No abstract

A series of copper (II) (1 and 3) and cobalt (II/III) (2, 4 and 5) complexes comprising different imino-phenolate ligands DCH, DTH and DBH 2 (where DCH = 2,4-dichloro-6-((mesitylimino)methyl)phenol, DTH = 2,4-di-tert-butyl-6-((mesitylimino)methyl) phenol and DBH 2 = 2,4-dibromo-6-((mesitylimino) methyl)phenol) have been prepared with excellent yield and high purity. By utilizing different spectroscopic tools such as UV-visible, electrospray ionization (ESI)-mass, Fourier-transform infrared (FTIR) spectrometry and elemental analysis, the prepared complexes (1-5) were thoroughly characterized. The molecular structure of the synthesized complexes was ascertained by using single-crystal X-ray diffraction studies (SCXRDs). The experiment reveals that Complexes 1-5 bind to calf thymus DNA (CT-DNA) through non-intercalative way with good interacting abilities. However, 1-5 are excellent quenchers of the fluorescence intensity of bovine serum albumin (BSA) following the static pathway. Additionally, they had shown remarkable cytotoxic potential against MCF-7 (mammary gland adenocarcinoma) and A549 (lung adenocarcinoma) cell lines. The IC 50 values associated with these complexes were much lower than the conventional drug cisplatin. Apoptosis-induced cell death was confirmed from the DNA fragmentation studies and Hoechst 33342 staining. The 2 0 ,7 0-dichlorofluorescein diacetate (DCFDA) assay indicates that the complex mediated reactive oxygen species (ROS) generation is accountable for governing the apoptosis mechanism via oxidative cell distress. Apart from these studies, by carrying out density functional theory (DFT) method, highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) energy gap calculations and optimized structures of the synthesized complexes were accomplished.

Five transition metal–BTC–BIm based coordination polymers with hierarchical structures were synthesized under hydro/solvothermal condition. Crystal structure analysis of the compounds showed that 1 forms a 1D chain, 2 and 3 have 2D layers, while 4 and 5 have three-dimensional architectures.

In recent decades Open-framework materials are emerging area of study in materials chemistry, because of their huge and vast class of applications in areas such as sorption, magnetism, fuel cell, electrical conductivity, and catalysis. Furthermore, these materials exhibit attractive structural and topological diversities having usual H-bonding and coordination bonding. The study started with aluminosilicate zeolites, using metal and primary building units like silicate, phosphate, sulfate, metal phosphates, sulfates, and selenate etc. constitute an important family of open-framework structures. The sulfite based framework were very few explored due to the inherent instability of sulfite anion in acidic as well as hydrothermal conditions using organic amine as template, where the sulfur atom in sulfite ion is in the +4 oxidation state, which is relatively unstable under hydrothermal and acidic conditions and easily converted in +6 oxidation state and form sulfate ion. We were interested in exploring the missing amine template sulfite oxyanion and sulfite-oxalate hybrid materials with varying structure dimensionalities, and their various applications. Here we present the results of the investigations of metal sulfites employing transition metal with diverse structures and dimensionalities in presence of organic templates. The introduction of oxalate anion into the framework materials change the crystallographic signatures of the crystal lattice and adds additional structural complexity where the oxalate moiety acts as a ligand or bridging species. Thus, oxalate anion has been exploited in conjunction with sulfite and their results. Here we represent the synthesis and characterisation of a varying structural dimensionality of open-framework metal sulfites and metal sulfites-oxalates materials.

Three novel metal-tiron (4,5-dihydroxy-1,3-benzenedisulfonic acid disodium salt) and other pillared ligand bpy (4,4-bipyridyl) centered coordination polymers were successfully synthesized and characterized.

The crystallographic signatures and characterization of two novel mixed metal hybrid open-frameworks [NaMn(CO)(SO)(HO)] 1 and [NaEu(CO)(SO)(HO)] 2 are reported for the first time; they are synthesized under hydrothermal conditions to generate 3D assemblies and honeycomb-like structures. They were further characterized by complementary techniques like PXRD, TGA and DSC. The magnetic properties of 1 show antiferromagnetic interactions between the metal centers and compound 2 shows good photoluminescence properties.

Three novel transition metal–sulfite coordination complexes are synthesized using different amines and the role of H-bonding to provide structures with different dimensionalities are discussed.

A series of six lanthanide‐containing germanotungstates of the formula: [(Ln2GeW10O38)4(W3O8)(OH)4(H2O)2]26− (Ln=Sm (1), Eu (2), Gd (3), Tb (4), Dy (5), Ho (6) have been synthesized under ambient conditions. The synthetic procedure involves the use of trilacunary Na10[A‐α‐GeW9O34]⋅16H2O as a preformed precursor along with lanthanide salts in 0.5 M potassium chloride solution. The interaction of the trilacunary Na10[A‐α‐GeW9O34]⋅16H2O with the lanthanide salts leads to the formation of a tetrameric structure with four [GeW10O36]8− dilacunary Keggin units incorporating eight lanthanide ions and three additional tungsten atoms. All the polyanions were structurally characterized by Fourier‐transform infrared spectroscopy (FT‐IR), Single Crystal X‐ray Diffraction (SC‐XRD), UV/Visible spectroscopy, thermogravimetric analysis (TGA), electrochemistry, Electron‐spray ionization mass spectroscopy (ESI‐MS), Powder X‐ray diffraction (PXRD) and photoluminescence. FT‐IR spectroscopy reveals that all the polyanions are isomorphous and SC‐XRD shows that all the polyanions are isostructural and crystalize in the triclinic crystal system with P1‾ space group. Some of the polyanions show good photoluminescence properties. The cyclic voltammograms (CVs) of all the six compounds exhibit the same shape, each being composed of a pronounced reduction wave.