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Four new trinuclear hetero-metallic complexes, [(CuL) 2 (μ-X) 2 Cd] where X = Cl, Br, I and NO 3 have been synthesized using N 2 O 2 donor Schiff base ligand and structurally characterized. Non-covalent interactions (i.e. π···π, C H···O and Cu···Cu interactions) of the molecules have been characterized by means of high level DFT calculations. • Four new tri-nuclear copper(II)-cadmium(II) complexes have been synthesized. • All of the complexes have been structurally characterized. • Extensive non-covalent interactions have been observed in all of four complexes. • An exclusive C H···O interaction has been observed in crystal packing of complex 4. • These interactions have been investigated by high level DFT calculations. Four new tri-nuclear hetero-metallic copper(II)-cadmium(II) complexes [(CuL) 2 CdCl 2 ] (1), [(CuL) 2 CdBr 2 ] (2), [(CuL) 2 CdI 2 ] (3) and [(CuL) 2 Cd(NO 3) 2 ] (4) have been synthesized using [CuL] as "ligand complex" (where H 2 L = N,N′-bis(2-hydroxynaphthyl-methylidene)-1,3-propanediamine) and characterized by elemental analysis, IR, UV–Vis spectroscopy and single crystal X-ray diffraction studies. Crystal structure analyses reveal that all four complexes consist of a tri-nuclear moiety in which two square-pyramidal [CuL] units are bonded to a central Cd(II) ion through double phenoxido bridges. The Cd(II) is in a six-coordinate octahedral environment being bonded additionally to two mutually trans chloride (in 1), bromide (in 2), iodide (in 3) and oxygen atoms of nitrate (in 4) ions. Presence of several non-covalent interactions (i.e. π···π, C H···O and Cu···Cu interactions) has been observed in the crystal packing of all the four molecules that assist the formation of 1D supramolecular assemblies in the solid state. The interactions were investigated by means of high level DFT calculations (PBE0-D3/def2-TZVP) with the help of TURBOMOLE 7.0 program, characterized using Bader's theory of "atoms-in-molecules" (AIM) and rationalized using molecular electrostatic potential (MEP) surface calculations. [ABSTRACT FROM AUTHOR]

Four new asymmetric Schiff bases, N - α -methylsalicylidene- N ′-2-hydroxynapthylidene-1,3-propanediamine (H 2 L 1 ), N - α -methylsalicylidene- N ΄-5-bromosalicylidene-1,3-propanediamine (H 2 L 2 ), N - α -methylsalicylidene- N ΄-3-methoxysalicylidene-1,3-propanediamine (H 2 L 3 ) and N -(3-methoxysalicylidene)- N΄ -(2-hydroxynapthylidene)-1,3-propanediamine (H 2 L 4 ) and their Cu(II) complexes [CuL 1 ] ( 1 ), [CuL 2 ] ( 2 ), [CuL 3 ] ( 3 ) and [CuL 4 ] ( 4 ) have been synthesized. All the complexes ( 1 – 4 ) have been structurally characterized by single crystal XRD. The Cu-atom is four coordinated square planar in complexes 1 – 3 but in 4 a water molecule coordinates to one of its axial positions making it penta-coordinated with square pyramidal geometry. The mononuclear complex molecules of 1 and 2 form infinite 1D columns that are arranged parallel forming 2D sheets where as in 3 they form self-assembled dimers that are inter-connected by weak van der Waals interactions and in 4 the molecules are packed in the form of infinite 1D ladders. The structure of a recently reported complex with a similar asymmetric ligand (H 2 L 5 ) N - α -methylsalicylidene- N ′-salicylidene-1,3-propanediamine where the phenoxido oxygen coordinates mutually to the axial position of another molecule to form a dimer is compared to the present complexes. The packing of the molecules in all the crystals are rationalized by theoretical molecular electrostatic potential surface (MEPS) calculations. DFT calculations show the significant role of CH·π (chelate ring) and π⋯π (chelate ring) interactions governing the crystal packing in all the complexes. Both the interactions are evaluated energetically by means of high level DFT calculations (M06-2X/def2-TZVP) and characterized using Bader's theory. Energetic differences between the monomeric and dimeric complexes in 1 and 5 have also been evaluated. [ABSTRACT FROM AUTHOR]

