Diammonium Cations Research Articles

Computational investigation of the hydration of alkyl diammonium cations in water clusters

The hydration behavior of α,ω-alkyl diammonium cations of varying alkyl chain length in water clusters has been investigated with molecular dynamics simulations. The OPLS force field was validated against high-level quantum-chemistry results and experimental data and subsequently used to describe the interatomic interactions in the simulations. The results were further validated with simulations performed with approximate density-functional theory (DFTB3). Surface solvation structures are found to be the most stable, accompanied by considerable ion conformational changes, especially in the case of longer dications. This work demonstrates that, depending on their structure, doubly charged cations may have a high affinity towards aqueous interfaces.

Deprotonation of resorcinarenes and novel ammonium salt complexes

The bowl shape cavity of resorcinarenes usually stabilized by four intramolecular hydrogen bonds offers an interesting array of binding modes such as C–H...π and cation...π interactions to recognize a variety of guests. The multiple hydroxyl groups can participate in a series of intermolecular hydrogen bonds with guest molecules. This unique cone conformation of resorcinarenes has led to the synthesis of many receptors with convergent arrangement of binding sites suitable for molecular recognition in many applications. Unfunctionalized resorcinarenes are known to easily form molecular complexes with guests of varying shapes and sizes. Amines are very common bases used in many catalytic processes. A good example is the use of amines as bases in the alkylation and acylation of resorcinarenes leading to cavitands, carcerands, hemicarcerands and velcrands. The use of amines in such reactions is to deprotonate the resorcinarene hydroxyl groups, hence facilitating the alkylation and acylation processes. The subsequently protonated ammonium cation then forms interesting supramolecular complexes with the anionic and dianionic resorcinarenes. Furthermore, secondary and tertiary ammonium salts possess hydrogen bond donating -NH2 and -NH respectively and these can further enhance their complexation through intermolecular hydrogen bonds. Here we present our recent examples of supramolecular assemblies resulting from the deprotonation of resorcinarenes by mono- and dibasic amines. Also, our latest supramolecular co-crystals between resorcinarenes as the receptors and a series of secondary and tertiary mono- and diammonium cations are illustrated.

Ionothermal synthesis of a new open-framework manganese(II) diphosphate

A novel open-framework manganese diphosphate compound, [NH3(CH2)2NH3][MnP2O7], denoted as JIS-13 (Jilin Ionothermal Synthesis-13), has been ionothermally synthesized by using a eutectic mixture of tetramethylammonium chloride and 2-imidazolidone as the solvent and template-delivery agent, which in situ yields ethylene diammonium cations (en2+) as the template. The structure of JIS-13 is determined by single-crystal X-ray diffraction and further characterized by powder X-ray diffraction (PXRD), inductively coupled plasma (ICP), thermogravimetric (TG), elemental analyses, X-ray photoelectron spectroscopy (XPS) and magnetic measurements. The alternation of MnO5 trigonal bipyramids and P2O7 units linking through their vertices forms the three-dimensional (3-D) open framework of JIS-13, which comprises 12-ring channels along the [100] direction. Protonated en2+ cations act as the templates to compensate the negative charges of the inorganic framework. Magnetic measurements reveal that weak antiferromagnetic interaction exists in JIS-13.

Complexation mechanism of cucurbit[6]uril with hexamethylene diammonium cations in saline solution.

Binding of cucurbit[6]uril (CB[6]) with the hexamethylene diammonium cation (HD(2+)) in the presence of sodium ions is elucidated at the atomic level. The most probable complex of CB[6] in saline solution is found to be CB[6]:Na(+). A two-stage binding process of CB[6]:Na(+) with HD(2+) is proposed.

N,N,N′,N′-Tetramethylethylenediammonium tetrachloridozincate

The asymmetric unit of the title compound, (C6H18N2)[ZnCl4], consists of one tetra­chlorido­zincate anion and two half-N,N,N′N′-tetra­methyl­ethylenedi­ammonium cations. Each of the two di­ammonium cations is located about an inversion center and one of them is disordered over two sets of sites in a 0.780 (17):0.220 (17) ratio. The ZnII atom has a slightly distorted tetra­hedral coordination environment. The cations and anions are connected via N—H⋯Cl hydrogen bonds into chains extending along [0-11].

