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Anticancer activities considering cell cytotoxicity, apoptosis and molecular docking have been explored in Zn(ii) co-crystals of phenanthroline involving infinite chair-like assemblies and unconventional layered infinite anion-water clusters.

In vitro anticancer activities have been explored in fumarato and phthalato bridged dinuclear Cu(ii) and Mn(ii) compounds involving infinite fumarate–water assemblies and unusual structure-guiding H-bonded synthons.

Anticancer activities considering cell viability, apoptosis and molecular docking have been explored in dinuclear Zn(ii) and polymeric Mn(ii) compounds involving energetically significant unconventional N(nitrile)⋯π(fum) contacts.

Two new coordination complexes of Cu(II) viz.; [Cu(bpy)2(NO3)]NO3·5H2O (1) and [Cu(phen)(Hdmpz)Cl2]·H2O (2) (bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline, Hdmpz = 3,5-dimethyl pyrazole) have been synthesized and characterized by single crystal X-ray diffraction, electronic spectroscopy, EPR, FT-IR spectroscopy and TGA. The nitrate anion and the water molecules in the lattice of 1 are involved in the formation of unconventional infinite supramolecular crown-like nitrate–water clusters. The unconventional enclathration of guest cationic complex moieties of 1 within the supramolecular nitrate–water crown hosts provides stability to the crystal structure. Crystal structure analysis of 2 reveals the presence of cooperative ternary π-stacked assemblies with enclathration of single guest water molecules in hexameric Cu(II) supramolecular host cavities. Theoretical calculations have been performed to analyse the non-covalent interactions in the compounds; focusing on the unusual H-bonding network/anion–π cooperative assemblies in 1 and two different π-stacked cooperative assemblies in 2. DFT studies reveal that the distribution and orientation of the H-bonds in the cooperative H-bonding network in 1 is the most favoured. The high interaction energies of (π–π)1 and (π–π)2 in π-stacked ternary assemblies of 2 can be attributed to the participation of the entire aromatic surfaces with antiparallel orientations and the cooperative C–H⋯Cl interactions respectively. The in vitro antiproliferative activities of the compounds considering cell cytotoxicity, apoptosis and DNA fragmentation assays reveal significant concentration dependent cytotoxicity in DL cancer cells with nominal effects in normal PBMC cells. The molecular docking and pharmacophore studies established the structure activity relationship of the compounds.

Distributed learning is an important paradigm in the current machine learning algorithms with large datasets. In this paper, distributed stochastic optimization problem of minimizing a nonconvex function in an adversarial setting is considered. A robust variant of the stochastic variance-reduced algorithm is proposed. In the distributed setup, we assume that a fraction of worker nodes (WNs) can be Byzantines. We assume that the batch gradients are computed at the WNs and the stochastic gradients are computed at the central node (CN). We provide the convergence rate of the proposed algorithm which employs the design of a novel filtering rule that is independent of the problem dimension. Furthermore, we capture the effect of Byzantines present in the network on the convergence performance of the algorithm. We evaluate the performance of the proposed algorithm and present the simulation results using real world datasets, in addition to providing the theoretical guarantees.

Two new coordination polymers of Zn(II), viz. {[Zn(Hdmpz)2(μ-male)]·(MeOH)(H2O)}n (1) and [Zn(3-AMpy)2(μ-fum)(H2O)2]n (2) (where Hdmpz = 3,5-dimethylpyrazole, male = maleate, fum = fumarate, and 3-AMpy = 3-aminopyridine), have been synthesized and characterized using elemental analysis, TGA, spectroscopic and single crystal X-ray diffraction techniques. The 1D polymeric chains of the polymers self-assemble into 2D supramolecular architectures via several non-covalent interactions. Differences in the structural topologies have been observed with the change of solvent from the methanol–water mixture in compound 1 to de-ionized water in compound 2. Unconventional enclathration of the solvent molecules, viz. MeOH, and the water in the crystal structure of 1 results in an interesting layered assembly. The influences of the metal coordination on the strength of the π-stacking interactions have been explored theoretically for compound 2, which confirms that the coordination of 3-AMpy to the Zn(II) centre strongly polarizes the π-cloud and increases the local dipole of 3-AMpy, thereby enhancing the strength of π-stacking interactions. The in vitro anticancer activities of the compounds have been explored in Dalton's lymphoma cancer cell lines considering cell cytotoxicity and apoptosis, and the results were compared with those observed for cisplatin (reference drug) under the same experimental conditions. The in silico molecular docking studies and the pharmacophore features further corroborate the cytotoxicity and apoptosis inducing ability of the compounds.

