33 research outputs found
Elusive Forms and Structures of <i>N</i>-Hydroxyphthalimide: The Colorless and Yellow Crystal Forms of <i>N</i>-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). The various forms of NHP differ in the way
in which the molecules adjoin one another through their N-hydroxyl groups and how the carbonyls of the
isoindole-1,3-dione ring differ through intermolecular hydrogen bonding. Although the hydrogen bonding
about the b axis is virtually the same, the isoindole-1,3-dione ring experiences different twists for the two
NHP forms. Both the colorless and yellow forms of NHP exhibit strong intermolecular hydrogen bonding
between O(3) and H(1). In the yellow form, the N-hydroxyl group is significantly out of the plane (∼1.19°),
but the N-hydroxyl group in the colorless form is only ∼0.06° out of the plane. Both forms of NHP reveal
an infinite chain of intermolecular hydrogen-bonded molecules in the direction of the b axis; however, the
molecules are ordered differently within the unit cells. The hydrogen-bond geometry for the yellow form of
NHP is O(2)−H(1)···O(3), with an angle of 185°, intermolecular distances of O(2)···O(3) = 2.68 Å and
H(1)···O(3) = 1.70 Å, and an intramolecular hydrogen bond of O(1)···H(1) = 1.17 Å. The colorless form of
NHP shows an intermolecular hydrogen-bond geometry between O(3) and H(1) with a distance of 1.78 Å;
the O(2)−O(3) distance is 2.71 Å. The O(2)−H(1)···O(3) angle is 159°, and the intramolecular distance is
O(1)···H(1) = 0.97 Å. The N-ethoxy derivative of NHP crystallizes in an orthorhombic space group (Pnma,
No. 62) and exhibits no hydrogen bonding, displaying a strong head-to-tail stacking of the planar rings along
the needle axis direction
Elusive Forms and Structures of <i>N</i>-Hydroxyphthalimide: The Colorless and Yellow Crystal Forms of <i>N</i>-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). The various forms of NHP differ in the way
in which the molecules adjoin one another through their N-hydroxyl groups and how the carbonyls of the
isoindole-1,3-dione ring differ through intermolecular hydrogen bonding. Although the hydrogen bonding
about the b axis is virtually the same, the isoindole-1,3-dione ring experiences different twists for the two
NHP forms. Both the colorless and yellow forms of NHP exhibit strong intermolecular hydrogen bonding
between O(3) and H(1). In the yellow form, the N-hydroxyl group is significantly out of the plane (∼1.19°),
but the N-hydroxyl group in the colorless form is only ∼0.06° out of the plane. Both forms of NHP reveal
an infinite chain of intermolecular hydrogen-bonded molecules in the direction of the b axis; however, the
molecules are ordered differently within the unit cells. The hydrogen-bond geometry for the yellow form of
NHP is O(2)−H(1)···O(3), with an angle of 185°, intermolecular distances of O(2)···O(3) = 2.68 Å and
H(1)···O(3) = 1.70 Å, and an intramolecular hydrogen bond of O(1)···H(1) = 1.17 Å. The colorless form of
NHP shows an intermolecular hydrogen-bond geometry between O(3) and H(1) with a distance of 1.78 Å;
the O(2)−O(3) distance is 2.71 Å. The O(2)−H(1)···O(3) angle is 159°, and the intramolecular distance is
O(1)···H(1) = 0.97 Å. The N-ethoxy derivative of NHP crystallizes in an orthorhombic space group (Pnma,
No. 62) and exhibits no hydrogen bonding, displaying a strong head-to-tail stacking of the planar rings along
the needle axis direction
Elusive Forms and Structures of <i>N</i>-Hydroxyphthalimide: The Colorless and Yellow Crystal Forms of <i>N</i>-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). The various forms of NHP differ in the way
in which the molecules adjoin one another through their N-hydroxyl groups and how the carbonyls of the
isoindole-1,3-dione ring differ through intermolecular hydrogen bonding. Although the hydrogen bonding
about the b axis is virtually the same, the isoindole-1,3-dione ring experiences different twists for the two
NHP forms. Both the colorless and yellow forms of NHP exhibit strong intermolecular hydrogen bonding
between O(3) and H(1). In the yellow form, the N-hydroxyl group is significantly out of the plane (∼1.19°),
but the N-hydroxyl group in the colorless form is only ∼0.06° out of the plane. Both forms of NHP reveal
an infinite chain of intermolecular hydrogen-bonded molecules in the direction of the b axis; however, the
molecules are ordered differently within the unit cells. The hydrogen-bond geometry for the yellow form of
NHP is O(2)−H(1)···O(3), with an angle of 185°, intermolecular distances of O(2)···O(3) = 2.68 Å and
H(1)···O(3) = 1.70 Å, and an intramolecular hydrogen bond of O(1)···H(1) = 1.17 Å. The colorless form of