(2R,2′S)-2,2′-Bipiperidine-1,1′-diium dibromide

The title compound, C10H22N2 2+·2Br−, was synthesized via reduction of 2,2′-dipyridyl with Ni–Al alloy/KOH, followed by separation of diastereoisomers (meso and rac) by recrystallization from ethanol. Although the two bridging C atoms are optically active, these two chiral centers adopt an (S,R) configuration; thus, the title compound contains an achiral meso form of 2,2′-bi­piperidine. Both of the piperidinium rings adopt chair conformations, and the two N atoms are trans to each other; an inversion center is located in the mid-point of the central C—C bond. The conformation of the organic moiety resembles that of 1,1′-bi(cyclo­hexa­ne). The organic di­ammonium cations are linked to each other through hydrogen bonding with bromide counter-ions, each of which forms two hydrogen bonds (N—H⋯Br) with two adjacent organic cations, thus linking the latter together in sheets parallel to (100).

Synthesis and characterization of vanadium ions containing chlorocadmiumphosphate CdHPO4Cl·[H3N (CH2)6NH3]0.5 crystals

VO2+ ions doped chlorocadmiumphosphate, CdHPO4Cl·[H3N(CH2)6NH3]0.5 crystals were synthesized at room temperature by using an organic amine, Hexa Methylene Di Amine as a templating molecule. The prepared crystals were characterized by powder XRD and several spectroscopic techniques. The powder XRD data was indexed to monoclinic crystal system with the lattice parameters, a=0.429, b=0.772, c=1.622nm and β=114.3°. The nature of doped VO2+ ions in the framework material has been identified by optical absorption and electron paramagnetic resonance techniques. FT-IR spectrum exhibited the characteristic vibrations of phosphate anions and hexane diammonium cations. Thermal studies revealed that the prepared crystals withstand its state up to 307°C. EPR and optical absorption spectrum confirmed that the doped VO2+ ions entered the complex material as distorted octahedral site symmetry. The evaluated bonding parameters revealed a partial covalent bonding between the doped metal ions and ligands.

Lead halide inorganic–organic hybrids incorporating diammonium cations

Diammonium cations of general formula (H3N–R–NH3) have been used as templating moieties on lead(II) halide motifs, forming a variety of inorganic–organic nanocomposites. The R group can have simple, straight alkyl chains, which if even-membered and greater than ethane, form 2-D layers based on the RbAlF4 structure type, as found in [(H3N(CH2)4NH3)PbBr4] (1), [(H3N(CH2)4NH3)PbI4] (2), [(H3N(CH2)8NH3)PbI4] (4), [(H3N(CH2)10NH3)PbBr4] (5), and [(H3N(CH2)12NH3)PbI4] (6). If the R group has fused aromatic rings like naphthalene, the 2-D layered perovskite-type motif is still adopted, as in [(H3NC10H6NH3)PbI4] (7). If the chain is odd-membered, a 0-D inorganic motif, consisting of isolated blocks of face-sharing PbI6 octahedra and isolated iodide anions is seen, as in [(H3N(CH2)7NH3)4Pb3I12·2I−] (3). 1-D motifs, which have edge-sharing twin-anionic chains of corner-sharing ribbons are also observed in the compounds [(H3NC2H4NH3)4PbBr4] (8) and [(H3NC6H4CH2C6H4NH3)PbI6] (9) respectively.

Erbium-formate frameworks templated by diammonium cations: syntheses, structures, structural transition and magnetic properties

Two structurally different Er-formate frameworks, one NaCl-like [dmenH(2)][Er(HCOO)(4)](2) (1) and the other pillared-layer type [tmenH(2)][Er(HCOO)(4)](2) (2), were obtained when templated by the corresponding protonated N,N'-dimethylethylenediamine (dmenH(2)) and N,N,N',N'-tetramethyl- ethylenediamine (tmenH(2)). The shape and size of the template cations dictate the different coordination geometries of erbium and consequently the framework topologies, though erbium adopts eight coordination in the two compounds. In the NaCl-like structure of 1, erbium is coordinated by eight anti-anti bridging formates in a square antiprism, while in the pillared-layer structure of 2, it is coordinated by six anti-anti bridging formates and one chelating formate in a pentagonal bipyramid. 2 exhibits a structural phase transition around -70 °C which is related to the disorder-order transition of the template cation. Both compounds behave as paramagnets between 2 and 300 K. However, they display field-dependent ac-susceptibilities with complicated field-induced magnetic relaxation processes, and the major slow ones probably results from spin-lattice relaxation.

