John N. R. Ruddick

Mössbauer and infrared spectroscopic studies of some organotin(IV) schiff base complexes

Several organotin(IV) complexes with quadri- and terdentate anionic Schiff base ligands have been investigated in the solid state using 119Sn Mossbauer and IR spectroscopies, Mossbauer parameters derived from both zero-field and magnetically perturbed spectra suggest that the R2Sn(Salen)(R = Me, Et, Ph) and Me2Sn(Saldap-2OH) complexes have similarly distorted trans-octahedral structures. However, in Ph2Sn(HSaldap-2-O) the ligand appears to be only terdentate, leading to a penta-coordinate structure similar to those of the R2Sn(Sal-N-2-OC6H4) derivatives (R = Me, Ph). For Ph3Sn(Sal-N-2-OC6H4) the asymmetry parameter of the electric field gradient is close to unity, confirming a mer-octahedral configuration for this complex.

Fixation of Ammoniacal Copper Preservatives: Reaction of Vanillin, a Lignin Model Compound with Ammoniacal Copper Sulphate Solution

A model for the fixation of ammoniacal copper preservatives in wood was examined through reaction of vanillin, a lignin model compound, with ammoniacal copper sulphate solution. The compound produced on evaporation of the aqueous ammoniacal solution has been characterized spectroscopically as di(amine)bis(vanillinato)copper(II) ; [Cu(vanillin) 2 (NH 3 ) 2 ]. Single crystal X-ray crystallographic studies showed that the crystals of [Cu(vanillin) 2 (NH 3 ) 2 ] are monoclinic with space group P21 with a = 5.4172(9), b = 15.452(2), c = 10.4595(9)A, Z = 2. The ligand arrangement around the Cu(II) is a distorted octahedron. Two Cu-N [2.014(5) and 2.034(5) A] and two Cu-O (hydroxyl) [1.969(4) and 1.972(4) A] bonds form a plane with Cu-O (methoxyl) [2.371(3) and 2.388(3) A] bonds in an axial direction at an angle 75° to the plane. The copper-nitrogen bonding is trans oriented in the plane. Electron spin resonance (ESR) was used to determine the g-tensor and hyperfine tensor elements from both a polycrystalline sample and a DMSO solution. The result suggests that ammoniacal copper wood preservatives can form stable copper-nitrogen-lignin complexes through reaction with guaiacyl units in lignin.

The microbial degradation of chlorophenolic preservatives in spent, pressure-treated timber

The reduction of pentachlorophenol in treated timber, after inoculation with pentachlorophenol-degrading bacterial species,Rhodococcus chlorophenolicus andFlavobacterium sp., and the white-rot fungusPhanerochaete chrysosporium, was monitored in solid substrate systems and in liquid culture suspensions. In solid substrate systems there was no significant pentachlorophenol degradation by the bacterial species under a variety of conditions. Under similar conditions,Phanerochaete chrysosporium transformed over 80% of the starting concentration of 500 ppm to pentachloroanisole. In liquid culture suspensions however, mid-exponential phaseFlavobacterium sp. cells were able to degrade over 99% of the pentachlorophenol in sawdust and wood chips due to the extraction of PCP from the timber as a water soluble salt. There were however no significant changes in the chlorinated dioxin components during this treatment.

The microdistribution of alkylammonium compounds in ponderosa pine sapwood

The distribution of an alkylammonium compound, iodobenzalkonium Chloride, in ponderosa pine sapwood was studied using Scanning Electron Microscopy coupled with an Energy Dispersive X-ray Analyser (SEM-EDX). Maximum adsorption of the iodobenzalkonium Chloride was obtained using a solution concentration of: 5 % for ray cells, 6 % for latewood and 10% för earlywood tracheids. Tracheid cell wall distribution of iodobenzalkonium Chloride showed an accumulation of iodine in the compound middle lamella, at solution concentrations of 6 % and higher. In general, higher chemical retentions were obtained by buffering the treating solution to alkaline conditions, cornpared with the unbuffered, or acidic buffered, Solutions. Middle lamella adsorption was also enhanced by the use of alkaline treating Solutions at3%.

Tin-119 Mössbauer spectra of organotin oxines in applied magnetic fields

Signs of the 119Sn quadrupole coupling constants and magnitudes of the asymmetry parameters for several mono-, di-, and tri-organotin oxines and two organotin Schiff base complexes have been determined from magnetically perturbed Mossbauer spectra. These results are used to deduce the probable structures of the compounds. Two of the triphenyltin derivatives are shown to be examples of less common structural types.

