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Abstract A new Werner type manganese(II) clatharate [Mn(Bz) 2 (H 2 O) 4 ]∙(4–CNpy)∙2H 2 O (1), where Bz = benzoate and 4–CNpy = 4–cyanopyridine, has been synthesized at room temperature and characterized by X-ray crystal structure analysis, FT-IR, electronic spectrum and TGA. The crystal structure of cocrystal hydrate of 1 involves a discrete host monomer with enclathrated water and 4-CNpy molecules. Crystallographic studies on the compound 1 reveal that enclathration of guest water molecules in the Mn(II) host units results in a supramolecular tetramer in the crystal structure of 1 involving weak C H⋯C contacts. The geometry of the supramolecular host tetramer with the guest 4–CNpy molecules has been fully optimized using the crystallographic coordinates and the computational results suggest that the observed C H⋯C interactions are energetically quite significant. It is observed that both electrostatics as well as dispersion interactions are the most dominant contributors towards the stabilization of the C H⋯C interaction. Highlights • A new unusual Werner type clatharate of Mn(II) has been reported. • Mn(II) host units results in a supramolecular tetramer involving weak C H⋯C contacts. • The observed C H⋯C contacts are energetically quite significant. • Both electrostatics and dispersion interactions contribute towards stabilization of the C H⋯C interaction. [ABSTRACT FROM AUTHOR]

Graphical abstract Crystal structures of two coordination complexes of Cu(II) and Co(II) involving 3,5-dimethyl pyrazole has been reported. An unusual σ-hole chalcogen bonding interaction at the tetrahedral sulfur atom was observed in the solid state of the polymeric Cu(II) complex. The polymeric chains are further self assemled into a 3D supramolecular architecture via hydrogen bonding interactions. The cationic units of the monomeric Co(II) complex self assembles into a 2D supramolecular architecture via chloride induced hydrogen bonding interactions. Highlights • Cu(II) and Co(II) complexes involving 3,5-dimethylpyrazole are structurally characterized. • Unprecedented chalcogen bonding interactions are confirmed in the polymeric Cu(II) complex. • 2D architecture of Co(II) Complex is induced by chloride anions in the lattice. Abstract Two coordination complexes of Cu(II) and Co(II) involving 3,5-dimethylpyrazole viz. {[Cu(μ-O,O′-SO 4)(Hdmpz) 2 (H 2 O)]·2H 2 O} n (1) and [Co(Hdmpz) 4 (H 2 O) 2 ]Cl 2 (2) (where Hdmpz = 3,5-dimethylpyrazole) have been synthesized in purely aqueous medium at room temperature. Crystal structure of complex 1 consists of a polymeric chain of distorted square pyramidal Cu(II) centers bridged by bidentate sulfato ligands. The polymeric chain in 1 has been stabilized by N–H⋯O and C–H⋯π interactions. Particularly relevant is the polymeric chain in 1 , since in addition to the afore mentioned non-covalent contacts, unprecedented chalcogen bonding interactions involving the σ-hole at the tetrahedral sulfur atom are observed and characterized using theoretical calculations. To our knowledge, σ-hole chalcogen bonding interactions involving tetrahedral sulfur atom have not been previously reported in the literature. The lattice water molecules self assembles the polymeric chains of 1 into a 3D supramolecular architecture via C–H⋯O hydrogen bonding interactions. The cationic units in the crystal structure of 2 self assembles via O–H⋯Cl, N–H⋯Cl and C–H⋯Cl weak hydrogen bonding interactions into a 2D supramolecular architecture induced by chloride anions in the lattice. PXRD patterns of 1 and 2 demonstrate good phase purity of the complexes. In addition, the thermal behaviour of the complexes has also been investigated. [ABSTRACT FROM AUTHOR]

