Diammonium Ions Research Articles

Dynamics of n-Alkylammonium Ions Intercalated in Saponite

Abstract Organo-clay composites of saponite intercalated with several kinds of n-alkylmono- and diammonium ions were prepared, and the dynamic properties of the intercalated cations were investigated by solid state NMR. It was found that the cationic motions are characterized by distributed correlation times due to an environmental inhomogeneity of the interlayer space of saponite.

Calorimetric Study of Ammonia Sorption on H4SiW12O40.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Calorimetric study of ammonia sorption on H4SiW12O40

Using a Microscal flow microcalorimeter, integral sorption and desorption enthalpies of ammonia on silicotungstic acid H4SiW12O40 dehydrated at 433 K and 483 K were determined. The quantitative coverage determination enabled us to estimate the amounts of the irreversibly as well as (much smaller) reversibly bonded ammonia at its equilibrium state in the gas phase (pNH3 = 1.01 kPa). It has been shown that irreversible sorption at 373 K results in the formation of NH4+ ions while at 298 K two NH3 molecules are adsorbed per one proton in heteropolyacids. This suggests the formation of an NH4+·NH3 adduct which is also present in N2H7I, the only known solid salt of a diammonium ion.

Crystal structure, DSC, IR and Raman studies in the compound NH 3(CH 2) 5NH 3HgCl 4

The penthylene-diammonium tetrachloromercurate (II) salt is triclinic centrosymmetric with the following unit cell dimensions: a= 7.7672(4) A ̊ , b= 7.9754(6) A ̊ , c= 10.9471(6) A ̊ , α= 98.915(2) o , β= 109.363(2) o and γ= 91.463(2) o with Z= 2. The structure consists of disordered penthylene-diammonium chains sandwiched between HgCl 6 octahedral layers. The chloromercurate sheet is packed as a result of hydrogen bonding to 1,5-penthylene diammonium ions. Ammonium groups at the ends of the chains fit into cavities of adjacent HgCl 4 layers and form N-H…Cl hydrogen bonds. Thermal analysis indicates a hysteresis phenomenon characteristic of a first order phase transition. The Raman and IR spectra of polycrystalline samples of NH 3(CH 2) 5NH 3HgCl 4 investigated at room temperature illustrate the conformational and statistical disorder of the organic chain. The system progressively gets ordered at low temperature, as the disorder of organic chains is due to a thermal effect.

Self-assembly directed by NH–O hydrogen bonding: new molecular assemblies derived from N, N-tetramethyl-1,2-diaminoethane and malonic or fumaric acid incorporating ‘proton transfered’ hydrogen bonds

Co-crystallisation of N, N-tetramethyl-1,2-diaminoethane (TMEN) and malonic or fumaric acid from water in a 1:1 ratio results in crystalline products whose X-ray structures show that they contain hydrogen-bonded motifs in self-assembled arrays. The stoichiometry of the malonate-containing assembly is 1:2, [TMENH 2(hydrogen malonate) 2], while that of the fumarate-containing assembly is 1:1:1 (TMENH 2, fumarate, fumaric acid). In each structure, protons from individual carboxylic acids have been transferred onto the nitrogens of N, N-tetramethyl-1,2-diaminoethane (TMEN) to yield diammonium cations; the ammonium protons hydrogen bond to carboxylate oxygens of hydrogen malonate in one case or to fumarate anions in the other. The hydrogen malonate-containing structure has layers of aligned diprotonated TMEN separated by layers of hydrogen malonate anions. Successive hydrogen malonate ions are hydrogen bound in an 'alternate’ manner between adjacent protonated TMEN layers. Each [TMENH 2(hydrogen malonate) 2] moiety describes an approximate 'Z’ configuration which are in turn stacked at an oblique angle; adjacent ‘columns of Zs’ are partially interlaced to form the overall array. The fumarate-containing structure consists of parallel ribbons of alternating, hydrogen bonded, fumarate dianions and fumaric acid molecules. These form layers alternating with layers of diammonium ions which lie essentially in the xy plane. The diammonium ions form parallel staggered head-to-tail chains along the y axis and so run at an angle across the fumarate-fumaric acid ribbons.