NHP shows an intermolecular hydrogen-bond geometry between O(3) and H(1) with a distance of 1.78 Å;
the O(2)−O(3) distance is 2.71 Å. The O(2)−H(1)···O(3) angle is 159°, and the intramolecular distance is
O(1)···H(1) = 0.97 Å. The N-ethoxy derivative of NHP crystallizes in an orthorhombic space group (Pnma,
No. 62) and exhibits no hydrogen bonding, displaying a strong head-to-tail stacking of the planar rings along
the needle axis direction
Elusive Forms and Structures of <i>N</i>-Hydroxyphthalimide: The Colorless and Yellow Crystal Forms of <i>N</i>-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). The various forms of NHP differ in the way
in which the molecules adjoin one another through their N-hydroxyl groups and how the carbonyls of the
isoindole-1,3-dione ring differ through intermolecular hydrogen bonding. Although the hydrogen bonding
about the b axis is virtually the same, the isoindole-1,3-dione ring experiences different twists for the two
NHP forms. Both the colorless and yellow forms of NHP exhibit strong intermolecular hydrogen bonding
between O(3) and H(1). In the yellow form, the N-hydroxyl group is significantly out of the plane (∼1.19°),
but the N-hydroxyl group in the colorless form is only ∼0.06° out of the plane. Both forms of NHP reveal
an infinite chain of intermolecular hydrogen-bonded molecules in the direction of the b axis; however, the
molecules are ordered differently within the unit cells. The hydrogen-bond geometry for the yellow form of
NHP is O(2)−H(1)···O(3), with an angle of 185°, intermolecular distances of O(2)···O(3) = 2.68 Å and
H(1)···O(3) = 1.70 Å, and an intramolecular hydrogen bond of O(1)···H(1) = 1.17 Å. The colorless form of
NHP shows an intermolecular hydrogen-bond geometry between O(3) and H(1) with a distance of 1.78 Å;
the O(2)−O(3) distance is 2.71 Å. The O(2)−H(1)···O(3) angle is 159°, and the intramolecular distance is
O(1)···H(1) = 0.97 Å. The N-ethoxy derivative of NHP crystallizes in an orthorhombic space group (Pnma,
No. 62) and exhibits no hydrogen bonding, displaying a strong head-to-tail stacking of the planar rings along
the needle axis direction
Elusive Forms and Structures of <i>N</i>-Hydroxyphthalimide: The Colorless and Yellow Crystal Forms of <i>N</i>-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). The various forms of NHP differ in the way
in which the molecules adjoin one another through their N-hydroxyl groups and how the carbonyls of the
isoindole-1,3-dione ring differ through intermolecular hydrogen bonding. Although the hydrogen bonding
about the b axis is virtually the same, the isoindole-1,3-dione ring experiences different twists for the two
NHP forms. Both the colorless and yellow forms of NHP exhibit strong intermolecular hydrogen bonding
between O(3) and H(1). In the yellow form, the N-hydroxyl group is significantly out of the plane (∼1.19°),
but the N-hydroxyl group in the colorless form is only ∼0.06° out of the plane. Both forms of NHP reveal
an infinite chain of intermolecular hydrogen-bonded molecules in the direction of the b axis; however, the
molecules are ordered differently within the unit cells. The hydrogen-bond geometry for the yellow form of
NHP is O(2)−H(1)···O(3), with an angle of 185°, intermolecular distances of O(2)···O(3) = 2.68 Å and
H(1)···O(3) = 1.70 Å, and an intramolecular hydrogen bond of O(1)···H(1) = 1.17 Å. The colorless form of
NHP shows an intermolecular hydrogen-bond geometry between O(3) and H(1) with a distance of 1.78 Å;
the O(2)−O(3) distance is 2.71 Å. The O(2)−H(1)···O(3) angle is 159°, and the intramolecular distance is
O(1)···H(1) = 0.97 Å. The N-ethoxy derivative of NHP crystallizes in an orthorhombic space group (Pnma,
No. 62) and exhibits no hydrogen bonding, displaying a strong head-to-tail stacking of the planar rings along
the needle axis direction
Elusive Forms and Structures of <i>N</i>-Hydroxyphthalimide: The Colorless and Yellow Crystal Forms of <i>N</i>-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). The various forms of NHP differ in the way
in which the molecules adjoin one another through their N-hydroxyl groups and how the carbonyls of the
isoindole-1,3-dione ring differ through intermolecular hydrogen bonding. Although the hydrogen bonding
about the b axis is virtually the same, the isoindole-1,3-dione ring experiences different twists for the two
NHP forms. Both the colorless and yellow forms of NHP exhibit strong intermolecular hydrogen bonding
between O(3) and H(1). In the yellow form, the N-hydroxyl group is significantly out of the plane (∼1.19°),
but the N-hydroxyl group in the colorless form is only ∼0.06° out of the plane. Both forms of NHP reveal
