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In the mononuclear title compound, [Ni(C8H7O2)2(C3H4N2)2(H2O)], the NiII atom is coordinated by three carboxylate O atoms (from a bidentate 4-methyl­benzoate ligand and a monodentate 4-methyl­benzoate ligand), two N atoms (from two imidazole ligands) and a water mol­ecule in an octa­hedral geometry. Inter­molecular O—H⋯O hydrogen-bonding inter­actions lead to infinite chains, which are further self-assembled into a supra­molecular network through inter­molecular N—H⋯O hydrogen-bonding inter­actions and π–π stacking [centroid–centroid distance = 3.717 (2) Å].

In the title mononuclear complex, [Ni(C8H7O2)2(C5H5N)2(H2O)], the NiII atom is in a distorted octa­hedral arrangement, coordinated by three carboxylate O atoms from one bidentate 4-methyl­benzoate ligand and one monodentate 4-methyl­benzoate ligand, two N atoms from pyridine ligands, axially positioned, and a water mol­ecule. The equatorially positioned water mol­ecule and uncoordinated carb­oxylate O atom form an intra­molecular hydrogen bond. An inter­molecular O—H⋯O hydrogen bond between the coordinated water mol­ecule and carboxylate O atom of the 4-methyl­benzoate ligand forms infinite chains along the b axis. These chains are connected by C—H⋯π inter­actions.

In the title compound, [Ni(C9H6N3O2)2(H2O)4]·10H2O, the NiII ion lies on a twofold rotation axis and displays a slightly distorted octa­hedral geometry defined by two N atoms from two monodentate 4-(1,2,4-triazol-4-yl)benzoate ligands and four water mol­ecules, two of which also lie on the twofold rotation axis. In the crystal, the complex mol­ecules and uncoordinated water mol­ecules are linked via inter­molecular O—H⋯N and O—H⋯O hydrogen bonds, forming a three-dimensional supra­molecular network. π–π inter­actions between the benzene rings provide additional stability of the crystal packing [centroid–centroid distance = 3.792 (2) Å].

As part of our interest into the bioinorganic chemistry of gallium, gallium(III) complexes of the azole ligands 2,1,3-benzothiadiazole (btd), 1,2,3-benzotriazole (btaH), and 1-methyl-4,5-diphenylimidazole (L) have been isolated. Reaction of btaH or btd with GaBr3 or GaCl3 resulted in the mononuclear complexes [GaBr3(btaH)2] (1) and [GaCl3(btd)2] (2), respectively, while treatment of GaCl3 with L resulted in the anionic complex (LH)2[GaCl4] (3). All three complexes were characterized by single-crystal X-ray crystallography and IR spectroscopy, while their antiproliferative activities were investigated against a series of human and mouse cancer cell lines.

A new 1-D coordination polymer {[Mn6O2(O2CMe)10(H2O)4]·2.5H2O}∞ (1·2.5H2O)∞ and the cluster [Mn6O2(O2(O2CPh)10 (py)2(MeCN)(H2O)]·2MeCN (2·2MeCN) are reported. Both compounds were synthesized by room temperature reactions of [Mn3(μ3-O)(O2CR)6(L)2(L′)] (R = Me, L = L′ = py, (1·2.5H2O)∞; R = Ph, L = py, L′ = H2O, 2·2MeCN) in the presence of 3-hydroxymethylpyridine (3hmpH) in acetonitrile. The structures of these complexes are based on hexanuclear mixed-valent manganese carboxylate clusters containing the [Mn4IIMn2III(μ4-O)2]10+ structural core. (1·2.5H2O)∞ consists of zigzag chain polymers constructed from [Mn6O2(O2CMe)10(H2O)4] repeating units linked through acetate ligands, whereas 2·2MeCN comprises a discrete Mn6-benzoate cluster.

