Microwave-assisted template synthesis of diazacyclam-based macrocyclic copper complex and forming octahedral, square planar and square pyramidal geometries by ion exchanging and introducing a novel 2D square-grid copper–mercury coordination polymer

Synthesis and characterization of a 2-periodic cadmium-based metal-organic framework: A study on reversible water adsorption

A previously-reported cadmium-based two-periodic metal-organic framework [Cd_1.5(BTC)(H₂O)_4.5]_n·nH₂O (CP1) has been re-synthesized, where H₃BTC = 1,3,5-benzenetricarboxylic acid. CP1 was characterized with single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD) followed by various thermal analyses such as thermogravimetric analysis (TGA), hot stage microscopy (HSM) and differential scanning calorimetry (DSC). CP1 is composed of 2-periodic layers, which are interdigitated. Heating can effectively remove the uncoordinated and coordinated water molecules resulting in an amorphous product CP1′. The original framework can be regenerated by readsorption of water from the atmosphere, indicating that the dehydration is reversible.

Coordination of a triazine ligand with CuII and AgI investigated by spectral, structural, theoretical and docking studies

Two complexes of 5-phenyl-3-(pyridin-2-yl)-1,2,4-triazine (PPTA), namely (ethanol-κO)bis(nitrato-κO)[5-phenyl-3-(pyridin-2-yl-κN)-1,2,4-triazine-κN²]copper(II), [Cu(NO₃)₂(C₁₄H₁₀N₄)(C₂H₆O)] or [Cu(NO₃)₂(PPTA)(EtOH)] (1), and bis[μ-5-phenyl-3-(pyridin-2-yl)-1,2,4-triazine]-κ³N¹:N²,N³;κ³N²,N³:N¹-bis[(nitrato-κO)silver(I)], [Ag₂(NO₃)₂(C₁₄H₁₀N₄)₂] or [Ag₂(NO₃)₂(μ-PPTA)₂] (2), were prepared and characterized by elemental analysis, FT-IR spectroscopy and single-crystal X-ray diffraction. The X-ray structure analysis of 1 revealed a copper complex with square-pyramdial geometry containing two O-donor nitrate ligands along with an N,N'-donor PPTA ligand and one O-donor ethanol ligand. In the binuclear structure of 2, formed by the bridging of two PPTA ligands, each Ag atom has an AgN₃O environment and square-planar geometry. In addition to the four dative interactions, each Ag atom interacts with two O atoms of two nitrate ligands on adjacent complexes to complete a pseudo-octahedral geometry. Density functional theory (DFT) calculations revealed that the geometry around the Cu and Ag atoms in 1^opt and 2^opt (opt is optimized) for an isolated molecule is the same as the experimental results. In 1, O-H...O hydrogen bonds form R₁²(4) motifs. In the crystal network of the complexes, in addition to the hydrogen bonds, there are π-π stacking interactions between the aromatic rings (phenyl, pyridine and triazine) of the ligands on adjacent complexes. The ability of the ligand and complexes 1 and 2 to interact with ten selected biomacromolecules (BRAF kinase, CatB, DNA gyrase, HDAC7, rHA, RNR, TrxR, TS, Top II and B-DNA) was investigated by docking studies. The results show that the studied compounds can interact with proteins better than doxorubicin (except for TrxR and Top II).

Spectral, structural and theoretical study of the effects of thiocyanato and dicyanamido ligands on the geometry of PbII complexes containing a triazinic ligand

Two lead(II) complexes of 5,6-bis(furan-2-yl)-3-(pyridin-2-yl)-1,2,4-triazine (DFPT), namely one-dimensional (1D) catena-poly[[bis[5,6-bis(furan-2-yl)-3-(pyridin-2-yl-κN)-1,2,4-triazine-κN²]lead(II)]-di-μ-thiocyanato-κ²N:S;κ²S:N], [Pb(NCS)₂(C₁₆H₁₀N₄O₂)₂]_n, 1, and binuclear di-μ-dicyanamido-κ²N¹:N⁵;κ²N⁵:N¹-bis{[5,6-bis(furan-2-yl)-3-(pyridin-2-yl-κN)-1,2,4-triazine-κN²](nitrato-κ²O,O')lead(II)}, [Pb₂(C₂N₃)₂(NO₃)₂(C₁₆H₁₀N₄O₂)₄], 2, as well as DFPT itself, were prepared and identified by elemental analysis, FT-IR, ¹H NMR spectroscopy and single-crystal X-ray structural analyses. In the double-chain 1D coordination polymer of 1 and the binuclear structure of 2, the Pb atom has a hemidirected-PbN₆S₂ and a rare holodirected-PbN₆O₂ environment, respectively, with a distorted cubic geometry. All the coordination modes of dicyanamide ligands within lead complexes were studied using the Cambridge Structural Database (CSD) to compare them with the structures of 1 and 2. In addition to hydrogen bonds, the crystal networks are stabilized by π-π stacking interactions between the triazine, furyl and pyridine aromatic rings. The most stable theoretical structures of the title compounds predicted by density functional theory (DFT) calculations were compared with the solid-state results.

