Potassium hydrogen phthalate crystals

Fig. 3 Idealized representations of potassium hydrogen phthalate crystal habits viewed down [010] with growth sectors delineated. Red luminophores are included in each of principal growth sectors, as shown by the patterns of luminescence. (View this art in color at WWW. dekker. com.)...

Fig. 4 Top row Successive (010) slices (200 p) of dyed potassium hydrogen phthalate crystals reveal the growth histories in their patterns of luminescence. Bottom row The orientation of the fast- and slow-moving steps of a growth hillock are shown on the (010) face in a comparison of images made by differential interference contrast microscopy and fluorescence microscopy. (View this art in...

Lithium fluoride is the optimum crystal for all wavelengths less than 3 A. Pentaerythritol (PET) and potassium hydrogen phthalate (KAP) are usually the crystals of choice for wavelengths from 3 to 20 A. Two crystals suppress even-ordered reflections silicon (111) and calcium fluoride (111). 

Potassium hydrogen phthalate is prepared by neutralization reaction of phthalic anhydride and potassium hydroxide, followed by crystallization ... 

The general theory of indirect detection was recently put forward [14] and its mechanism stimulated pioneering model makers to provide a realistic, practical and rational description of IPC [15,16]. For example, a UV-absorbing mobile phase containing potassium hydrogen phthalate and triethanolamine allowed the indirect detection of sulfur and nitrogen anions in atmospheric liquids separated on a cetylpyridinium-coated C18 column [17]. Crystal violet was used as the IPR in the... 

For determinations of reaction constants, anomeric purity is not necessary, but for the determination of initial rotations, only one anomer can be present. Pure anomers can often be obtained by slow crystallization from a suitable solvent in the presence of nucleating crystals of the desired form and in the absence of crystals of other forms. For measurements in aqueous solution, use of mM potassium hydrogen phthalate as a buffer (pH 4.4) is recommended, to avoid variation in acidity during measurements. Precautions for purification, drying, and use of organic solvents have been described by Lowry and Baker. Anomeric impurities can be removed by lixiviation with a solvent (such as aqueous alcohol) in which both anomers are slightly soluble. 

Superstructiu e design at each level was controllable by changing the polymer concentration and the observed hierarchy was attributed to the interaction between crystals and polymers and the diffusion-controlled conditions [252]. A similar hierarchical system was recently found for potassium hydrogen phthalate and PAA [253]. Again, plate-hke units were composed of... 

Potassium sulfate and potassium hydrogen phthalate both formed a nacrelike structure when the PAA concentration was adjusted to a suitable value [235-237] (Fig. 17). Just like the nacre in Nature (Japanese pearl oyster Pinctada fucata) [235], the nacre-Uke structure of potassium sulfate-PAA and potassiiun hydrogen phthalate-PAA can absorb and store dyes [235-237] (Fig. 17). With a different concentration of PAA, the K2SO4 crystal exhibited a different hierarchical architecture by iso-oriented assembly or oriented attachment mechanisms [236]. 

To prepare the standard pH buffer solutions recommended by the National Bureau of Standards (U.S.), the indicated weights of the pure materials in Table 8.15 should be dissolved in water of specific conductivity not greater than 5 micromhos. The tartrate, phthalate, and phosphates can be dried for 2 h at 100°C before use. Potassium tetroxalate and calcium hydroxide need not be dried. Fresh-looking crystals of borax should be used. Before use, excess solid potassium hydrogen tartrate and calcium hydroxide must be removed. Buffer solutions pH 6 or above should be stored in plastic containers and should be protected from carbon doxide with soda-lime traps. The solutions should be replaced within 2 to 3 weeks, or sooner if formation of mold is noticed. A crystal of thymol may be added as a preservative. 

---