The reaction of N, N-bis(2-hydroxyethyl)glycine (bicine; bicH3) with Cd(O2CPh)2 · 2H2O in MeOH yielded the polymeric compound [Cd2(O2CPh)2(bicH2)2]n(1). The complex crystallizes in the tetragonal space group P41212. The lattice constants are a = b = 12.737(5) and c = 18.288(7) Å. The compound contains chains of repeating {Cd2(O2CPh)2(bicH2)2} units. One CdII atom is coordinated by two carboxylate oxygen, four hydroxyl oxygen, and two nitrogen atoms from two symmetry-related 2.21111 (Harris notation) bicH2− ligands. The other CdII atom is coordinated by six carboxylate oxygen atoms, four from two bicH2− ligands and two from the monodentate benzoate groups. Each bicinate(-1) ligand chelates the 8-coordinate, square antiprismatic CdII atom through one carboxylate oxygen, the nitrogen, and both hydroxyl oxygen atoms and bridges the second, six-coordinate trigonal prismatic CdII center through its carboxylate oxygen atoms. Compound 1 is the first structurally characterized cadmium(II) complex containing any anionic form of bicine as ligand. IR data of 1 are discussed in terms of the coordination modes of the ligands and the known structure.

A V-shaped ligand Bis(2-benzimidazolymethyl)amine (bba) and its nickel(II) picrate (pic) complex, with composition [Ni(bba)2](pic)2·3MeOH, have been synthesized and characterized on the basis of elemental analyses, molar conductivities, IR spectra, and UV/vis measurements. In the complex, the Ni(II) ion is six-coordinated with a N2O4 ligand set, resulting in a distorted octahedron coordination geometry. In addition, the DNA-binding properties of the Ni(II) complex have been investigated by electronic absorption, fluorescence, and viscosity measurements. The experimental results suggest that the nickel(II) complex binds to DNA by partial intercalation binding mode.

The title compound, [Ni2(C7H5O3)4(C7H6N2)4][Ni(C7H5O3)2(C7H6N2)2]·6H2O, is a mononuclear/dinuclear nickel(II) cocrystal, the two mol­ecular species inter­acting through hydrogen bonds that involve the uncoordinated water mol­ecules. In the mononuclear species, the NiII ion, located on an inversion center, is coordinated by two 1H-benzimidazole (bzim) ligands and two 3-hydroxy­benzoate (hba) anions in a square-planar geometry. In the centrosymmetric dinuclear species, the NiII ion is coordinated by two bzim ligands and three hba anions in a square-pyramidal geometry; of the two independent hba anions, one bridges two NiII ions with both carboxylate and hydroxyl groups whereas the other coordin­ates in a unidentate manner to the NiII ion. The apical Ni—Ohydrox­yl bond is 0.39 Å longer than the basal Ni—Ocarbox­yl bonds. The face-to-face separation of 3.326 (9) Å indicates the existence of π–π stacking between parallel bzim ligands of adjacent dinuclear entities. Extensive N—H⋯O and O—H⋯O hydrogen bonds help to stabilize the crystal structure.

The synthesis and characterization of two new tetronic acid zinc (II) complexes of the empirical formulae [Zn(L–H)2(H2O)2] (1) and [Zn(L–H)2(H2O)(MeOH)]H2O (2) found within the same crystal are reported. The zinc ions bind through alkoxide and carbonyl groups of the ligand 3-methoxycarbonyl-5-phenyl tetronic acid (LH) as indicated by 1H NMR and X-ray crystallographic studies. These complexes promote intra- and intermolecular interactions, such as hydrogen bonding and π stacking, giving place to the formation of molecular aggregates.

In the mononuclear title compound, [Ni(C8H7O3)2(C6H6N2O)2(H2O)2]·2H2O, the NiII ion is located on a crystallographic inversion center. The asymmetric unit further contains one 4-meth­oxy­benzoate anion, one nicotinamide (NA) ligand and one coordinated and one uncoordinated water mol­ecule; all ligands are monodentate. The four O atoms in the equatorial plane around the NiII ion form a slightly distorted square-planar arrangement, while the slightly distorted octa­hedral coordination is completed by the two pyridine N atoms of the NA ligands in the axial positions. The dihedral angle between the carboxyl­ate group and the attached benzene ring is 7.2 (1)°, while the pyridine and benzene rings are oriented at a dihedral angle of 72.80 (4)°. An intra­molecular O—H⋯O hydrogen bond links the uncoordinated water mol­ecule to one of the carboxyl­ate groups. In the crystal structure, inter­molecular O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds link the mol­ecules into a three-dimensional network.