Two new dinuclear cadmium(II) complexes, [Cd(L 1 ) 2 Cd(SeCN-κ-Se) 2 ] ( 1 ) and [Cd(L 2 ) 2 Cd(SeCN-κ-Se) 2 ] ( 2 ), where HL 1 = {2-(3-(dimethylamino)propyliminomethyl)-6-methoxyphenol} and HL 2 = {2-(3-(dimethylamino)propyliminomethyl)-6-ethoxyphenol}, have been prepared and characterized by elemental and spectral analysis and single crystal X-ray diffraction studies. Both complexes contain cadmium-selenium bonds. Non-covalent interactions were also investigated using DFT calculations at the BP86-D3/def2-TZVP level of theory. Both complexes show florescence upon irradiation with visible light. [ABSTRACT FROM AUTHOR]

Herein we report the synthesis and X-ray characterization of a neutral mercury(II) complex of composition [Hg(L) 2 ] n ( 1 ), [L = N 1 -(3-hydroxypropyl)-5-fluorouracilate]. The Hg(II) is bound to the N(3) atoms of both ligands in an essentially linear geometry. Mercury also interacts through short contacts with the O(4) atoms of the uracil rings. The two bases are almost coplanar. Surprisingly, two hydroxyl groups from two different units are also weakly bound in apical positions. Single-crystal X-ray crystallography showed that the molecular complex aggregates into a coordination polymer. The packing assemblies observed in the solid state have been analysed and studied by means of theoretical DFT calculations. Unprecedented antiparallel C O⋯C–F interactions are described since they have a strong influence in the crystal packing of the complex. We have also used the Cambridge Structural Database to examine the occurrence of C O⋯C–F interaction in the solid state of X-ray structures. [ABSTRACT FROM AUTHOR]

Two new cadmium(II) complexes, [Cd(L 1 )(OOCCH 3 )(OH 2 )] ( 1 ), [Cd 2 (L 2 ) 2 (μ-1,3-SCN) 2 (CH 3 OH) 2 ] ( 2 ), have been synthesized using two halosalicylaldimine Schiff bases, HL 1 and HL 2 {where HL 1 = 2-(2-(ethylamino)ethyliminomethyl)-4-bromophenol, and HL 2 = 2-(2-(dimethylamino)ethyliminomethyl)-4-chlorophenol}, respectively. Both complexes have been characterized by elemental and spectral analysis and their structures have been confirmed by single crystal X-ray diffraction studies. Complex 1 is mononuclear and the cadmium(II) centre is apparently coordinated by a tridentate Schiff base, a water molecule and a bidentate chelating acetate. The acetate group could also be thought of as a single entity occupying just one stereochemical site as evident from the small value of chelate bite angle. Complex 2 is dinuclear and contain octahedral cadmium(II) bridged by double end-to-end thiocyanates. Supramolecular interactions in both complexes were also explored. The theoretical study, carried out using density functional theory (DFT) calculations, is devoted to the analysis of the interesting supramolecular assemblies in the solid state of the structures, paying special attention to hydrogen bonding interactions involving the coordinated solvent molecules. [ABSTRACT FROM AUTHOR]

Graphical abstract A thiocyanato bridged polymeric Cu(II)-hydrazone complex has been synthesized and characterized with several spectroscopic analysis and variable temperature magnetism. Molecular Electrostatic Potential (MEP) analysis shows that there exist π-acidic regions in the molecule which can interact with electron rich atoms and develop non-covalent interactions which are energetically estimated. Highlights • A thiocyanato bridged copper-hydrazone polymeric chain has been synthesized. • The complex has been characterized with FT-IR, UV-Vis and EPR spectroscopy. • Redox characterization of the complex has been performed by cyclic voltammetry. • Magnetostructural correlation is obtained from variable temperature magnetic susceptibility measurement. • The presence of non-covalent intermolecular interaction has been established by DFT calculations. Abstract One dimensional polymeric copper-hydrazone complex {[Cu(H 0.5 L)(µ 1,3 -SCN)]0.5ClO 4 ·0.5MeOH} n (1) has been synthesized with Cu(ClO 4) 2 · x H 2 O and N' -(1-(pyridin-2-yl)ethylidene)acetohydrazide (HL) in presence of NaSCN. The ligand and the complex have been characterized by several spectroscopic techniques (IR, UV–Vis and EPR), cyclic voltammetry and the structure of 1 has been determined by single crystal X-ray diffraction. The complex is an infinite one dimensional polymer bridged by thiocyanate. The magneto-structural correlation has been determined and the non-covalent interactions present in the molecule have been energetically evaluated by means of DFT calculations. [ABSTRACT FROM AUTHOR]