Two new coordination compounds involving hexanuclear Cu(ii), viz., [Cu6(phen)6(μ4-adpt)4(H2O)2](NO3)4·10H2O (1) and polymeric Co(ii), viz., {[(μ2-adpt)4Co(μ2-H2O)2Co(H2O)4]·4H2O}n (2) (phen = 1,10-phenanthroline; adpt = adipate) have been synthesized and characterized using elemental analysis, TGA, spectroscopic (IR, electronic and ESR), PXRD and single crystal X-ray diffraction techniques. Discrete nitrate-water clusters involving the [(H2O)3NO3]- core in 1 and linear (H2O)4 core in 2 provide stability to the layered network of the structures of the compounds. Interestingly, the water clusters in polymer 2 are encapsulated as guests in the voids of the host square grid that extends in 2D architecture. Theoretical studies have revealed the presence of interesting energetically significant cooperativity effects of π-stacking contacts that are responsible for the hexanuclear structure of compound 1. Both complexes significantly inhibit cell viability by inducing apoptotic cell death in the DL cancer cell line with negligible cytotoxicity in normal cells (PBMC). An assessment of ROS (reactive oxygen species) level study revealed a rapid increase of ROS in DL cells indicating cytotoxicity of the compounds against the DL cells. A decrease in MMP (mitochondrial membrane potential) is associated with an opening of the mitochondrial permeability transition pores which corroborates the apoptotic features of 1 and 2. The mode of action of the cytotoxic activities of the compounds has been explored with respect to their in silico docking ability and further inhibition of antiapoptotic proteins as evidenced by western blot analysis. SAR analyses based on pharmacophore modelling reveal that the molecular features of the structures of the compounds play important roles in biological activities.

Two new coordination complexes of Cu(II) and Mn(II), viz., [Cu(bpy)(H2O)4]SO4·2H2O (1) and [Mn(4-CNpy)2(H2O)3SO4]·H2O (2) (bpy = 2,2′-bipyridine, 4-CNpy = 4-cyanopyridine), have been synthesized and characterized by using single crystal X-ray diffraction, elemental analysis, FT-IR spectroscopy, electronic spectroscopic techniques and TGA. The crystal structure of 1 uncovers the formation of sulfate–water assemblies involving lattice and coordinated water molecules, while complex 2 reveals the presence of unconventional weak T-shaped CN⋯CN contacts in the layered architecture. We have analysed the unconventional interesting interactions using DFT calculations, molecular electrostatic potential (MEP), the NCI plot and QTAIM computational tools. The interaction energies of the two H-bonded dimers in 1 are very large because of the coulombic attraction between the dicationic H-bonded donor and the dianionic acceptor. It is interesting to observe that despite the energy of the H-bonds being very small compared to the total dimerization energy, the final geometry of the assembly in 1 is due to the charge assisted directional H-bonds instead of the non-directional ion-pair interactions. The DFT study reveals that the T-shaped CN⋯CN interaction in 2 is very weak, in good agreement with the small MEP energy at the nitrile carbon atom. Anticancer studies of the compounds have been carried out using Dalton's lymphoma cell line using MTT and apoptosis assay. The results of compound 1 and 2 mediated cell cytotoxicity on the DL cancer cell line showed a significant concentration-dependent reduction in cell viability, while negligible cytotoxicity was observed in normal (PBMC) cells. The docking simulation results also confirm the interaction of the complexes with the active sites of amino acids of the target proteins. Furthermore, pharmacophore models (2D and 3D) for the compounds were mapped to the H-bond donor, positive ionisable area and hydrophobic features that are important for establishing biological activities. No hematotoxicity was recorded for the compounds after treatment in normal mice.