The title mixed-ligand copper(I) complex, [Cu(C18H13N4O5S)(C18H15P)2], was synthesized via solvothermal reaction of [Cu(PPh3)2(MeCN)2]ClO4 and sulfasalazine [systematic name: 2-hydr­oxy-5-(2-{4-[(2-pyridylamino)sulfon­yl]phen­yl}diazen­yl)benzoic acid]. The mononuclear complex displays a trigonal coordination geometry for the Cu(I) atom, which is surrounded by two P-atom donors from two different PPh3 ligands and one O-atom donor from the monodentate carboxyl­ate group of the sulfasalazinate ligand. The latter ligand is found in a zwitterionic form, with a deprotonated amine N atom and a protonated pyridine N atom. Such a feature was previously described for free sulfasalazine. The crystal structure is stabilized by C—H⋯O, C—H⋯N, N—H⋯N and O—H⋯O hydrogen bonds.

In the title ZnII complex, [Zn(C8H8NO2)2(C6H6N2O)2]·H2O, the Zn atom is coordinated by two 4-methyl­amino­benzoate (MAB) and two isonicotinamide (INA) ligands in a distorted trigonal-bipyramidal geometry; one of the MAB ions acts as a bidentate ligand while the other MAB and the two INA are monodentate ligands. The dihedral angles between the carboxyl groups and the adjacent benzene rings are 8.52 (22) and 5.10 (14)°. In the crystal, inter­molecular O—H⋯O and N—H⋯O hydrogen bonding links the mol­ecules into a supra­molecular structure. Weak inter­molecular C—H⋯O inter­actions are also present.

The use of 2-pyridinealdoxime (paoH)/N,N′-donor ligand (L-L) “blend” in cobalt chemistry has afforded two cationic mononuclear cobalt(III) complexes of the general type [Co(pao)2(L-L)]+, where L-L = 1,10-phenanthroline (phen) and 2,2′-bipyridine (bpy). The CoCl2/paoH/L-L (1 : 2 : 1) reaction system in MeOH gives complexes [CoIII(pao)2(phen)]Cl·2H2O (1·2H2O) and [CoIII(pao)2(bpy)]Cl·1.5MeOH (2·1.5MeOH). The structures of the complexes were determined by single-crystal X-ray crystallography. The CoIII ions are six-coordinate, surrounded by three bidentate chelating ligands, that is, two pao− and one phen or bpy. The deprotonated oxygen atom of the pao− ligand remains uncoordinated and participates in hydrogen bonding with the solvate molecules. IR data of the complexes are discussed in terms of the nature of bonding and the known structures.

The title complex, [Ni(C8H8NO2)2(H2O)4], is centrosymmetric with the NiII ion located on a centre of symmetry. It contains two 4-(methyl­amino)benzoate (PMAB) anions and four coordinated water mol­ecules. The four O atoms in the equatorial plane around the NiII ion form a slightly distorted square-planar arrangement, while the slightly distorted octa­hedral coordination is completed by two O atoms of the PMAB anions in the axial positions. In the crystal structure, inter­molecular O—H⋯O, O—H⋯N, N—H⋯O and C—H⋯O hydrogen bonds link the mol­ecules into a three-dimensional network.

The first study into the alcohol solvation of lanthanum halide [LaX3] derivatives as a means to lower the processing temperature for the production of the LaBr3 scintillators was undertaken using methanol (MeOH). Initially the de-hydration of {[La(µ-Br)(H2O)7](Br)2}2 (1) was investigated through the simple room temperature dissolution of 1 in MeOH. The mixed solvate monomeric [La(H2O)7(MeOH)2](Br)3 (2) compound was isolated where the La metal center retains its original 9-coordination through the binding of two additional MeOH solvents but necessitates the transfer of the innersphere Br to the outersphere. In an attempt to in situ dry the reaction mixture of 1 in MeOH over CaH2, crystals of [Ca(MeOH)6](Br)2 (3) were isolated. Compound 1 dissolved in MeOH at reflux temperatures led to the isolation of an unusual arrangement identified as the salt derivative {[LaBr2.75•5.25(MeOH)]+0.25 [LaBr3.25•4.75(MeOH)]−0.25} (4). The fully substituted species was ultimately isolated through the dissolution of dried LaBr3 in MeOH forming the 8-coordinated [LaBr3(MeOH)5] (5) complex. It was determined that the concentration of the crystallization solution directed the structure isolated (4 concentrated; 5 dilute) The other LaX3 derivatives were isolated as [(MeOH)4(Cl)2La(µ-Cl)]2 (6) and [La(MeOH)9](I)3•MeOH (7). Beryllium Dome XRD analysis indicated that the bulk material for 5 appear to have multiple solvated species, 6 is consistent with the single crystal, and 7 was too broad to elucidate structural aspects. Multinuclear NMR (139La) indicated that these compounds do not retain their structure in MeOD. TGA/DTA data revealed that the de-solvation temperatures of the MeOH derivatives 4 – 6 were slightly higher in comparison to their hydrated counterparts.

