Oxido- and Dioxidovanadium(V) Complexes with O-vanillin Semicarbazone: Synthesis and Crystal Structure

Two vanadium(V) complexes comprising VO3+ and VO2+ cores with o-vanillin semicarbazone (H2L) have been synthesized and characterized by IR, NMR spectroscopies and single-crystal X-ray diffraction study. The coordination polyhedra are a O5N distorted octahedron in the mono-oxidovanadium complex [VO(HL)(EtO)(EtOH)0.6(H2O)0.4][VO(HL)(SO4)(EtO)]•0.4EtOH (1) and a O4N square-pyramid in the dioxidovanadium compound [VO2(HL)]•2H2O (2)

NICKEL(III) COMPLEX DERIVED FROM 2-HYDROXY-3-METHOXYBENZALDEHYDE SEMICARBAZONE AND 2,2’-BIPYRIDINE

An ONO tridentate semicarbazone Schiff base and a bidentate dipyridyl ligand give a nickel(II) dimer, where atom centers are bridged by phenolate oxygen donors

Synthesis, crystal structure and characterizations of iron(III) and copper(II) complexes with the hydrazone ligand obtained from 2-formyl-pyridine and Girard's T reagent

The condensation of 2-formyl-pyridine with Girard's T reagent yields a new hydrazone in the form of an ammonium quaternary salt: [H(2-PyGT)]Cl. This tridentate ligand is readily soluble in water and reacts with iron(III) or copper(II) chlorides to give [Fe(2-PyGT)Cl3] (1) or [Cu(2-PyGT)Cl2]-(H2O) (2) complexes, respectively. Single-crystal X-ray studies in 1 and 2 reveal that the coordination reaction gives rise to the deprotonation of the organic ligand that is coordinated using its NNO donor atoms in the form of a zwitterion species. The coordination spheres around the transition metal ions in complexes 1 and 2 are quite different. In 1, the iron site adopts a distorted octahedral coordination sphere, while the Cu(II) ions in 2 show a distorted tetragonal-pyramid geometry. As expected, the magnetic properties of these compounds reveal only weak antiferromagnetic interaction between spin carriers

MOESM1 of Synthesis, structure and toxicity evaluation of ethanolamine nitro/chloronitrobenzoates: a combined experimental and theoretical study

Additional file 1. Additional information includes UV-vis spectra, FT-IR spectra, selected bond lenghts (Å) and angles (°), the difference between HOMO and LUMO energies

p-Aminobenzoate Organic Salts as Potential Plant Growth Regulators for Tomatoes

The discovery of environmentally friendly and inexpensive plant growth regulators (PGRs) for agronomically important crops is a necessity and must be considered a priority worldwide. This study provides the synthesis, structure determination and the biological evaluation of two binary organic salts as potential PGRs. New compounds have dual biological activity and are based on natural metabolite p-aminobenzoic acid (pABAH) and different alkanolamines. Studied compounds exhibit hydrogen-bonded 3D supramolecular architectures with different crystal packing due to the formation of one homosynthon and various heterosynthons. The biological profile of new compounds was investigated in laboratory and greenhouse on Solanum lycopersicum L., revealing the efficiency in promoting plant rooting and plant productivity. The results may have a positive impact on agricultural economics, developing new sustainable PGRs for tomatoes

Crystal Engineering of Schiff Base Zn(II) and Cd(II) Homo- and Zn(II)M(II) (M = Mn or Cd) Heterometallic Coordination Polymers and Their Ability to Accommodate Solvent Guest Molecules

