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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]

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]

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]

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]