The equilibrium form of a crystal is the shape which minimizes the total surface tension for a given volume. The surface tension itself is considered to be a function of the orientation of the crystal face within the crystal lattice. This function of orientation is identified with the stable norm on the second homology classes of a Riemannian 3-torus. Minimizing the total surface tension of the...

metal complexes, ml (m=ni, cu, co and zn) of unsymmetrical tetradentate schiff base have been synthesized by the template reaction of the half-units n-(1-hydroxy-2-acetonaphthone)-1-amino-2-phenyleneimine)(hl1) with 2-pyrroleca-rbaldehyde. the complexes have been characterized by elemental analysis, ir, 1h nmr and uv spectroscopy. the crystal structure of the ni(ii) complex has been determine...

To clarify further the mechanism of regulation by phosphorylation of isocitrate dehydrogenase, cocrystallization of isocitrate dehydrogenase and isocitrate dehydrogenase kinase/phosphatase in the presence of an ATP analog was attempted. Although cocrystallization was unsuccessful, a new crystal form of isocitrate dehydrogenase was obtained which provides insight into the phosphorylation mechani...

The purpose of this investigation is to characterize nevirapine from commercial samples and samples crystallized from different solvents under various conditions. The solid-state behavior of nevirapine samples was investigated using a variety of complementary techniques such as microscopy (optical, polarized, hot stage microscopy), differential scanning calorimeter, thermogravimetric analysis, ...

Five crystal modifications of water insoluble artesunate were generated by recrystallizing it from various solvents with improved physicochemical properties. These generated crystal forms were characterized to select the most potent and soluble form. SEM of all the forms showed changes in external shape leading them to be different morphologically. DSC thermograms of Form III and Form V showed ...

The initial stage of the reaction between sodium stearate (NaSt) and AgNO(3) produces silver stearate (AgSt) micelles, [(C(18)H(35)O(2))(x)(Na(x-y))(Ag(y))(H(2)O)(z)], and aggregations of these AgSt micelles in the form of cubic pre-AgSt crystals. When cubic grains of 50 nm AgBr are added to the NaSt dispersion prior to the AgNO(3), the reaction proceeds to form the silver stearate micelles, bu...

High-pressure crystallisation has been successfully used as an alternative technique to prepare Form II of a non-steroidal anti-inflammatory drug, mefenamic acid (MA). A single crystal of Form II, denoted as high-pressure Form II, was grown at 0.3 GPa from an ethanolic solution by using a diamond anvil cell. A comparison of the crystal structures shows that the efficient packing of molecules in...

Although crystal polymorphism of carbamazepine (CBZ), an anticonvulsant used to treat epilepsy, has been known for decades, the phenomenon has only recently been noted for its keto-derivative oxcarbazepine (OCB). Here it is demonstrated that OCB possesses at least three anhydrous polymorphs. Although all forms are morphologically similar, making differentiation between crystal modifications by ...