Maciej Hodorowicz

Adsorption isotherms of homologous alkyldimethylbenzylammonium bromides on sodium montmorillonite

The adsorption of homologous alkyldimethylbenzylammonium bromides, [C(6)H(5)CH(2)N(CH(3))(2)R]Br, on sodium montmorillonite from aqueous NaCl solutions at room temperature has been studied. R stands for the methyl-, butyl-, hexyl-, octyl-, decyl-, and dodecyl-group, and the corresponding ammonium cations will be denoted as C1+, C4+, C6+, C8+, C10+, and C12+, respectively. C1+, the reference cation, attains the plateau region of adsorption at a level close to the cation exchange capacity (CEC) of the clay. The chain-length dependence on adsorptivity of the homologous cations exhibits an unexpected peculiarity. In the case of short-chain homologues of C1+ their adsorption onto sodium montmorillonite decreases in the order C1+>C4+>C6+. This behavior is due, presumably, to the growing steric hindrances at the surface of clay, which occur because of the limited area available for the bulky organic cations at the exchange sites. These limitations appear to be out-balanced in the case of higher homologues for which the increasingly growing hydrophobic effects lead to the expected sequence of adsorptivity of the cations, i.e., C1+<C8+<C10+<C12+. The extent of adsorption of the long-chain homologous cations at the plateau region exceeds the CEC value and indicates the commencement of formation of a bilayer or admicelle. As expected, the adsorption data for the short-chain homologues fit fairly well to the Langmuir isotherm, whereas the data for the C10+ and C12+ cations show an increasing departure from linearity of the corresponding plots. Results of X-ray analysis of organo-clays fully loaded with C1+, C4+, and C12+ cations suggest that in the case of short-chain homologues, the ammonium cations lay flatly and interact relatively strongly with the montmorillonite packet surface, whereas the long-chain homologue forms an interdigitated system of coiled hydrocarbon chains.

A novel single-site manganese(II) complex of a pyridine derivative as a catalase mimetic for disproportionation of H2O2 in water.

A novel single site Mn(II) complex was successfully synthesized and tested in the aqueous disproportionation of hydrogen peroxide. The complex was found to be stable (HR-XAS) and exhibits catalase-like activity in neutral pH. Theoretical calculations suggested a reaction mechanism involving two complexes, changes in metal oxidation state and proton shuttling.

Eight- and six-coordinated Mn(II) complexes of heteroaromatic alcohol and aldehyde: crystal structure, spectral, magnetic, thermal and antibacterial activity studies.

Crystal, molecular and electronic structure of new manganese(II) compounds: [Mn(2-CH2OHpy)2(NO3)2] (1), [Mn(4-CHO-5-MeIm)2(NO3)2] (2) and [Mn(4-CHO-5-MeIm)2Cl2] (3), where 2-hydroxymethylpyridine (2-CH2OHpy) and 5(4)-carbaldehyde-4(5)-methylimidazole (5(4)-CHO-4(5)-MeIm), have been characterised using X-ray, spectroscopic, magnetic and TG/DTG data. In compounds 1 and 2, the Mn(II) ion is eight-coordinated forming distorted pseudo-dodecahedron, that is rather unusual for the manganese(II) complexes, whereas in 3 the Mn(II) ion environment is a distorted octahedron. The high coordination number (CN=8) of 1 and 2 results from bidentate character of the nitrate ligands. The X-band EPR spectra of compounds 2 and 3 exhibit fine structure signals resulting from zero-field splitting (ZFS) of the spin states for high spin d(5) Mn(II), whereas for 1 the broad isotropic signals were observed. The estimation of ZFS for individual Mn(II) ions was carried out for all compounds using DFT calculations. The free ligands and their manganese(II) complexes have been tested in vitro against gram-positive and gram-negative bacteria in order to assess their antimicrobial properties.

Synthesis and physicochemical characterization of two lead(II) complexes with O-, N-donor ligands. Lone pair functionality and crystal structure.