A novel ligand transfer reaction: Transferring an N3-donor amine ligand from Ni(II) to Cu(II)—structural, spectral, theoretical, and docking studies

Two complexes of N1-(2-aminoethyl)propane-1,3-diamine (AEPD), [Ni(AEPD)2](NO3)2 (1) and [Cu2( μ-Cl)2(AEPD)2](NO3)2·2H2O (2), are prepared and identified by elemental analysis, Fourier transform infrared spectroscopy and UV–Vis spectroscopy, and single-crystal X-ray diffraction (for 2). Spectral and structural data reveal that the AEPD ligand transfers from nickel to copper in the reaction between 1 and copper chloride. All coordination modes of the AEPD-based ligands are studied by analysis of the Cambridge Structural Database. The nickel atom in 1 has octahedral geometry (NiN6) while X-ray structure analysis revealed that the copper atom in the binuclear structure of 2 has an elongated square-pyramidal geometry with a CuN3OCl2 environment. In the crystal network of 2, water molecules and cationic complex units along with the nitrate ions form different hydrogen bond motifs. The thermodynamic stability of the compounds and their charge distribution patterns is studied by density functional theory and natural bond orbital analysis. The ability of AEPD and its complexes to interact with 10 selected biomacromolecules is investigated by docking calculations.

Docking studies on an N4-donor Schiff base ligand and its Cu(II) complex supported by structural, spectral and theoretical studies

A new asymmetrical Schiff base ligand, N1-(3-((pyridin-2-ylmethylene)amino)propyl)ethane-1,2-diamine, and its copper(II) complex, [Cu(PPEA)Br]Br·H2O (1), have been prepared. The copper complex has an elongated square pyramidal geometry with a CuN4Br environment. The thermodynamic stability of the compounds and their charge distribution patterns were studied by Density Functional Theory and natural bond orbital analysis. The ability of the ligand and its copper complex to interact with 10 selected biomacromolecules (BRAF kinase, CatB, DNA gyrase, HDAC7, rHA, RNR, TrxR, TS, Top II and B-DNA) was investigated by docking studies and compared with that of doxorubicin.

Spectral, Structural, Theoretical and Docking Studies of a Mn(II) Complex with an N4-Donor Ligand

The complex [Mn(EMMP)(OAc)2]·3H2O, [EMMP = N,N′-(ethane-1,2-diyl)bis(1-phenyl-1-{pyridin-2-yl}methanimine] has been prepared and has a distorted square-faced bicapped trigonal prismatic geometry. In the crystal network of the complex, the water molecules form stronger hydrogen bonds than the complex molecules and participate in the formation of R44(8) hydrogen bond motifs. The ability of the complex and its ligand to interact with the biomacromolecules (BRAF kinase, CatB, DNA gyrase, HDAC7, rHA, RNR, TrxR, TS and Top II) has been investigated by docking calculations and compared with that of doxorubicin.

An ionic Cd/Hg mixed-metal complex with an aminoalcohol ligand

A cadmium–mercury mixed-metal complex of cis-2-((2-((2-hydroxyethyl)amino)ethyl)amino)cyclohexan-1-ol (HEAC), [Cd(HEAC)2][HgI4] (1), was prepared and identified by elemental analysis, FT-IR, 1H NMR spectroscopy, and single-crystal X-ray diffraction. The X-ray analysis revealed an ionic structure for 1 in which the cadmium and mercury atoms have CdN4O2 and HgI4 environments, with distorted octahedral and tetrahedral geometries, respectively. The packing of the components in the crystal of 1 is supported by O–H···I hydrogen bonds, and these interactions lead to the formation of an R 4 4 ${\rm{R}}_4^4$ (22) motif.

Anticancer activities of a β-amino alcohol ligand and nanoparticles of its copper(ii) and zinc(ii) complexes evaluated by experimental and theoretical methods

2-(2-(2-Hydroxyethylamino)ethylamino)cyclohexanol (HEAC) and copper and zinc complexes, [Cu(HEAC)Cl]Cl (1), [Cu(HEAC)Br]Br (2), [Zn(HEAC)Cl₂] (3), were prepared and identified by elemental analysis, FT-IR, UV-Vis, ¹H NMR spectroscopy and single-crystal X-ray diffraction. Also nanoparticles of 1–3 were prepared for anticancer studies by ultrasonic irradiation. Particle size and morphology of the nano particles are investigated by PXRD and SEM, respectively. X-ray analysis revealed that the ionic complexes 1 and 2 are isostructural. In the structure of complexes 1 and 2, the metal atom has a CuN₂O₂X (X: Cl (1), Br (2)) environment with square-pyramidal geometry, containing the tetradentate N₂O₂-donor HEAC. The bond length of the axial position in the square-pyramidal geometry of 1 and 2 is elongated. Complex 3 has a ZnN₂OCl₂ environment with trigonal bipyramidal geometry around the zinc atom in which the HEAC acts as mer-N₂O-donor. The ability of HEAC and nano particles 1–3 to interact with the nine biomacromolecules (BRAF kinase, CatB, DNA gyrase, HDAC7, rHA, RNR, TrxR, TS and Top II) are investigated by docking calculations. For examination of the docking results, the in vitro activities of four compounds against the human leukemia cell line K562 were investigated by evaluation of IC₅₀ values and mode of cell death (apoptosis). The thermodynamic stability of the compounds along with the charge distribution pattern were studied by DFT and NBO analysis, respectively.