Two structurally similar mononuclear vanadium(V) complexes, [VO 2 (L 1 )] ( 1 ) and [VO 2 (L 2 )] ( 2 ) [where HL 1 = 1-(2-(dimethylamino)ethyliminomethyl)naphthalen-2-ol and HL 2 = 1-(2-(diethylamino)ethyliminomethyl)naphthalen-2-ol] have been synthesized and characterized by elemental and spectral analysis. Structures of both complexes have been confirmed by single crystal X-ray diffraction studies. Weak non-covalent interactions lead to the formation of extended supramolecular assemblies in them. The crystal packing in complex 2 is different compared to that in complex 1 due to the presence of ethyl groups instead of methyl groups bonded to the nitrogen atoms in the ligand moieties. The importance of non-covalent C H⋯π, π⋯π (chelate ring) and hydrogen bonding interactions in the solid state of both complexes has been described by means of DFT and MEP calculations and characterized using Bader’s theory of “atoms in molecules” (AIM). Particular attention has been paid to those interactions involving the chelate ring that are referred as uncommon interactions in this manuscript. [ABSTRACT FROM AUTHOR]

Three new copper(II) complexes, [Cu 2 L 2 Cl 2 (4,4′-bpy)]·2.7H 2 O ( 1 ), [CuL(4,4′-bpy)(H 2 O)]NO 3 ( 2 ) and [CuL(4,4′-bpy)(H 2 O)]ClO 4 ( 3 ), where HL = 1-[1-(2-Dimethylamino-ethylimino)-ethyl]-naphthalen-2-ol, have been synthesized and characterized by elemental analysis, IR, UV–Vis spectroscopy and single crystal X-ray diffraction studies. Complex 1 is a centrosymmetric dinuclear species in which 4,4′-bipyridine acts as bridging bidentate linker between the two copper(II) ions whereas, complexes 2 – 3 are rare mononuclear complexes in which the 4,4′-bpy ligand shows monodentate coordination mode stabilized by H-bonding interactions through its electronegative non-coordinated N-atom. These interactions involve imine and methylene hydrogen atoms of the Schiff-base ligand for 2 , whereas a single H-bond with one of the hydrogen atoms of the coordinated water is established in 3 . In addition, several non-covalent interactions like hydrogen bonding and π-based interactions (C–H/π, anion–π and π–π stacking) are also observed in crystal packing of all three complexes. These interactions have been investigated by means of DFT calculations and assigned with discrete interaction energies. The strong influence of the coordination of the 4,4′-bpy ligand to the copper(II) centers upon the binding strength of the π-based interactions has also been demonstrated. [ABSTRACT FROM AUTHOR]

A new solvated complex of the uranyl ion, [UO 2 (quin) 2 (H’quin)]·DMF ( 1 ), (Hquin = 8-hydroxyquinoline and H’quin = quinolinium-8-olate, i.e. the zwitterionic form of H quin ) was synthesized and investigated by means of elemental analysis, IR spectroscopy and X-ray crystallography. Interestingly one coordinated 8-hydroxyquinoline is protonated, thus provoking the simultaneous existence of an electron rich and electron poor ring in the same molecule. This clearly enhances the ability of this ring to form antiparallel stacking interactions that are responsible for the solid state architecture of compound 1 . This aspect has been analyzed by means of density functional theory calculations (DFT), molecular electrostatic potential (MEP) tool and Bader’s theory of “atoms in molecules”. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A centrosymmetric copper(II) Schiff base complex has been Synthesized. • The Schiff base is trapped in its zwitterionic form. • Supramolecular interactions lead to the formation supra-molecular architecture. • Anion⋯anion interaction between the perchlorate anions have been analyzed. Abstract A centrosymmetric square planar bis-ligand copper(II) complex, [Cu(HL) 2 ](ClO 4) 2 , with a potential tetradentate Schiff base, HL = 2-(2-(ethylamino)ethyliminomethyl)-6-ethoxyphenol, containing pendant side arm, has been prepared and characterized by elemental and spectral analysis and single crystal X-ray diffraction studies. The potential tetradentate Schiff base is trapped in its zwitterionic form and shows a bidentate bonding mode. Several weak forces like hydrogen bonding and C H∙∙∙π interactions lead to the formation of supra-molecular architecture. The existence of an anion⋯anion interaction between the perchlorate anions have been analyzed using DFT calculations, the Bader's theory of atoms-in-molecules (AIM) and the non-covalent interaction index (NCI plot). The O⋯O distance is 2.848(2) Å. [ABSTRACT FROM AUTHOR]