A dinuclear [Pb2(4-CHO-5-MeIm)6(NO3)2](NO3)2 (1) and a polynuclear [Pb(2-pzc)2(H2O)]n (2) complexes (where 5(4)-carbaldehyde-4(5)-methylimidazole (5(4)-CHO-4(5)-MeIm) and pyrazine-2-carboxylic acid (2-pzcH)) have been synthesized and characterized by elemental analysis, IR spectroscopy and X-ray crystallography. Structural determination for complex 1 reveals a cationic species [Pb(4-CHO-5-MeIm)3]2+ connected through bridging nitrate(V) ions. There are also an uncoordinated nitrate ions as counterions. Complex 2 is a three-dimensional architecture consisting of Pb6O12 building units. The pyrazine-2-carboxylato ligand behaves as a chelating agent and a bi-connective bridge. The coordination polyhedra around lead(II) ion could be described as a distorted docecahedron (1) or monocapped trigonal prism (2). The luminescent properties of 1 and 2 investigated in the solid state at room temperature indicate structure-dependent photoluminescent properties. The DFT calculations and the X-ray structural data point on rather hemidirected type of coordination around Pb(II) ions of 1 and 2.

Bulky substituent and solvent-induced alternative nodes for layered Cd–isophthalate/acylhydrazone frameworks

A series of three cadmium-based two-dimensional (2D) metal–organic frameworks, featuring 4-pyridinecarboxaldehyde isonicotinoyl hydrazone bridging pillars (pcih) and either 5-tert-butyl-substituted or non-substituted isophthalate linkers, have been prepared and characterized. Isophthalates with bulky tert-butyl substituents (tBu-iso2−) form two-dimensional (2D) frameworks with various metal node nuclearities: [Cd(tBu-iso)(pcih)(DMF)]n or [Cd2(tBu-iso)2(pcih)2]n, dependent on synthetic conditions; whereas, in contrast, unsubstituted isophthalates (iso2−) yield only the framework with dinuclear nodes [Cd2(iso)2(pcih)2]n, regardless of the conditions. Diverse nodes of interdigitated layers have a significant influence on the thermal stability and adsorption behavior of the materials.

7-Meth­oxy-2-phenyl­chroman-4-one

In the title compound, C16H14O3, the ring O atom and the two adjacent non-fused C atoms, as well as the attached phenyl ring, exhibit static disorder [occupancy ratio 0.559 (12):0.441 (12)]. The crystal packing features π–π [centroid–centroid distance = 3.912 (1) Å] and C—H⋯π interactions.

Templated metalophilicity: synthesis of halometallic double salts directed by a dicopper(I) hydrazinyl-tetraimine nanocation

A nanometric size dication [Cu2(dih)2]2+ (where dih – 1,2-di[[2-(pyridin-2-yl)hydrazin-1-ylidene]methyl]benzene) of a molecular volume of 0.5 nm3 is described. The solvothermal synthesis and crystal structures of a new class of inclusion double salts, exhibiting d10–d10 and d10–d5 metallophilicity, of the formula [Cu2(dih)2]2[Cu(4 − y)MyCl8], where M is either Cu+ or heterometal of valency y (in this paper Mn2+ or La3+), are reported. UV-vis spectroscopy and square-wave voltammetry complement the characterisation of the luminescent salts.

Self‐assembly of long‐chain quaternary ammonium cations in a hybrid inorganic–organic material with one‐dimensional polymeric tribromidoplumbate(II)

catena-Poly[benzyldecyldimethylammonium [plumbate(II)-tri-μ-bromido]], {(C(19)H(34)N)[PbBr(3)]}(n), crystallizes as an inorganic-organic hybrid following monoclinic space-group symmetry P2(1)/c. The structure consists of extended chains running along the [001] direction and built of [PbBr(3)](-) units. These inorganic chains are separated by interdigitated ammonium cations which form hydrophilic layers through weak C-H···Br interactions. The architecture is essentialy the same as found for n-alkylbenzyldimethylammonium bromides.

(2Z)-2-Anilino-2-[oxido(phen-yl)iminio]-N-(2-pyrid-yl)acetamide methanol 0.425-solvate.

The title compound, C19H16N4O2·0.425CH4O, crystallizes with two formula units per asymmetric unit. Researching its crystal structure constitutes part of a study of the nature of interactions between the N+—O− group and the vicinal NH group. The nitrone group and methanol solvent molecules are linked via four N—H⋯O and one O—H⋯O hydrogen bonds, with donor–acceptor distances of 2.603 (3)–2.730 (3) and 2.770 (3) Å, respectively. The crystal structure also involves two intermolecular N—H⋯N hydrogen bonds.

Benzyl­ethyl­dimethyl­ammonium bromide

The crystal structure of the title compound, C11H18N+·Br−, has been determined as part of an ongoing study of the influence of the alkyl chain length on amphiphilic activity of quaternary ammonium salts. The title salt forms a three-dimensional network of ionic contacts through weak C—H⋯Br hydrogen bonds, with donor–acceptor distances in the range 3.757 (2)–3.959 (2) Å, in which methyl groups serve as donors.