels are identified as HCCCC+H₂ and C₂H+HCCH. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1522–1535, 2001     

N‐Benzylnicotinamide and N‐benzyl‐1,4‐dihydronicotinamide: useful models for NAD+ and NADH

3‐Aminocarbonyl‐1‐benzylpyridinium bromide (N‐benzylnicotinamide, BNA), C₁₃H₁₃N₂O⁺·Br⁻, (I), and 1‐benzyl‐1,4‐dihydropyridine‐3‐carboxamide (N‐benzyl‐1,4‐dihydronicotinamide, rBNA), C₁₃H₁₄N₂O, (II), are valuable model compounds used to study the enzymatic cofactors NAD(P)⁺ and NAD(P)H. BNA was crystallized successfully and its structure determined for the first time, while a low‐temperature high‐resolution structure of rBNA was obtained. Together, these structures provide the most detailed view of the reactive portions of NAD(P)⁺ and NAD(P)H. The amide group in BNA is rotated 8.4 (4)° out of the plane of the pyridine ring, while the two rings display a dihedral angle of 70.48 (17)°. In the rBNA structure, the dihydropyridine ring is essentially planar, indicating significant delocalization of the formal double bonds, and the amide group is coplanar with the ring [dihedral angle = 4.35 (9)°]. This rBNA conformation may lower the transition‐state energy of an ene reaction between a substrate double bond and the dihydropyridine ring. The transition state would involve one atom of the double bond binding to the carbon ortho to both the ring N atom and the amide substituent of the dihydropyridine ring, while the other end of the double bond accepts an H atom from the methylene group para to the N atom.     

Hypervalent radical formation probed by electron transfer dissociation of zwitterionic tryptophan and tryptophan‐containing dipeptides complexed with Ca2+ and 18‐crown‐6 in the gas phase

The relationship between peptide structure and electron transfer dissociation (ETD) is important for structural analysis by mass spectrometry. In the present study, the formation, structure and reactivity of the reaction intermediate in the ETD process were examined using a quadrupole ion trap mass spectrometer equipped with an electrospray ionization source. ETD product ions of zwitterionic tryptophan (Trp) and Trp‐containing dipeptides (Trp‐Gly and Gly‐Trp) were detected without reionization using non‐covalent analyte complexes with Ca²⁺ and 18‐crown‐6 (18C6). In the collision‐induced dissociation, NH₃ loss was the main dissociation pathway, and loss related to the dissociation of the carboxyl group was not observed. This indicated that Trp and its dipeptides on Ca²⁺(18C6) adopted a zwitterionic structure with an NH₃⁺ group and bonded to Ca²⁺(18C6) through the COO^? group. Hydrogen atom loss observed in the ETD spectra indicated that intermolecular electron transfer from a molecular anion to the NH₃⁺ group formed a hypervalent ammonium radical, R‐NH₃, as a reaction intermediate, which was unstable and dissociated rapidly through N–H bond cleavage. In addition, N–C_α bond cleavage forming the z₁ ion was observed in the ETD spectra of Trp‐GlyCa²⁺(18C6) and Gly‐TrpCa²⁺(18C6). This dissociation was induced by transfer of a hydrogen atom in the cluster formed via an N–H bond cleavage of the hypervalent ammonium radical and was in competition with the hydrogen atom loss. The results showed that a hypervalent radical intermediate, forming a delocalized hydrogen atom, contributes to the backbone cleavages of peptides in ETD. Copyright © 2015 John Wiley & Sons, Ltd.     

Two Uranyl Complexes with Pyromellitic Acid. A Heterometallic Complex with U=O–CuII Interaction

Two uranyl complexes based on pyromellitic acid were hydrothermally synthesized, and their X‐ray single‐crystal diffraction structures were determined. Complex [UO₂(Hbtec)]^–(Himd)⁺ · H₂O ( 1 ) (H₄btec = pyromellitic acid, imd = imidazole), is an ionic complex, which shows a typical (4, 4) topological structure in the space. A heterometallic complex, UO₂Cu(btec)(phen) ( 2 ) (phen = 1,10‐phenanthroline) results from the reaction of uranyl nitrate and copper(II) bromide with pyromellitic acid. The structure of complex 2 revealed that the chains of UO₇ and CuO₃N₂ units were connected to each other through the carboxyl groups and U=O–Cu interactions to create a two‐dimensional framework.     