The title compound, [Zn(C7H4FO2)2(C6H6N2O)2]·H2O, is a monomeric complex. It contains two 4-fluoro­benzoate and two nicotinamide ligands and one uncoordinated water mol­ecule. The 4-fluoro­benzoates act as bidentate chelating ligands, while the nicotinamides are monodentate. The six-coordinate geometry around the ZnII atom may be described as highly distorted octa­hedral, with the two nicotinamide ligands arranged cis. Inter­molecular O—H⋯O and N—H⋯O hydrogen bonds link the mol­ecules into a supra­molecular structure.

In the title compound, [Ni(C2O4)(C12H12N2O)2]n, the NiII atom, lying on a twofold rotation axis, is coordinated by two N atoms from two monodentate 3-(1H-imidazol-1-yl)-1-phenyl­propan-1-one (L) ligands and four O atoms from two oxalate anions in a distorted octa­hedral geometry. The oxalate anion has a twofold rotation axis through the mid-point of the C—C bond and acts as a bridging ligand, linking the NiII atoms into a polymeric chain along [010]. Weak inter­molecular C—H⋯O hydrogen bonds connect the chains, resulting in a three-dimensional supra­molecular structure. >

The title NiII complex, [Ni(C8H8NO2)2(C6H6N2O)2(H2O)2], is centrosymmetric with the Ni atom on an inversion center. The mol­ecule contains two 4-methyl­amino­benzoate (MAB) and two nicotinamide (NA) ligands and two coordinated water mol­ecules, all ligands being monodentate. The four O atoms in the equatorial plane around the Ni atom form a slightly distorted square-planar arrangement, while the slightly distorted octa­hedral coordination is completed by the two N atoms of the NA ligands in the axial positions. The dihedral angle between the carboxyl­ate group and the adjacent benzene ring is 2.09 (14)°, while the pyridine and benzene rings are oriented at a dihedral angle of 66.15 (4)°. In the crystal structure, inter­molecular O—H⋯O and N—H⋯O hydrogen bonds link the mol­ecules into a three-dimensional network.

The title NiII complex, [Ni(C8H7O2)2(C6H6N2O)2(H2O)2], is centrosymmetric with the Ni atom located on an inversion center. The mol­ecule contains two 4-methyl­benzoate (PMB) and two nicotinamide (NA) ligands and two coordinated water mol­ecules, all ligands being monodentate. The four O atoms in the equatorial plane around the Ni atom form a slightly distorted square-planar arrangement, while the slightly distorted octa­hedral coordination is completed by the two N atoms of the NA ligands in the axial positions. The dihedral angle between the carboxyl­ate group and the adjacent benzene ring is 26.15 (10)°, while the pyridine and benzene rings are oriented at a dihedral angle of 87.81 (4)°. In the crystal structure, inter­molecular O—H⋯O and N—H⋯O hydrogen bonds link the mol­ecules into a three-dimensional network. The π–π contact between the benzene rings [centroid–centroid distance = 3.896 (1) Å] may further stabilize the crystal structure. A weak C—H⋯π inter­action involving the pyridine ring also occurs.

In the monomeric and centrosymmetric title NiII complex, [Ni(C7H4ClO2)2(C10H14N2O)2(H2O)2], the NiII ion is located on an inversion center. The asymmetric unit contains one 2-chloro­benzoate ligand, one diethyl­nicotinamide (DENA) ligand and one coordinating water mol­ecule, the ligands being monodentate. The four O atoms in the equatorial plane around the NiII ion form a slightly distorted square-planar arrangement, while the slightly distorted octa­hedral coordination is completed by two N atoms of the DENA ligands in axial positions. The dihedral angle between the benzene ring and the attached carboxyl­ate group is 87.36 (10)°, while the pyridine and benzene rings are oriented at an angle of 41.90 (5)°. In the crystal structure, inter­molecular O—H⋯O hydrogen bonds link the mol­ecules into a two-dimensional network parallel to (10).