A new oxalato bridged polymeric Mn(III) coordination compound, {[Mn2(η2-C2O4)(H2O)2Cl4] 2(4-CNpy)}n (1) (C2O4 = oxalate, 4-CNpy = 4-cyanopyridine), has been synthesized and characterized using elemental analysis, and spectroscopic (IR, electronic, XPS) and single crystal X-ray diffraction techniques. Electronic and XPS analyses of the compound justify the presence of a Mn(III) center that is charge compensated by the two chlorido ligands and the oxygen atom of the bridged oxalate. 4-CNpy molecules in the lattice form unconventional H-bonded supramolecular dimers in the solid state assisted by antiparallel CN⋯CN dipole⋯dipole interactions, which has been confirmed using QTAIM and NCI plot analysis and supported by MEP surface analysis. Remarkably, this dimer concurrently establishes a weak anion–π interaction with the coordinated chlorido ligand. Unexpectedly, QTAIM analysis reveals the existence of an interesting O⋯π-hole(nitrile) contact involving the coordinated water molecule and the nitrile moiety that also contributes to the stabilization of the dimer in the crystal structure. To the best of our knowledge, the existence of such π-hole interaction involving nitrile derivatives has not been reported before. Compound 1 has been further screened for anticancer activity in the malignant Dalton's lymphoma (DL) cell line and the results were confirmed by molecular docking and pharmacophore features. Our findings indicated that the cytotoxicity of compound 1 is initially increased in a dose dependent manner (0.01–1 μM) and then decreased (5–10 μM), which is also affected by the reactive oxygen species (ROS) in the cells. Interestingly, very low cytotoxicity (5–14%) was observed in the case of healthy cells (PBMC) for similar experimental conditions.

In this work, we consider the problem of inferring links in a communication network, using limited, passive observations of network traffic. Our approach leverages transfer entropy (TE) as a metric for quantifying the strength of the automatic repeat request (ARQ) mechanisms present in next-hop routing links. In contrast with existing approaches, TE provides an information-theoretic, model-free approach that operates on externally available packet arrival times. We show, using discrete event simulation of a wireless sensor network, that the TE based topology inference approach described here is robust to varying degrees of connection quality in the underlying network. Compared to an existing approach which uses the linear regression based formulation of Granger Causality for network topology inference, our approach has better asymptotic time complexity, and shows significant improvement in network topology reconstruction performance. Our approach, though sub-optimal, also has better time complexity, while still retaining reasonable performance, compared to a causation entropy based optimal algorithm proposed in the literature.

Two new coordination compounds, viz., [Co(phen)(bz)(H2O)3]·bz (1) and [Zn(phen)2(H2O)Cl]·Cl·bzH·2H2O (2) (phen = 1,10-phenanthroline, bz = benzoate, bzH = benzoic acid) were synthesized from purely aqueous media, and characterized using elemental analysis, spectroscopic (IR, UV-Vis-NIR) and single crystal X-ray diffraction techniques. In the crystal structures of 1 and 2, supramolecular networks have been built involving the association of O–H⋯O, C–H⋯O, and π–π stacking interactions. The enclathration of the guest bzH molecule in the host monomers of Zn(II) brings rigidity to the structure of compound 2. Theoretical investigations have been carried out to rationalize interesting supramolecular assemblies that include cooperative anion–π/π–π/π–anion in 1 and DNA-relevant HB-array⋯π/π–π/π–HB-array interactions in 2, which have been characterized using NCI plots and Bader's theory of “atoms-in-molecules”. The complexes significantly inhibit cell viability by inducing apoptotic cell death in a Dalton's lymphoma (DL) cell line with negligible cytotoxicity in normal cells. A molecular docking study and pharmacophore features reveal that compounds 1 and 2 interact and are accommodated well in the active site of anti-apoptotic proteins. Antimicrobial studies against a few pathogenic organisms suggest that the compounds are active against Gram-positive and Gram-negative bacteria and have relatively better antibacterial activity in comparison to phen.

Rubber torsional vibration dampers are often used on mid-range engines. Usually, the geometry of a rubber torsional vibration damper is such that the rubber element in it undergoes shear. However, in the work presented, a compression rubber damper is being proposed, in which the rubber element undergoes compression rather than shear. The proposed compression rubber damper, just like the shear rubber damper, is a tuned damper. An analytical tool is being used to evaluate the stiffness of compression rubber design and thus evaluate its performance. The rubber geometry, material and plate design are selected through simulations. The analytical tool demonstrates the functionality of the compression rubber damper paper and focuses on simulation-based product development using ANSYS for FEA and an in-house tool for torsional vibration analysis.