The Mn(II) complex {[Mn(atpa)(H 2 O) 2 ]·H 2 O} n ( 1 ),with the dicarboxylate ligand 2-aminoterephthalic acid (H 2 atpa), has been synthesized and crystallographically, spectroscopically and magnetically characterized. Complex 1 shows a very unusual 1 κ 2 N,O coordination mode of the aminoterephthalate dianion with the Mn(II) ion. One of the carboxylate groups shows a syn-anti-μ 2 - η 1 : η 1 binding mode to form a 2D square grid. The magnetic properties of this compound can be very well reproduced with a regular S = 5/2 chain model with a very weak antiferromagnetic coupling constant of J = −0.2 cm −1 through the single syn-anti carboxylate bridges. EPR measurement also supports the experimental data obtained from the magnetic study. The influence of the torsion angle between the carboxylate groups on the various interaction energies of 1 is calculated by means of DFT study. [ABSTRACT FROM AUTHOR]

Treatment of lead(II) acetate, Pb(CH 3 COO) 2 ·3H 2 O, with an isonicotinoylhydrazone building block (HL) and in the presence of two different salts (NaN 3 or NaClO 4 ) as a source of auxiliary ligand, resulted in two novel coordination compounds, namely a discrete 0D complex [Pb 4 (μ 3 -L)(L)(μ-N 3 )(N 3 )][Pb(L)(N 3 )(MeOH)]·0.75MeOH ( 1 ) and a 2D coordination polymer [Pb(μ-L)(μ-CH 3 COO)Na(μ-ClO 4 )(MeOH)] n ( 2 ), respectively. A related reaction of Pb(NO 3 ) 2 with HL afforded a different product [Pb(μ-L)(NO 3 ] n ( 3 ), which is a 1D coordination polymer. All compounds were isolated in good yields as air-stable solids and were fully characterized by elemental analysis, FTIR spectroscopy, single crystal X-ray diffraction, topological analysis, and theoretical calculations. An interesting feature of all structures 1 – 3 concerns the hemi-directional coordination of Pb(II) atoms and the observation of tetrel bonds [noncovalent Pb⋯N/O interactions], which were analyzed in detail by DFT calculations and Hirshfeld surface analysis. In fact, tetrel bonding interactions are responsible for the extension [0D → 2D (in 1 ) or 1D → 2D (in 3 )] or reinforcement [(2D → 2D (in 2 )] of the crystal structures, thus giving rise to intricate 2D supramolecular layers. After simplification, these layers were analyzed and classified from the topological perspective, disclosing binodal 3,5-connected underlying nets with the same 3,5L24 topology in 1 and 2 but being constructed from structurally distinct components, and a binodal 3,6-connected net with the 3,5L60 topology in 3 . [ABSTRACT FROM AUTHOR]

Two new mixed valence copper(II)–copper(I) complexes, [Cu(L 1 ) 2 CuI 3 ] ( 1 ) and [Cu(L 2 ) 2 ] 2 [Cu(L 2 ) 2 (Cu 2 I 5 ) 2 ]·2CH 3 CN ( 2 ) where L 1 = N,N-dimethylethane-1,2-diamine and L 2 = N-ethylethane-1,2-diamine, have been synthesized using isomeric chelating diamines and iodide. Complexes are characterized by elemental analyses, IR and UV–Vis spectroscopy. Single crystal X-ray diffraction studies confirm their structures. The degree of delocalization of the unpaired spin has been investigated by computing the spin density using the crystallographic coordinates. Interestingly, it can be observed from that the unpaired electron is delocalized between both copper centers in complex 1 , whereas complex 2 is a completely localized mixed valence complex. [ABSTRACT FROM AUTHOR]

