2-Phenyl-4-hydroxyphthalazin-1-one: A Benzoannelated Derivative of Maleic Hydrazide

1998 ◽  
Vol 54 (5) ◽  
pp. 671-676 ◽  
Author(s):  
D. Becker ◽  
M. Botoshansky ◽  
N. Gasper ◽  
F. H. Herbstein ◽  
M. Karni
Keyword(s):  
Hydrogen Bonding ◽  
Electron Correlation ◽  
Maleic Hydrazide ◽  
Van Der Waals Interactions ◽  
Asymmetric Unit ◽  
Parent Molecule ◽  
Molecular Arrangement ◽  
Independent Molecules ◽  
High Level ◽  
Good Agreement

The monoclinic crystals (space group P21/a, Z = 8) of 2-phenyl-4-hydroxyphthalazin-1-one, C14H10N2O2, have two independent molecules (A and B) in the asymmetric unit. Both occur as the lactim–lactam (hydroxy–one) structure, which is also found in the parent molecule maleic hydrazide (both triclinic and monoclinic polymorphs), dichloromaleic hydrazide and luminol (3-aminophthalhydrazide). The molecular arrangement is based on strings of alternating A and B molecules linked by hydroxyl...carbonyl hydrogen bonds, with only van der Waals interactions between adjacent strings. Comparison is made of the measured bond lengths for (monoclinic) maleic hydrazide and values from high-level ab initio calculations, and reasonably good agreement is obtained, with indications of improvements when allowance is made for electron correlation and hydrogen bonding.

The first crystal structures of six- and seven-membered tellurium- and nitrogen-containing (Te—N) heterocycles: 2H-1,4-benzotellurazin-3(4H)-one and 2,3-dihydro-1,5-benzotellurazepin-4(5H)-one

2016 ◽  
Vol 72 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Joshua P. Myers ◽  
Frank R. Fronczek ◽  
Thomas Junk
Keyword(s):  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Boat Conformation ◽  
Asymmetric Unit ◽  
Bond Lengths ◽  
Independent Molecules ◽  
Twist Boat ◽  
Good Agreement

There is a paucity of data concerning the structures of six- and seven-membered tellurium- and nitrogen-containing (Te—N) heterocycles. The title compounds, C8H7NOTe, (I), and C9H9NOTe, (II), represent the first structurally characterized members of their respective classes. Both crystallize with two independent molecules in the asymmetric unit. When compared to their sulfur analogs, they exhibit slightly greater deviations from planarity to accommodate the larger chalcogenide atom, with (II) adopting a pronounced twist-boat conformation. The C—Te—C angles of 85.49 (15) and 85.89 (15)° for the two independent molecules of (I) were found to be somewhat smaller than those of 97.4 (2) and 97.77 (19)° for the two independent molecules of (II). The C—Te bond lengths [2.109 (4)–2.158 (5) Å] are in good agreement with those predicted by the covalent radii. Intermolecular N—H...O hydrogen bonding in (I) forms centrosymmetricR22(8) dimers, while that in (II) forms chains. In addition, intermolecular Te...O contacts [3.159 (3)–3.200 (3) Å] exist in (I).

3-n-Butyl-2-methoxy-1-benzothieno[3,2-d]pyrimidin-4(3H)-one

2006 ◽  
Vol 62 (4) ◽  
pp. o1319-o1320 ◽  
Author(s):  
Min-Hui Cao ◽  
Sheng-Zhen Xu ◽  
Yang-Gen Hu
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Benzene Ring ◽  
Title Compound ◽  
Thiophene Ring ◽  
Stacking Interactions ◽  
Asymmetric Unit ◽  
Compound C ◽  
Π Stacking ◽  
Independent Molecules

The title compound, C15H16N2O2S, contains a five-membered thiophene ring fused to a benzene ring and a substituted pyrimidinone ring. All three rings in each of the independent molecules of the asymmetric unit lie in approximately the same plane. The crystal structure is stabilized by intermolecular C—H...O hydrogen bonding and π–π stacking interactions.

scholarly journals (S)-2-[(4-Fluorophenyl)formamido]-3-phenylpropanoic acid

IUCrData ◽  
2020 ◽  
Vol 5 (7) ◽  
Author(s):  
Kathleen S. Lee ◽  
Luke Turner ◽  
Cynthia B. Powell ◽  
Eric W. Reinheimer
Keyword(s):  
Hydrogen Bonding ◽  
Title Compound ◽  
Phenyl Ring ◽  
Room Temperature ◽  
Solid Phase ◽  
Independent Molecule ◽  
Asymmetric Unit ◽  
Torsion Angles ◽  
Compound C ◽  
Independent Molecules

The title compound, C16H14FNO3, was synthesized via solid phase methods; it exhibits monoclinic (P21) symmetry at room temperature. The two independent molecules that comprise the asymmetric unit display distinct torsion angles of 173.2 (2) and 72.6 (2)° along the central sp 3 C—N bond. In the crystal, hydrogen bonding through N—H...O contacts couples the asymmetric unit molecules into pairs that align in layers extending parallel to (100) via additional O—H...O interactions. The phenyl ring of one independent molecule was found to be disordered over two sets of sites in a 0.55 (3):0.45 (3) ratio.

