Nitric acid promoted formation of an N-confused porphyrin-derived porphodimethene and a violinoid

2006 ◽  
Vol 10 (07) ◽  
pp. 953-961 ◽  
Author(s):  
Chen-Hsiung Hung ◽  
Chia-Chi Liaw ◽  
Wei-Ming Chin ◽  
Gao-Fong Chang ◽  
Chuan-Hung Chuang

The nitration of free-base N -confused porphyrin led to a novel 5,10-meso-dihydroxy- N -confused porphodimethene and an open-ring N -confused violinoid. The results support nitration occurring first, followed by nucleophilic addition of a hydroxyl group and a parallel reaction of oxygenolysis to cause the ring-opening. The nitro group substituted at the inner carbon of the inverted pyrrole ring is located on both the porphodimethene and violinoid. In the case of the porphodimethene, two dihydroxyl groups with υ( OH ) at 3404 cm−1 are arranged in a syn conformation at the same side with the nitro group. The violinoid exhibits υ( C = O ) at 1659 cm−1. NMR and structure determination suggest that oxygenolysis occurs selectively at the C=C bond between the α-pyrrole and meso carbon closest to the amino NH of the inverted pyrrole ring. The single crystal structure of porphodimethene gave a 50% disorder between the peripheral nitrogen and carbon atom on the inverted pyrrole ring, while a dimeric structure assembled through hydrogen bonding interactions was observed in the crystal lattice of the violinoid.

2020 ◽  
Vol 35 (2) ◽  
pp. 129-135
Author(s):  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton

The crystal structure of atazanavir has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Atazanavir crystallizes in space group P21 (#4) with a = 15.33545(7), b = 5.90396(3), c = 21.56949(13) Å, β = 96.2923(4)°, V = 1941.134(11) Å3, and Z = 2. Despite being labeled as “atazanavir sulfate”, the commercial reagent sample consisted of atazanavir free base. The structure consists of an array of extended-conformation molecules parallel to the ac-plane. Although the atazanavir molecule contains only four classical hydrogen bond donors, hydrogen bonding is, surprisingly, important to the crystal energy. Both intra- and intermolecular hydrogen bonds are significant. The hydroxyl group forms bifurcated intramolecular hydrogen bonds to a carbonyl oxygen atom and an amide nitrogen. Several amide nitrogens act as donors to the hydroxyl group and carbonyl oxygen atoms. An amide nitrogen acts as a donor to another amide nitrogen. Several methyl, methylene, methyne, and phenyl hydrogens participate in hydrogen bonds to carbonyl oxygens, an amide nitrogen, and the pyridine nitrogen. The powder pattern is included in the Powder Diffraction File™ as entry 00-065-1426.


2019 ◽  
Vol 34 (1) ◽  
pp. 50-58
Author(s):  
James A. Kaduk ◽  
Nicholas C. Boaz ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton

The crystal structure of oxybutynin hydrochloride hemihydrate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Oxybutynin hydrochloride hemihydrate crystallizes in space group I2/a (#15) with a = 14.57266(8), b = 8.18550(6), c = 37.16842(26) Å, β = 91.8708(4)°, V = 4421.25(7) Å3, and Z = 8. The compound exhibits X-ray-induced photoreduction of the triple bond. Prominent in the layered crystal structure is the N–H⋅⋅⋅Cl hydrogen bond between the cation and anion, as well as O–H⋅⋅⋅Cl hydrogen bonds from the water molecule and hydroxyl group of the oxybutynin cation. C–H⋅⋅⋅Cl hydrogen bonds also contribute to the crystal energy, and help determine the conformation of the cation. The powder pattern is included in the Powder Diffraction File™ as entry 00-068-1305.


2006 ◽  
Vol 62 (7) ◽  
pp. o2765-o2767
Author(s):  
Hong-Li Wang ◽  
Bin Zhang ◽  
Yi Dai

The title compound, C10H9N3, is essently planar, except for the methyl H atoms. The asymmetric unit consists of two molecules. In the crystal structure, weak intramolecular C—H...N hydrogen-bonding interactions occur, linking the molecules into chains propagating along the a axis.