Our synthetic approach demonstrates that pyridine-2,6-dicarboxylic acid N -oxide can form a stable Fe III complex with the rare 1:3 metal-to-ligand ratio. This study provides more information about packing features of one crystalline compound, (H9a-acr) 3 [Fe(pydco) 3 ]·6H 2 O ( 1 ) (where H 2 pydco = pyridine-2,6-dicarboxylic acid N -oxide and 9a-acr = 9-aminoacridine) via proton transfer methodology. The structure of 1 was characterized by IR spectroscopy, X-ray diffraction methods and the elemental analysis was performed to check the purity of the compound. On the basis of crystallographic data, compound 1 contains a monomeric anion with distorted octahedral geometry. The metal center is coordinated to six oxygen atoms by three bidentate pyridine-2,6-dicarboxylic acid N -oxide ligands to form a ceiling fan-shaped entity in which only the N -oxide oxygen and one carboxylate oxygen generate a six-membered chelate ring as seen for other N -oxides. Furthermore, the [Fe(pydco) 3 ] 3− and (9a-acr) + units in 1 form 2D anionic and cationic layers. The intermolecular interactions in this novel system consist of electrostatic attraction between ion pairs, different kinds of H-bonding and π-stacking all of which join the 2D layers to create 3D supramolecular architectures. Since pyridine-2,6-dicarboxylic acid N -oxide and pyridine-2,6-dicarboxylic acid have similar frameworks, we also highlighted some areas of current interest in the coordination behavior of the latter ligand in mononuclear monomeric compounds in the reported structures up to now and investigated the influence of the N -oxide moiety on the coordination mode(s) in the crystal lattice as well. [ABSTRACT FROM AUTHOR]

The complexes [Mn 4 (L1) 4 (N 3 ) 4 ] ( 1 ), [Mn 4 (L2) 4 (μ-N 3 ) 2 (N 3 ) 2 (OCH 3 ) 2 ] ( 2 ) and [Mn 4 (μ-L3) 4 (NCS) 4 ]·6CH 3 OH ( 3 ) [ L1 = N -1-(pyridin-2-yl)ethylidenepicolinohydrazonate, L2 = N -phenyl(pyridin-2-yl)methylenepicolino hydrazonate, and L3 = ((phenyl(pyridin-2-yl)methylene)hydrazinyl)((Z)-2-(phenyl(pyridin-2-yl)methylene)hydrazinyl)methanolate] have been synthesized, and their structures characterized. The structures of 1 and 3 can be described as tetranuclear and are formed from four Mn(II) ions bridged by four ligands. Complex 2 exhibits a centrosymmetric tetranuclear structure with two types of Mn(II) centers with double end-on (EO) azido bridges. All the complexes have similar magnetic behavior and exhibit weak intramolecular antiferromagnetic coupling, which is consistent with the oxygen-bridged square structures with large Mn–O–Mn bridge angles. Theoretically obtained J values of −1.7 cm −1 (for 1 ), −0.7 cm −1 (for 2 ) and −3.3 cm −1 (for 3 ) corroborate well the experimental results. Moreover, a Hirshfeld surface (HS) analysis was employed to gain additional insight into interactions responsible for packing of complexes 1 – 3 (with d norm and shape-index functions). Quantitative examination of 2D fingerprint plots revealed, amongst others, the dominating participation of H⋯H and H⋯C interactions in the molecular packing. [ABSTRACT FROM AUTHOR]

As part of ongoing studies of the effects of O - donor ligands based on pyridine-2,6-dicarboxylic acid N-oxide on the geometry, topology and dimensionality of their metal complexes, the salt (H9a-acr) 2 (pydco)·2H 2 O ( 1 ) and two new coordination complexes with formulas, {(H9a-acr) 2 [Cu(pydco) 2 (H 2 O) 2 ]·4H 2 O} ( 2 ), and {(H9a-acr) 2 [Ni(pydco) 2 (H 2 O) 2 ]·4H 2 O} ( 3 ) (where H 2 pydco = pyridine-2,6-dicarboxylic acid N-oxide and 9a-acr = 9-aminoacridine) have been synthesized by proton transfer from H 2 pydco to 9a-acr. The structures of 1 – 3 were characterized by elemental analysis, infrared spectroscopy and X-ray diffraction methods. Thermogravimetric analysis (TGA) was also carried out on compounds 1 and 2 . All three compounds have similar crystal packing, features, namely alternating 2D cationic and anionic layers which are held together by an extensive network of hydrogen bonds and π-stacking interactions to create three-dimensional supramolecular architectures. Despite the different conditions of temperature and stoichiometric ratio in the synthesis of complexes 2 and 3 , the products are isostructural and Cu 2+ and Ni 2+ have distorted octahedral geometry with two (pydco) 2− ions coordinated as chelating bidentate ligands. In all three compounds, protonated 9-aminoacridiunium cations are arranged in an anti-parallel stacking mode. This behavior is described and analyzed via density functional theory (DFT) calculations, molecular electrostatic potential (MEP) tools and the NCI method. [ABSTRACT FROM AUTHOR]

