Marko Petrič

COMPLEXES OF COPPER(II) ACETATE WITH NICOTINAMIDE : PREPARATION, CHARACTERIZATION AND FUNGICIDAL ACTIVITY; CRYSTAL STRUCTURES OF CU2(O2CCH3)4(NIA) AND CU2(O2CCH3)4(NIA)2

Abstract Three new copper (II) acetate complexes with nicotinamide (nia) were synthesized analyzed and characterized by standard chemical and physical methods and tested for fungicidal activity The crystal and molecular structures of the compounds [Cu2 (O2CCH3)4 (nia)] (1B) and [Cu2 (O2CCH3)4 (nia)2] (2) were determined by X-ray diffraction Both consist of binuclear units of bridging tetracarboxylate type however they differ in the bonding mode of nicotinamide molecules They are bonded at the apical positions of the dimers and connect them in an infinite chain in 1B On the other hand the dimers remain isolated in the structure of the compound 2 It seems that compound 1B is the first example where a nicotinamide molecule acts as a bidentate bridging ligand The results of EPR spectra agree with the dimeric nature of the complexes Dissolved in water or DMSO the compounds completely stop mycelial growth at a concentration of 50×10−3 mol l−1 Less concentrated solutions (up to 10×10−3 mol l−1) show weaker fungicidal activity.

Changes in EPR spectra of wood impregnated with copper-based preservatives during exposure to several wood-rotting fungi

Summary The tolerance of various fungi against copper was examined. For this purpose, we impregnated Norway spruce (Picea abies) specimens with two different aqueous solutions: copper(II) octanoate with ethanolamine or copper(II) sulfate (cCu = 1.0 × 10−2 mol/l). Impregnated and unimpregnated test specimens were then exposed to brown rot fungi Antrodia vaillantii and Gloeophyllum trabeum or to white-rot fungi Schizophyllum commune and Trametes versicolor. After 2, 4, 6 and 12 weeks of exposure Electron Paramagnetic Resonance, Atomic Absorption Spectroscopy and mass loss measurements were performed. The results indicate that A. vaillantii, G. trabeum and T. versicolor transform copper(II) sulfate in wood into non-soluble, and therefore non-toxic, copper oxalate. The intensity of this reaction depends on the amount of excreted oxalic acid and was the highest for A. vaillantii and the lowest for T. versicolor. In the presence of ethanolamine, formation of insoluble copper oxalate was not possible and therefore, decay could not proceed. The major portion of copper remained in the wood and only minor amounts were in some cases translocated into nutrient media.

Microdistribution of Some Copper and Zinc Containing Waterborne and Organic Solvent Wood Preservatives in Spruce Wood Cell Walls

Summary The microdistribution of copper and zinc in the cell walls of spruce wood treated with water borne copper chloride, ammoniacal copper octanoate, ammoniacal zinc octanoate and with copper carboxylates dissolved in an organic solvent was studied using transmission electron microscopy with X-ray microanalysis. The highest content of copper and zinc was measured in cell corners and middle lamellae, that is in the constituents with the highest proportions of lignin. The same feature was observed also in the case of copper carboxylates dissolved in white spirit. On the basis of these results it was presumed that, within wood, lignin functional groups are preferential adsorption sites for transition metal ions irrespective of the carrier solvent.

Patination of cherry wood and spruce wood with ethanolamine and surface finishes

SummariesThe appearance of age or the so-called patina of cherry wood and spruce wood was obtained by treatment with ethanolamine vapours. Chemical changes in the treated wood were investigated by FT-IR spectroscopy, electron paramagnetic resonance and nitrogen content analysis. It was shown that the use of aggressive and toxic ammonia could be replaced by fuming with ethanolamine. Extensive colour stability experiments of patinated cherry wood that was coated with linseed oil varnish, linseed oil, beeswax or nitro-cellulose lacquer indicated that the described antiquing method represents a new possibility for producing various wood products with the appearance of age.RésuméLe bois de cerisier et d’épicéa a pris un air antique, c’est à dire de la patination, après être traité à la vapeur d’éthanolamine. Des changements physiques dans le bois traité ont été investigués par le moyen de la spectroscopie TF-IR, de la résonance paramagnétique électronique et de l’analyse de la teneur en azote II a été montré que l’emploi de l’ammoniac qui est agressif et toxique pouvait être remplacé par une exposition à la vapeur d’éthanolamine. Des expériences extensives dans le domaine de la stabilité de la couleur du bois de cerisier patiné revêtu d’huile de lin, de vernis à l’huile de lin, de cire d’abeille ou de laque nitro-cellulosique ont indiqué que la méthode décrite de rendre plus antique l’apparence du bois représente une nouvelle possibilité dans le domaine de la production d’objets en bois qui aient l’air antique.ZusammenfassungKirsch- und Fichtenholz wurde durch Behandlung mit Ethanolamingas künstlich gealtert und die chemischen Veränderungen durch FT-IR-Spektroskopie, elektromagnetische Resonanz und Messungen des Stickstoffgehaltes ermittelt. Es zeigte sich, daß man die Verwendung von aggressivem und giftigem Ammoniak durch die Bedampfung mit Ethanolaminen ersetzen kann. Wir führten extensive Tests zur Farbstabilität von künstlich gealtertem Kirschbaumholz durch, das mit Leinöl, Leinöllack. Bienenwachs oder Nitrozelluloselack behandelt worden war. Die Tests zeigten, daß die Behandlung mit Ethanolaminen eine praktikable Methode ist, verschiedene künstlich gealterte Holzprodukte herzustellen.

