Themed collection Equilibrium Solution Coordination Chemistry

Welcome to this themed issue of New Journal of Chemistry entitled “Equilibrium Solution Coordination Chemistry”.

We review the state-of-the-art and recent advances in the determination of radionuclide speciation in seawater.

Kinetic information that cannot be acquired with other techniques can be obtained by carefully planned and dynamic NMR experiments.

The lead(II)-lone pair leads to ambivalency: hemidirected (distorted, non-spherical) coordination spheres result from electronegative O-coordination and holodirected (symmetric, spherical) ones from less electronegative S-coordination.

We discuss the potential correlation between the antimicrobial peptide–metal binding mode, structure, thermodynamics and mode of action.

A critical perspective on (metallo)porphyrins in security-related applications: the past, present and future of explosives detection, CBRN defense, and beyond.

The speciation of Tc(VII) and its reactivity with H₂O₂, methanol and H₂S in H₂SO₄, HClO₄ and HNO₃ is reviewed.

The design of various types of synthetic heme models has allowed the fine tuning of the location of hydrogen bond donors around the ferrous coordination site. Through the years, it has migrated from a lateral to a quasi-apical position. Still, the unambiguous existence of an actual H-bond with the dioxygen adduct remains to be established.

The relationships between lengths of bridging chains and self-locked behaviors of dipillar[5]arene-based pseudo[1]rotaxanes and bispseudo[1]rotaxanes were studied in detail.

Factors governing the ground spin state of iron(I) complexes are analyzed by DFT methods. An efficient benchmarking procedure is reported.

A monolayer of the neutral Cu²⁺ complex of a silane-bearing diamino–diamido ligand is formed on glass, exhibiting (decreased) antibacterial properties.

Flexible nanotweezers including Co(II) dispersed single-walled carbon nanotubes in methanol.

Half-sandwich iridium(III) and cobalt(III) porphyrin-C₆₀ co-crystals, C₆₀·Ir^III(ttp)Ph and C₆₀·Co^III(ttp)Ph/C₇H₈, and triangular-sandwich C₆₀·3Ir^III(ttp)Ph, where ttp = tetra-p-tolylporphyrinato dianion, were synthesized.

A chiral ancillary ligand that has more steric bulk results in an increased reactivity of a ruthenium complex with biomolecules.

Donepezil and tacrine hybrids, containing a 2-hydroxyphenyl-benzimidazole chelating moiety and with multifunctional anti-AD activity, are evaluated in terms of metal (Cu and Zn) chelating capacity.

A ^99mTc-labelled bis-benzothiazolone-DTPA radio-complex as a SPECT neuroimaging agent.

Optical sensor for iron(III) detection via Fe(III) complexation in the solid phase.

N,O,S-donors platinum(II) complexes were synthesized and well characterized. We demonstrate that modification of coordination sphere by insertion of dmso molecule and bulky triazolopyrimidine ligand is good direction for the design effective less toxic platinum(II) complexes.

Mechanism of the interaction of a dinuclear aluminium/cacodylate complex with nucleic acids.

Novel C,N-chelated organotin(IV) complexes bearing weakly coordinating carborane moieties were prepared and used as a catalyst precursor for the direct synthesis of dimethyl carbonate (DMC) from CO₂ and methanol.

The topology and degree of electron transfer in self-assembled redox reactions between copper(I) species and nitrosoarenes are controlled by ligand properties.

The synthesis and characterization of 2,7-diphenyl- and 2,7-dithienyl-1,3,6,8-tetramethyl bis(difluoroboron)-1,2-bis((1H-pyrrol-2-yl)methylene)hydrazine (BOPHY) derivatives 1 and 2 are described.

The derivatization influence was studied for twelve 2,6-di(1H-imidazol-2-yl)phenols, whereby a strong fluorescent sensitivity for Cr(III) was reported, while Zn(II)/Cd(II) sensing potentials also appeared.

8-HQA is a good sequestering agent towards Fe²⁺ and Fe³⁺ over a wide pH range.

