Structures of the 2-nitrophenol alkali complexes in solution and the solid state.

The materials studied in this investigation were aqueous solutions (0.02-25.0 mM) of the salts of alkali metal ion (Me(+)) and 2-nitrophenol (2-NP).

Two dimensional crystallization of three solid lipid A-diphosphate phases.

Surface-tension-induced liquid-crystal growth of monomeric lipid A-diphosphate in aqueous dispersions is reported as a function of concentration, (c), and temperature, (T), and at low ionic strength (10(-3) M). As the temperature was varied, a solid-liquid transition was revealed in the surface layer at a fixed lipid A-diphosphate bulk concentration. Here, the development of different two-dimensional (2-d) faceted crystal morphologies was observed and, as growth proceeded, these faceted 2-d crystals became unstable.

Phase transformations in lipid A-diphosphate initiated by sodium hydroxide.

The nature of the fluid phase transitions of charged-stabilized spherical lipid A-diphosphate clusters in aqueous dispersions was explored using a combination of small-angle X-ray scattering (SAXS) and electron microscopy. In contrast to previous studies, rather than removing NaCl, NaOH was added to the dispersions to promote crystallization. The fluid phase experiments were carried out employing titrations with mM·L(-1) NaOH (c(S)), along with variations in the particle-number density, n.

Studies on structures of lipid A-monophosphate clusters.

Single crystalline clusters of lipid A-monophosphate were grown from organic dispersions containing 5-15% (v/v) water at various volume fractions, φ, and temperatures. The morphology of the single lipid A-monophosphate crystals was either rhombohedral or hexagonal. The hexagonal crystals were needlelike or cylindrical in shape, with the long dimension parallel to the c axis of the unit cell.

Two new colloidal crystal phases of lipid A-monophosphate: order-to-order transition in colloidal crystals.

A study of the structure of stable regular-shaped nanocrystals of hexa-acylated (C(14)) lipid A-monophosphate from Escherichia coli was carried out using dilute electrostatically stabilized aqueous dispersions at low ionic strength (I=1.0x10(-5)M NaCl). An order-to-order transition of colloidal clusters of lipid A-monophosphate was found at two volume fractions: phi=5.

Nucleation of calcium carbonate as polymorphic crystals in the presence of lipid A-diphosphate.

The well-defined structure of lipid A-diphosphate in aqueous solutions provides a way of observing the formation of calcium carbonate crystals. The crystals are either tetrahedral or rhombohedral calcite at a volume fraction of phi = 5.4 x 10 (-4) at pH 5.

The phase diagram of charged colloidal lipid A-diphosphate dispersions.

Small-angle X-ray-scattering, light-scattering, and electron microscope experiments were used to determine the phase transitions of colloidal lipid A-diphosphate aqueous dispersions. The phases detected were a correlated liquid phase, a face-centered cubic (Fd3m) and a body-centered cubic (Im3m) colloidal crystal phase and a new glass phase. These experimentally determined phases were shown to be in accord with theoretically predicted equilibrium phases.

Observations of liquidlike order of charged rodlike lipid A diphosphate assemblies at pH 8.5.

A new structural form of charged lipid A diphosphate, with a molecular weight of 5.9x10(6) Da and a rodlike shape (L=800 nm), was found in aqueous solutions at pH 8.5.

Ordering of lipid A-monophosphate clusters in aqueous solutions.

In this investigation, a study of the self-assembly of electrostatically stabilized aqueous dispersions of nanometric lipid A-monophosphate clusters from Escherichia coli was carried out in three different volume-fraction regimes. The experimental techniques used in the investigation were osmotic pressure, static and quasielastic light scattering, scanning electron microscopy and transmission electron microscopy, and small-angle x-ray scattering. Experiments were carried out at low ionic strength (I=0.

Elusive forms and structures of N-hydroxyphthalimide: the colorless and yellow crystal forms of N-hydroxyphthalimide.

A comprehensive structural characterization of the colorless and yellow forms of N-hydroxyphthalimide (NHP), the deuterated form (NDP), and the ethoxylated form (ethoxy-NHP) has been carried out using single-crystal X-ray diffraction, FTIR and Raman spectroscopies, and scanning electron microscopy. Both NHP and NDP forms crystallize in the monoclinic space group (P21/c, No. 14).