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Hydrogen Phthalate (hydrogen + phthalate)

Distribution by Scientific Domains

Chemistry	66%

Kinds of Hydrogen Phthalate

potassium hydrogen phthalate

Selected Abstracts

Habit modification and improvement in properties of potassium hydrogen phthalate (KAP) crystals doped with metal ions

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 3 2006
S. K. Geetha
Abstract Potassium hydrogen phthalate (KAP) single crystals were grown by slow evaporation and slow cooling techniques. The growth procedure like temperature cooling rate, evaporation rate, solution pH, concentration of the solute, supersaturation ratio etc., has been varied to have optically transparent crystals. Efforts were made to dope the KAP crystals with rubidium, sodium and lithium ions. The dopant concentration has been varied from 0.01 to 10 mole percent. Good quality single crystals were grown with different concentrations of dopants in the mother phase. Depending on the concentration of the dopants and the solution pH value, there is modification of habit. Rubidium ions very much improve the growth on the prismatic faces. The transparency of the crystals is improved with rubidium and sodium doping. The role of the dopants on the non-linear optical performance of KAP indicates better efficiency for doped crystals. The grown crystals were characterized with XRD, FT-IR, chemical etching, Vickers microhardness and SHG measurements. The influence of the dopants on the optical, chemical, structural, mechanical and other properties of the KAP crystals was analysed. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim [source]

Enhancement of crystalline perfection by organic dopants in ZTS, ADP and KHP crystals as investigated by high-resolution XRD and SEM

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 6 2006
S. Parthiban
To reveal the influence of complexing agents on crystalline perfection, tristhiourea zinc(II) sulfate (ZTS), ammonium dihydrogen phosphate (ADP) and potassium hydrogen phthalate (KHP) crystals grown by slow-evaporation solution growth technique using low concentrations (5 × 10,3M) of dopants like ethylenediamminetetraacetic acid (EDTA) and 1,10-phenanthroline (phen) were characterized by high-resolution X-ray diffractometry (XRD) and scanning electron microscopy (SEM). High-resolution diffraction curves (DCs) recorded for ZTS and ADP crystals doped with EDTA show that the specimen contains an epilayer, as observed by the additional peak in the DC, whereas undoped specimens do not have such additional peaks. On etching the surface layer, the additional peak due to the epilayer disappears and a very sharp DC is obtained, with full width at half-maximum (FWHM) of less than 10,arcsec, as expected from the plane wave dynamical theory of X-ray diffraction for an ideally perfect crystal. SEM micrographs also confirm the existence of an epilayer in doped specimens. The ZTS specimen has a layer with a rough surface morphology, having randomly oriented needles, whereas the ADP specimen contains a layer with dendric structure. In contrast to ADP and ZTS crystals, the DC of phen-doped KHP shows no additional peak, but it is quite broad (FWHM = 28,arcsec) with a high value of integrated intensity, , (area under the DC). The broadness of the DC and the high value of , indicate the formation of a mosaic layer on the surface of the crystal. However, similar to ADP and ZTS, the DC recorded after etching the surface layer of the KHP specimen shows a very sharp peak with an FWHM of 8 arcsec. An SEM photograph of phen-doped KHP shows deep cracks on the surface, confirming the mosaicity. After removing the surface layer, the SEM pictures reveal a smooth surface. A similar trend is observed with other complexing agents, like oxalic acid, bipy and picolinic acid. However, only typical examples are described in the present article where the effects were observed prominently. The investigations on ZTS, ADP and KHP crystals, employing high-resolution XRD and SEM studies, revealed that some organic dopants added to the solution during the growth lead to the formation of a surface layer, due to complexation of these dopants with the trace metal ion impurities present in the solution, which prevents the entry of impurities, including the solvent, into the crystal, thereby assisting crystal growth with high crystalline perfection. The influence of organic dopants on the second harmonic generation efficiency is also investigated. [source]

Synthesis and supramolecular self-assembly of thermosensitive amphiphilic star copolymers based on a hyperbranched polyether core