The present work aims at developing an effective technologies in treating such effluents from Indigo Carmine (IC) dye industry through the use of the industrial wastes such as red mud. Red mud, hazardous aluminium industry waste in its activated form using hydrazine sulphate is employed in the removal of the IC dye by batch adsorption operation. The adsorbent is characterized by FESEM, EDX and FTIR methods and found to be potent enough in up-taking the IC dye. However, sensitivity analysis is carried out in identifying the optimum operating conditions at which the ultimate the adsorption capacity of the red mud is found to be 62.6 mg/g with 94.0% overall removal of the IC dye. The adsorption mechanism is analysed by various adsorption isotherm models and the kinetics of the adsorption process is examined. Further, the thermodynamic investigation projected the operation to be spontaneous and endothermic. Regeneration studies indicated the recyclability of the developed adsorbent with % removals not falling below 85.0% even after five regenerations cycles. However, the adsorbent is tested for its reliability by applying it to the water effluents gathered from commercial IC dye polluting industry and found effective enough in its use as a potential adsorbent in water treatment operations.

We consider the distributed stochastic optimization problem of minimizing a nonconvex function f in an adversarial setting. All the w worker nodes in the network are expected to send their stochastic gradient vectors to the fusion center (or server). However, some (at most α-fraction) of the nodes may be Byzantines, which may send arbitrary vectors instead. Vanilla implementation of distributed stochastic gradient descent (SGD) cannot handle such misbehavior from the nodes. We propose a robust variant of distributed SGD which is resilient to the presence of Byzantines. The fusion center employs a novel filtering rule that identifies and removes the Byzantine nodes. We show that$T = \tilde O\left( {\frac{1}{{w{\varepsilon ^2}}} + \frac{{{\alpha ^2}}}{{{\varepsilon ^2}}}} \right)$ iterations are needed to achieve an -approximate stationary point (x such that${\left\| {\nabla f(x)} \right\|^2} \leq \varepsilon $) for the nonconvex learning problem. Unlike other existing approaches, the proposed algorithm is independent of the problem dimension.

Scalable and decentralized algorithms for Cooperative Self-localization (CS) of agents, and Multi-Target Tracking (MTT) are important in many applications. In this work, we address the problem of Simultaneous Cooperative Self-localization and Multi-Target Tracking (SCS-MTT) under target data association uncertainty, i.e., the associations between measurements and target tracks are unknown. Existing CS and tracking algorithms either make the assumption of no data association uncertainty or employ a hard-decision rule for measurement-to-target associations. We propose a novel decentralized SCS-MTT method for an unknown and time-varying number of targets under association uncertainty. Marginal posterior densities for agents and targets are obtained by an efficient belief propagation (BP) based scheme while data association is handled by marginalizing over all target-to-measurement association probabilities. Decentralized single Gaussian and Gaussian mixture implementations are provided based on average consensus schemes, which require communication only with one-hop neighbors. An additional novelty is a decentralized Gibbs mechanism for efficient evaluation of the product of Gaussian mixtures. Numerical experiments show the improved CS and MTT performance compared to the conventional approach of separate localization and target tracking., 16 pages, 7 figures

Two new isostructural coordination compounds of Ni(II) and Mn(II) viz. [Ni(H2O)4(Hdmpz)2]ADS (1) and [Mn(H2O)4(Hdmpz)2]ADS (2) (where, Hdmpz = 3,5-dimethylpyrazole, ADS = anthraquinone-1,5-disulfonate) have been synthesized in aqueous medium at room temperature and characterized them using elemental analysis, TGA, FT-IR, electronic spectroscopy and single crystal X-ray diffraction techniques. Coordination compounds involving ADS anions in the crystal lattice are scarcely reported in the literature. Crystal structure analysis reveals the presence of unconventional O∙∙∙O dichalcogen bonding interaction between the O-atoms of neighbouring ADS moieties of the compounds. Aromatic π-stacking and unusual charge assisted O‒H∙∙∙O and C‒H∙∙∙O hydrogen bonds (CAHBs) are also involved in the stabilization of the crystal structures. Theoretical calculations have been performed to analyze the CAHBs, π-stacking and O∙∙∙O dichalcogen bonding interactions observed in the solid-state structures of 1 and 2 using DFT calculations, MEP surface analysis, QTAIM and NCI plot index computational tools. The relatively larger interaction energy observed for Ni(II) compound can be attributed to the higher contribution of the CAHBs than that for the Mn(II) complex. The energy associated to the O•••O dichalcogen bonding interaction is small (0.6 kcal/mol) and comparable with the weak C‒H•••O contact observed in compound 2. In vitro antiproliferative activities of the compounds considering cell cytotoxicity and apoptosis reveal the cytotoxic potential of the compounds in Dalton's Lymphoma (DL) cancer cells with negligible cytotoxicity in normal PBMC cells. Molecular docking simulation of the compounds with antiapoptotic proteins reveals significant affinity of the compounds with the active sites of the antiapoptotic proteins.