Insights into Intramolecular Trp and His Side‐Chain Orientation and Stereospecific π Interactions Surrounding Metal Centers: An Investigation Using Protein Metal‐Site Mimicry in Solution

Metal‐binding scaffolds incorporating a Trp/His‐paired epitope are instrumental in giving novel insights into the physicochemical basis of functional and mechanistic versatility conferred by the Trp–His interplay at a metal site. Herein, by coupling biometal site mimicry and ¹H and ¹³C NMR spectroscopy experiments, modular constructs EDTA‐(L ‐Trp, L ‐His) (EWH; EDTA=ethylenediamino tetraacetic acid) and DTPA‐(L ‐Trp, L ‐His) (DWH; DTPA=diethylenetriamino pentaacetic acid) were employed to dissect the static and transient physicochemical properties of hydrophobic/hydrophilic aromatic interactive modes surrounding biometal centers. The binding feature and identities of the stoichiometric metal‐bound complexes in solution were investigated by using ¹H and ¹³C NMR spectroscopy, which facilitated a cross‐validation of the carboxylate, amide oxygen, and tertiary amino groups as the primary ligands and indole as the secondary ligand, with the imidazole (Im) N3 nitrogen being weakly bound to metals such as Ca²⁺ owing to a multivalency effect. Surrounding the metal centers, the stereospecific orientation of aromatic rings in the diastereoisomerism is interpreted with the Ca²⁺–EWH complex. With respect to perturbed Trp side‐chain rotamer heterogeneity, drastically restricted Trp side‐chain flexibility and thus a dynamically constrained rotamer interconversion due to π interactions is evident from the site‐selective ¹³C NMR spectroscopic signal broadening of the Trp indolyl C3 atom. Furthermore, effects of Trp side‐chain fluctuation on indole/Im orientation were the subject of a 2D NMR spectroscopy study by using the Ca²⁺‐bound state; a C? H2(indolyl)/C? H5(Im⁺) connectivity observed in the NOESY spectra captured direct evidence that the N? H1 of the Ca²⁺–Im⁺ unit interacted with the pyrrole ring of the indole unit in Ca²⁺‐bound EWH but not in DWH, which is assignable to a moderately static, anomalous, T‐shaped, interplanar π⁺–π stacking alignment. Nevertheless, a comparative ¹³C NMR spectroscopy study of the two homologous scaffolds revealed that the overall response of the indole unit arises predominantly from global attractions between the indole ring and the entire positively charged first coordination sphere. The study thus demonstrates the coordination‐sphere/geometry dependence of the Trp/His side‐chain interplay, and established that π interactions allow ¹³C NMR spectroscopy to offer a new window for investigating Trp rotamer heterogeneity near metal‐binding centers.     

A study of the planarity of the pyrrolone fragment in 2‐isopropyl‐2,3‐dihydro‐1H‐isoindol‐1‐one

Orthophthalaldehyde (o‐phthalaldehyde, OPA) is an aromatic dialdehyde bearing two electron‐withdrawing carbonyl groups. The reactions of OPA with primary amines are broadly applied for the synthesis of important heterocyclic compounds with biological relevance. A number of such reactions have been investigated recently and several structures of condensation products have been reported, however, the complex reaction mechanism is still not fully understood and comprises concurrent as well as consecutive reactions. The reaction products depend on the primary amine which reacts with OPA, the reaction environment (solvent) and the proportion of the reactants. The title molecule, C₁₁H₁₃NO, the product of the reaction of OPA with isopropylamine, contains a five‐membered pyrrole C₄N ring with a carbonyl substituent, which forms part of the isoindolinone unit. Though this pyrrole ring contains one C atom in the sp³‐hybridized state, it is fairly planar. The title molecule has been compared with similar structures retrieved from the Cambridge Structural Database in order to study this phenomenon. The planarity of this fragment has been explained by the presence of partially delocalized C—C, C—N and C—O bonds, and by an inner angle in the planar pentagonal ring (∼108°), which is close to the ideal tetrahedral value for the sp³‐hybridized state of the constituent C atom. Due to this propitious angle, this C atom can be present in states intermediate between sp³‐ and sp²‐hybridized in different structures, while still maintaining the planarity of the ring. There are only weak intermolecular C—H…O hydrogen bonds and C—H…π‐electron ring interactions in the structure. In particular, it is the pyrrole ring which is involved in these interactions.     

