David C. Weatherburn

Identification of Particulate Matter Sources on an Hourly Time-Scale in a Wood Burning Community

Particulate matter (PM) sources at two different sites in a rural town in New Zealand were investigated on an hourly time-scale. Streaker samplers were used to collect hourly, size-segregated PM(10-2.5) and PM(2.5) samples that were analyzed for elemental content using ion beam analysis techniques. Black carbon concentrations were determined using light reflection and PM(10) concentrations were recorded using colocated continuous PM monitors. PM(10) concentrations at both sites displayed a diurnal pattern, with hourly PM(10) concentration maxima in the evening (7 pm-midnight) and in the morning (7-9 am). One of the monitoring sites experienced consistently higher average PM(10) concentrations during every hour and analysis indicated that katabatic flows across the urban area contributed to the increased concentrations observed. Source apportionment using positive matrix factorization on the hourly data revealed four primary PM(10) sources for each site: biomass burning, motor vehicles, marine aerosol and crustal matter. Biomass burning was the most dominant source at both sites and was responsible for both the evening and morning PM(10) concentration peaks. The use of elemental speciation combined with PM(10) concentrations for source apportionment on an hourly time-scale has never been reported and provides unique and useful information on PM sources for air quality management.

A ship-based methodology for high precision atmospheric oxygen measurements and its application in the Southern Ocean region

Amethod for achieving continuous high precision measurements of atmospheri O2 is presented based on a commercially available fuel-cell instrument, (Sable Systems, Oxzilla FC-II) with a precision of 7 per meg (approximately equivalent to 1.2 ppm) for a 6-min measurement. The Oxzilla was deployed on two voyages in the Western Pacific sector of the Southern Ocean, in February 2003 and in April 2004, making these the second set of continuous O2 measurements ever made from a ship. The results show significant temporal variation in O2, in the order of 10 per meg over 6-hourly time intervals, and substantial spatial variation. Data from both voyages show an O2 maximum centred on 50°S, which is most likely to be the result of biologically driven O2 outgassing in the region of subtropical convergence around New Zealand, and a decreasing O2 trend towards Antarctica. O2 from the ship-based measurements is elevated compared with measurements from the Scripps Institution of Oceanography flask-sampling network, and the O2 maximum is also not captured in the network observations. This preliminary study shows that ship-based continuous measurements are a valuable addition to current fixed site sampling programmes for the understanding of ocean.atmosphere O2 exchange processes.

Composition and source contributions of air particulate matter pollution in a New Zealand suburban town

Wainuiomata, a suburban town located at the southern end of the North Island of New Zealand, is subject to air particulate matter pollution episodes during the winter. The results of fine (PM2.5) and coarse (PM2.5–10) particulate matter monitoring in Wainuiomata from July 2006–September 2008 are presented. Receptor modeling was used to determine the sources contributing to particulate matter pollution and mass contributions to ambient particle concentrations from emission sources were estimated. PM10 concentrations displayed a seasonal pattern, with peak concentrations occurring during the winter. The results demonstrate that marine aerosol and crustal matter sources were the primary contributors to the coarse particle fraction, while the fine particle fraction was dominated by biomass burning with smaller contributions from marine aerosol and secondary sulfate particles. Arsenic was found to be present in the fine particle fraction and was associated with biomass burning, suggesting the use of copper chrome arsenate treated timber for domestic heating. Analysis of seasonal differences revealed that biomass burning was largely responsible for fine particle pollution episodes during the winter. Marine aerosol featured significantly as a PM10 source all year due to New Zealand’s remote oceanic location.

Steric constraints imposed by triazamacrocyclic ligands. Crystal and molecular structure of two copper(II) complexes with triazamacrocyclic ligands : μ-chloro-μ-hydroxo-bis(1,5,9-triazacyclododecane)dicopper(II) perchlorate and bromo-(1,5,9-triazacyclotetradecane)copper(II) perchlorate

Abstract Crystal structures of two complexes of copper(II) with triazamacrocycles have been determined. The dimeric complex [Cu:(L1) 2 (μ-OH)(μ-Cl)](ClO 4 ) 2 (L1=1,5,9-triazacyclododecane) crystallizes in the monoclinic space group P 2 1 / n with a =14.29(1), b =9.292(9), c =25.63(2) A, β=102.23(6)°, Z =4. The structure has been refined to an R of 0.081 ( R w 0.0847). The coordination sphere of the copper(II) is best described as trigonal bipyramidal with two nitrogens of the macrocycle and the O atom occupying the trigonal plane. The CuN bond distances vary from 1.99(1)–2.06(1) A. [Cu(L6)Br](ClO 4 ) (L6=1,5,9- triazacyclotetradecane) crystallizes in the orthorhombic space group Pnma , a =14.365(4), b =11.491(6), c =10.194(3) A, Z =4. The data have been refined to R of 0.077 ( R w 0.075). The copper has a very distorted four-coordinate geometry, the CuN bond distances are equal within experimental error (2.02 A); the bond angles around the copper range from 92–148°. Electrochemical and ESR spectral studies of the [Cu(L6)] 2+ complex are reported.

