P.A. Suchetan

Bio: P.A. Suchetan is an academic researcher from Mangalore University. The author has contributed to research in topics: Dihedral angle & Sulfonamide. The author has an hindex of 9, co-authored 56 publications receiving 236 citations.

N-Benzo-ylbenzene-sulfonamide.

Abstract: In the crystal structure of the title compound, C13H11NO3S, the conformation of the N—H bond in the C—SO2—NH—C(O)—C segment is anti to the C=O bond. The molecule is twisted at theN atom with a dihedral angle of 86.5(1)° between the sulfonyl benzene ring and the —SO2—NH—C=O segment. Furthermore, the dihedral angle between the two benzene rings is 80.3(1)°. The crystal structure features inversion-related dimers linked by pairs of N—H⋯O(S) hydrogen bonds.

N-Benzoyl-2-chloro-benzene-sulfonamide.

Abstract: In the crystal structure of the title compound, C13H10ClNO3S, the conformation of the of the N—H bond in the C—SO2—NH—C(O) segment is anti to the C=O bond. The dihedral angle between the two benzene rings is 73.3 (1)°. In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds occur.

N-Benzoyl-2-methyl­benzene­sulfonamide

Abstract: In the title compound, C14H13NO3S, the conformation of the N—H bond in the C—SO2—NH—C(O) segment is anti to the C=O bond. The tolyl and benzoyl groups are twisted about the S—N bond, with a C—S—N—C torsion angle of 68.8 (4)°. The dihedral angle between the sulfonyl and the benzoyl benzene rings is 73.9 (1)°. In the crystal, the mol­ecules are linked into C(4) chains along the c axis by N—H⋯O hydrogen bonds.

N-(4-Chloro­benzo­yl)benzene­sulfonamide

Abstract: In the crystal structure of the title compound, C13H10ClNO3S, the conformation of the N—H bond in the C—SO2—NH—C(O) segment is anti to the C=O bond. The dihedral angle between the two aromatic rings is 68.6 (1)°. The mol­ecule is twisted at the S atom with a dihedral angle of 75.7 (1)° between the sulfonyl benzene ring and the —SO2—NH—C—O segment; the dihedral angle between the latter and the benzoyl ring is 8.3 (2)°. In the crystal, mol­ecules are linked by N—H⋯O(S) hydrogen bonds.

2-Methyl-N-(4-methyl-benzo-yl)benzene-sulfonamide.

Abstract: The asymmetric unit of the title compound, C15H15NO3S, contains two independent mol­ecules. The conformations of the N—C bonds in the C—SO2—NH—C(O) segments have gauche torsions with respect to the SO bonds. Further, the mol­ecules are twisted at the S atoms with torsion angles of −53.1 (2) and 61.2 (2)° in the two mol­ecules. The dihedral angles between the sulfonyl benzene rings and the —SO2—NH—C—O segments are 86.0 (1) and 87.9 (1)°. Furthermore, the dihedral angles between the sulfonyl and the benzoyl benzene rings are 88.1 (1) and 83.5 (1)° in the two mol­ecules. In the crystal, mol­ecules are linked by N—H⋯O(S) hydrogen bonds.

N-H···X(X = F, Cl, Br, and I) hydrogen bonding in aromatic amide derivatives in crystal structures

Abstract: Intramolecular N-H…X (X = F, Cl, Br, and I) hydrogen bonding patterns of aromatic amides in the solid state are summarized. It is revealed that the key for the formation of this kind of weak intramolecular hydrogen bonding in X-ray crystal structures is to suppress the competition of strong intermolecular N-H…O-C hydrogen bonding of the amide unit. For amides with identical backbones, the bonding capacity of halogen atoms as hydrogen bonding acceptors is in the order of F>Cl>Br>I, which is in accordance with their electronegativity strength. Generally, the five-membered hydrogen bonding is easier to form than the six-membered one.

N-Benzoyl-2-chloro-benzene-sulfonamide.

Abstract: In the crystal structure of the title compound, C13H10ClNO3S, the conformation of the of the N—H bond in the C—SO2—NH—C(O) segment is anti to the C=O bond. The dihedral angle between the two benzene rings is 73.3 (1)°. In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds occur.

N-Benzoyl-2-methyl­benzene­sulfonamide

Abstract: In the title compound, C14H13NO3S, the conformation of the N—H bond in the C—SO2—NH—C(O) segment is anti to the C=O bond. The tolyl and benzoyl groups are twisted about the S—N bond, with a C—S—N—C torsion angle of 68.8 (4)°. The dihedral angle between the sulfonyl and the benzoyl benzene rings is 73.9 (1)°. In the crystal, the mol­ecules are linked into C(4) chains along the c axis by N—H⋯O hydrogen bonds.

Supramolecular Packing of a Series of N-Phenylamides and the Role of NH···O=C Interactions.

Abstract: A series of seven N-phenylamides [R–C(O)NHPh, in which R: CH3, C(CH3)3, Ph, CF3, CCl3, CBr3, and H] were used as models in this study. Molecular packing and intermolecular interactions were evaluated by theoretical calculations, solution NMR, and quantum theory of atoms in molecules analyses. Crystallization mechanisms were proposed based on the energetic and topological parameters using the supramolecular cluster as demarcation. Concentration-dependent 1H NMR experiments corroborated the proposed interactions between molecules. For all compounds (except for R: H, which initially formed tetramers), layers (two-dimensional) or chains (one-dimensional) were formed in the first stage of the proposed crystallization mechanisms. The presence of strong intermolecular NH···O═C interactions promoted the first stages. The study in solution provided different values of association constant (Kass) governed by the hydrogen bond NH···O═C, showing that the stronger interactions are directly influenced by the substituen...