Supramolecular 2D/3D Isomerism in a Compound Containing Heterometallic CuII2CoII Nodes and Dicyanamide Bridges

Supramolecular clumps of μ2-1,3-acetate bridges of Cd(II)-Salen complex: Synthesis, spectroscopic characterization, crystal structure, DFT quantization's, and antifungal photodynamic therapy

The article divulges the crystal growth, synthesis, and X-ray structure characterization of one centrosymmetric cadmium complex, [Cd{CdL(μ2-1,3-acetate)}2] using Salen ligand (SL). The complex is further characterized using spectroscopic and analytical techniques, including DRS, SEM-EDX, PXRD, and ICP-MS. The crystallographic study showed that the complex has a monoclinic space P21/c. Addison parameters (Ʈ) show the hexagonal geometry of the central Cd(II) metal ion. Hirshfeld surface and 2-D fingerprint confirm supramolecular contacts despite weak C-H⋯O and C-H···π interactions. Energy frameworks, FMOs, global reactivity parameters, MEP, and energy bandgap explain the complex reactivity outlook. The complex inter- and intramolecular bonding interactions were explored through natural bond orbital (NBO), QTAIM, NCI-RDG, Electron Location Function (ELF), and Localized Orbital Locator (LOL) quantization methods. In addition, the complex and its synthetic components in vitro antibacterial efficacy were investigated using Gram-positive and Gram-negative microbial strains. SAR (structure-activity relationship) correlates with biological potency. Molecular docking assessed antimicrobial potency with proteins S. aureus (PDB ID: 1JIJ), C. albicans (PDB ID: 1M7A), E. coli (PDB ID: 1T9U), P. aeruginosa (PDB ID: 2UV0), and A. Niger (PDB ID: 3K4P). The findings are backed by the Protein-Ligand Interaction Profiler (PLIP). The antifungal potency and cell viability test of C. albicans were conducted using photodynamic therapy (APDT).

Structural Transformation of Copper Coordination Complexes with Inducing Supramolecular Chirality

Four copper coordination complexes [CuL(CH3OH)]n (1), [CuL(C2H5OH)]n (2), [(CuL)·0.5H2O]n (3), and [CuL(H2O)·0.5H2O]n (4) with a tridentated Schiff base ligand (H2L = (E)-2-((4-fluoro-2-hydroxybenzylidene)amino)acetate) were obtained in different solvents and reaction times....

Change in molecular shapes of the trinuclear CuII2ZnII complexes on Schiff base reduction: structural and theoretical investigations

Structural analyses and theoretical studies of two new Cu₂Zn compounds and other analogous species established that subtle modification in a ligand system can stabilize various structures with versatile coordinating azide ion and flexible trinuclear core.

Recurrent π(arene)⋯π(chelate ring) motifs in four trinuclear CuII2MII (M = Cd/Zn) complexes derived from an unsymmetrical N2O2 donor ligand: structural and theoretical investigations

Detailed DFT calculations of four new trinuclear Cu₂M (M = Zn^II and Cd^II) complexes derived from a N₂O₂ donor unsymmetrical Schiff base ligand have been accomplished.

A combined experimental and computational study on supramolecular assemblies in hetero-tetranuclear nickel(ii)-cadmium(ii) complexes with N2O4-donor compartmental Schiff bases

Two new hetero-tetranuclear nickel(ii)/cadmium(ii) complexes, a cubane [(CH₃CO₂)₂Ni₂(L¹)₂Cd₂(NCS)₂] (1) and a linear tetramer [(DMSO)₂NiL²Cd(NCS)(μ_1,3-SCN)Ni(DMSO)L²Cd(NCS)₂] (2) {where H₂L¹ = N,N'-bis(3-methoxysalicylidene)propane-1,3-diamine and H₂L² = N,N'-bis(3-ethoxysalicylidene)propane-1,3-diamine are potential octadentate compartmental Schiff bases}, were synthesized and characterized. The structures of both complexes were confirmed by single crystal X-ray diffraction studies. Complex 1 contained a Ni₂Cd₂O₄ cubane core, whereas complex 2 featured an end-to-end thiocyanate-bridged tetranuclear moiety. Furthermore, complex 1 showed C-HH-C interactions, whereas a unique Sπ interaction was observed in complex 2. Theoretical studies were performed using several computational tools such as NBO and AIM analyses. Both complexes showed photoluminescence in DMSO medium at room temperature upon irradiation with ultraviolet light. The lifetimes of the excited states were ∼27 ns.