Effect of temperature and moisture on CCA fixation

Method: Hem-fir (a commercial mixture of Tsuga heterophylla and Abies amabilis) 100 x 100 mm sections, 30 cm in length were end-sealed with epoxy resin, pressure treated with CCA type C (2.09% w/w on an ocide basis) using a full cell process. After treatment the sections were immediately placed in a conditioning chamber, where the temperature and humidity were controlled. The air velocity was 2 m/s. At selected time intervals, cores were removed from each section for examination of the conversion of the hexavalent chromium to the insoluble trivalent form. The split cores were placed on filter paper and a few drops of a 0.5% solution of the disodium salt of 5-dihydroxy-2,7-naphthalene disulphonic acid in sulphuric acid were applied to the wood surface. A purple colour transferring to the paper indicated the presence of hexavalent chromium.

Investigation of copper solubilization and reaction in micronized copper treated wood by electron paramagnetic resonance (EPR) spectroscopy

Abstract The purpose of this study was to compare the reaction chemistry of micronized copper and alkaline copper treatments with wood and to determine how fast copper is solubilized during the reaction between the acidic functionality in wood and the basic copper carbonate (CuCO3). Copper species produced in wood by various treatment methods were analyzed by electron paramagnetic resonance (EPR) spectroscopy. The effects of time and solution concentration on the spectral parameters of copper complexes in sawdust treated with copper sulfate solutions were examined, followed by study on the structure and the rate of formation of the copper complexes in sawdust treated with basic CuCO3 suspension. The study further attempted to identify the soluble copper species formed in wood during treatment with micronized copper preservatives. Comparisons were made among the fixed copper complexes in wood treated with micronized copper preservatives, copper sulfate solutions, basic CuCO3 suspensions and alkaline copper solution. The results showed rapid formation of fixed copper complexes in wood treated with aqueous suspensions of basic CuCO3. These complexes can resist leaching, and they have similar stereochemistry to those formed between wood and copper sulfate. This finding supports the premises that soluble copper is generated during the treatment of sawdust with basic CuCO3, and it can bond to wood cell components by migrating into the cell wall in a manner similar to other soluble copper species. Such copper complexes formed are different from those of alkaline copper treated wood, which can be easily distinguished by EPR.

The structure of bis(trialkyltin) carbonates: Evidence for two non-equivalent tin sites

Abstract Bis(tributyltin) oxide or trimethyltin hydroxide react with carbon dioxide to afford the bis(trialkyltin) carbonates, (R 3 SnO) 2 CO; 119 Sn NMR (in the case of R = Bu) or 119m Sn Mossbauer spectroscopy show that these compounds contain 4- and 5-coordinate tin atom sites.

Quantification of mobilized copper(II) levels in micronized copper-treated wood by electron paramagnetic resonance (EPR) spectroscopy

Abstract Sapwood sawdust from southern pine was treated with micronized copper (MC) under various conditions and the mobilized copper(II) (Cumob) concentrations were determined in the treated wood by electron paramagnetic resonance (EPR) spectroscopy. The spectral parameters for the copper sulfate (CuSO4)-treated sapwood and those of the MC-treated sapwood were very similar. A linear correlation was found between the intensities of copper (Cu) EPR spectra and those of Cu energy-dispersive X-ray fluorescence spectroscopy in a series of CuSO4-treated sapwood reference samples. Thus, the EPR signal intensities could be reliably correlated to the mass of reacted Cu present using this calibration curve. The amount of the Cumob in sawdust treated by MC suspensions increased during the first 2–3 days after the initial treatment and then reached a maximum during the 7-day monitoring period. In the case of the treatment with MC alone or MC azole, an increased MC concentration led to an elevated amount of Cu (to a maximum of ∼0.23% Cu) solubilized by the sapwood. If the wood was treated with MC quat, the Cumob initially increased, but at higher concentrations the Cumob content decreased, due to the interference by the quat cobiocide on the acid reaction between the wood and the basic Cu carbonate. An examination of commercially-treated wood confirmed the laboratory observations.

A New Procedure for the Analysis of Chlorophenols in Preservative Treated Utility Poles

Abstract Preservative concentration in pentachlorophenol (PCP) treated wood has been traditionally determined in the industry using x-ray spectrometry or titrametric analysis of chloride. Although the methods are simple and inexpensive, they have a number of drawbacks. One of the main limitations is that the individual concentration of PCP, tetrachlorophenol (TCP), and other chlorinated chemicals cannot be determined. They are also sensitive to interferences. In the present study, procedures were developed to analyze PCP, TCP, pentachloroanisole (PCA) and trichlorophenols using gas chromatography-mass spectrometry (GC-MS). The wood to be analyzed was ground into sawdust and extracted with methanol/acetic acid in a sonicator. The extract was then pre-purified using either a FlorisilTM column (for softwood samples) or an ion exchange column (for heartwood samples) before GC-MS analysis. No PCA or trichlorophenols were detected in eight jackpine poles which has been in service for 13-37 years. The concentrat...