In the title compound, [Cr2Ni(C16H14N2O2)2(CN)4(C10H24N4)]·2CH3OH, each [Cr(salen)(CN)2] unit {salen is 2,2′-[ethane-1,2-diylbis(nitrilo­methyl­idyne)]diphenolate} acts as a monodentate ligand through one of its two cyanide groups N bound to a central [Ni(cyclam)]2+ core (cyclam is 1,4,8,11-tetra­azacyclo­tetra­deca­ne). Each CrIII ion is coordinated by two N and two O atoms from a salen ligand situated in the equatorial plane with two trans cyanide C atoms, yielding a distorted octa­hedral coordination geometry. The NiII atom lies on an inversion center and is octa­hedrally coordinated by a cyclam ligand lying in the equatorial plane and by two cyanide N atoms. The asymmetric unit contains one half of the complex mol­ecule and a methanol solvent mol­ecule. In the crystal structure, the complex mol­ecule is linked to the methanol solvent mol­ecules via O—H⋯O and N—H⋯O hydrogen bonds. Individual complex mol­ecules are linked by C—H⋯N hydrogen bonds, forming chains along b.

A series of cobalt, nickel, copper, and zinc complexes of bidentate Schiff bases derived from the condensation reaction of 4-amino-5-mercapto-3-methyl/ethyl-1,2,4-triazole with 2,4-dichlorobenzaldehyde were synthesized and tested as antimicrobial agents. The synthesized Schiff bases and their metal complexes were characterized with the aid of elemental analyses, magnetic moment measurements, spectroscopic and thermogravimetric techniques. The presence of coordinated water in metal complexes was supported by infrared and thermal gravimetric studies. A square planar geometry was suggested for Cu(II) and octahedral geometry proposed for Co(II), Ni(II), and Zn(II) complexes. The Schiff bases and their metal complexes have been screened for antibacterial (Pseudomonas aeruginosa, Bacillus subtilis) and antifungal activities (Aspergillus niger, A. flavus). The metal complexes exhibited significantly enhanced antibacterial and antifungal activity as compared to their simple Schiff bases.

In the title mononuclear complex, [Cu(C8H7O2)Cl(C12H8N2)(H2O)], the CuII atom is coordinated by one carboxylate O atom from a monodentate 4-methyl­benzoate ligand, two N atoms from the 1,10-phenanthroline ligand, one chloride ion and one water mol­ecule in a square-pyramidal geometry. The crystal structure exhibits inter- and intra­molecular C—H⋯Cl, C—H⋯O, O—H⋯Cl and O—H⋯O hydrogen bonds, as well as C—H⋯π inter­actions of phenanthroline and methyl H atoms towards the π-systems of neighboring 4-methyl­benzoate units and the pyridine rings of the phenanthroline system [centroid–centroid distances are 2.706 (2) and 2.992 (1) Å, respectively].

In the title complex, [Ni(C13H9N2O3)2(H2O)2]·2H2O, the NiII atom, located on a twofold rotation axis, is in a distorted octa­hedral geometry, defined by four N atoms from two 2-hy­droxy-5-[(pyridin-2-yl)methyl­idene­amino]­benzoate ligands and two O atoms from two water mol­ecules. In the crystal, inter­molecular O—H⋯O hydrogen bonds link the complex mol­ecules and uncoordinated water mol­ecules into a three-dimensional network. Intra­molecular O—H⋯O hydrogen bonds are present between the hy­droxy and carboxyl­ate groups.

In the title mononuclear complex, [Zn(C7H4NO4)2(C8H8N2S)2], the ZnII atom is coordinated by two N atoms from two 2-amino-6-methyl-1,3-benzothia­zole and by two carboxylate O atoms from two 4-nitro­benzoate ligands, adopting a slightly distorted tetra­hedral coordination geometry. In the crystal, inter­molecular N—H⋯O hydrogen bonds between the amino group of 2-amino-6-methyl-1,3-benzothia­zole and the carboxyl­ate group of 4-nitro­benzoate link these discrete mononuclear units into a one-dimensional supra­molecular chain extending parallel to [100].