4,4′-Dibenzyl-5,5′-(pyridine-2,6-diyl)bis(3,4-dihydro-2H-1,2,4-triazole-3-thione)

2006 ◽  
Vol 62 (5) ◽  
pp. o1822-o1823
Author(s):  
Sibel Demir ◽  
Muharrem Dinçer ◽  
Ahmet Çetin ◽  
Osman Dayan ◽  
Ahmet Cansız
Keyword(s):  
Hydrogen Bonding ◽  
Title Compound ◽  
Tautomeric Form ◽  
Asymmetric Unit ◽  
Compound C ◽  
Hydrogen Bonding Interactions ◽  
Independent Molecules

The title compound, C23H19N7S2, adopts the ketoamine tautomeric form and displays C—H...N hydrogen-bonding interactions. There are two independent molecules in the asymmetric unit.

scholarly journals (3aR*,8bR*)-3a,8b-Dihydroxy-1-(4-methylphenyl)-2-methylsulfanyl-3-nitro-1,8b-dihydroindeno[1,2-b]pyrrol-4(3aH)-one

2014 ◽  
Vol 70 (3) ◽  
pp. o279-o280
Author(s):  
R. A. Nagalakshmi ◽  
J. Suresh ◽  
R. Ranjith Kumar ◽  
V. Jeyachandran ◽  
P. L. Nilantha Lakshman
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Dihedral Angles ◽  
Asymmetric Unit ◽  
Compound C ◽  
Dimensional Network ◽  
Independent Molecules ◽  
Hydroxy Groups

The asymmetric unit of the title compound, C19H16N2O5S, contains four independent molecules (A,B,CandD), with two molecules (BandD) displaying disorder in their methylsulfanyl groups [occupancy ratios of 0.797 (11):0.203 (11) and 0.85 (2):0.15 (2)]. The nitro groups are twisted slightly out of the planes of the 2-pyrroline rings to which they are bonded with dihedral angles of 10.17 (1), 8.01 (1), 9.44 (1) and 8.87 (1)° in moleculesA,B,CandD, respectively. The 2-pyrroline rings are almost orthogonal to the attached tolyl rings, forming dihedral angles of 73.44 (1), 81.21 (1), 88.18 (8) and 73.94 (1)° for moleculesA,B,CandD, respectively. A weak intramolecular O—H...O interaction is observed in moleculesBandC. The two hydroxy groups in each molecule are involved in intermolecular O—H...O hydrogen bonding. In the crystal, molecules are connectedviaO—H...O and C—H...O hydrogen bonds, forming a complex three-dimensional network.

scholarly journals 1-(4-Chlorobutanoyl)-3-(2-nitrophenyl)thiourea

2012 ◽  
Vol 68 (6) ◽  
pp. o1801-o1801 ◽  
Author(s):  
Nurziana Ngah ◽  
Maisara Kadir ◽  
Bohari M. Yamin ◽  
M. Sukeri M. Yusof
Keyword(s):  
Hydrogen Bonding ◽  
Benzene Ring ◽  
Title Compound ◽  
Dihedral Angles ◽  
Intermolecular Hydrogen Bonding ◽  
Asymmetric Unit ◽  
Compound C ◽  
Thioamide Group ◽  
Independent Molecules

The asymmetric unit of the title compound, C11H12ClN3O3S, contains two independent molecules with different conformations in which the benzene ring and the thiourea fragment form dihedral angles of 87.28 (12) and 66.44 (10)°. The O atom of the thioamide group is involved in bifurcated N—H...O intra- and intermolecular hydrogen bonding; the latter interaction links the independent molecules into a dimer. In the crystal, N—H...S interactions link the molecules into chains propagating along the c axis.

scholarly journals The crystal structure of 1-(2-hydroxy-5-methoxyphenyl)ethanone 4,4-dimethylthiosemicarbazone

2015 ◽  
Vol 71 (11) ◽  
pp. o811-o812
Author(s):  
Brian J. Anderson ◽  
Michael B. Freedman ◽  
Victoria A. Smolenski ◽  
Jerry P. Jasinski
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Methyl Groups ◽  
Asymmetric Unit ◽  
Compound C ◽  
Thioamide Group ◽  
The Mean ◽  
Independent Molecules ◽  
The Individual

The asymmetric unit of the title compound, C12H17N3O2S, contains two independent molecules,AandB. Both molecules are nearly planar with the dihedral angle between the mean planes of the thioamide group and benzene ring being 7.5 (1)° inAand 4.3 (2)° inB. In each molecule, the hydroxy group participates in intramolecular O—H...N hydrogen bonding, while the amino H atom is not involved in hydrogen bonding because of the steric hinderence caused by two neighboring methyl groups. In the crystal, the individual molecules are linked by weak C—H...O hydrogen bonds, formingA–AandB–Binversion dimers. The dimers are linkedviaC—H...π interactions which help stabilize the packing.