Electrostatically enhanced π-π interactions have been analyzed by DFT calculations, molecular electrostatic potential (MEP) surface and non-covalent interaction (NCI plot) index computational tools. The cytostatic potential in Dalton's lymphoma (DL) cell line by MTT assay, apoptosis assay have been further corroborated with molecular docking simulation. Three new isostructural coordination solids viz. [Co(3-CNpy) 2 (2-ClBz) 2 (H 2 O) 2 (1), [Mn(3-CNpy) 2 (2-ClBz) 2 (H 2 O) 2 (2) and [Zn(3-CNpy) 2 (2-ClBz) 2 (H 2 O) 2 (3) (3-CNpy = 3-cyanopyridine, 2-ClBz = 2-chlorobenzoate) have been synthesized from purely aqueous media and characterized by X-ray crystal structure analysis, FT-IR, electronic spectra and TGA. Several non-covalent hydrogen bonding interactions of the types O H⋯O, C H⋯O, C H⋯N, C H⋯Cl and π-π stacking contacts build up the supramolecular networks in the crystal structures. Electrostatically enhanced π-π interactions are observed in 1 – 3 between the phenyl rings of 2-ClBz and pyridine ring of 3-CNpy of the monomeric units of the complexes. We have used the molecular DFT calculations to evaluate energetically the strength of these contacts and also to analyze the effect of the metal on the interaction energies. The energetic features of the H-bonding and π-stacking interactions for 1 – 3 reveal that the H-bonded assembly is more favorable than the π-stacked contacts. The electrostatically enhanced energy of the π-stacking interactions is stronger than that usually observed for π-stacking interactions involving arenes. The cytostatic potential of all complexes have been studied in Dalton's lymphoma (DL) cell line by MTT assay, apoptosis assay and further corroborated with molecular docking simulation. The complexes exhibit cytotoxicity (∼25–30%) through apoptotic cell death with negligible cytotoxicity (∼5–10%) in normal PBMC cells. In silico-docking techniques have been performed with apoptosis regulator protein BCL-2 for the identification of critical amino acids and their possible binding affinity with the synthesized complexes. The pharmacophore features based on structure activity relationship (SAR) of the complexes have been identified and the study reveal that the features viz., hydrophobic, aromatic, positive ionizable, negative ionizable, H-bond donor and acceptor and halogen bond donor properties play important role for the biological activities of the complexes. [ABSTRACT FROM AUTHOR]

Antiparallel π-stacking interactions observed in the solid state structures of three new complexes have been analyzed by DFT calculations, molecular electrostatic potential (MEP) surface and non-covalent interaction (NCI plot) index computational tools. All the compounds interact with anti-apoptotic cancer target proteins and the results are comparable with respective reference inhibitors. • Supramolecular association in Co(II), Ni(II) and Cu(II) coordination compounds. • Energetically significant antiparallel π-stacking contacts. • DFT calculations and NCI plot analyses. • Anti-proliferative potential and in silico docking simulation. • Pharmacophore and ADMET features based on structure activity relationship (SAR). Three new coordination compounds of types [Co(py)(2,6-PDC)(H 2 O) 2 .H 2 O (1), [Ni(py)(2,6-PDC)(H 2 O) 2 .H 2 O (2) and [Cu(py)(2,6-PDC)(H 2 O)].2H 2 O (3) (py = pyridine, 2,6-PDC = Pyridine-2,6-dicarboxylate) have been synthesized from purely aqueous media and characterized using elemental analysis, spectroscopic (IR and electronic) and single crystal X-ray diffraction techniques. Several supramolecular contacts of types O H⋯O, C H⋯O, C H⋯π, C H⋯C and π–π stacking stabilize the crystal structures. The layers in the crystal structures stack in perpendicular direction resulting in 1D channel with enclathrated water molecules. The strength of the antiparallel π-stacking interactions involving the pyridine rings in the supramolecular dimer of the compounds have been evaluated using DFT calculations and the influence of the pyridine coordination to the strength of the stacking assembly have been confirmed. The anti-proliferative potential of the compounds has been studied in Dalton's lymphoma (DL) cell line by using MTT cell viability assay and apoptosis assay. All the three complexes exhibit short term (24 h) cytotoxicity (∼20–30%) through apoptotic cell death with negligible cytotoxicity (∼5–10%) in normal cells. In silico docking simulation has been performed with apoptosis regulator protein BCL-2 for the identification of possible molecular mode of action of the synthesized complexes. The pharmacophore features based on structure activity relationship (SAR) of the complexes have been identified. The SAR results reveal that the molecular features such as, hydrophobic, aromatic, positive ionizable, negative ionizable, H-bond donor and acceptor and halogen bond donor associated with the structures of the compounds play important role in the biological activities. The ADMET features, viz., physicochemical properties, pharmacokinetics, drug-likeness and medicinal chemistry friendliness of the synthesized complexes have been investigated. [ABSTRACT FROM AUTHOR]