Compounds of copper(II) and nickel(II) with 6,6,13,13-tetracarboxy-(andE-6,13-dicarboxy-) substituted 1,4,8,11-tetrazacyclotetradecanes, and carbomethoxy- and carbethoxy- derivatives. Structures of two isomericE-6,13-dicarboxy- (and anE-6,13-dicarbomethoxy-)1,4,8,11-tetrazacyclotetradecane copper(II) perchlorates

SummaryBis(ethanediamine) complex cations of CuII and NiII react with formaldehyde and diethyl- (or dimethyl-) malonate to form complexes of 6,6,13,13-tetracarbomethoxy- (or carbethoxy-) 1,4,8,11-tetraazacyclotetradecane macrocycles. These hydrolyse in base to give tetracarboxy-substituted cations, which decarboxylate in acid toE-6,13-dicarboxy-substituted cations. For CuII, salts of this cation were isolated in a metastable form, which converted in base to the stable form. These isomeric dicarboxy-substituted cations esterified to form perchlorate salts of the isomeric CuII compounds of theE-dicarbomethoxy-substituted cations. The structures of the perchlorate salts of the two isomers of the 6,13-dicarboxy-and the metastable isomer of the 6,13-dicarbomethoxy-substituted macrocycles were determined by x-ray diffraction. All have the macrocycles in squareplanar coordination in theRSSR configuration, with perchlorate oxygen atoms weakly coordinated axially. The metastable dicarboxy- and dicarbomethoxy compounds have the substituent groups axially oriented (1α, 4β, 6β, 8β, 11α, 13α) while the stable dicarboxy-compound has the substituents equatorially oriented (1α, 4β, 6β, 8β, 11α, 13α). The compounds are demetallated very slowly in acid, allowing the isolation of freeE-6,13-dicarboxy-1,4,8,11-tetrazacyclotetradecane.

Triazamacrocyclic complexes with 8- and 9-membered chelate rings. Preparation, structures and agostic interactions in complexes of 1,5,9-triazacyclotetradecane and 1,5,9-triazacyclopentadecane

Abstract Cobalt(II), copper(II) and nickel(II) complexes of the ligands 1,5,9-triazacyclotetradecane (tatd) and 1,5,9-triazacyclopentadecane (tapd), which have 8- and 9-membered chelate rings, respectively, have been prepared and characterised. Crystal structures of [Ni(tatd)(NCS)2]·H2O and [Co(tatd)(NCS)2] have been determined. The nickel(II) complex has a distorted square pyramidal geometry and the cobalt(II) complex has a distorted trigonal bipyramidal geometry. Agostic interactions between a hydrogen on the central carbon of the 8-membered chelate ring and the metal ion are observed in both complexes.

The crystal and molecular structures of aqua(1,4,7,10,13-pentaazacyclopentadecane)nickel(II) nitrate perchlorate [Ni[15]aneN5·H H2O](NO3)(ClO4) and (1,5,9,13,17-pentaazacycloeicosane)-nikel(II) nitrate hydrate [Ni[20]aneN5](NO3)2·H2O

SummaryThe structures of NiII complexes of the macrocyclic ligands 1,4,7,10,13-pentaazacyclopentadecane, [15]aneN5 and 1,5,9,13,17-pentaazacycloeicosane, [20]aneN5 have been determined. [Ni(C10H25N5)H2O]-(NO3)(ClO4) monoclinic, space group P21/n,a=8.265(3)Å,b=6.201(6)Å,c=13.672(4)Å, β=93.35(3)°· 2394 unique reflections were used in the structure determination and the refinement proceeded to an R value of 0.045. The ligand is coordinated to the metalvia all five nitrogens in theracemic conformation and a water molecule completes the coordination sphere of the metal ion. The complex cation shows considerable distortion from octahedral geometry which may rationalise the unusual spectroscopic properties and the low enthalpy of formation of the complex cation. [Ni(C15H35N5)](NO3)2·H2O monoclinic, space group P21/n,a=15.437(9)Å,b=9.573(6)Å,c=15.942(8)Å, β=109.24(4)°. 2715 unique observed reflections were used in the structure refinement which proceeded to an R value of 0.035. The five nitrogens of the macrocycle are bound to Ni(II) in a distorted square pyramidal coordination geometry. The NiII lies 0.35Å above the basal plane of the four nitrogen atoms.

13 C nuclear magnetic resonance study of the protonation of 2,2,4-trimethyl-1,5,9-triazacyclododecane

13 C N.m.r. spectroscopy has been used to investigate the protonation of 2,2,4-trimethyl-1,5,9-triazacyclododecane. The chemical shifts which occur upon protonation are interpreted as indicating that each protonation step results in the protonation of only one nitrogen atom, and that the sequence is probably N-5, N-9, and then N-1. There is some evidence indicating that a hydrogen bond is formed between N-1 and N-9 during the second protonation step. Chemical shifts observed are due to protonation of the nitrogen atom and to conformational changes within the molecule. The significance of these results for the determination of the protonation sequence of aliphatic polyamines is discussed.