A molecular turnstile based on a luminescent pyridyl-benzimidazole stator and a rotor containing a pyridyl coordinating site may be reversibily switched between its open and closed states upon binding/unbinding of silver cations.

Synthesis and characterization of MTPP(NO₂)Cl₇ have been reported. Zn^II porphyrins exhibited higher Lewis acidity as compared to perbromoporphyrins. Co^II porphyrins were utilized for the selective rapid visual detection of cyanide ions.

The rotational movement of molecular brakes based on two Zn–porphyrin units interconnected by a spacer may be reversibly locked by addition of an external auxiliary ligand.

Complex formation equilibria of calcium, magnesium, copper and nickel with amino-bisphosphonic ligands are described, together with a speciation study along with calorimetric outcome and cytotoxicity characteristics.

The acid-base properties of morin and its complexation with the Zn^II cation are investigated by experimental and theoretical approaches.

This technique has a high DGT capacity, wide tolerance of pH and ionic strength and good performance as an in situ monitoring tool.

A new highly efficient tris-hydroxypyridinone chelator for iron and aluminum, with promising capacity as a potential metal decorporation agent.

Phospho(i)nate derivatives of dipicolylamine show excellent selectivity for Zn(II) over alkaline earth metal ions.

The complex [Ni₂L]²⁺ exhibits a pre-organized binding pocket, whose walls direct the coordination of pseudohalide ions via repulsive CH⋯π interactions.

This paper summarizes the application of the coupled HPLC-ICP-AES technique to study the substitution of niobium by tungsten in [Nb₆O₁₉]⁸⁻ or [(OH)TeNb₅O₁₈]⁶⁻ Lindqvist anions and the screening of mixed [PMo_12−xNb_xO₄₀]ⁿ⁻ Keggin anion formation.

The Fe(III) complexation properties of ladanein, a potent antiviral flavone, and related analogues (negletein and salvigenin), have been studied in solution under quasi-physiological conditions using physico-chemical tools and provided important insights into their stability/reactivity in solution.

Novel, non-symmetrical bis(aminoalkyl)phosphinic acids exhibit enhanced efficiency in Cu(II) ion binding.

Tazoc-Mar@: a simple device that turns into a deep blue colour in presence of Pd(II) at very low concentration.

Manganese excess can induce in humans neurological disorders known as manganism.

The speciation studies of Ln(III) complexes with triptycene-based tripodal ligands reveal slow transformations of tetranuclear assemblies in metal excess.

Relative order of the pH-dependent conditional stability of the hydroxamate type (O,O) and (N_amino,N_hydroxamato) chelates determines the coordination modes in the various mono- and dinuclear complexes of [(η⁵-Cp*)Rh^III(H₂O)₃]²⁺ with α-, β- and γ-aminohydroxamic acids.

Two ditopic PPD based ligands are able to discriminate Cd^II over Zn^II in aqueous solution based on the difference in their ionic radii, acting as OFF–ON fluorescent probes.

Four mono-DMSO ligated cobalt corroles with one or three meso-nitrophenyl substituents on the macrocycle were synthesized and investigated as to their electrochemical and spectroscopic properties in CH₂Cl₂ and DMSO.

A ratiometric cation FRET system containing two binding centers demonstrates distinct fluorescence changes upon interaction with alkaline, alkaline earth and heavy metal cations.

Equilibrium, dissociation kinetics, relaxometric and electrochemical properties of the [Mn(PhDTA)]²⁻ complex were investigated and the structure of the [Mn(PhDTA)]²⁻ complex was studied by using DFT calculations.

The loss of a coordinating donor atom in the ligand leads to lower thermodynamic stability, but higher kinetic inertness of Mn²⁺ complexes.

Pioneering the red region of emission! β-acrolein substituted Ga corroles show the longest fluorescence emission reported for monomeric corroles.

Chemico-physical properties, metal chelating ability, antiproliferative activity and DNA binding of new curcuminoids with improved stability.

The thermodynamics and kinetics of formation/dissociation of Eu(III) and Tb(III) with the H₂DO2A macrocyclic ligand were studied by time-resolved fluorescence spectroscopy.

