Hydrate Of Salt Research Articles

First crystal structure of a Pigment Red 52 compound: DMSO solvate hydrate of the monosodium salt.

Pigment Red 52, Na2[C18H11ClN2O6S], is an industrially produced hydrazone-laked pigment. It serves as an inter-mediate in the synthesis of the corresponding Ca2+ and Mn2+ salts, which are used commercially for printing inks and lacquers. Hitherto, no crystal structure of any salt of Pigment Red 52 is known. Now, single crystals have been obtained of a dimethyl sulfoxide solvate hydrate of the monosodium salt of Pigment Red 52, namely, monosodium 2-[2-(3-carb-oxy-2-oxo-1,2-di-hydro-naphthalen-1-yl-idene)hydrazin-1-yl]-5-chloro-4-methyl-benz-ene-sulfonate dimethyl sulfoxide monosolvate monohydrate, Na+·C18H12ClN2O6S-·H2O·C2H6OS, obtained from in-house synthesized Pigment Red 52. The crystal structure was determined by single-crystal X-ray diffraction at 173 K. In this monosodium salt, the SO3 - group is deprotonated, whereas the COOH group is protonated. The residues form chains via ionic inter-actions and hydrogen bonds. The chains are arranged in polar/non-polar double layers.

Effect of pressure on slit channels in hydrate of sodium salt of guanine: a link to nucleobase intermolecular interactions

Effect of pressure on slit channels in hydrate of sodium salt of guanine: a link to nucleobase intermolecular interactions

Octasodium bis-(Nitrilo-tris-Methylenephosphanatooxovanadate(IV))-Dioxo-bis-Oxovanadium(IV) Icosohydrate Na8[(VO)2(μ−O)2{(VO)μ3−N(CH2PO3)3}2]·20H2O

Crystal hydrate of sodium salt of an oxovanadium(IV) complex with nitrilo-tris-methylenephosphonic (NTP) acid Na8[(VO)2(μ−O)2{(VO)μ3−N(CH2PO3)3}2]·20H2O is synthesized, isolated, and studied: space group P1, Z = 2, a = 12.5829(2) A, b = 13.9297(2) A, c = 15.1051(3) A, α = 72.233(2)°, β = 76.907(2)°, γ = 70.388(2)°. The NTP ions are completely deprotonated and hexadentate. In coordinating the VO2+ ion each NTP ion closes three N–V–O–P–C cycles with a common N–V bond. By means of bridging vanadyl ions and oxo ligands the four-membered V–O–V–O cycle and the [–V–O–P–O–]4 macrocycle are closed. Coordination V polyhedra are distorted tetragonal pyramids. With regard to the occurrence of weak V–N bonds the polyhedra of two V atoms can be completed to strongly distorted octahedra.

Effect of pressure on slit channels in guanine sodium salt hydrate: a link to nucleobase intermolecular interactions

The crystal structure of a hydrate of the sodium salt of guanine (2Na+·C5H3N5O2−·7H2O) was studied at high pressure by single-crystal X-ray diffraction and Raman spectroscopy.

The structures of 1-(2-halo-6-fluorophenylmethyl)-1-methylimidazolium bromide salts

The crystal structures of 1-(2-halo-6-fluorophenylmethyl)-1-methylimidazolium bromide salts and 1-(2-trifluoromethyl-6-fluorophenylmethyl)-1-methylimidazolium bromide [MeNC3H3NCH2C6H3X-2-F-6]+·Br− [X = F (1), Cl (2), Br (3), I (4), CF3 (5)] have been determined. The crystal structure of the hydrate of salt 1 contains π–π stacked imidazolium⋯difluorophenyl⋯difluorophenyl⋯imidazolium units. Those of salts 2, 4 and 5 possess bromide⋯halofluorophenyl⋯halofluorophenyl⋯bromide motifs comprising anion–π and π–π stacking interactions. That of salt 4 also contains bromide⋯iodide halogen bonding. The crystal structure of the sesquihydrate of salt 3 possesses bromine⋯halofluorophenyl⋯halofluorophenyl⋯bromine motifs.

