d10 Metal complexes assembled from isomeric benzenedicarboxylates and 3-(2-pyridyl)pyrazole showing 1D chain structures: syntheses, structures and luminescent properties

Steric and Electronic Effects on the Structure and Photophysical Properties of Hg(II) Complexes

Since many factors influence the coordination around a metal center, steric and electronic effects of the ligands mainly determine the connectivity and, thus, the final arrangement. This is emphasized on Hg(II) centers, which have a zero point stabilization energy and, thus, a flexible coordination environment. Therefore, the unrestricted Hg(II) geometry facilitates the predominance of the ligands during the structural inception. Herein, we synthesized and characterized a series of six Hg(II) complexes with general formula (Hg(Pip)₂(dPy)) (Pip = piperonylate, dPy = 3-phenylpyridine (3-phpy) (1), 4-phenylpyridine (4-phpy) (2), 2,2′-bipyridine (2,2′-bipy) (3), 1,10-phenanthroline (1,10-phen) (4), 2,2′:6′,2′-terpyridine (terpy) (5), or di(2-picolyl)amine (dpa) (6)). The elucidation of their crystal structures revealed the arrangement of three monomers (3, 5, and 6), one dimer (4), and two coordination polymers (1 and 2) depending on the steric requirements of the dPy and predominance of the ligands. Besides, the study of their photophysical properties in solution supported by TD-DFT calculations enabled us to understand their electronic effects and the influence of the structural arrangement on them.

Six Hg(II) complexes containing 1,3-benzodioxole-5-carboxylic acid and pyridine derivatives bearing N-, N^N′-, and N^N^N-donor sites have been characterized and their crystal structure elucidated. Steric crowding defined the predominance of the linkers in the structural arrangement, varying from monomers to coordination polymers. Their photophysical properties were analyzed through experimental and TD-DFT calculations, identifying the character and regions involved on each electronic transition. In addition, seclusion of the HOMO from the LUMO defined them as appropriate to selective band gap tuning.

Mimicking cellular phospholipid bilayer packing creates predictable crystalline molecular metal–organophosphonate macrocycles and cages

Evolution of metal–organophosphonates from macrocycles into cages.

An asymmetric binuclear zinc(ii) complex with mixed iminodiacetate and phenanthroline ligands: synthesis, characterization, structural conversion and anticancer properties

A water-soluble asymmetric binuclear zinc(ii) complex with mixed iminodiacetate and 1,10-phenanthroline ligands exhibited promising anticancer activity and low toxicity, suggesting potential as a chemotherapeutic agent.

Metal Ion-Driven Assembly of Two New Coordination Polymers Constructed by Asymmetric Tricarboxylate and Imidazole-Containing Ligands: Syntheses, Crystal Structures, and Luminescent Properties

Two new coordination polymers, namely, {[Cd3(bpt)2(bimb)2]·2(H2O)}n (1) and [Zn3(bpt)2(bimb)2]n (2) (bpt = biphenyl-3,4′,5-tricarboxylate, bimb = 1,4-bis(1-imidazol-yl)-2,5-dimethyl benzene), have been obtained under hydrothermal conditions. Their structures have been determined by single-crystal X-ray diffraction analysis and further characterised by elemental analysis and infrared spectroscopy. Complex 1 exhibits a trinodal (4,4,4)-connected topology with Schläfli symbol of (4.62.83)4.(64.82). Complex 2 is also a three-dimensional structure and displays a (3,4,6)-connected topology with Schläfli symbol of (4.62)2.(42.66.85.102).(64.82). It is shown that the asymmetrically tricarboxylate can bear diverse structures regulated by metal ions. The photoluminescence behaviours of compounds 1 and 2 were also discussed.

Crystal structures, topologies and luminescent properties of three Zn(ii)/Cd(ii) coordination networks based on naphthalene-2,6-dicarboxylic acid and different bis(imidazole) linkers

Three new coordination polymers (CPs) based on H₂ndc acid have been synthesized and structurally characterized. Three CPs exhibit structural diversity depending on different bis(imidazole) bridging ligands and center metal ions.

A Nd-containing coordination ploymer: syntheses, crystal structure and application as a nucleating agent for isotactic polypropylene

This coordination polymer can increase the overall crystallization rate and decrease the spherulite size of iPP.