Joining of trinuclear (CuL)2M (M = MnII and CdII) nodes by 1,3- and 1,4-benzenedicarboxylate linkers: positional isomeric effect on co-crystallization

Among the four one-dimensional coordination polymers obtained by joining (CuL)₂M (M = Mn^II and Cd^II) nodes with 1,3- and 1,4-benzenedicarboxylate linkers, the chains derived from 1,3-benzenedicarboxylate are co-crystallized with dimeric Cu^II units.

Control of nuclearity in heterometallic CuII–MnIIcomplexes derived from asymmetric Schiff bases: structures and magnetic properties

Among three asymmetric Schiff bases used for the synthesis of heterometallic Cu^II–Mn^IIcomplexes, the one with N₂O₂donor atoms yielded a tetranuclear and a trinuclear complex whereas two N₂O₃donor ligands produced solely dinuclear complexes. The results of magnetic measurements have been justified by DFT study.

Syntheses, crystal structures, magnetic properties and ESI-MS studies of a series of trinuclear CuIIMIICuII compounds (M = Cu, Ni, Co, Fe, Mn, Zn)

Six homo/heterotrinuclear Cu^IIM^IICu^II (M = Mn–Zn) compounds derived from salicylaldehyde-trans-1,2-diaminocyclohexane, which is a rarely utilized ligand, are reported.

Solvent-induced construction of two zinc supramolecular isomers: synthesis, framework flexibility, sensing properties, and adsorption of dye molecules

Solvent-induced construction of two zinc supramolecular isomerism, sensing properties and adsorption of dye molecules.

Four supramolecular isomers of dichloridobis(1,10-phenanthroline)cobalt(II): synthesis, structure characterization and isomerization

Crystal engineering can be described as the understanding of intermolecular interactions in the context of crystal packing and the utilization of such understanding to design new solids with desired physical and chemical properties. Free-energy differences between supramolecular isomers are generally small and minor changes in the crystallization conditions may result in the occurrence of new isomers. The study of supramolecular isomerism will help us to understand the mechanism of crystallization, a very central concept of crystal engineering. Two supramolecular isomers of dichloridobis(1,10-phenanthroline-κ(2)N,N')cobalt(II), [CoCl2(C12H8N2)2], i.e. (IA) (orthorhombic) and (IB) (monoclinic), and two supramolecular isomers of dichloridobis(1,10-phenanthroline-κ(2)N,N')cobalt(II) N,N-dimethylformamide monosolvate, [CoCl2(C12H8N2)2]·C3H7NO, i.e. (IIA) (orthorhombic) and (IIB) (monoclinic), were synthesized in dimethylformamide (DMF) and structurally characterized. Of these, (IA) and (IIA) have been prepared and structurally characterized previously [Li et al. (2007). Acta Cryst. E63, m1880-m1880; Cai et al. (2008). Acta Cryst. E64, m1328-m1329]. We found that the heating rate is a key factor for the crystallization of (IA) or (IB), while the temperature difference is responsible for the crystallization of (IIA) or (IIB). Based on the crystallization conditions, isomerization behaviour, the KPI (Kitajgorodskij packing index) values and the density data, (IB) and (IIA) are assigned as the thermodynamic and stable kinetic isomers, respectively, while (IA) and (IIB) are assigned as the metastable kinetic products. The 1,10-phenanthroline (phen) ligands interact with each other through offset face-to-face (OFF) π-π stacking in (IB) and (IIB), but by edge-to-face (EF) C-H...π interactions in (IA) and (IIA). Meanwhile, the DMF molecules in (IIB) connect to neighbouring [CoCl2(phen)2] units through two C-H...Cl hydrogen bonds, whereas there are no obvious interactions between DMF molecules and [CoCl2(phen)2] units in (IIA). Since OFF π-π stacking is generally stronger than EF C-H...π interactions for transition-metal complexes with nitrogen-containing aromatic ligands, (IIA) is among the uncommon examples that are stable and densely packed but that do not following Etter's intermolecular interaction hierarchy.