Mobile nanostructures (cybotactic groups) as a basis of generalised phenomenological model of aqueous electrolyte solutions

In this paper, we briefly review our researches into concentrated electrolyte solutions by means of a proposed phenomenological model. Electrolyte solutions are complex systems with a multitude of interactions. However, totality of interactions in solution is reflected in its constitution. The description of solution structure includes all parameters that define short-range ordering of particles, a full description of all possible coexistent vibrationally averaged structures (V-structures). We believe that information about the presence of the concentration ranges with different dominant structures and boundaries may be derived from the solubility polytherm (phase diagram) of the water-salt system. The boundary concentration corresponds to the eutectic composition (EC). In the range of pre-eutectic concentrations the dominant structure is the proper structure of water, and ion hydration is the major type of interaction between components. A crystalline hydrate or anhydrous salt crystallises at reduced temperatures from solutions with post-eutectic concentrations; hence, the dominant solute included V-structures are the structures of corresponding crystalline hydrate or quasi-crystalline fragments of anhydrous salt. For above-discussed spatial ordering of particles we used Stewart's term 'cybotactic group' (CG), which is a nanodimensional mobile V-structure that corresponds to the unit cell of a solid phase, which crystallises from solution under freezing. Analysis of concentration dependences of structural-sensitive properties (parameters) serve as information source about structural changes in solution, and 'special points' or singularities as the concentration boundaries of structural changes in solution correspond to eutectic and peritectics on solubility diagram. We proposed a new method of sounding to probe some peculiarities and differences in the solution structure. This method consists of monitoring of structural and dynamical features of new micro components introduced into the system under investigation. As such micro components one can use small additives of salts of transition and rare-earth metals. The structure of solution has a pronounced effect on the condition of complex-forming cations, which are presented as additives. If dominant structure (CG) has changed, there are alterations in structural and dynamical parameters of micro components, thus indicating that their behaviour 'obeys' the overall structural rearrangement in the solution. Such alterations of micro components can serve for probing some differences in the dominant structure of the supporting solution.

Two polymorphs and one hydrate of a molecular salt involving phenazopyridine and salicylic acid

Two anhydrous polymorphs (AH-I, AH-II) and one monohydrate (MH) of a molecular salt involving phenazopyridine and salicylic acid, are reported. The charge-assisted N–H⋯O hydrogen bond provides the main driving force for the direct binding of the two compounds. AH-I is the stable anhydrous form with a low hygroscopicity, a high solubility and a simple preparation method.

Sodiump-toluenesulfinate tetrahydrate

The title compound, Na+·C7H7O2S−·4H2O, is the hydrate of the sodium salt of para-toluene­sulfinic acid. The mol­ecular geometry around the sulfur atom is tetra­hedral with X–S–Y angles spanning a range of 102.23 (6)–110.04 (6)°. In the crystal, the water mol­ecules connect the sodium cations into chains along the b axis via O—H⋯O hydrogen bonds. An inter­molecular O—H⋯π inter­action is also observed.

Double clathrate hydrates of tetrabutylammonium fluoride + helium, neon, hydrogen and argon at high pressures

Decomposition curves of double ionic clathrate hydrates of tetrabutylammonium fluoride with helium, neon, hydrogen and argon were studied at pressures up to 800 MPa. Formation of double hydrates with helium, neon and hydrogen does not lead to any significant increase of the temperatures of decomposition of these hydrates; at high temperatures the hydrates may decompose even at lower temperatures than the hydrate of pure tetraalkylammonium salt does. Decomposition temperatures of double hydrates with argon in all cases were 4–8 °C higher in comparison with the decomposition temperature of ionic clathrate hydrates of tetrabutylammonium fluoride. We suppose that this behavior is caused by simultaneous effect of three factors on hydrate decomposition temperature: (1) partial filling of the small cavities in the framework of the hydrate with water molecules, (2) weakness of the van der Waals interactions between the gas molecules and the host water molecules, and (3) dissolution of helium, hydrogen and neon in the solution of tetrabutylammonium salt causing a decrease of melting temperatures of the hydrates formed from these solutions.