BODIPYs bearing up to three glucose units were synthesized and their cytotoxicity and uptake investigated in human HEp2 cells.

Zinc–nucleotide complexes in alkaline solutions exhibit strong fluorescence enhancement and red shift, thus enabling an optical discrimination between the nucleotides.

In this research combined HPLC-ICP-AES technique was used to study formation of mixed [XW₁₁O₄₀]ⁿ⁻ (X = P, Ge, B) complexes.

Competing magnetic exchange in 1a and 2a with predominant participation of antiferromagnetic interactions in 1a and ferromagnetic exchange in 2a.

The protein fragment C4YJH2 of Candida albicans has the ability to tightly coordinate Zn(II) at its C-terminal region by means of an evolutionarily well-conserved histidine-rich sequence.

An original Co(II) porphyrin conductive polymer is electrosynthesized which efficiently catalyzes sulphite oxidation in water offering opportunities for sensor development.

A method to recover Pd and Pt from a silver nitrate electrolyte was developed.

Thanks to preorganization, 1,2-PIPOH, the six-membered ring cyclic hydroxamic acid, binds uranyl six times more strongly than its linear, methyl-substituted homolog (NMAH).

The Michael-type addition of DDQ on a zwitterionic ligand is described together with the chiral separation and full characterization of the two enantiomers of one derivative. These adducts offer a novel entry into chiral zwitterionic quinoidal ligands.

The fluorination of thiolate ligands is applied as a tool that allows control of the prevalence of thiophilic (Au–S) interactions over the expected aurophilic contacts in luminescent gold compounds.

The complexation of NpO₂⁺ with acetate is studied in aqueous solution by absorption spectroscopy as a function of the total ligand concentration (NaAc), ionic strength (I_m = 0.5–4.0 mol kg⁻¹ Na⁺(Cl⁻/ClO₄⁻)) and temperature (T = 20–85 °C).

Complexation of Pa(V) with nitrilotriacetic acid (NTA) in aqueous solution (1 M (Na,H)ClO₄) was studied by solvent extraction at different acidities (pcH = 0.6; 1.0; 2.0 and 2.5) with the element at the tracer scale (C_Pa < 10⁻¹⁰ M).

An efficient strategy was developed to obtain carboxyphenyl porphyrin, chlorins and metal complexes, with potential applications in photonics and biology.

Two new PAMAM metallodendrimers have been synthesized and characterized and their antimicrobial activity in solution and after deposition on textile fabrics has been described.

For nickel(II)-SSNX-NH₂ an equilibrium between the common (NH₂,3N⁻(peptide)) and (NH₂,2N⁻(peptide),N⁻(asparagine)) coordination modes was observed in a basic solution resulting in an increased stability of the complexes.

Responsive colloids made from copper(II) coordination polymers are readily dissolved in acidic medium following a controlled depolymerization of the polymer chains.

The toxicity of heavy metals such as lead (Pb), cadmium (Cd) and tin (Sn) has long been known but accidental exposures of large populations to these elements remain unfortunately a topical issue.

A new series of iron triferrocenylcorroles with three different axial ligands, NO, Cl⁻ and σ-Ph, is synthesized and characterized using ¹H NMR, electrochemical and spectroelectrochemical techniques in nonaqueous media.

EPR/⁵¹V-NMR parallel studies of [VO(3,4-HPO)₂] complexes in MOPS buffer and POPC liposome suspensions provide information regarding solvents for oral administration.

Four two-photon absorbing fluorophores A1–A4 are reported and their spectroscopic properties are analyzed for use, in combination with palladium–porphyrinato complexes C1 and C2, as two-photon absorbing antennas and energy donors for FRET-based antenna-core oxygen sensitive phosphorescent probes.

The flexibility/rigidity of the linker causes different relaxometric behavior in both mononuclear and trinuclear Gd^III complexes based on DO3A-like structures.

The leachate humic fraction is a good sequestering agent towards toxic metal ions, influencing their aqueous solution behaviour and their environmental impact.