A 3-D metal–organic framework with a rutile topology network, right- or left- handed helical chains and tunable UV-to-visible photoluminescence

A solvothermally synthesized 3-D Cd(ii) metal–organic framework with rutile topology was found containing right- or left- handed helices in its structure, and emitting tunable UV-to-visible photoluminescence.

Photoluminescent and cytotoxic properties of multinuclear complexes and multinuclear-based polymers with group 12 metals and a tripodal ligand

Group 12 metal-based complexes constructed with a novel tripodal ligand display prominent photoluminescence, and zinc complex shows potential antitumor activity.

A spectroscopic study on the coordination and solution structures of the interaction systems between biperoxidovanadate complexes and the pyrazolylpyridine-like ligands

In order to understand the substitution effects of pyrazolylpyridine (pzpy) on the coordination reaction equilibria, the interactions between a series of pzpy-like ligands and biperoxidovanadate ([OV(O2)2(D2O)](-)/[OV(O2)2(HOD)](-), abbrv. bpV) have been explored using a combination of multinuclear ((1)H, (13)C, and (51)V) magnetic resonance, heteronuclear single quantum coherence (HSQC), and variable temperature NMR in a 0.15 mol L(-1) NaCl D2O solution that mimics the physiological conditions. Both the direct NMR data and the equilibrium constants are reported for the first time. A series of new hepta-coordinated peroxidovanadate species [OV(O2)2L](-) (L = pzpy-like chelating ligands) are formed due to several competitive coordination interactions. According to the equilibrium constants for products between bpV and the pzpy-like ligands, the relative affinity of the ligands is found to be pzpy > 2-Ester-pzpy ≈ 2-Me-pzpy ≈ 2-Amide-pzpy > 2-Et-pzpy. In the interaction system between bpV and pzpy, a pair of isomers (Isomers A and B) are observed in aqueous solution, which are attributed to different types of coordination modes between the metal center and the ligands, while the crystal structure of NH4[OV(O2)2(pzpy)]·6H2O (CCDC 898554) has the same coordination structure as Isomer A (the main product for pzpy). For the N-substituted ligands, however, Isomer A or B type complexes can also be observed in solution but the molar ratios of the isomer are reversed (i.e., Isomer B type is the main product). These results demonstrate that when the N atom in the pyrazole ring has a substitution group, hydrogen bonding (from the H atom in the pyrazole ring), the steric effect (from alkyl) and the solvation effect (from the ester or amide group) can jointly affect the coordination reaction equilibrium.

Novel coordination polymers of Zn(ii) and Cd(ii) tuned by different aromatic polycarboxylates: synthesis, structures and photocatalytic properties

Six fascinating coordination polymers (CPs) showed good photocatalytic activities for the degradation of methylene blue (MB).

Homo- and heteropolymetallic 3-(2-pyridyl)pyrazolate manganese and rhenium complexes

Heteropolymetallic complexes with pyridylpyrazolates bridging Mn and Na or K are tetrametallic and contain bridging pyridylpyrazolates with an unprecedented coordination mode, whereas the Mn/Li complex is bimetallic.

A series of interdigitated Cd(ii) coordination polymers based on 4,6-dibenzoylisophthalic acid and flexible triazole ligands

Different bridging ligands with various flexibilities and lengths were utilized to assemble interdigitated coordination polymers with Cd(ii) cations. The length and flexibility of the ligands could significantly influence the interdigitation level of the crystal structure.

Solvothermal synthesis, crystal structure and photoluminescence properties of four Cd(ii) coordination polymers with different topological structures

Four coordination polymers assembled by tetrabromoterephthalic acid and various bis(imidazole) ligands: synthesis, topological structures and luminescence properties.

Four cobalt(ii) coordination polymers with diverse topologies derived from flexible bis(benzimidazole) and aromatic dicarboxylic acids: syntheses, crystal structures and catalytic properties

Four metal–organic frameworks (MOFs) were obtained from the hydrothermal reaction of Co(ii) and with dicarboxylic acid and flexible bis(5,6-dimethylbenzimidazole) and characterized. The four MOFs exhibit distinct 2D or 3D structural frameworks.