Two new Ni(II) coordination complexes involving fumarate and 1,10-phenathroline viz.; [Ni2(phen)2(µ-fum)(H2O)6](fum)·6H2O (1) and [Ni(phen)2(H2O)2](0.5 fum)(NO3)·4H2O (2) (fum = fumarate, phen = 1,10-phenanthroline) have been isolated in aqueous medium at room temperature. Crystal structure analyses of the compounds reveal the presence of cooperative (π–π)2/(π–π)1/(π–π)2 stacked ternary assemblies which provide stabilities to the layered architectures. The lattice water and the large counter anions in the lattice of the compounds are involved in the formation of unconventional discrete cyclic fumarate-water, fumarate-water-nitrate clusters and infinite nitrate-water 1D chains that are very scarcely reported in the literature. The energetically significant π-stacked dimers observed in the biologically relevant ternary assemblies of the crystal structures are further studied theoretically using DFT calculations and NCI plot index computational tools. DFT calculations reveal that the cooperative (π–π)2 binding mode of compound 1 is energetically more significant than (π–π)1 Moreover, the study also reveals that for the equivalent cooperative (π–π)1 stacking interactions in both the structures, the energy is unexpectedly higher for compound 2 than that observed for compound 1. Both the compounds induce significant cytotoxicity in Dalton's lymphoma (DL) cancer cells by inducing apoptotic cell death with negligible cytotoxicity in normal cells. Decrease in the mitochondrial membrane potential (MMP) of DL cells after treatment with the compounds also corroborates the apoptotic cell death. The molecular docking and pharmacophore features reveal that the compounds interact and accommodated well with the active sites of anti-apoptotic proteins.

Two Ni(II) and Cu(II) coordination compounds viz. [Ni(phen)3](0.5adp)(2NO3)·4.5H2O (1) and [Cu4(phen)4(H2O)2(OH)4]4NO3·2H2O (2) (where, phen = 1,10-phenanthroline and adp = adipic acid) have been isolated in aqueous medium and characterized by single crystal XRD, TGA, elemental analysis and spectroscopic techniques (FT-IR and electronic). Crystal structure analysis of compound 1 reveals the unconventional enclathration of adp moieties in the tetrameric supramolecular host cavities via O(adp)···π and C–H···π interactions. The formation of discrete [(NO3)4(H2O)10]4− cores in 1 and unusual enclathration of the nitrate water clusters in the supramolecular host cavity of 2 provide additional reinforcement to the layered assemblies. DFT calculations and NCI plot computational tools have been employed to investigate the energetically significant enclathrated adp moieties in supramolecular host cavities of 1 and the antiparallel π-stacked ternary assemblies involving regium-π(chelate) interaction in 2. To the best of our knowledge, this is the first report of enclathration of adipic acid, a long chain aliphatic dicarboxylic acid; and non-covalent regium-π bonding interaction involving chelate ring in metal organic compounds. Finally, the compounds have been screened for in vitro antiproliferative activities in Dalton's Lymphoma (DL) cancer cell lines considering cell cytotoxicity, apoptosis and molecular docking. The compounds exhibit considerable cytotoxicity in DL cells with nominal effects in healthy normal PBMC cells. The docking study reveals the effective binding affinity of the compounds with the active sites of BCL family antiapoptotic proteins.

