Reversible covalent bonding is often used for the creation of novel supramolecular structures, multi-component assemblies and sensing ensembles. Despite the remarkable success of dynamic covalent systems, the reversible binding of a mono-alcohol with high strength is challenging. Here, we show that a strategy of carbonyl activation and hemiaminal ether stabilization can be embodied in a four-co...

Lanthanide complexes with a series of hexapeptides-incorporating two unnatural chelating amino acids with aminodiacetate groups, Ada(1) and Ada(2)-have been examined in terms of their speciation, structure, stability and luminescence properties. Whereas Ada(2) acts as a tridentate donor in all cases, Ada(1) may act as a tetradentate donor thanks to the coordination of the amide carbonyl functio...

A series of molybdenum(vi) cis-dioxo complexes containing tetradentate salan ligands with different para-substitutions on the phenoxy group have been prepared. These complexes catalyse the oxygen atom transfer reaction between dimethylsulfoxide and triphenylphosphine. During oxo transfer catalysis, the complexes are resistant to formation of catalytically inactive oxo-bridged dimeric Mo(v) comp...

In the crystal structure of the title mononuclear Cu(II) complex, [Cu(C11H16N3O2)(NO3)]·0.25C2H5OH, the complex molecules are linked by N-H⋯O and O-H⋯O hydrogen bonds, forming a dimer with an approximate non-crystallographic twofold rotation axis of symmetry. In the monomeric unit, the Cu(2+) ion exhibits a distorted square-pyramidal configuration, whereby the anionic [HL](-) Schiff base ligand...

Three new Co-based MOFs with a nanosized tetradentate pyridine ligand, N,N,N′,N′-tetrakis(4-(4-pyridine)-phenyl) biphenyl-4,4′-diamine (TPPBDA) and carboxylate co-ligands, [Co(TPPBDA)(NO3)2]n·2H2O (1), [Co2(TPPBDA)(bpdc)2 (H2O)]n·2DMA (2) and [Co(TPPBDA)0.5(hfipbb)(H2O)]n·3.5H2O (3) (H2bpdc = biphenyldicarboxylic acid, H2hfipbb = 4,4′-(hexafluoroisopropylidene)bis-(benzoic acid), DMA = N,N-dime...

The tetradentate ligands (R)N4 ((R)N4 = N,N'-di-alkyl-2,11-diaza[3,3](2,6)pyridinophane, R = Me or iPr) were found to stabilize cationic ((R)N4)PdMe(2) and ((R)N4)PdMeCl complexes in both Pd(III) and Pd(IV) oxidation states. This allows for the first time a direct structural and reactivity comparison of the two Pd oxidation states in an identical ligand environment. The Pd(III) complexes exhibi...

A series of highly unsymmetric heterobinuclear Mn/Co complexes is reported, in which an organometallic CpMn(CO)z fragment and a classical Werner-type cobalt(II) subunit are arranged in close proximity by means of a bridging pyrazolate. Two ligand scaffolds are employed that differ by the chelate size of the tripodal tetradentate {N41 binding site for cobalt. Molecular structures of three comple...

A no vel series of co mplexes of the type [M(C28H24N4)X]X2, where M = Cr(III), Fe(III) or Mn(III), X = Cl−, NO3, CH3COO and (C28H24N4) corresponds to the tetradentate macrocyclic ligand, were synthesized in methanolic media by the template condensation of 1,8-diaminonaphthalene and 2,3-butanedione (diacetyl) in the presence of trivalent metal salts. The complexes were characterized by elemental...

New tetradentate N(2)O(2) donor Schiff bases and their mononuclear Co(II), Ni(II), Cu(II), and Pd(II) complexes were synthesized and characterized extensively by IR, (1)H-, (13)C-NMR, mass, ESR, conductivity measurements, elemental and thermal analysis. Specifically the magnetic and electronic spectral measurements demonstrate the octahedral structures of cobalt(II), nickel(II) complexes and sq...