Complexes of copper(II) carboxylates with 2-aminoethanol - syntheses, characterization and fungicidal activity; crystal structure of Cu(O2CC8H17)2(NH2C2H4OH)2

Abstract Complexes of copper(II) octanoate, nonanoate and decanoate with 2-aminoethanol (ethanolamine) have been synthesized and characterized. The crystal structure of Cu(O2CC8H17)2(NH2C2H4OH)2 consists of mononuclear units with pairs of amino nitrogen atoms and deprotonated nonanoato oxygen atoms forming a square coordination plane around the central copper. The hydroxyl oxygen atoms from the 2-aminoethanol ligands are positioned axially with respect to the coordination plane. Results of screening for fungicidal activity against the wood-rotting fungus Trametes versicolor (L. ex Fr.) Pilat show that the complexes totally inhibit fungal growth at a concentration of 1.0 × 10−3 mol/1 but only partially at a concentration of 5.0 × 10−4 mol/1.

Preparation and characterization of copper(II) coordination compounds with linear chain fatty acids with 7–12 carbon atoms and pyridine. Crystal structure of Cu(O2CC8H17)2(py)2(H2O)

Abstract Mononuclear compounds of the composition CuX2(py)2(H2O) and binuclear of the composition Cu2X4(py)2 (py = pyridine, X = heptanoate, octanoate, nonanoate, decanoate or dedecanoate) were prepared, analysed and characterized by vibrational spectroscopy and thermogravimetry. Generally, the complexes are unstable, the mononuclear being even less stable than binuclear, losing pyridine in air at room temperature. The X-ray crystal structure of the mononuclear adduct of copper(II) nonanoate with pyridine, Cu(O2CC8H17)2(py)2(H2O), was determined by X-ray diffraction. The copper(II) ion is in a square pyramidal environment with two pyridine nitrogen atoms and two oxygen atoms from unidentate nonaoato ligands forming the basal plane of the pyramid and a water molecule coordinated at the apex. The carboxylate oxygen O(2) is not coordinated to copper, but is bound to water from a neighbouring molecule by the OHO(2) hydrogen bond of 2.691 (5) A.

The crystal and molecular structure of tetrakis(μ-octanoato-O,O′)-bis(pyridine)dicopper(II)

Abstract The crystal structure of the adduct of copper(II) octanoate with pyridine, (Cu2(C7H15COO)4(C5H5N)2, has been determined by X-ray diffraction. The complex forms discrete centrosymmetric tetracarboxylate-bridged dimers with pyridine moieties in the apical positions.

Investigations of Ammoniacal Copper(II) Octanoate in Aqueous Solutions and its Determination in Impregnated Wood

Copper(II) octanoate in aqueous ammonia Solutions belongs to the group of relatively new environment friendly waterborne preservatives, arnmoniacaJ copper carboxylates. Electron paramagnetic resonance, EPR, was used to study the behaviour of Cu(II) octanoate in aqueous ammonia solution and in spruce sapwood, impregnated with this solution. From the comparison of EPR spectra of CuSCX and Cu(II) octanoate aqueous ammonia Solutions it was established that in the Cu(II) octanoate-water-ammonia System, Cu(II) remains in Cu(II) octanoateammonia complex. That means that the active substance in treatment of wood with this solution is copper(II) octanoate-ammonia complex and not tetraamminecopper(II). The samples of spruce sapwood were impregnated with l 10~mol/l copper(II) octanoate-waterammonia solution and EPR spectra of the dried samples were recorded. It was stated that in wood Cu(II) from Cu(II) octanoate-water-ammonia solution is complexated. After soaking the samples for 24 hours in the Cu(ll) octanoate aqueous ammonia solution, the radial penetration depth of 1.2mm for Cu(II) was determined. Preliminary experiments on leaching of the investigated substance showed that after first 24 hours of the experiment, copper concentration in the impregnated samples decreased for approximately 35 % and that subsequent leaching did not further change the Cu(II) concentration, within the detection limit.

Performance of Waterborne Cu(II) Octanoate/Ethanolamine Wood Preservatives

Summary Various aqueous wood preservative solutions containing Cu(II) in the form of copper(II) sulphate or copper(II) octanoate, ethanolamine and in one case octanoic acid were investigated by spectrophotometry, polarography and Electron Paramagnetic Resonance (EPR) spectroscopy. Results have shown the same coordination environment around Cu(II) in all solutions with ethanolamine. Computer simulation of the EPR spectra also revealed that the coordination in the first coordination sphere of copper is the same at low concentration of ethanolamine. At 20% ethanolamine concentration, a mixture of two complexes (one with two nitrogens and the other with three) could be detected. The active compound in the investigated ethanolamine containing solutions is the same when previously synthesised copper(II) octanoate was used, or when copper(II) sulphate and octanoic acid were utilized instead. Fungicidal and leaching experiments with the treated wood resulted in the same conclusion: it is not necessary to use pre-synthesised copper(II) octanoate for the preparation of waterborne copper/ethanolamine wood preservatives. Preservative preparation time and costs can be reduced by simply dissolving copper(II) sulphate and octanoic acid in aqueous ethanolamine solutions.

Upgrading of spruce wood with ethanolamine treatment

Wood is the most abundant non-toxic, recycable and biodegradable natural material, valued as a construction material because of its appearance and its high strength at low density. On the other hand its biodegradability is an important drawback. Improvement of decay resistance of wood with ethanolamine is described in this paper. Ethanolamine chemically reacts with wood (Norway spruce sapwood) and does not evaporate from it. During this reaction, significant amounts of oxygen are consumed. Upgraded specimens show increased fungal activity and increased combustibility. The treatment of the spruce wood samples with aqueous solutions of ethanolamine resulted in colour changes.