Two Mn(II) and Ni(II) coordination complexes viz. [Mn(phen)2(2,6-PDC)]·2CH3OH (1) and [Ni(2,6-PDC)2][Ni(H2O)4(en)]·6H2O (2) (phen = 1,10-phenanthroline, 2,6-PDC = 2,6-pyridinedicarboxylate and en = ethylenediamine) have been isolated at ambient conditions and characterized by elemental analysis, FT-IR, electronic spectroscopy, TGA and single crystal X-ray diffraction. Switching the solvent from methanol to water has changed the structural topologies of the compounds. Compound 1 is composed of a hepta-coordinated Mn(II) centre with two bidentate phen and one tridentate 2,6-PDC; whereas compound 2 is composed of cationic [Ni(H2O)4(en)]2+ and anionic [Ni(2,6-PDC)2]2– moieties with hexa-coordinated Ni(II) centers. Crystal structure analysis of compound 1 unfolds the presence of unorthodox O H(methanol)⋯π interactions involving the uncoordinated methanol molecules. The unusual enclathration of dual H-bonded guest (H2O)4 cores in the hexameric Ni(II) hosts in compound 2 provides rigidity to the crystal structure. The antiparallel π-stacked dimers and anti-cooperative HB···anion-π···HB assemblies observed in the solid-state structures of 1 and 2 respectively have been studied theoretically using DFT calculations and NCI plot index computational tools. In vitro anticancer evaluation of the compounds considering cell cytotoxicity and apoptosis assay showed significant concentration dependent cytotoxicity in Dalton’s lymphoma (DL) cancer cells with nominal effects in normal PBMC cells. To elucidate the possible mode of action of the cytotoxic behavior of the compounds, in silico docking studies have been carried out which revealed the efficient interaction of the compounds with the active sites of antiapototic cancer target proteins. The inhibitions of the activities of antiapoptotic target proteins have been further investigated using western blot analysis.

Two new benzoato bridged Mn(II) and Cu(II) dinuclear coordination compounds viz. [Mn2(bipy)2(4-Clbz)2(H2O)4]2(4-Clbz) (1) and [Cu2(bz)4(2-MePy)2] (2) (bipy = 2,2-bipyridine, 4-Clbz = 4-chlorobenzoate, bz = benzoate, 2-MePy = 2-methylpyridine) have been synthesized and characterized using elemental analysis, TGA, spectroscopic (FTIR, electronic, EPR) and single crystal X-ray diffraction techniques. Crystal structure analysis of compound 1 reveals the enclathration of guest 4-Clbz moiety in the supramolecular host tetramer which provides rigidity to the crystal structure. Further analysis reveals the presence of cooperative (π–π)2/(π–π)1/(π–π)2 ternary assemblies involving alternate coordinated and uncoordinated 4-Clbz moieties. In compound 2, intermolecular C H∙∙∙O, C H∙∙∙π and C H∙∙∙C contacts are involved in the formation of dimeric paddle wheel supramolecular assemblies which stabilizes the layered architecture. The cooperative interplay of H-bonding and π-stacked ternary assemblies of 1 has been studied theoretically using DFT calculations, MEP surface and NCI Plot computational tools. The large interaction energies along with the NCI plot index analysis confirm that the π-stacking assemblies in combination with the H-bonds are strong binding motifs. In vitro anticancer activity of the compounds considering cytotoxicity and apoptosis assays reveal significant concentration dependent cytotoxicity in Dalton's lymphoma (DL) cancer cell lines with nominal effects in normal healthy PBMC cells. Molecular docking study reveals the efficient interaction of the compounds with the antiapoptotic BCL family target proteins.

Two pyridinedicarboxylato bridged 1D coordination polymers of copper(II) viz.; {[Cu(2,5-PDC)(Hdmpz)2]·H2O}n (1) and {[Cu(2,3-PDC)]·10H2O}n (2) (where, Hdmpz = 3,5-dimethyl pyrazole, PDC = pyridinedicarboxylate) have been isolated and characterized using TGA, elemental analysis, spectroscopic (IR, electronic) and single crystal X-ray diffraction techniques. Crystal structure analysis of the compounds 1 and 2 reveals that unconventional C–H⋯π(carbonyl) and intramolecular O⋯C π-hole interactions provide stability to the crystal structures, respectively. Such C–H⋯π(carbonyl) and intramolecular O⋯C π-hole interactions are scarcely reported in the literature. Theoretical calculations have been performed to analyze the unconventional non-covalent interactions observed in the solid-state structures of 1 and 2 using NCI plot and QTAIM computational tools. We have also theoretically explored the semi-coordination (regium) Cu-Oaxial bonds present in the compound 2. The polymers have been further investigated for potential antiproliferative activities considering cell viability and apoptosis assays against Dalton’s lymphoma (DL) cancer cell lines and the results were compared with cisplatin (reference drug) in the same experimental conditions. The compounds significantly induce cytotoxicity in DL cells with nominal cytotoxicity in normal PBMC cells. The molecular doking simulation performed with the antiapoprotic protiens reveals strong binding affinities of the compounds with the active sites of the target proteins. To establish structure activity relationship (SAR), pharmacophore studies have been carried out to investigate the key pharmacophore features of the structures of the compounds responsible for biological activities.