Ion Association of Primary Ammonium Ions with Aromatic Anions by Capillary Zone Electrophoresis

Abstract Ion associability of some alkylammonium-type ion association reagents with the positional isomers of aromatic anions has been examined in an aqueous solution through electrophoretic mobility changes of the corresponding anions in capillary zone electrophoresis. Ion associability of the alkylammonium ions was investigated for monovalent and divalent cationic groups, considering the hydrophilicity and hydrophobicity of cationic groups and the hydration of the ionic sites. When such monovalent cationic reagents as hexylmethylammonium, hexyltrimethylammonium, and hexyltriethylammonium ions were used, the ion associability increased with an increase in the number and bulkiness of alkyl groups of the cations. On the other hand, hexylammonium ion, a primary ammonium ion, showed different behavior: Higher ion associability was obtained with aromatic anions possessing two carboxylate groups at adjacent positions. Also ion associability of the primary diammonium ions with phthalate and naphthalene-2,3-dicarboxylate ions was the highest among their positional isomers, which was the reverse behavior from that obtained with quaternary diammonium ions. Such characteristic ion associability in the primary ammonium ions could be explained from the hydrophilicity of the ionic groups of the pairing ions: A primary ammonium group is more ion associable with hydrophilic anionic groups.

Unique "cradled barbell" complex between a secondary diammonium ion and bis(m-phenylene)-32-crown-10.

[formula: see text] The complexation between N,N'-dibenzyl(m-xylylene)diammonium bis(hexafluorophosphate) (2) and bis(m-phenylene)-32-crown-10 (5) was shown to occur in solution by nuclear magnetic resonance with 1:1 stoichiometry and a Ka value of 189 +/- 19 M-1. A crystal structure of 2:5 revealed a unique 1:1 "exo" or "cradled barbell" complex, instead of the expected pseudorotaxane. This unexpected result illustrates that caution be used in interpreting the results from these types of complexes in the solution and "gas" phases on the basis of crystal structures.

Polyrotaxanes and pseudopolyrotaxanes of polyamides and cucurbituril

Pseudopolyrotaxanes and polyrotaxanes of polyamide and the macrocycle cucurbituril are synthesized easily by interfacial polycondensation. With different diammonium ions and diacid chlorides a great variety of poly(amide rotaxane)s is obtained. The structure of the diacid chloride influences the possible motion of cucurbituril on the polymer chain. First attempts to characterize these polyrotaxanes using IR, DTA, 1H-NMR and elemental analyses are reported.

Microcalorimetric titration of a tetra- p-sulphonated calix[4]arene with α, ω-alkyl diammonium ions in an aqueous solution

25,26,27,28-Tetrahydroxycalix[4]arene-5,11,17,23-tetrasulphonate was in a heat-conduction calorimeter titrated with α, ω-alkyl diammonium ions, +H 3N(CH 2) n NH + 3 n=(3–7), in an aqueous solution at pH 7.1. Apparent concentration binding constants ( K c) and enthalpy changes are reported for a 1 : 1 binding model at minimized concentration ranges. The standard Gibbs energy change, Δ G 0=− RTln K c, has a non-linear dependence of the alkyl chain length, n. The interaction is strongest at n≥5. A similar trend is observed for the enthalpy change. However, the fit of the experimental data to the 1 : 1 model was quite poor and neither 1 : 2 nor 2 : 1 models gave any further improvement. Concentration-dependent results were also obtained. It is therefore concluded that the interaction observed is more complex.