2D and 3D Anilato-Based Heterometallic M(I)M(III) Lattices: The Missing Link

The similar bis-bidentate coordination mode of oxalato and anilato-based ligands is exploited here to create the first examples of 2D and 3D heterometallic lattices based on anilato ligands combining M(I) and a M(III) ions, phases already observed with oxalato but unknown with anilato-type ligands. These lattices are prepared with alkaline metal ions and magnetic chiral tris(anilato)metalate molecular building blocks: [M(III)(C6O4X2)3](3-) (M(III) = Fe and Cr; X = Cl and Br; (C6O4X2)(2-) = dianion of the 3,6-disubstituted derivatives of 2,5-dihydroxy-1,4-benzoquinone, H4C6O4). The new compounds include two very similar 2D lattices formulated as (PBu3Me)2[NaCr(C6O4Br2)3] (1) and (PPh3Et)2[KFe(C6O4Cl2)3](dmf)2 (2), both presenting hexagonal [M(I)M(III)(C6O4X2)3](2-) honeycomb layers with (PBu3Me)(+) in 1 or (PPh3Et)(+) and dmf in 2 inserted between them. Minor modifications in the synthetic conditions yield the novel 3D lattice (NEt3Me)[Na(dmf)][NaFe(C6O4Cl2)3] (3), in which hexagonal layers analogous to 1 and 2 are interconnected through Na(+) cations, and (NBu3Me)2[NaCr(C6O4Br2)3] (4), the first heterometallic 3D lattice based on anilato ligands. This compound presents two interlocked chiral 3D (10,3) lattices with opposite chiralities. Attempts to prepare 4 in larger quantities result in the 2D polymorph of compound 4 (4'). Magnetic properties of compounds 1, 3, and 4' are reported, and in all cases we observe, as expected, paramagnetic behaviors that can be satisfactorily reproduced with simple monomer models including a zero field splitting (ZFS) of the corresponding S = 3/2 for Cr(III) in 1 and 4' or S = 5/2 for Fe(III) in 3.

Influence of the central metal ion in controlling the self-assembly and magnetic properties of 2D coordination polymers derived from [(NiL)2M](2+) nodes (M = Ni, Zn and Cd) (H2L = salen-type di-Schiff base) and dicyanamide spacers

Three new 2D coordination polymers (CPs) (2)∞[(NiL)2Ni(μ1,5-N(CN)2)2]n (), (2)∞[(NiL)2Cd(μ1,5-N(CN)2)2]n () and (2)∞[(NiL)2Zn(μ1,5-N(CN)2)2]n () have been synthesized by reacting a [NiL] "metalloligand" (where H2L = N,N'-bis(salicylidene)-1,3-propanediamine) with three different metal(ii) (Ni, Cd and Zn) perchlorates and sodium dicyanamide, with identical molar ratios of the reactants. All three products have been characterized by IR and UV-Vis spectroscopies, elemental analyses, powder and single crystal X-ray diffraction and variable temperature magnetic measurements. The isomorphous compounds and consist of similar [(NiL)2M(μ1,5-N(CN)2)] (M = Ni for and Cd for ) angular trinuclear units in which two terminal "metalloligands" [NiL] coordinate to the central nickel(ii) (in ) or cadmium(ii) (in ) ion through phenoxido oxygen atoms. The μ1,5-bridging dicyanamido spacers connect the central Ni(ii) or Cd(ii) of one node to terminal Ni(ii) of two different nodes giving rise to 2D CPs. Compound also contains trinuclear units with the same formula as those of and : [(NiL)2M(μ1,5-N(CN)2)] (M = Zn in ). The main differences are that these units are linear in and the dicyanamide spacers link only the nickel atoms of neighbouring nodes. As in and , these trinuclear units are connected to four other units via four μ1,5-bridging dicyanamido ligands, giving rise to 2D CP with a similar topology: a uninodal 4-connected underlying net with the sql (Shubnikov tetragonal plane net) topology and (4(4)·6(2)) point symbol. The magnetic properties show the presence of moderate intra-trimer antiferromagnetic interactions in (J = -12.9 cm(-1)) and weak antiferromagnetic interactions between the terminal Ni(ii) ions in (J = -2.4 cm(-1)). In the Ni(ii) ions are well isolated by the central Zn(ii) ion and accordingly, only a very weak antiferromagnetic interaction through the single μ1,5-bridging dicyanamido ligands is observed (J = -0.44 cm(-1), D = -3.9 cm(-1)).

Solvent-controlled three families of Zn(ii) coordination compounds: synthesis, crystal structure, solvent-induced structural transformation, supramolecular isomerism and photoluminescence

The assembly, topological structure, supramolecular isomerism and luminescence of three solvent-controlled families of Zn(ii) coordination compounds were reported here.

Bis(4-pyridyl)mercury – a new linear tecton in crystal engineering: coordination polymers and co-crystallization processes

Three new coordination polymers have been obtained using bis(4-pyridyl)mercury (py₂Hg) as a spacer: [Cu(Hmea)₂(py₂Hg)](ClO₄)₂·2(py₂Hg) (1), [Cu₂(pa)₂(py₂Hg)(ClO₄)₂]·0.5(py₂Hg)·H₂O (2), and [Cu₂(pa)₂(py₂Hg)₂](BF₄)₂ (3) (Hmea = monoethanolamine; Hpa = propanolamine).