2014 ◽  
Vol 70 (9) ◽  
pp. o1051-o1052 ◽  
Author(s):  
Ignez Caracelli ◽  
Stella H. Maganhi ◽  
Paulo J. S. Moran ◽  
Bruno R. S. de Paula ◽  
Felix N. Delling ◽  
...  

In the title compound, C17H14N2O6, the conformation about the C=C double bond [1.345 (2) Å] isE, with the ketone moiety almost coplanar [C—C—C—C torsion angle = 9.5 (2)°] along with the phenyl ring [C—C—C—C = 5.9 (2)°]. The aromatic rings are almost perpendicular to each other [dihedral angle = 86.66 (7)°]. The 4-nitro moiety is approximately coplanar with the benzene ring to which it is attached [O—N—C—C = 4.2 (2)°], whereas the one in theorthoposition is twisted [O—N—C—C = 138.28 (13)°]. The molecules associateviaC—H...O interactions, involving both O atoms from the 2-nitro group, to form a helical supramolecular chain along [010]. Nitro–nitro N...O interactions [2.8461 (19) Å] connect the chains into layers that stack along [001].


2013 ◽  
Vol 739 ◽  
pp. 26-29
Author(s):  
Hai Xing Liu ◽  
Jing Zhong Xiao ◽  
Huan Mei Guo ◽  
Qing Hua Zhang ◽  
Zhang Xue Yu ◽  
...  

A novel Zn complex [Zn (C12H8N2)(C4H4O5)(H2O)](H2O) has been synthesized from a hydrothermal reaction and the crystal structure has been determined by means of single-crystal X-ray diffraction. The Zn atom is six-coordinated by two phenanthroline N atoms, three O atoms from malic acid anion and one O atom from water. The crystal packing is stabilized by O-H...O hydrogen bonding interactions.


2022 ◽  
Author(s):  
Zhi-Gang Yin ◽  
Xiong-Wei Liu ◽  
Hui-Juan Wang ◽  
Min Zhang ◽  
Xiong-Li Liu ◽  
...  

A highly efficient synthesis of structurally diverse ortho-acylphenol–diindolylmethane hybrids 3 using carboxylic acid-activated chromones as versatile synthetic building blocks is reported here for the first time, through 1,4-nucleophilic addition and followed by a decarboxylation and pyrone ring opening reaction process.


2018 ◽  
Vol 34 (1) ◽  
pp. 59-65
Author(s):  
Austin M. Wheatley ◽  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton

The crystal structure of minocycline hydrochloride dihydrate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Minocycline hydrochloride dihydrate crystallizes in space groupP212121(#19) witha= 7.40772(1),b= 14.44924(3),c= 22.33329(4) Å,V= 2390.465(12) Å3, andZ= 4. The minocycline cation is a zwitterion: both dimethylamino groups are protonated and one hydroxyl group is ionized. A potential ambiguity in the orientation of the amide group was resolved by considering Rietveld refinement residuals and displacement coefficients, as well as DFT energies. The crystal structure is dominated by hydrogen bonds. Both water molecules and a hydroxyl group act as donors to the chloride anion. Both protonated dimethyl amine groups act as donors to the ionized hydroxyl group. Several intramolecular O–H···O hydrogen groups help determine the conformation of the cation. The powder pattern is included in the Powder Diffraction File™ as entry 00-066-1606.


Author(s):  
Andrew J. Cigler ◽  
James A. Kaduk

The crystal structure of poly[μ-citrato-dilithium(I)potassium(I)], [Li2K(C6H5O7)] n , has been solved and refined using laboratory X-ray powder diffraction data, and optimized using density functional techniques. The citrate anion triply chelates to the K+ cation through the hydroxyl group, the central carboxylate, and the terminal carboxylate. The KO7 coordination polyhedra share edges, forming chains parallel to the a axis. These chains share edges with one tetrahedral Li ion, and are bridged by edge-sharing pairs of the second tetrahedral Li ion, forming layers parallel to the ac plane.


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