Complexes of cucurbituril with alkyl mono- and diammonium ions in aqueous formic acid studied by calorimetric titrations

The thermodynamic data of the complexation reaction between the ligand cucurbituril and different alkylmonoamine and alkyldiamine hydrochlorides have been studied in aqueous formic acid. The stability constants, the reaction enthalpies and the reaction entropies are obtained from calorimetric titrations. At both rims of the cavity of cucurbituril the carbonyl groups interact with ions by ion-dipole interactions. If ammonium ions with longer alkyl chains enter the hydrophobic cavity of cucurbituril hydrophobic interactions participate in the complex formation. The hydrophobic contribution to the reaction enthalpy is calculated for the alkyl monoammonium ions. In 50% (v/v) formic acid the enthalpies of the hydrophobic interactions contribute more to the experimental reaction enthalpy than the ion-dipole interactions.

Extended Conformation of Putrescine Occurring on a Center of Symmetry in its 1:2 Complex with Malonic Acid

The 1,4-butane diammonium (putrescine) ion co-crystalizes with propanedioic acid (malonic acid) monoanions in space group Pcab (1,4-butane diammonium hydrogen propanedioate, (C4H14N2)2+.2(C3H3O4)−). One of the carboxylate moieties of malonic acid is protonated. The asymmetric unit of the crystal contains one molecule of malonic acid and half a molecule of putrescine. All three H atoms of the putrescine amino groups participate in hydrogen bonding.

ChemInform Abstract: Functionalized Basket‐Shaped Hosts. Synthesis and Complexation Studies with (Alkali) Metal and Ammonium and Diammonium Ions.

AbstractThe basket‐shaped hosts such as (IIIa) are prepared by reaction of the concave building block (I) with primary amines such as (II).

Functionalized basket-shaped hosts. Synthesis and complexation studies with (alkali) metal and ammonium and diammonium ions

Functionalized basket-shaped hosts have been synthesized from the concave building block 1,3:4,6-bis(3,6-dihydroxy-1,2-xylylene)tetrahydro-3a,6a-diphenylimidazo[4,5-d]imidazole-2,5(1H,3H)-dione (1). To this end, N-substituted 1,4,10,13-tetraoxa-7-azatridecamethylene bridges were attached to the 3,6- and 3',6'-positions of the xylylene rings of 1. The substituents at the nitrogen atom in the bridge include: 5-hydroxy-3-oxapentyl, benzyl, hydrogen, 5-(N-(benzyloxycarbonyl)-L-histidyl)-3-dioxapentyl, and 5-acetyl-3-oxapentyl. The baskets complex alkali metal and ammonium guests, as well as aliphatic and aromatic diammonium guests, all in a 1:1 ratio. Using the picrate extraction technique, free energies of binding for the new hosts with 19 guests were determined. Extremely strong binding (-ΔG° values up to 18 kcal mol −1 ) was observed for the complexes between the hosts and o-phenylenediammonium dipicrate. The host with histidyl substituents easily forms a 1:1 complex with Zn(OTf) 2

The crystal structure of Di (propan(1, 3)diammonium) divanadate

Di (propan(1, 3)diammonium) divanadate has been synthesized and the structure determined from single crystal diffractometer data. (NH 3(CH 2) 3NH 3) 2 2+ (V 2O 7) 4− 3H 2O has been prepared by dissolving V 2O 5 in an aqueous solution of propan(1, 3)diamin. The unit cell is triclinic, space group P1̄, a = 9.402(1), b = 13.204(2), c = 8.300(1) A ̊ , α = 90.39(1), β = 116.16(1) and γ = 107.47(1)°; Z = 2. Final R and wR are 0.033 and 0.050, respectively. Isolated divanadate anions are arranged in sheets nearly parallel to the ac-plane. Furthermore, within these sheets the water molecules are also located. The divanadate group shows a staggered configuration and hence, the structure belongs to the thortveitite structure type. Between the V 2O 7 sheets the two propan(1, 3)-diammonium molecules are situated. The structure is held together by hydrogen bonds between the water molecules and from water and propan(1, 3)diammonium to vanadate oxygen atoms. Each propan(1, 3)-diammonium ion connects four divanadates via hydrogen bonds, two V 2O 7 above and below the propan(1, 3)diammonium.