Based on solvothermal synthesis, self-assembly of the heptadentate 2,6-diacetylpyridine bis(nicotinoylhydrazone) Schiff base ligand (H2L) and Zn(II) and/or Cd(II) salts has led to the formation of three homometallic [CdL]n (1), {[CdL]∙0.5dmf∙H2O}n (2) and {[ZnL]∙0.5dmf∙1.5H2O}n (3), as well as two heterometallic {[Zn0.75Cd1.25L2]∙dmf∙0.5H2O}n (4) and {[MnZnL2]∙dmf∙3H2O}n coordination polymers. Compound 1 represents a 1D chain, whereas 2–5 are isostructural and isomorphous two-dimensional structures. The entire series was characterized by IR spectroscopy, thermogravimetric analysis, single-crystal X-ray diffraction and emission measurements. 2D coordination polymers accommodate water and dmf molecules in their cage-shaped interlayer spaces, which are released when the samples are heated. Thus, three solvated crystals were degassed at two temperatures and their photoluminescent and adsorption–desorption properties were recorded in order to validate this assumption. Solvent-free samples reveal an increase in volume pore, adsorption specific surface area and photoluminescence with regard to synthesized crystals

Supramolecular Assembly and Ab Initio Quantum Chemical Calculations of 2‑Hydroxyethylammonium Salts of <i>para</i>-Substituted Benzoic Acids

Crystal structures of seven salts of 2-hydroxyethylamine with benzoic acid (<b>1</b>) and different substituted benzoic acids, such as <i>p</i>-methylbenzoic acid (<b>2</b>), <i>p</i>-methoxybenzoic acid (<b>3</b>), <i>p</i>-hydroxybenzoic acid (<b>4</b>), <i>p</i>-chlorobenzoic acid (<b>5</b>), <i>p</i>-bromobenzoic (<b>6</b>), and <i>p</i>-iodobenzoic (<b>7</b>) have been studied. The salts units of <b>1</b>–<b>7</b> serve as building blocks (BB) of the supramolecular architecture. In a crystal they are held together <i>via</i> proton-transferred N–H···O and normal O–H···O hydrogen bonds. The substituents on anions influence dipole–dipole interactions between anions and cations in molecular aggregates. As a result, they are organized in building blocks either <i>via</i> one charge-assisted (<b>1</b>, <b>2</b>) hydrogen bond or <i>via</i> two (<b>3</b>–<b>7</b>) hydrogen bonds. The dispersion interaction significantly contributes to intermolecular force fields driving the organization of hydrogen bonds in BB. In all studied compounds, building blocks are consolidated into 2-D layers through the N–H···O and O–H···O hydrogen bonds. For the crystal structures of <b>2</b>–<b>7</b>, with non-centrosymmetric space groups and the BB self-assembled by two hydrogen bonds, the macroscopic polarizations of a unit cell is practically perpendicular to the layers

New template reactions of salicylaldehyde S-methyl-isothiosemicarbazone with 2-formylpyridine promoted by Ni(II) or Cu(II) metal ions

The template reaction between salicylaldehyde S-methyl-isothiosemicarbazone and 2-formylpyridine in presence of nickel(II) or copper(II) salts yields two new coordination compounds with general formula [NiL1]2 (1) and [CuL2]2 (2) (L1 = the dianionic (N1-salicylidene)(N4-(hydroxy(pyridin-2-yl)methyl) Smethyl- isothiosemicarbazide) ligand and L2 = the doubly deprotonated (N1-salicylidene)(N4-(picolinoyl) S-methyl-isothiosemicarbazide) ligand). In the complex 1, the formed L1 ligand appears as result of an addition reaction of the precursors, while for 2 a redox mechanism is implicated in the formation of L2. Despite the fact that the initial organic precursors are the same, the resulting ligands obtained in the template reaction are different. In 1, the Ni(II) metal ion adopts a square-planar geometry and the [NiL1] units are forming dimerized chains through weak Ni...Ni interactions (3.336 and 3.632 Å). In 2, the Cu(II) metal ions adopt a square-pyramidal geometry and form dinuclear species through weak Cu...O (phenoxo) interactions. The magnetic susceptibility measurements of the complexes reveal the diamagnetic nature of 1 as expected for a square planar Ni(II) complex and a paramagnetic behavior for 2 with weak intra-dimer antiferromagnetic interaction (J/kB = -2.1(1) K). 2011 Elsevier B.V. All rights reserved