Transmission of electronic effects by icosahedral carboranes; skeletal carbon-13 chemical shifts and ultraviolet–visible spectra of substituted aryl-p-carboranes (1,12-dicarba-closo-dodecaboranes)

A series of para-carboranes (1,12-dicarba-closo-dodecaboranes) substituted at one or both carbon atoms by phenyl groups bearing a range of electron-releasing or -withdrawing substituents (X = NMe2, NH2, OH, OMe, Me, CF3 or NO2), principally at the para positions, has been prepared. The carbon-13 NMR shifts of the monoaryl compounds (4-XC6H4)CB10H10CH showed a linear increase in shielding of the unsubstituted (antipodal) cage carbon, C12, and a linear decrease at the substituted position, C1, with increasing electron-donating power of the substituent represented by its Hammett σP value. Purely inductive, σI, or resonance σR, parameters gave less satisfactory plots. The diaryl series of 4-nitrophenyl derivatives showed the same relationships. Calculations of electron densities showed that the 13C NMR shifts correspond with charge density in the tangential p orbitals. The UV absorptions of the monoaryl p-carboranes have substantial red-shifts compared with the corresponding substituted benzenes, while those of the 4-nitrophenyl compounds having 4-dimethylamino or 4-oxide anion substituents in the second phenyl group extend into the visible. The colour is attributed to changes in the nitro n → π* absorption rather than conjugation or intermolecular charge transfer. Two anhydrous polymorphs and a hydrate of the (18-crown-6)potassium salt of this nitrophenoxide have been identified (18-crown-6 = 1,4,7,10,13,16-hexaoxacyclooctadecane). The results establish that p-carborane transmits electronic effects, perhaps as a formally unsaturated system or possibly in a similar manner to the staffanes (bicyclo[1.1.1]pentanes) and other formally saturated hydrocarbon linkages.

A hydrate of the sodium salt of a penem carboxylic acid

The crystal structure of sodium (5R,6S)-6-[(R)-1-hydroxyethyl]-7-oxo-3-[(R)-2-tetrahydrofuryl]-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate 2.5-hydrate, Na + .C 12 H 14 NO 5 S - .5/2H 2 O, a member of a new class of β-lactam antibiotics, has been determined by X-ray diffraction. The C(3)-S(1) bond (bridgehead C atom) is longer than the C(2)-S(1) bond, although the latter is usually longer in penicillins and cephalosporins. The crystal packing shows a three-layer sheet in which two layers of the molecules are held together by Na + ions and by water molecules through a network of hydrogen bonds

Minor saponins from the starfish Asteriasforbesi

The structures of three new saponins from the starfish Asteriasforbesi have been elucidated by spectroscopic means. Forbeside F is the hydrate of the monosodium salt of 6α-O-{β-D-fucopyranosyl(1 → 4)-O-[β-D-quinovopyranosyl(1 → 2)]-O-β-D-quinovopyranosyl(1 → 3)-O-6-deoxy-β-D-xylo-hexos-4-ulopyranosyl}-20S-hydroxy-3β-sulfo-oxy-5α-cholest-9(11)-en-23-one. Forbeside G is the hydrate of the monosodium salt of 6α-O-{[β-D-quinovopyranosyl(1 → 2)]-O-β-D-quinovopyranosyl(1 → 3)-O-6-deoxy-β-D-xylo-hexos-4-ulopyranosyl}-20S-hydroxy-3β-sulfo-oxy-5α-cholest-9(11)-en-23-one. Forbeside H is the monosodium salt of 6α-O-{[β-D-quinovopyranosyl(1 → 2)]-β-D-xylopyranosyl(1 → 3)-B-D-quinovopyranosyl}-20S-hydroxy-3β-sulfo-oxy-5α-cholest-9(11)-en-23-one. Keywords: Asteriasforbesi; forbesides F, G, and H; starfish saponins; sterol glycosides.

Forbeside C, a saponin from Asteriasforbesi. Complete structure by nuclear magnetic resonance methods

The structure of forbeside C, a saponin from the starfish Asteriasforbesi, has been deduced totally by nuclear magnetic resonance methods applied to the undegraded molecule. Using principally 2D-COSY, HCORR, RCT, and 1D-nOe experiments, forbeside C is shown to be the hydrate of the monosodium salt of 6α-O-{β-D-fucopyranosyl(1 → 2)-O-β-D-fucopyranosyl(1 → 4)-O-[β-D-quinovopyranosyl(1 → 2)]-O-β-D-quinovopyranosyl(1 → 3)-O-6-deoxy-β-D-xylo-hexos-4-ulopyranosyl}-20S-hydroxy-3β-sulfo-oxy-5α-cholest-9(11)-en-23-one, the structure reported previously for ovarian asterosaponin 1.