Mixed substrate supermolecules: binding of organic substrates and of metal ions to heterotopic coreceptors containing porphyrin subunits

The macroteracyclic and macropentacyclic compounds (1)–(3), which combine porphyrin rings and [18]-N2O4aza-oxamacrocycles as substrate selective binding subunits, complex diammonium ions +H3N–[CH2]n–NH3+(anchored to the [18]-N2O4sites and included in the central molecular cavity) and /or ZnIIions (bound to the porphyrin groups), thus yielding organic/inorganic mixed substrate supramolecular structures.

Equilibrium exchange selectivity of alkaline earth, quaternary ammonium, and alkane diammonium ions in the release of Co(pn) 33+ from H-Co(pn) 3-bentonite

The selectivity coefficients of the bivalent inorganic ions in the release of Co(pn) 3 3+ from H-Co(pn) 3-bentonite are found to be much lower than those of the organic ions studied. However, both the hydrated ionic radius and the Debye-Hückel parameter a 0 of the alkaline earth metal cations give linear correlation with the relative affinities of the ions for the clay surface. In the lower concentrations of the tetraalkylammonium ions the effectiveness of the exchange of Co(pn) 3 3+ is in the sequence (CH 3) 4N < (C 2H 5) 4N < (C 3H 7) 4N < (C 4H 9) 4N while the order is just reversed at higher concentrations of the ions in solution. This behavior has been attributed to the collapse of the silicate layers in suspension once a critical level of surface coverage by these large organic ions has been achieved. The exchanging ability of the long chain surface active ions and alkane diammonium ions increases with the chain length of the ions. This is probably due to the progressive increase in the magnitude of the van der Waals forces between the clay and the organic ions and changes in hydration of the ions in the clay interlayer. The comparatively smaller bivalent inorganic ions, tetraalkylammonium and alkane diammonium ions desorb a much greater amount of Co(pn) 3 3+ from the clay matrix than the larger cetyltrimethylammonium or cetyl pyridinium ions. The lower displacement of Co(pn) 3 3+ could be caused due to the blocking of some of the exchange sites by the long chain surface active ions lying flat onto the clay surface.

Regulation of n-acetylglucosamine uptake in yeast

Various yeasts have been investigated for their ability to grow on N-acetylglucosamine as the sole carbon source and only those which are associated with the disease, candidiasis, gave positive results. The yeasts unable to grow on N-acetylglucosamine lacked the capacity to transport the aminosugar across the cell membrane. In pathogenic yeasts, two systems of different affinity for substrate were found to operate in the uptake of N-acetylglucosamine. In glucose-grown cells a constitutive, low affinity uptake system was present, but upon addition of inducer, a specific high affinity uptake system was synthesized. Experiments with the inhibitors of macromolecule synthesis suggested that the synthesis of RNA and protein is necessary for induction whereas the synthesis of DNA is not. In glucose-grown Candida albicans cells which are devoid of N-acetylglucosamine enters into the cells as phosphorylated form using a constitutive uptake system. Uranyl acetate (0.01 mM) which binds to cell membrane-associated polyphosphates, inhibited completely the inducible uptake of N-acetylglucosamine. Labelling experiments, designed to determine the temporal sequence of appearance of N-acetylglucosamine in intracellular free sugar and sugar-phosphate pools, indicated that N-acetylglucosamine first appeared in the cells as phosphorylated form. Similar results were obtained with Saccharomyces cerevisiae 3059 and some other yeasts which are devoid of N-acetylglucosamine kinase in both uninduced and induced conditions. These results are consistent with the model of van Steveninck that involves phosphorylation during transport. Furthermore, inhibitors of energy metabolism (arsenate, azide and cyanide), proton conductor ( m-chlorocarbonylcyanide phenylhydrazine) and dibenzyl diammonium ion (membrane permeable cation) inhibited the inducible N-acetylglucosamine uptake in C. albicans.