Nano particles of copper and zinc complexes with an amino alcohol ligand were prepared under ultrasonic irradiation and their anticancer activates were investigated along with the docking studies and DFT calculations.

A coordination polymer of mercury(II) formed by triazole-based and chloride linkers

In this work, a coordination polymer formed from 4,5-diamino-3-methyl-4H-1,2,4-triazol-1-ium chloride (DAMT·HCl) and HgCl2 formulated as [Hg5(μ-DAMT)2(μ-Cl)6(μ 3-Cl)2Cl2] n has been prepared and characterized by elemental analysis, FT-IR, 1H NMR spectroscopy, and single-crystal X-ray diffraction. X-ray analysis of the complex revealed an organic-inorganic hybrid coordination polymer containing three different mercury atoms with coordination numbers of 4 (HgN(μ-Cl)2(μ 3-Cl)), 5 (Hg(μ-Cl)3(μ 3-Cl)Cl), and 6 (HgN2(μ-Cl)2(μ 3-Cl)2) and seesaw, octahedral, and square pyramidal geometries, respectively. The polymeric chains are extended to a three-dimensional (3D) array by C–H···Cl and N–H···Cl interactions. In addition to these hydrogen bonds, there are Hg···Cl interactions with the mercury atoms with coordination numbers 4 and 5 to complete their pseudo-square planar and -octahedral geometries, respectively.

DNA binding affinity of a macrocyclic copper(II) complex: Spectroscopic and molecular docking studies

The interaction of a novel macrocyclic copper(II) complex, ([CuL(ClO₄)₂] that L is 1,3,6,10,12,15-hexaazatricyclo[13.3.1.1^6,10]eicosane) with calf thymus DNA (ct-DNA) was investigated by various physicochemical techniques and molecular docking at simulated physiological conditions (pH = 7.4). The absorption spectra of the Cu(II) complex with ct-DNA showed a marked hyperchroism with 10 nm blue shift. The intrinsic binding constant (K_b) was determined as 1.25 × 10⁴ M^-1, which is more in keeping with the groove binding with DNA. Furthermore, competitive fluorimetric studies with Hoechst33258 have shown that Cu(II) complex exhibits the ability to displace the ct-DNA-bound Hoechst33258 indicating that it binds to ct-DNA in strong competition with Hoechst33258 for the groove binding. Also, no change in the relative viscosity of ct-DNA and fluorescence intensity of ct-DNA-MB complex in the present of Cu(II) complex is another evidence to groove binding. The thermodynamic parameters are calculated by van't Hoff equation, which demonstrated that hydrogen bonds and van der Waals interactions played major roles in the binding reaction. The experimental results were in agreement with the results obtained via molecular docking study.

Structural study of the coordination behavior of a tetradentate NO3-donor amino alcohol ligand toward a CdII:HgII mixture

In this work, the reaction of 2,2′,2″-nitrilotriethanol (NTE) with a 1:1 mixture of CdI2 and HgI2 is investigated. The complex [Cd(NTE)2][Hg2(μ-I)2I4] was synthesized and identified by elemental analysis, FT-IR, 1H NMR spectroscopy and single-crystal X-ray diffraction. The structure of the [HNTE]Cl salt is also presented. In the crystal structure of the complex, the cadmium atom has a CdN2O6 environment in a slightly distorted cube geometry. This geometry is one of the rare cube geometries with a minimum distortion among the Cambridge Structural Database structures for cadmium complexes. The anionic moiety has a binuclear structure with the mercury atoms being in tetrahedral environments. In the network of the complex, in addition to O−H · · · I hydrogen bonds, there are I · · · I interactions which lead to ten-membered rings.

Synthesis and characterization of a macrocyclic copper complex containing the 14-membered 1,3,5,8,10,12-hexaazacyclotetradecane unit

In this work, a new macrocyclic copper complex, [Cu(ACE)(SCN)2]; ACE: 1,3,6,10,12,15-hexaazatricyclo[13.3.1.16,10]eicosane, was prepared and characterized by elemental analysis, FT-IR, Raman spectroscopy and single-crystal X-ray diffraction. X-ray analysis of [Cu(ACE)(SCN)2] reveals an elongated octahedral geometry around the copper atom in a centrosymmetric CuN6 environment.