Dihydrogen Catalysis of the Reversible Formation and Cleavage of CH and NH Bonds of Aminopyridinate Ligands Bound to (η5‐C5Me5)IrIII

This study focuses on a series of cationic complexes of iridium that contain aminopyridinate (Ap) ligands bound to an (η⁵‐C₅Me₅)Ir^III fragment. The new complexes have the chemical composition [Ir(Ap)(η⁵‐C₅Me₅)]⁺, exist in the form of two isomers ( 1⁺ and 2⁺ ) and were isolated as salts of the BAr_F^? anion (BAr_F=B[3,5‐(CF₃)₂C₆H₃]₄). Four Ap ligands that differ in the nature of their bulky aryl substituents at the amido nitrogen atom and pyridinic ring were employed. In the presence of H₂, the electrophilicity of the Ir^III centre of these complexes allows for a reversible prototropic rearrangement that changes the nature and coordination mode of the aminopyridinate ligand between the well‐known κ²‐N,N′‐bidentate binding in 1⁺ and the unprecedented κ‐N,η³‐pseudo‐allyl‐coordination mode in isomers 2⁺ through activation of a benzylic C?H bond and formal proton transfer to the amido nitrogen atom. Experimental and computational studies evidence that the overall rearrangement, which entails reversible formation and cleavage of H?H, C?H and N?H bonds, is catalysed by dihydrogen under homogeneous conditions.     

3,5‐Bis(4‐methoxy­benzyl­idene)‐1‐methyl‐4‐piperidone and 3,5‐bis(4‐methoxy­benzyl­idene)‐1‐methyl‐4‐oxopiperidinium chloride: potential biophotonic materials

In the title compound 3,5‐bis(4‐methoxy­benzyl­idene)‐1‐methyl‐4‐piperidone, C₂₂H₂₃NO₃, (I), the central heterocyclic ring adopts a flattened boat conformation, while in the related salt 3,5‐bis(4‐methoxy­benzyl­idene)‐1‐methyl‐4‐oxopiperidin­ium chloride, C₂₂H₂₄NO₃⁺·Cl⁻, (II), the ring exhibits a `sofa' conformation in which the N atom deviates from the planar fragment. The pendant benzene rings are twisted from the heterocyclic ring planes in both mol­ecules in the same direction, the range of dihedral angles between the ring planes being 24.5 (2)–32.7 (2)°. The dominant packing motif in (I) involves centrosymmetric dimers bound by weak intermolecular C—H⋯O hydrogen bonds. In (II), cations and anions are linked by strong N—H⋯Cl hydrogen bonds, while weak C—H⋯O and C—H⋯Cl hydrogen bonds link the cations and anions into a three‐dimensional framework.     

Supramolecular patterns in benzyladeninium p‐toluenesulfonate

In the title compound (systematic name: 6‐benzylamino‐7H‐purin‐3‐ium p‐toluenesulfonate), C₁₂H₁₂N₅⁺·C₇H₇O₃S⁻, the adenine moiety exists as the N³‐protonated N⁷—H tautomer. The dihedral angle between the adenine ring system and the phenyl ring is 82.76 (11)°. Two of the sulfonate O atoms form C—H...O and N—H...O hydrogen bonds with the H atoms on the N and C atoms in the 3‐ and 8‐positions, respectively, of the adenine moiety, leading to a zigzag chain. Two antiparallel zigzag chains are linked by the remaining sulfonate O atom through Hoogsteen‐site H atoms (i.e. those on the N atoms in the 6‐ and 7‐positions) of the adenine moiety, leading to a double chain. An annulus formed by a pair of inversion‐related anions and cations has been identified. An intramolecular toluenesulfonate–phenyl C—H...π interaction is also present.