A neutron diffraction study of the crystal structures and magnetic studies of (NH 3CH 2CH 2CH 2NH 3)MnCl 4 and (NH 3CH 2CH 2NH 3)FeCl 4: Layer structures with two-dimensional magnetic interactions

The crystal structure of the 1,3-propylenediammonium chloride salts of two divalent transition metals, Fe 2+ and Mn 2+. is reported. The isomorphous compounds crystallize in the orthorhombic space group Imma with lattice constants a = 7.108, b = 18.57, and c = 3.378 A and a = 7.172, b = 19.00, and c = 7.361 A, respectively. Data were collected on an automated neutron diffraction instrument at the Argonne CP-5 reactor for all reflections with 2θ < 110° and 2θ < 100° respectively (λ = 1.141 A). The structure parameters were refined by a least squares process to R 1 = 0.096 and 0.091. The structures consist of two-dimensional metal-halogen networks interleaved by layers of the diammonium ions. The metal ions have compressed octahedral geometry with the two shorter M-Cl bonds nearly perpendicular to the layer. (Fl-CL = 2.404 A and Mn-Cl = 2.491 A), and the four longer bonds in the layer (Fe-Cl = 2.573 A and Mn-Cl = 2.584 A) The bridging M-Cl-M angle is 169.1° and 167.7° for the ferrous and manganous salt respectively. The diammonium ions are disordered and have a large librational thermal motion about the long axis of the ion. A broadline NMR study of the manganese salt indicates that this disorder is of a dynamic nature at room temperature. Evidence for the two-dimensional nature of the magnetic interactions in these salts is presented, based on the angular dependence of the EPR line widths. In both compounds, this dependence is given by Δ H pp = a + b (3 cos 20–1) + c(3cos 2-–1) 2. The zero field magnetic susceptibility for the manganese salt is reported.

Infrared spectra and rotational isomerism of ethylenediammonium ion in aqueous solution

The infrared spectra of ethylenediamine hydrochloride, sulfate and their N-deuterium derivatives in water or heavy water were studied at various pH or pD and at various concentrations. The frequencies of the CH 2 deformation vibration bands in the region 1500-1250 dm −1 were found to be sensitive to the conformation of the ethlenediamine molecule and mono- and diammonium ions. The behaviors of these bands indicate that in aqueous solution the ethylenediamine molecule takes the gauche form, the ethylenemonoamine monoammonium ion takes mostly the gauche form and the ethylenediammonium ion takes both the trans and gauche forms.

PH-dependence of the ceruloplasmin catalyzed oxidation of dimethyl-p-phenylenediamine.

1 The steady-state rate equation for the ceruloplasmin catalyzed oxidation of dimethyl-p-phenylenediamine (DPD) was found to be of the first degree with respect to substrate concentrations. Apparent kinetic coefficients for this substrate and its stable radical DPD+ were determined over the range pH 4.5–6.0. 2 Acid-base titrations established that the diammonium ion dimethyl-p-phenylenediamine 2 H+ titrated as a dibasic acid, and that DPD+ has ampholytic properties. Equilibrium constants were determined for the different proton dissociation steps. 3 Examination of the pH-dependence of the apparent kinetic coefficients provided evidence that four substrate forms affect the rate equation in the ceruloplasmin-DPD system. 4 Maximum activities appeared to be identical for the four substrates, and were found to decrease with pH in a way suggesting that a histidyl residue is involved in the rate-determining step of the enzymatic process. 5 K m-values appeared to be independent of pH over the range 4.5–6.0, but were shown to vary exponentially with the energy of the highest occupied molecular orbital of the substrates.