scholarly journals Crystal structure of 8-(4-methylphenyl)-2′-deoxyadenosine hemihydrate

2018 ◽  
Vol 74 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Ajaykumar V. Ardhapure ◽  
Yogesh S. Sanghvi ◽  
Yulia Borozdina ◽  
Anant Ramakant Kapdi ◽  
Carola Schulzke
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Water Molecule ◽  
Title Compound ◽  
Crystal Packing ◽  
The Other ◽  
Independent Molecule ◽  
Asymmetric Unit ◽  
Solvent Water ◽  
Independent Molecules

In the asymmetric unit, equalling the unit cell (triclinic,P1,Z= 1), two molecules of the title compound, 8-(4-methylphenyl)-D-2′-deoxyadenosine, C17H19N5O3, are present, with distinct conformations of the two sugar moieties, together with one solvent water molecule. All three ribose O atoms are involved in hydrogen bonding and the crystal packing is largely determined by hydrogen-bonding or hydrogen–heteroatom interactions (O—H...O, O—H...N, N—H...O, C—H...O and C—H...N) with one independent molecule directly linked to four neighbouring molecules and the other molecule directly linked to six neighbouring molecules. The two independent molecules of the asymmetric unit display three weak intramolecular C—H-to-heteroatom contacts, two of which are very similar despite the different conformations of the deoxyribosyl moieties. The aromatic ring systems of both molecules are in proximity to each other and somehow aligned, though not coplanar. The absolute structures of the two molecules were assumed with reference to the reactant 8-bromo-D-2′-deoxyadenosine as they could not be determined crystallographically.

scholarly journals 16α,17α-Epoxy-5α-hydroxy-6β-nitrooxy-20-oxopregnan-3β-yl acetate

2009 ◽  
Vol 65 (6) ◽  
pp. o1271-o1272 ◽  
Author(s):  
R. M. A. Pinto ◽  
A. Matos Beja ◽  
J. A. R. Salvador ◽  
J. A. Paixão
Keyword(s):  
Hydrogen Bonding ◽  
Ring Opening ◽  
Membered Ring ◽  
Asymmetric Unit ◽  
Bond Lengths ◽  
Envelope Conformation ◽  
Independent Molecules ◽  
Hydrogen Bonding Network

The title steroid, C23H33NO8, is a pregnane derivative obtained regio-, stereo- and chemoselectively from the ring opening of the corresponding 5α,6α;16α,17α-diepoxide with bismuth(III) nitrate. There are two symmetry-independent molecules in the asymmetric unit that show no significant differences concerning bond lengths and angles. All rings aretrans-fused. The conformations of the six-membered rings are close to chair forms, while the five-membered ring adopts an envelope conformation. The molecules are held together by an extensive O—H...O hydrogen-bonding network of chains runnning along theaaxis.

scholarly journals Crystal structure of 4,8-di-tert-butyl-6,6-dichloro-13-ethyl-2,10-dimethyl-13,14-dihydro-12H-dibenzo[d,i][1,3,7,2]dioxazasilecine toluene 0.25-solvate

2015 ◽  
Vol 71 (12) ◽  
pp. o1065-o1066
Author(s):  
Ekaterina A. Kuchuk ◽  
Kirill V. Zaitsev ◽  
Sergey S. Karlov ◽  
Mikhail P. Egorov ◽  
Andrei V. Churakov
Keyword(s):  
Solvent Molecule ◽  
The Other ◽  
Asymmetric Unit ◽  
Torsion Angles ◽  
Orthogonal Least Squares ◽  
Compound C ◽  
Distorted Trigonal Bipyramid ◽  
Independent Molecules ◽  
Cl Atom ◽  
Good Agreement

The coordination polyhedron at the silicon atom in the title compound, C26H37Cl2NO2Si·0.25C7H8, is typical for pentacoordinated silicon derivatives and represents a slightly distorted trigonal bipyramid with an N atom and a Cl atom in the apical positions and the two O atoms and the other Cl atom occupying the equatorial sites. There are two independent molecules in the asymmetric unit. The N–Si–Cl fragment in each is close to linear [178.24 (5) and 178.71 (5)°], in good agreement with 4e–3ctheory, as is the elongation of the apical bond lengths [Si—Cl = 2.1663 (7) and 2.1797 (7) Å] in comparison with the equatorial bonds [Si—Cl = 2.0784 (7) and 2.0748 (7) Å]. Orthogonal least-squares fitting of the two independent molecules resulted in r.m.s. deviation of 0.017 Å. The conformations of the two molecules are almost the same, with corresponding torsion angles differing by less than 5.5°. The toluene solvent molecule is disordered about an inversion centre.

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