Two new coordination compounds viz. [Ni(phen)2(NO3)](NO3)·4H2O (1) and [Ni(phen)2(H2O)Cl]Cl·4H2O (2) (phen = 1,10-phenanthroline) have been synthesized and characterized using elemental analysis, TGA, PXRD, electronic, FT-IR spectroscopy and single crystal X-ray diffraction techniques. Crystal structure analysis reveals the formation of discrete water and anion-water clusters that contribute to the layered assemblies of the compounds. Moreover, the enclathration of (H2O)4 cluster in the layered assembly of 2 also provides rigidity to the crystal structure. Unconventional anion-π interaction is also observed in compound 1 involving the π-system of the chelate ring of coordinated phen. Detailed structural investigation reveals the presence of biologically relevant cooperative π-stacked (π–π)1/(π–π)2/(π–π)1 ternary assemblies in both the compounds. Interestingly, DFT calculations reveal that (π-π)2 binding mode in 2 is energetically significant than in compound 1 which is further analyzed by NCI plot index computational tool. The compounds have been screened for anticancer activities considering cell cytotoxicity and apoptosis in Dalton's lymphoma (DL) malignant cancer cell line. The complexes significantly inhibit cell viability by inducing apoptotic cell death in cancer cell lines with negligible cytotoxicity in normal cells. DNA ladder assay results in the degradation of genomic DNA into small inter-nucleosomal fragments (damage DNA) which is a biochemical hallmark of DL cells undergoing apoptosis. Lactate dehydrogenase (LDH) leakage assay also reveals the release of the intracellular enzyme LDH from DL cells indicating the irreversible cell death involving cell membrane damage. The molecular docking simulations reveal that the compounds interact and accommodated well with the active site of anti-apoptotic BCL proteins. Structure activity relationship (SAR) analysis based on pharmacophore modelling reveal that the molecular features of the compounds play important roles in the biological activities.

Two new coordination compounds of Ni(II) and Cu(II), viz. [Ni(phen)2Cl(H2O)] 4-NO2bz·3H2O (1) and [Cu(phen)2Cl]Cl·5H2O (2) (phen = 1,10-phenanthroline, 4-NO2bz = 4-nitrobenzoate) have been synthesized and characterized by single crystal X-ray diffraction, elemental analysis, FT-IR, electronic spectroscopy, TGA and EPR. The detailed crystal structure analysis of the Werner Type Clathrate 1 reveals the self-assembled unconventional enclathration of 4-NO2bz moieties in supramolecular Ni(II) hosts. In addition to the conventional discrete (H2O)n clusters in the crystal structure of 2, the layered architecture involves enclathration of single guest water molecules in the Cu(II) supramolecular hosts. We have theoretically analysed the biologically relevant anti-parallel π-stacking interactions in compound 1 and two types of anion–π interactions involving coordinated and uncoordinated chloride ions in compound 2. MEP surface analysis and DFT calculations reveal that the anti-parallel π-stacking interaction in 1 is energetically significant and enhanced upon complexation of the ligands to the Ni(II) centre. Remarkably, studies also reveal that in addition to the conventional anion⋯π interaction involving the chloride anion in the lattice, the unusual Cl(chlorido)⋯π interaction observed in the crystal assembly of 2 is also energetically significant. The antiproliferative potential of the compounds 1 and 2 have been studied in Dalton’s Lymphoma (DL) malignant cancer cell lines considering MTT cell viability and apoptosis assays. The compounds 1 and 2 exhibited significant concentration dependent increase in cell cytotoxicity and apoptosis in DL cells with negligible cytotoxicity in normal (PBMC) cells.