Mohamad J. Al-Jeboori

Comparison of the structural motifs and packing arrangements of six novel derivatives and one polymorph of 2-(1-phenyl-1H-1,2,3-triazol-4-yl)pyridine.

The crystal structures of a new polymorph and seven new derivatives of 2-(1-phenyl-1H-1,2,3-triazol-4-yl)pyridine have been characterized and examined along with three structures from the literature to identify trends in their intermolecular contact patterns and packing arrangements in order to develop an insight into the crystallization behaviour of this class of compound. Seven unique C-H···X contacts were identified in the structures and three of these are present in four or more structures, indicating that these are reliable supramolecular synthons. Analysis of the packing arrangements of the molecules using XPac identified two closely related supramolecular constructs that are present in eight of the 11 structures; in all cases, the structures feature at least one of the three most common intermolecular contacts, suggesting a clear relationship between the intermolecular contacts and the packing arrangements of the structures. Both the intermolecular contacts and packing arrangements appear to be remarkably consistent between structures featuring different functional groups, with the expected exception of the carboxylic acid derivative 4-(4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl) benzoic acid (L11), where the introduction of a strong hydrogen-bonding group results in a markedly different supramolecular structure being adopted. The occurrence of these structural features has been compared with the packing efficiency of the structures and their melting points in order to assess the relative favourability of the supramolecular structural features in stabilizing the crystal structures.

Co(II) and Cd(II) Complexes Derived from Heterocyclic Schiff-Bases: Synthesis, Structural Characterisation, and Biological Activity

New monomeric cobalt and cadmium complexes with Schiff-bases, namely, N′-[(E)-(3-hydroxy-4-methoxyphenyl)methylidene]furan-2-carbohydrazide (L1) and N′-[(E)-(3-hydroxy-4-methoxyphenyl)methylidene]thiophene-2-carbohydrazide (L2) are reported. Schiff-base ligands L1 and L2 were derived from condensation of 3-hydroxy-4-methoxybenzaldehyde (iso-vanillin) with furan-2-carboxylic acid hydrazide and thiophene-2-carboxylic acid hydrazide, respectively. Complexes of the general formula [M(L)2]Cl2 (where M = Co(II) or Cd(II), L = L1 or L2) have been obtained from the reaction of the corresponding metal chloride with the ligands. The ligands and their metal complexes were characterised by spectroscopic methods (FTIR, UV-Vis, 1H, and 13C NMR spectra), elemental analysis, metal content, magnetic measurement, and conductance. These studies revealed the formation of four-coordinate complexes in which the geometry about metal ion is tetrahedral. Biological activity of the ligands and their metal complexes against gram positive bacterial strain Bacillus (G+) and gram negative bacteria Pseudomonas (G−) revealed that the metal complexes become less resistive to the microbial activities as compared to the free ligands.

Metal Complexes of Macrocyclic Schiff-Base Ligand: Preparation, Characterisation, and Biological Activity

A new macrocyclic multidentate Schiff-base ligand Na4L consisting of two submacrocyclic units (10,21-bis-iminomethyl-3,6,14,17-tricyclo[17.3.1.1]tetracosa-1(23),2,6,8,10,12(24),13,17,19,21,-decaene-23,24-disodium) and its tetranuclear metal complexes with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) are reported. Na₄L was prepared via a template approach, which is based on the condensation reaction of sodium 2,4,6-triformyl phenolate with ethylenediamine in mole ratios of 2 : 3. The tetranuclear macrocyclic-based complexes were prepared from the reaction of the corresponding metal chloride with the ligand. The mode of bonding and overall geometry of the compounds were determined through physicochemical and spectroscopic methods. These studies revealed tetrahedral geometries about Mn, Co, and Zn atoms. However, square planar geometries have been suggested for Ni(II) and Cu(II) complexes. Biological activity of the ligand and its metal complexes against Gram positive bacterial strain Staphylococcus aureus and Gram negative bacteria Escherichia coli revealed that the metal complexes become more potentially resistive to the microbial activities as compared to the free ligand. However, these metal complexes do not exhibit any effects on the activity of Pseudomonas aeruginosa bacteria. There is therefore no inhibition zone.