Three new manganese(II) complexes, namely [Mn(NCS) 2 (L) 2 (CH 3 OH) 2 ]·2CH 3 OH ( 1 ), [Mn(NCS) 2 (L) 2 (C 2 H 5 OH) 2 ]·2C 2 H 5 OH ( 2 ) and [Mn(NCS) 2 (μ-L) 2 ] n ( 3 ) (L = 4-acetylpyridine nicotinoylhydrazone) have been synthesized and characterized by elemental analysis, IR spectra, single-crystal and powder X-ray diffraction analysis. In order to investigate the effect of solvent, methanol, ethanol and acetonitrile have been used in the synthesis of complexes 1 – 3 , respectively. When using methanol as solvent, complex 1 was obtained. Complex 2 was synthesized under the similar synthetic conditions of complex 1 using ethanol instead of methanol as a solvent. To further examine the effect of solvent on the structure, we used CH 3 CN as a solvent instead of the ethanol. Unlike the complexes 1 and 2 , complex 3 was formed with 1D chain structure. The energetic features of the noncovalent interactions observed in the solid state of compounds 1 and 2 have been studied by means of DFT calculations. [ABSTRACT FROM AUTHOR]

Nickel(II), cobalt(II) and zinc(II) mononuclear Schiff base complexes of general formula [M II L(H 2 O) 3 ]·2H 2 O (where M = Ni, Co and Zn) have been synthesized using a new Schiff base ligand (LH 2 = 2-((Pyridin-2-yl)methyleneamino)benzene-1,4-dioic acid). All the complexes and the ligand have been characterized by various physical measurements such as elemental analyses, FT-IR and UV–Vis spectroscopic techniques. The crystal structure analyses of the complexes revealed that extensive supramolecular interactions such as hydrogen bond and π – π stacking results 3D array of packing. The hydrogen bonding interaction distances are very similar in all complexes and are around 2.0 Å and for the π – π interactions the values are close to 3.8 Å. The interaction energies are comparable for Ni and Co complexes and is somewhat stronger for Zn complex. The strength of the aforementioned interactions have been evaluated by means of DFT calculations. For in vitro antimicrobial activity study, the complexes were screened against some bacteria and fungi. This study shows that the zone of inhibition against growth of microorganisms is much larger for Zn complex due to strong binding energy. The Hirshfeld surfaces of Ni, Co and Zn complexes were also analyzed to clarify the nature of the intermolecular interactions. Thermogravimetric analyses were performed to investigate the thermal stability of the complexes. [ABSTRACT FROM AUTHOR]

Reaction of ZnII-acetate with two N, N, O-donor Schiff-base ligands, HL¹ {4-Chloro-2-[(2-morpholin-4-yl-ethylimino)-methyl]-phenol} and HL² {4-Chloro-2-[(3-morpholin-4-yl-propylimino)-methyl]-phenol}, which are formed in situ via condensation of 5-chlorosalicylaldehyde and N-(2-aminoethyl/propyl)morpholine, produce one tri- and one mononuclear species, Zn3L¹(OAc)4 (1) and ZnL²(OAc) (2). The hypothetical ZnL¹(OAc) and Zn3L²(OAc)4 are energetically unfavorable by 9.2 and 5.1 kcal/mol, in compare with their respective real counterparts 1 and 2 evidenced from DFT calculations. Both 1 and 2 catalyze the hydrolytic cleavage of phosphoester bond of (4-nitrophenyl) phosphate where 1 shows higher activity than that of 2. The proposed mechanistic pathways of phosphatase activity of 1 and 2 and the higher efficiency of the latter have been rationalized by DFT study. DNA cleavage activities have been investigated using supercoiled pET28a plasmid DNA where both the complexes show dose dependent DNA cleavage activity with varying degree. Complex 1 shows excellent breakage activity even at a concentration of 20 µM. However, in both cases hydroxyl radical pathway is most probably operative in DNA cleavage activity. [ABSTRACT FROM AUTHOR]