an infinite chain of intermolecular hydrogen-bonded molecules in the direction of the b axis; however, the
molecules are ordered differently within the unit cells. The hydrogen-bond geometry for the yellow form of
NHP is O(2)−H(1)···O(3), with an angle of 185°, intermolecular distances of O(2)···O(3) = 2.68 Å and
H(1)···O(3) = 1.70 Å, and an intramolecular hydrogen bond of O(1)···H(1) = 1.17 Å. The colorless form of
NHP shows an intermolecular hydrogen-bond geometry between O(3) and H(1) with a distance of 1.78 Å;
the O(2)−O(3) distance is 2.71 Å. The O(2)−H(1)···O(3) angle is 159°, and the intramolecular distance is
O(1)···H(1) = 0.97 Å. The N-ethoxy derivative of NHP crystallizes in an orthorhombic space group (Pnma,
No. 62) and exhibits no hydrogen bonding, displaying a strong head-to-tail stacking of the planar rings along
the needle axis direction
Elusive Forms and Structures of <i>N</i>-Hydroxyphthalimide: The Colorless and Yellow Crystal Forms of <i>N</i>-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). The various forms of NHP differ in the way
in which the molecules adjoin one another through their N-hydroxyl groups and how the carbonyls of the
isoindole-1,3-dione ring differ through intermolecular hydrogen bonding. Although the hydrogen bonding
about the b axis is virtually the same, the isoindole-1,3-dione ring experiences different twists for the two
NHP forms. Both the colorless and yellow forms of NHP exhibit strong intermolecular hydrogen bonding
between O(3) and H(1). In the yellow form, the N-hydroxyl group is significantly out of the plane (∼1.19°),
but the N-hydroxyl group in the colorless form is only ∼0.06° out of the plane. Both forms of NHP reveal
an infinite chain of intermolecular hydrogen-bonded molecules in the direction of the b axis; however, the
molecules are ordered differently within the unit cells. The hydrogen-bond geometry for the yellow form of
NHP is O(2)−H(1)···O(3), with an angle of 185°, intermolecular distances of O(2)···O(3) = 2.68 Å and
H(1)···O(3) = 1.70 Å, and an intramolecular hydrogen bond of O(1)···H(1) = 1.17 Å. The colorless form of
NHP shows an intermolecular hydrogen-bond geometry between O(3) and H(1) with a distance of 1.78 Å;
the O(2)−O(3) distance is 2.71 Å. The O(2)−H(1)···O(3) angle is 159°, and the intramolecular distance is
O(1)···H(1) = 0.97 Å. The N-ethoxy derivative of NHP crystallizes in an orthorhombic space group (Pnma,
No. 62) and exhibits no hydrogen bonding, displaying a strong head-to-tail stacking of the planar rings along
the needle axis direction
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
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 ϕ = 5.4 × 10−4 at pH 5.8 or the vaterite polymorph of CaCO3 at a volume fraction of ϕ = 7.8 × 10−4 at pH 5.8. In both cases, nucleation, adsorption pH, and the shape-dependent template of lipid A-diphosphate control the formation of the calcite and vaterite
Elusive Forms and Structures of <i>N</i>-Hydroxyphthalimide: The Colorless and Yellow Crystal Forms of <i>N</i>-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). The various forms of NHP differ in the way
in which the molecules adjoin one another through their N-hydroxyl groups and how the carbonyls of the
isoindole-1,3-dione ring differ through intermolecular hydrogen bonding. Although the hydrogen bonding
about the b axis is virtually the same, the isoindole-1,3-dione ring experiences different twists for the two
NHP forms. Both the colorless and yellow forms of NHP exhibit strong intermolecular hydrogen bonding
between O(3) and H(1). In the yellow form, the N-hydroxyl group is significantly out of the plane (∼1.19°),
but the N-hydroxyl group in the colorless form is only ∼0.06° out of the plane. Both forms of NHP reveal
an infinite chain of intermolecular hydrogen-bonded molecules in the direction of the b axis; however, the
molecules are ordered differently within the unit cells. The hydrogen-bond geometry for the yellow form of
NHP is O(2)−H(1)···O(3), with an angle of 185°, intermolecular distances of O(2)···O(3) = 2.68 Å and
H(1)···O(3) = 1.70 Å, and an intramolecular hydrogen bond of O(1)···H(1) = 1.17 Å. The colorless form of
NHP shows an intermolecular hydrogen-bond geometry between O(3) and H(1) with a distance of 1.78 Å;
the O(2)−O(3) distance is 2.71 Å. The O(2)−H(1)···O(3) angle is 159°, and the intramolecular distance is
O(1)···H(1) = 0.97 Å. The N-ethoxy derivative of NHP crystallizes in an orthorhombic space group (Pnma,
No. 62) and exhibits no hydrogen bonding, displaying a strong head-to-tail stacking of the planar rings along
the needle axis direction