Chemical and structural data of (1,2,3-triazol-4-yl)pyridine-containing coordination compounds

The data presented in this paper are related to the research article entitled “Novel dichloro(bis{2-[1-(4-methylphenyl)-1H-1,2,3-triazol-4-yl-κN3]pyridine-κN})metal(II) coordination compounds of seven transition metals (Mn, Fe, Co, Ni, Cu, Zn and Cd)” (Conradie et al., 2018) [1]. This paper presents characterization and structural data of the 2-(1-(4-methyl-phenyl)-1H-1,2,3-triazol-1-yl)pyridine ligand (L2) (Tawfiq et al., 2014) [2] as well as seven dichloro(bis{2-[1-(4-methylphenyl)-1H-1,2,3-triazol-4-yl-κN3]pyridine-κN})metal(II) coordination compounds, [M(L2)2Cl2], all containing the same ligand but coordinated to different metal ions. The data illustrate the shift in IR, UV/VIS, and NMR (for diamagnetic complexes) peaks when L is coordinated to the metals, as well as the influence of the different metals on the peak positions. Solid state structural data is presented for M = Ni and Zn, while density functional theory calculated energies, structures and optimized coordinates are provided for the lowest energy cis and trans conformations for L2 as well as [M(L2)2Cl2] with M = Mn, Fe, Co, Ni, Cu, Zn and Cd.

Crystal structure of N-phenyl-2-(propan-2-ylidene)hydrazine-1-carbothioamide, C10H13N3S

Abstract C10H13N3S, monoclinic, P21/c (no. 14), a = 12.2463(8) Å, b = 7.6397(5) Å, c = 11.6544(9) Å, β = 102.684(2)°, V = 1060.72(11) Å3, Z = 4, Rgt(F) = 0.0448, wRref(F2) = 0.1211, T = 301(2) K.

Metal Complexes of Heterocyclic Hydrazone Schiff-bases; Preparation, Spectral Characterisation and Biological Study

New isatinic hydrazone Schiff-base ligands namely; furan-2-carboxylic acid (2-oxo-1,2-dihydro-indol-3-ylidene)-hydrazide) (L1), thiophene-2-carboxylic acid (2-oxo-1,2-dihydro-indol-3-ylidene)-hydrazide (L2) and 2-(pyridine-2-yl-hydrazono)-1,2-dihydro-indol-3-one) (L3) are reported. The ligands were prepared by the condensation of furan-2-carboxylic acid hydrazide (L1), thiophene-2-carboxylic acid hydrazide (L2), and 2-hydrazino pyridine (L3) with isatine. Monomeric complexes were prepared from the reaction of the corresponding metal chloride with the ligands. The ligands and their nine new complexes of the general formulae [M(Ln)2]Cl2 (where M= Co(II), Zn(II) and Cd(II); n= L1, L2 and L3), were characterised by spectroscopic methods (FTIR, UV-Vis, 1H, 13C NMR), elemental analysis, metal content, magnetic measurement and molar conductance. These studies revealed the formation of six coordinate complexes, in which the geometry about metal atom is a distorted octahedral. Biological activity of the ligands and their metal complexes against gram positive bacterial strain Bacillus (G+) and gram negative bacteria Ecoli (G-) are evaluated. The effects of prepared compounds depend on the type of tested bacteria. It is clear that, the ligands and their metal complexes have a potential effect on the gram positive (G+) and gram negative (G-) strains of the tested bacteria.

Formation of Polymeric Assemblies of Six-Coordinate Metal Complexes with Mixed Bridges of Dicarboxylato-Azido

New polydentate ligand namely bis(N-carboxylatoethyl)-4,4`-dipyridinium) L was synthesised from the reaction of 4,4`-dipyridine with ethyl chloropropionate. Polymeric complexes of general formulae [Cr2(L)(N3)4]Cl2.H2O, Na2[Ag2(L)(N3)4].H2O and [M2(L)(N3)4].nH2O, where (M= Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II); (where n = 2;1;1;1;0;1 and 1, respectively)) are reported. The mode of bonding and overall geometry of the complexes were determined through physico-chemical and spectroscopic methods. These studies revealed octahedral geometry complexes. Molecular structure for the complexes has been optimised by CS Chem 3D Ultra Molecular Modelling and Analysis Program and supported a six coordinate geometry.

Formation of polymeric assemblies of six-coordinate metal complexes with mixed bridges of dicarboxylato-azido moieties

New biscarboxylato zwitterionic ligands, namely bis(N-carboxylatoethyl)-4,4′-dipyridinum) L1 and bis(N-carboxylatopropyl)-)-4,4′-dipyridinum) L2, were synthesized from the reaction of 4,4′-dipyridine with 3-bromopropanoic acid and 4-bromobutanoic acid, respectively. The reaction of these ligands and the azido coligand with some metal ions resulted in the formation of polymeric complexes of general formulae [Cr2(Ln)(N3)4]Cl2·H2O and [M2(Ln)(N3)4] xH2O, where (M=Mn (II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II); n=1, 2; x=1, 1, 1, 1, 0, 1, and 1, respectively.) The oxygens of the carboxylato group are coordinated to the metal ion in a bidentate fashion. The mode of bonding and overall geometry of the complexes were determined through IR, UV–VIS, NMR and mass spectral studies, magnetic moment measurements, elemental analysis, metal content, chloride content and conductance. These studies revealed the formation of polymeric assemblies of six-coordinate complexes with distorted octahedral geometries about metal centers.