A novel type of coordination mode of chloranilic acid leading to the formation of polymeric coordination ribbon in the series of mixed-ligand copper(II) complexes with 1,10-phenanthroline

Nitrochloranilic acid: a novel asymmetrically substituted quinoid bridging ligand for design of coordination polymers

A series of alkali salts and transition metal complexes of a novel asymmetrically substituted quinoid ligand, 3-nitro-6-chloro-2,5-dihydroxyquinone (nitrochloranilic acid, H₂NCA) was prepared and characterised.

Light intensity-induced photocurrent switching effect

A better control over processes responsible for the photocurrent generation in semiconductors and nanocomposites is essential in the fabrication of photovoltaic devices, efficient photocatalysts and optoelectronic elements. Therefore, new approaches towards photochemical properties tuning are intensively searched for. Among numerous parameters, the photocurrent polarity is of great importance to the overall performance of a device. Usually, the polarity is controlled through an alignment of electronic states/bands, tailoring of applied potential or suitable selection of incident light wavelengths. In most scenarios though, the influence of light intensity is somehow neglected and either some arbitrarily chosen, natural conditions are mimicked or this parameter is varied only in a narrow range. Here we present a ternary nanocomposite in which the persistent photocurrent polarity switching is achieved through changes in the light intensity. We also present arguments suggesting this behaviour is of a general character and should be considered also in other photochemical systems.

π-Orbital Yin–Yang Kagome bands in anilato-based metal–organic frameworks

π-Orbital Yin–Yang Kagome bands consisting of two flat bands with opposite Chern numbers have been disclosed in anilato-based metal–organic frameworks.

Towards understanding π-stacking interactions between non-aromatic rings

The first systematic study of π interactions between non-aromatic rings, based on the authors' own results from an experimental X-ray charge-density analysis assisted by quantum chemical calculations, is presented. The landmark (non-aromatic) examples include quinoid rings, planar radicals and metal-chelate rings. The results can be summarized as: (i) non-aromatic planar polyenic rings can be stacked, (ii) interactions are more pronounced between systems or rings with little or no π-electron delocalization (e.g. quinones) than those involving delocalized systems (e.g. aromatics), and (iii) the main component of the interaction is electrostatic/multipolar between closed-shell rings, whereas (iv) interactions between radicals involve a significant covalent contribution (multicentric bonding). Thus, stacking covers a wide range of interactions and energies, ranging from weak dispersion to unlocalized two-electron multicentric covalent bonding ('pancake bonding'), allowing a face-to-face stacking arrangement in some chemical species (quinone anions). The predominant interaction in a particular stacked system modulates the physical properties and defines a strategy for crystal engineering of functional materials.

Nitranilic acid as a basis for construction of coordination polymers: from discrete monomers to 3D networks

Six novel transition metal complexes of nitranilic acid, a highly versatile ligand, were studied. Topologies of coordination polymers ranging from 0D (discrete monomers) to 3D were observed.

Phosphine oxide-based tricarbonylrhenium(i) complexes from phosphine/phosphine oxide and dihydroxybenzoquinones

Neutral phosphine oxide (P[double bond, length as m-dash]O) donor-based organometallic complexes [{Re(CO)3O[double bond, length as m-dash]PCy3}{μ-DHBQ}{Re(CO)3O[double bond, length as m-dash]PCy3}] (1), [{Re(CO)3O[double bond, length as m-dash]PPh3}{μ-DHBQ}{Re(CO)3O[double bond, length as m-dash]PPh3}] (2), [{Re(CO)3O[double bond, length as m-dash]PCy3}{μ-THQ}{Re(CO)3O[double bond, length as m-dash]PCy3}] (3), [{Re(CO)3O[double bond, length as m-dash]PPh3}{μ-THQ}{Re(CO)3O[double bond, length as m-dash]PPh3}] (4), [{Re(CO)3O[double bond, length as m-dash]PCy3}{μ-CA}{Re(CO)3O[double bond, length as m-dash]PCy3}] (5), and [{Re(CO)3O[double bond, length as m-dash]PPh3}{μ-CA}{Re(CO)3O[double bond, length as m-dash]PPh3}] (6) were assembled from phosphine/phosphine oxide, a dihydroxybenzoquinone donor and Re2(CO)10via a one-pot solvothermal approach. The soft phosphine donor was transformed into a hard phosphine oxide donor during the formation of 1, 3, 4, 5, and 6. The complexes 1-6 were air and moisture stable and were soluble in polar organic solvents. The complexes were characterized by elemental analysis, FT-IR, and NMR spectroscopic methods. The molecular structures of 1, 2, 4, and 6 were analyzed by single-crystal X-ray diffraction analysis. The UV-Visible absorption studies indicated that 1-6 in THF display strong visible light absorption in the range of ∼350-700 nm.

Varying structural motifs, unusual X-band electron paramagnetic spectra, DFT studies and superoxide dismutase enzymatic activity of copper(ii) complexes with N′-[(E)-phenyl(pyridin-2-yl)methylidene]benzohydrazide

A diverse set of new copper(ii) complexes synthesized as possible models for antioxidant superoxide dismutase mimics.

Multifunctionality and size of the chloranilate ligand define the topology of transition metal coordination polymers

A series of eight novel complexes of chloranilic acid (CA) with the first-row transition metals (M = Mn, Cr, Ni, Co) were prepared and characterised by single-crystal X-ray diffraction, IR spectroscopy and polycrystalline X-band electron spin resonance (ESR) spectroscopy.

From mononuclear to linear one-dimensional coordination species of copper(ii)–chloranilate: design and characterization

A series of copper(ii) complexes with chloranilic acid with different topologies is prepared and a design strategy for the preparation of such complexes is discussed.

A sequential logic gate-based “smart probe” for selective monitoring of Cu2+, Fe3+ and CN−/F−via differential analyses

A sequential logic gate-based probe for the detection of Cu²⁺, Fe³⁺, CN⁻ and F⁻ at ppm levels in water.

Self-triggered conformations of disulfide ensembles in coordination polymers with multiple metal clusters

Five coordination polymers containing manganese(ii) ions, 6,6′-dithiodinicotinate, and/or N-donor coligands display mononuclear, trinuclear cluster and polymeric metal oxide wire and exhibit intrinsic biomimetic characteristics.