Synthesis, crystal structures and anticancer activities of two decavanadate compounds

Two ammonium decavanadate(V) compounds, (H2tmen)3V10O28·6H2O (1) and (H2en)3V10O28·2H2O (2), where H2tmen and H2en represent the doubly protonated N,N,N′,N′-tetramethylethylenediammonium ion and doubly protonated ethylenediammonium ion, respectively, have been synthesized and structurally characterized by elemental analyses, spectroscopic (i.r., e.s.r.) studies, and single-crystal X-ray diffraction. Both crystal structures reveal the presence of the [V10O28]6− cluster anions, doubly protonated diammonium cations, and lattice water molecules. Hydrogen bonds assemble these two compounds to form three-dimensional networks. The in vitro anticancer activity against A549 and P388 tumor cells lines has also been determined by the MTT-based assay, and the results suggest that both compounds can inhibit proliferation of these two kinds of tumor cells.

Poly[1,4-bis(ammoniomethyl)cyclohexane [di-μ-chlorido-dichloridoplumbate(II)

The title compound, {(C8H20N2)[PbCl4]}n, crystallizes as an layered inorganic–organic hybrid perovskite-type structure. Corner-sharing PbCl6 octa­hedra extend parallel to the ac plane. Adjacent layers are staggered relative to one another, with diammonium cations separating these layers. The cations exhibit symmetry and inter­act with the inorganic sheets via N—H⋯Cl hydrogen bonding in the right-angled halogen sub-type of the terminal halide hydrogen-bonding motif.

Poly[1,4-bis(ammoniomethyl)cyclohexane [di-μ-bromido-dibromidoplumbate(II)

The title compound, {(C8H20N2)[PbBr4]}n, crystallizes as an inorganic–organic hybrid with alternating layers of diammonium cations and two-dimensional corner-sharing PbBr6 octa­hedra extending parallel to the bc plane, which are eclipsed relative to one another. Both PbBr6 octa­hedra and the organic cation exhibit symmetry. The cations inter­act via N—H⋯Br hydrogen bonding in the right-angled halogen sub-type of the terminal halide hydrogen-bonding motif.

Synthesis, structure, and cation complexation of a novel crown ether porphyrin

A new porphyrin appended with four crown ether units at meso-positions via an acetylene bridge was synthesized and structurally characterized, and its complexation with a variety of metal and diammonium cations was investigated.

Tetrachloroferrate(III) Complexes of some Organic Diammonium Cations: Structures and Magnetic Properties

With aqueous acidic iron(III) chloride, the three diamines ethylenediamine (en), tetramethylethylenediamine (tmeda) and 4:4′-tetramethyldiaminodiphenylmethane (ddmp) yield the aquapentachloroferrate(III) and a pair of [FeCl4]− Cl− double salts, respectively. Their structures indicate that N–H···Cl hydrogen bonding is present, but the Fe···Fe distances are all quite long. The magnetic data show that, while all the materials display antiferromagnetic coupling on cooling, in none of the cases was any transition observed above 1.8 K.

New Three‐Dimensional (3,4)‐Net Zincophosphites Templated by Linear Diammonium Cations: H3N (CH2)5NH3×Zn3 (HPO3)4 and β‐H3N (CH2)6NH3×Zn3 (HPO3)4.

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New three-dimensional (3,4)-net zincophosphites templated by linear diammonium cations: H 3N(CH 2) 5NH 3·Zn 3(HPO 3) 4 and β-H 3N(CH 2) 6NH 3·Zn 3(HPO 3) 4

The mild-condition syntheses, single-crystal structures and properties of H 3N(CH 2) 5NH 3·Zn 3(HPO 3) 4 and β-H 3N(CH 2) 6NH 3·Zn 3(HPO 3) 4 are reported. Both are constructed from (3,4)-nets of ZnO 4 tetrahedra and HPO 3 pyramids, sharing vertices to result in three-dimensional anionic open-frameworks. In both materials, the organic species interacts with the framework by way of N–H⋯O bonds. Crystal data: H 3N(CH 2) 5NH 3·Zn 3(HPO 3) 4, M r = 620.22, orthorhombic, Pccn (No. 56), a = 9.5364 (9) Å, b = 21.8015 (19) Å, c = 9.1118 (7) Å, V = 1894.4 (3) Å 3, Z = 4, R( F) = 0.044, wR( F 2) = 0.111. β-H 3N(CH 2) 6NH 3·Zn 3(HPO 3) 4, M r = 634.25, monoclinic, P2 1/ n (No. 14), a = 8.7627 (1) Å, b = 13.8117 (2) Å, c = 16.6187 (3) Å, β = 92.680 (1)°, V = 2009.12 (5) Å 3, Z = 4, R( F) = 0.072, wR( F 2) = 0.187.

