Nassir N. Al-Mohammed

Synthesis and Antibacterial Evaluation of Some Novel Imidazole and Benzimidazole Sulfonamides

Several new substituted sulfonamide compounds were synthesized and their structures were confirmed by 1H-NMR, 13C-NMR, FT-IR, and mass spectroscopy. The antibacterial activities of the synthesized compounds were screened against standard strains of six Gram positive and four Gram negative bacteria using the microbroth dilution assay. Most of the compounds studied showed promising activities against both types of bacteria.

Tetrakis-imidazolium and benzimidazolium ionic liquids: a new class of biodegradable surfactants

Novel series of tetra-cationic ionic liquids containing alkyl or phenyl side chains and ester groups within the same molecule were successfully prepared. Based on imidazolium and benzimidazolium, these ionic liquids were synthesized from readily available starting materials in high yield. Surfactant properties including liquid crystalline behaviour and surface properties as well as their biodegradability were investigated. Tetrakis-imidazolium ionic liquid compounds showed assembly behaviour in the pure form (i.e. spontaneously) and in the presence of polar or nonpolar solvents, while both imidazolium and benzimidazolium ionic liquids effectively reduced the surface tension of water in the range of 29–34 mN m−1. The incorporation of tetra alkyl or phenyl side chains into imidazolium and benzimidazolium ionic liquids with tetra-ester groups, significantly improved the biodegradation. ‘Closed-Bottle Test’ OECD 301D and sodium n-dodecyl sulphate (SDS) as a reference were used for evaluation. The linear alkyl side chains (i.e. butyl, hexyl, octyl, decyl and dodecyl) in both tetrakis-imidazolium and benzimidazolium ionic liquids promote the increasing in biodegradation and phase behaviour results comparing to aromatic side-chains.

Bis-imidazolium and benzimidazolium based gemini-type ionic liquids structure: synthesis and antibacterial evaluation

Based on bis-imidazolium and benzimidazolium, new sets of geminal dicationic ionic liquids containing a sulphonamide moiety were successfully synthesized with good yields. Their structures were confirmed by 1H-NMR, 13C-NMR, FT-IR, and mass spectroscopy. Selected physicochemical properties of these ILs including thermal stability by TGA and miscibility in some common organic solvents and water were also determined. Most of the prepared dicationic ILs displayed significant levels of antibacterial activities against ten selected bacterial strains of Gram-positive and Gram-negative using a micro-broth dilution assay.

1-Carb-oxy-methyl-3-octylimidazolium bromide.

In the title compound, C13H23N2O2 +·Br−, the octyl chain has an all-trans conformation. In the crystal, the cations are linked by C—H⋯O bonds into a zigzag chain along the b axis. The bromide anions further link the chains via C—H⋯Br interactions into a two-dimensional array parallel to the ab plane. An O—H⋯Br interaction is also observed.

N,N′-{[Ethane-1,2-diylbis(­oxy)]bis­(ethane-2,1-di­yl)}bis­(4-methyl­benzene­sulfonamide)

The asymmetric unit of the title compound, C20H28N2O6S2, contains one half-molecule, related to the other half by a twofold rotation axis. The two aromatic rings of the molecule make a dihedral angle of 50.91 (7)°. The O—CH2—CH2—O and N—CH2—CH2—O fragments both adopt gauche conformations, with torsion angles of 76.0 (4) and 70.4 (3)°, respectively. In the crystal, adjacent molecules are linked through N—H⋯O hydrogen bonds into chains along the a-axis direction. The chains are further connected via C—H⋯O interactions into a two-dimensional supramolecular network in the ac plane.

tert-Butyl 2-(1H-benzimidazol-1-yl)acetate.

In the title compound, C13H16N2O2, the planes of the benzimidazole ring system and the acetate O—C=O fragment make a dihedral angle of 84.5 (3)°. In the crystal, molecules are connected through C—H⋯N hydrogen bonds to form infinite chains in the [-110] direction.

1-Tosyl-2-[(1-tosyl-1H-benzimidazol-2-yl)methyl-sulfanyl]-1H-benzimidazole.

In the title compound, C29H24N4O4S3, the two N-tosylbenzimidazolyl unit are connected through a —S—CH2— fragment, the dihedral angle between the benzimidazole rings being 76.09 (5)°. The methylthio group is disordered with respect to exchange of the S and C atoms in a 0.547 (4):0.453 (4) ratio. In the crystal, C—H⋯O and C—H⋯π interactions connect adjacent molecules into infinite layers parallel to the ab plane. The crystal packing is further stabilized by a π–π interaction [centroid–centroid separation = 3.5187 (4) Å].

2-Methyl-3-[(4-methyl-phen-yl)sulfon-yl-oxy]-2-{[(4-methyl-phen-yl)sulfon-yloxy]meth-yl}propyl 4-methyl-benzene-sulfonate.

The title molecule, C26H30O9S3, adopts an extended conformation whereby two approximately parallel benzene rings [dihedral angle = 8.32 (10)°] are orientated in opposite directions along the pseudo-threefold axis through the central quaternary C atom, while a third ring occupies a position mid-way and face-on to these rings [dihedral angles = 82.28 (10) and 78.81 (7)°]. The crystal packing is dominated by C—H⋯O contacts and π–π interactions [ring centroid distance = 3.6902 (12) Å].

Imidazo[1,2-b]isoquinoline-5,10-dione.

The title butterfly-shaped molecule, C11H6N2O2, is folded slightly along the O=C⋯C=O line, the dihedral angle between the two parts being 6.42 (3)°. In the crystal, adjacent molecules are linked through C—H⋯O hydrogen bonds into infinite layers parallel to the ac plane. The layers are further connected into a three-dimensional netweork via π–π interactions formed between pairs of antiparallel arranged molecules, with a centroid–centroid distance between the central six-membered ring and the benzene ring of 3.4349 (9) Å.

1,1′-{2,2′-[1,4-Phenyl­enebis(methyl­ene)]bis­(­oxy)bis­(2,1-phenyl­ene)}diethanone

The asymmetric unit of the title compound, C24H22O4, contains one half-molecule, the other half being generated by a crystallographic center of inversion. The central benzene ring makes a dihedral angle of 72.49 (5)° with the terminal benzene ring. In the crystal, adjacent molecules are linked through C—H⋯O interactions, forming a sheet structure parallel to the bc plane. The sheets are stacked along the a axis via π–π interactions formed between the terminal benzene rings [centroid–centroid separation = 3.7276 (6) Å].