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 2 2008
Haiyan Hong
Abstract A novel amphiphilic thermosensitive star copolymer with a hydrophobic hyperbranched poly (3-ethyl-3-(hydroxymethyl)oxetane) (HBPO) core and many hydrophilic poly(2-(dimethylamino) ethyl methacrylate) (PDMAEMA) arms was synthesized and used as the precursor for the aqueous solution self-assembly. All the copolymers directly aggregated into core,shell unimolecular micelles (around 10 nm) and size-controllable large multimolecular micelles (around 100 nm) in water at room temperature, according to pyrene probe fluorescence spectrometry and 1H NMR, TEM, and DLS measurements. The star copolymers also underwent sharp, thermosensitive phase transitions at a lower critical solution temperature (LCST), which were proved to be originated from the secondary aggregation of the large micelles driven by increasing hydrophobic interaction due to the dehydration of PDMAEMA shells on heating. A quantitative variable temperature NMR analysis method was designed by using potassium hydrogen phthalate as an external standard and displayed great potential to evaluate the LCST transition at the molecular level. The drug loading and temperature-dependent release properties of HBPO- star -PDMAEMA micelles were also investigated by using indomethacin as a model drug. The indomethacin-loaded micelles displayed a rapid drug release at a temperature around LCST. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 668,681, 2008 [source]

Charge-assisted hydrogen-bonded supramolecular networks in acetoguanaminium hydrogen phthalate, acetoguanaminium hydrogen maleate and acetoguanaminium 3-hydroxypicolinate monohydrate

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2010
Kaliyaperumal Thanigaimani
In 2,4-diamino-6-methyl-1,3,5-triazin-1-ium (acetoguanaminium) hydrogen phthalate, C4H8N5+·C8H5O4,, (I), acetoguanaminium hydrogen maleate, C4H8N5+·C4H3O4,, (II), and acetoguanaminium 3-hydroxypicolinate monohydrate, C4H8N5+·C6H4NO3,·H2O, (III), the acetoguanaminium cations interact with the carboxylate groups of the corresponding anions via a pair of nearly parallel N,H...O hydrogen bonds, forming R22(8) ring motifs. In (II) and (III), N,H...N base-pairing is observed, while there is none in (I). In (II), a series of fused R32(8), R22(8) and R32(8) hydrogen-bonded rings plus fused R22(8), R62(12) and R22(8) ring motifs occur alternately, aggregating into a supramolecular ladder-like arrangement. In (III), R22(8) motifs occur on either side of a further ring formed by pairs of N,H...O hydrogen bonds, forming an array of three fused hydrogen-bonded rings. In (I) and (II), the anions form a typical intramolecular O,H...O hydrogen bond with graph set S(7), whereas in (III) an intramolecular hydrogen bond with graph set S(6) is formed. [source]

N,H...O and O,H...O hydrogen-bonded supramolecular networks in 4-chloroanilinium, 2-hydroxyanilinium and 3-hydroxyanilinium hydrogen phthalates

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2009
R. Jagan
The title salts, 4-chloroanilinium hydrogen phthalate (PCAHP), C6H7ClN+·C8H5O4,, 2-hydroxyanilinium hydrogen phthalate (2HAHP), C6H8NO+·C8H5O4,, and 3-hydroxyanilinium hydrogen phthalate (3HAHP), C6H8NO+·C8H5O4,, all crystallize in the space group P21/c. The asymmetric unit of 2HAHP contains two independent ion pairs. The hydrogen phthalate ions of 2HAHP and 3HAHP show a short intramolecular O,H...O hydrogen bond, with O...O distances ranging from 2.3832,(15) to 2.3860,(14),Å. N,H...O and O,H...O hydrogen bonds, together with short C,H...O contacts in PCAHP and 3HAHP, generate extended hydrogen-bond networks. PCAHP forms a two-dimensional supramolecular sheet extending in the (100) plane, whereas 2HAHP has a supramolecular chain running parallel to the [100] direction and 3HAHP has a two-dimensional network extending parallel to the (001) plane. [source]

Cation-, interaction between the aromatic organic counterion and DTAB micelle in mixed solvents

CHINESE JOURNAL OF CHEMISTRY, Issue 10 2004
Dong-Shun Deng
Abstract The cation-, interaction between the aromatic organic counterion potassium hydrogen phthalate (KHP) and DTAB micelle in aqueous mixture of EG was investigated, using the techniques of conductivity measurements, W absorption spectrum and NMR spectrum. The conductivity and UV spectrum studies were with respect to the effect of KHP on DTAB and that of DTAB micelle on KHP, respectively. According to the chemical shift changes of the aromatic ring and the surfactant methylene protons, it can be assumed that KHP penetrated into DTAB micelle with its carboxylic group protruding out of the micellar surface. And the strength of the interaction became weaker with the content of EG in the mixed solvent increasing. [source]