nan Dinesh

Synthesis, x-ray structure and N-H…O interactions in 1,3-d iphenyl-urea

The synthesis, X-ray structure and role of intermolecular interactions have been studied in case of 1,3-diphenyl-urea, owing to its medicinal importance. The compound crystallizes in orthorhombic crystal system (space group,Pna21)with unit cell parameters,a= 9.118(3), b = 10.558(2),c= 11.780(3) Å and Z = 4. The structure has been solved by direct methods and refined to a final R-value of 00316. The oxygen atom of the carbonyl group is responsible for the existence of two N—H…O intermolecular interactions.

Crystal structure analysis of 4-phenylquinolin-2-(1H)-one

The crystal structure of 4-phenylquinolin-2-(1H)-one (C15H11NO) is determined by X-ray diffraction. The compound crystallizes in the orthorhombic crystal system (space group Pbca) with the unit cell parameters a = 7.382(2) Å, b = 21.795(3) Å, c = 14.066(5) Å, and Z = 8. The structure is solved by direct methods and refined to an R-value of 0.0398 for 1360 observed reflections [F0 > 4σ (F0)]. The quinoline moiety and the substituted phenyl ring are nearly planar. The dihedral angle between these two moieties is 64.65(6)°. The crystal structure is stabilized by two intermolecular N-H⋯O and C-H⋯O interactions.

Structure Analysis of Methyl-3,4-dihydro-3-(p-methylphenyl)-4-oxo-2-quinazolinyl thiopropionate

The crystal structure of methyl-3, 4-dihydro-3-(p-methylphenyl)-4-oxo-2-quinazolinyl thiopropionate (C 19 H 18 N 2 O 3 S) has been determined by X-ray diffraction methods. The compound crystallizes in the triclinic space group P1 with unit cell parameters: a = 9.094(2), b = 9.428(3), c = 10.612(3) A, a 94.55(3), β = 95.44(2), y = 106.75(3) ° and Z = 2. The structure has been refined to an R-value of 0.054 for 2533 observed reflections [F o >4σ(F o )]. The quinazoline moiety and the methyl substituted phenyl ring is almost planar. The dihedral angle between these two moieties is 84.96(8)°. The crystal structure is stabilized by an intermolecular C-H…O interaction.

Weak C-H…O hydrogen bonds in alkaloids: An overview

An overview of general classification scheme, medicinal importance and crystal structure analysis with emphasis on the role of hydrogen bonding in some alkaloids is presented in this paper. The article is based on a general kind of survey while crystallographic analysis and role of hydrogen bonding are limited to only those alkaloids whose three-dimensional structure has been reported by us. The C-H…O hydrogen bonding in the solid state in alkaloids has been found to be predominant and this observation makes the role of hydrogen bonding in organic molecular assemblies very important.

X-ray crystallography of cholest-3,5-diene-7-one

The molecular structure of cholest-3,5-diene-7-one (C27H42O) is determined by X-ray diffraction. The compound crystallizes in the orthorhombic crystal system (space group P212121) with unit cell parameters a = 11.281(5) Å, b = 11.350(5) Å, c= 18.518(5) Å, and Z = 4. The structure is solved by direct methods and refined to an R-value of 0.054 for 1070 observed reflections [Fo > 4σ(Fo)]. Ring A adopts a distorted half-chair conformation, ring B exists in sofa conformation, ring C acquires a chair conformation, and the five-membered ring D occurs in distorted half-chair conformation. The crystal structure is stabilized by van der Waals forces.

Crystallographic Investigations of 3β-acetoxy-5α-cholestan-6-one-semicarbazone - A Steroid

The crystal structure of 3β-acetoxy-5a-cholestan-6-one-semicarbazone (C 30 H 51 O 3 N 3 ) has been determined by X-ray diffraction methods. It crystallizes in the orthorhombic space group P2 1 2 1 2 1 with cell parameters a = 11.641(1), b = 16.552(1) c = 31.181(4) A and Z = 8. The structure has been refined to an R-value of 0.050 for 4407 observed reflections. Two molecules in the asymmetric unit have been observed. In both the crystallographically independent molecules, all the three six-membered rings (A, B and C ) of steroid nucleus exist in chair conformation, while the five- membered ring D exists in 13β distorted-envelope in molecule-I and 13β, 14α half-chair conformation in molecule-II. Three intermolecular N-H...O hydrogen bonds have been observed.

Crystallographic investigations of 1,4-benzothiazin-2(1H)one and 3-methyl-1,4-benzothiazin-2(1H)one

AbstractThe crystal structures of 1,4-benzothiazin-2(1H)one (C8H7SNO) (I) and 3-methyl-1,4-benzothiazin-2(1H)one (C9H9SNO) (II) have been determined by X-ray diffraction methods. I crystallizes in the monoclinic system with space group P21/n, while II crystallizes in triclinic with space group P

Crystal structure of cholest-4-ene-3,6-dione: A steroid

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