Mixed-ligand complexes of Zn(II), Cd(II) and Cu(II) with triethanolamine and p-nitrobenzoic acid: Syntheses and crystal structures

Crystal structure of di-chlorido-1κCl,2κCl-(μ2-3,5-dimethyl-1H-pyrazolato-1κN 2:2κN 1)(3,5-dimethyl-1H-pyrazole-2κN 2){μ-2-[(2-hy-droxy-eth-yl)amino-1κ2 N,O]ethano-lato-1:2κ2 O:O}dicopper(II)

The title compound, [Cu2(C5H7N2)(C4H10NO2)Cl2(C5H8N2)], is a pyrazolate amino-alcohol complex which contains two di-methyl-pyrazole mol-ecules in monodentate and bidentate-bridged coordination modes and a monodeproton-ated di-ethano-lamine mol-ecule. Both copper atoms are involved in the formation of non-planar five-membered chelate rings. One Cu atom is in a distorted tetra-hedral environment formed by the pyridine nitro-gen atom of the protonated di-methyl-pyrazole mol-ecule, the N atom of the deprotonated bridged di-methyl-pyrazole, the Cl atom and the bridged O atom of the monodeprotonated di-ethano-lamine. The second Cu atom has an inter-mediate environment between trigonal bipyramidal and square pyramidal, formed by the N atom of the deprotonated bridged di-methyl-pyrazole, the Cl atom and the N atom of the amino-alcohol, and two O atoms of the deprotonated and protonated OH groups. In the crystal, N-H⋯Cl hydrogen bonds link the molecules into anti-symmetric chains running along the a-axis direction. Adjacent chains are connected by O-H⋯O hydrogen bonds involving the hydroxyl group as donor.

Crystal Structure and Hirshfeld Surface Analysis of Bis(Triethanolamine)Nickel(II) Dinitrate Complex and a Revelation of Its Characteristics via Spectroscopic, Electrochemical and DFT Studies Towards a Promising Precursor for Metal Oxides Synthesis

Metal complexes with chelating ligands are known as promising precursors for the synthesis of targeted metal oxides via thermal decomposition pathways. Triethanolamine (TEA) is a versatile ligand possessing a variety of coordination modes to metal ions. Understanding the crystal structure is beneficial for the rational design of the metal complex precursors. Herein, a bis(triethanolamine)nickel (II) dinitrate (named as Ni-TEA) crystal was synthesized and thoroughly investigated. X-ray crystallography revealed that Ni(II) ions adopt a distorted octahedral geometry surrounded by two neutral TEA ligands via two N and four O coordinates. Hirshfeld surface analysis indicated the major contribution of the intermolecular hydrogen-bonding between —OH groups of TEA in the crystal packing. Moreover, several O–H stretching peaks in Fourier transformed infrared spectroscopy (FTIR) spectra emphasizes the various chemical environments of —OH groups due to the formation of the hydrogen-bonding framework. The Density-functional theory (DFT) calculation revealed the electronic properties of the crystal. Furthermore, the Ni-TEA complex is presumably useful for metal oxide synthesis via thermal decomposition at a moderate temperature (380 °C). Cyclic voltammetry indicated the possible oxidative reaction of the Ni-TEA complex at a lower potential than nickel(II) nitrate and TEA ligand, highlighting its promising utility for the synthesis of mixed valence oxides such as spinel structures.

3-Amino-1-propanol and N-methylaminoethanol: coordination to zinc(ii) vs. decomposition to ammonia

The coordination of amino alcohols 3-amino-1-propanol and N-methylaminoethanol to zinc(ii) and their decomposition to ammonia were investigated.

Adamantylated organosilatranes: design, synthesis, and potential appraisal in surface modification and anti-protozoal activity

A series of organosilatranes tethered with the privileged adamantane motif has been prepared and their pharmacokinetic profiles were scrutinized.

Crystal structure of dimethanolo-bis[μ-(2-(2-(5-(pyridin-2-yl)-1H-1,2,4-triazol-3-yl)phenoxy)benzoato)-κ5 O,O′,N:N′,N′′]dicopper(II) — methanol (1/2), C46H48Cu2N8O12

C46H32Cu2N8O12, monoclinic, P21/c, a = 9.5638(9)Å, b = 20.2142(19) Å, c = 12.0825(11) Å, β = 94.696(1)°, V = 2328.0(4) Å3, Z = 2, R gt(F) = 0.0273, wR ref(F 2) = 0.0711, T = 100 K.

Crystal structure of trans-bis-(di-ethano-lamine-κ(3) O,N,O')manganese(II) bis-(3-amino-benzoate)

Reaction of m-amino-benzoic acid (MABA), di-ethano-lamine (DEA) and MnCl2·4H2O led to the formation of the title salt, [Mn(C4H11NO2)2](C7H6NO2)2. In the complex cation, the Mn(2+) ion is located on an inversion centre and is coordinated by two symmetry-related tridentate DEA mol-ecules, leading to the formation of a slightly distorted MnN2O4 octa-hedron. The MABA(-) counter-anions are connected to the complex ion by a pair of rather strong O-H⋯O hydrogen bonds, yielding a 1:2 supra-molecular aggregate. Much weaker N-H⋯O hydrogen bonds connect neighbouring aggregates into a three-dimensional network structure.

Crystal structure of the salt bis-(tri-ethano-lamine-κ(4) N,O,O',O'')cadmium bis[2-(2-oxo-2,3-di-hydro-1,3-benzo-thia-zol-3-yl)acetate]

The reaction of 2-(2-oxo-2,3-di-hydro-1,3-benzo-thia-zol-3-yl)acetic acid (NBTA) and tri-ethano-lamine (TEA) with Cd(CH3OO)2 resulted in the formation of the title salt, [Cd(C6H15NO3)2](C9H6NO3S)2. In its crystal structure, the complex cation [Cd(TEA)2](2+) and two independent NBTA(-) units with essentially similar geometries and conformations are present. In the complex cation, each TEA mol-ecule behaves as an N,O,O',O''-tetra-dentate ligand, giving rise to an eight-coordinate Cd(II) ion with a bicapped trigonal-prismatic configuration. All ethanol groups of each TEA mol-ecule form three five-membered chelate rings around the Cd(II) ion. The Cd-O and Cd-N distances are in the ranges 2.392 (2)-2.478 (2) and 2.465 (2)-2.475 (3) Å, respectively. O-H⋯O hydrogen bonds between the TEA hy-droxy groups and carboxyl-ate O atoms connect cationic and anionic moieties into chains parallel to [110]. Each NBTA(-) anion is additionally linked to a symmetry-related anion through π-π stacking inter-actions between the benzene and thia-zoline rings [minimum centroid-to-centroid separation = 3.604 (2) Å]. Together with additional C-H⋯O inter-actions, these establish a double-layer polymeric network parallel to (001).

Performance evaluation of triethanolamine as corrosion inhibitor for magnesium alloy in 3.5 wt% NaCl solution

The anti-corrosion performance of triethanolamine with Mg alloy in 3.5 wt% NaCl solution has been studied by immersion experiment, electrochemical impedance spectroscopy, potentiodynamic polarization, surface analysis, and quantum chemical methods.