Hydrothermal Synthesis, Crystal Structure, Spectroscopic and Magnetic Properties of (C3H12N2)0.75 [FeII1.5FeIII1.5 (AsO4)F6

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Hydrothermal Synthesis, Crystal Structure, Spectroscopic and Magnetic Properties of (C3H12N2)0.75[FeII1.5FeIII1.5(AsO4)F6

AbstractA new iron(II)‐iron(III) mixed valence fluoro‐arsenate compound templated by propanediammonium cations has been synthesized by using mild hydrothermal conditions. The crystal structure has been solved from single‐crystal x‐ray diffraction data. This phase crystallizes in the Imam space group with the unit‐cell parameters a = 7.566(2), b = 11.034(3) and c = 13.233(5) Å. The compound exhibits a three‐dimensional framework constructed from two kinds of chains which delimit cavities in which the pro pane diammonium cations are located. Mössbauer and diffuse reflectance spectroscopies confirm the presence of Fe(II, III) mixed valence cations and the existence of slightly distorted octahedral environments for the metallic centres. Magnetic measurements indicate the existence a three‐dimensional antiferromagnetic ordering at 6 K. However, at low temperatures, a small hysteresis loop is observed. The values of the remanent magnetization and coercitive field are 400 emu/mol and 1180 G, respectively. These results are in good agreement with the existence of a ferromagnetic component due to a spin descompensation by the mixed valence nature of this phase.

Novel double layer salts of copper(I) bromide with N-substituted ethylenediammonium cations.

The structures of three hybrid organic/inorganic halometalate salts are reported, and the layer structures developed are contrasted. Crystal structures of the isostructural N-methylethylenediammonium (MEDA(2+)) and N-ethylethylenediammonium (EEDA(2+)) salts of copper(I) bromide are both triclinic, space group P1, with lattice constants a = 6.284(7), b = 7.842(6), and c = 12.03(1) A, alpha = 84.84(3), beta = 83.08(2), and gamma = 88.00(3) degrees, and V = 586(1) A(3) with Z = 2 for (MEDA)Cu(2)Br(4) while (EEDA)Cu(2)Br(4) has lattice constants a = 6.27(2), b = 7.78(2), and c = 13.12(3) A, alpha = 84.69(4), beta = 78.18(3), and gamma = 88.17(7) degrees, and V = 623(3) A(3) with Z = 2. The dominant inorganic feature in both salts is anionic (CuBr(2))(n)(n-) chains of edge-shared CuBr(4) tetrahedra. The diammonium cations hydrogen bond these chains together into a unique double layer structure. For comparison purposes, the crystal structure of (CHA)PbBr(3) (CHA(+) = cyclohexylammonium) is reported (monoclinic, space group P2(1)/n, a = 8.088(2) A, b = 7.912(2) A, and c = 19.572(4) A, beta = 96.98(4) degrees, and V = 1243.2(4) A(3) with Z = 4). This contains (PbBr(3))(n)(n-) halometalate chains, this time of face-shared PbBr(6) octahedra. However, here the organic cations tie the chains together into the more common single layer structure.

A comparative structural study of four para-sulphonato-calix-[4]-arene organic di- and triammonium cation complexes

The solid state structures of the complexes of para-sulphonato-calix-[4]-arene with putrescine, cadaverine, cis-1,2-cyclohexanediamine and spermidine have been determined. Di- or triammonium cations are included in the calix-[4]-arene molecular cavity and are held in place by hydrogen bonds and hydrophobic interactions. In two of the compounds, diammonium cations are present external to the cavity and are clathrated in tubes formed by the para-sulphonato-calix-[4]-arene network. All four structures show the classic bilayer “organic clay” packing arrangement of opposing para-sulphonato-calix-[4]-arene molecules, with either capsules for the linear diammonium cations, or slipped pairs for the bulky cis-cyclohexane diammonium and triammonium cations.