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The use of plastics is extremely prevalent in society, with most individuals likely to handle several plastic items per day. It is therefore not surprising that many exhibits recovered from the scene of a crime are plastics, which are processed and examined for traces such as fingermarks. Societal trends have been pushing towards more environmentally friendly products with alternatives to traditional disposable plastics becoming increasingly available. These alternate plastics have different chemical compositions and physical properties, which may impact fingermark development for these substrates. As most detection techniques are known to be substrate-dependent, it is crucial to review current methods and procedures to examine how effective they are on new materials. The aim of this research was to assess a range of fingermark detection techniques on biodegradable plastics and provide recommendations for the preferred technique. First, the prevalence of these materials in the Australian market was evaluated. Over 40 different plastics obtained within the Sydney area were then divided into six broad categories using consumer information in combination with ATR-FTIR spectroscopy analysis. Following this, selected plastics from each category were used as substrates for the fingermark development study. In total, 6480 fingermark specimens were collected as split marks, to form 2160 fingermark comparisons. Each substrate was then developed with four fingermark detection techniques suitable for plastic substrates: cyanoacrylate (CA) fuming, vacuum metal deposition (VMD), powder suspensions (PS), and single metal deposition (SMD). SMD resulted in the most consistent development method across all tested substrates. VMD was able to successfully develop fingermarks on polyethylene-based plastics, but led to poorer results on alternative plastics, while CA fuming and PS were notably more dependent on the surface texture. This research was successful in confirming that biodegradable plastics do in fact have an impact on fingermark development techniques commonly applied on traditional plastics and recommendations have been formed to aid in operational contexts to improve the potential to recover latent fingermarks from biodegradable plastics.

In recent years, sawn-off shotguns have been regularly encountered in firearm-related incidents. Shotgun represents a community threat due to their ability to be shortened in order to improve their concealability. In practice, forensic scientists and investigators may be asked to determine if a shotgun used in a particular event might have been shortened based on the pellet distribution. To investigate the effect of altering the barrel length on pellet distribution, five 12-gauge shotguns were progressively shortened. Each shotgun was assessed at six barrel lengths and a single discharge of No. 4 shot shotshell ammunition was fired at a fixed fabric target. The shotguns were positioned at six different distances from target and experiments conducted in triplicate. The fabric targets containing pellet pattern underwent data analysis to calculate the pellet distribution area. At short distances from target (≤ 1.0 m), the pellet penetration was observed as a single entry point as the pellets did not have a sufficient flight time to spread from each other. For distances of 2.5 m, 5 m and 10 m, pellet penetration patterns were observed and a quantitative analysis was performed on the samples containing pellet distribution patterns. At each of these distances, it was detected that there was a noticeable increase in pellet distribution area between the unaltered shotgun and altered barrel lengths for all shotguns. The distance from the target as well as the presence of a choke in the shotgun's barrel was found to have a greater impact on the pellet distribution than the barrel length.

Pressure sensitive tapes such as duct tape are a common trace type sent for forensic analysis. The limited variation of tape backings and adhesives can provide valuable linkage evidence between a scene, a victim or a person of interest. Fingermarks are also often found on tapes and prioritised over tape analyses. This project aimed to investigate the effects of fingermark enhancement chemicals, namely Wet Powder™, cyanoacrylate and cyanoacrylate stained with rhodamine 6G, on various tapes and their comparison with untreated tapes. The changes in physical and optical features were observed using a Video Spectral Comparator (VSC) and microscopy. Chemical changes were analysed by Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR). Most physical and optical properties were not heavily affected by the treatments. An increase in fluorescence was observed with specimens stained with rhodamine 6G as might be expected. Significant chemical changes were observed in the FTIR spectra produced from cyanoacrylate fuming. Polyethylene backings and rubber adhesives were heavily affected while polypropylene backings were moderately affected. Cellulose backings, polyester and polyacrylate adhesives were not significantly affected. Wet Powder™ treatment proved useful for enhancing fingermarks on most adhesives while leaving behind little chemical residue that might interfere in a forensic comparison.

Students in first-year chemistry classes come from a variety of backgrounds, with many students unaware of the qualities and behaviors of a professional scientist. Throughout their degree, students will gradually develop their cognitive skills, but they may not be adequately taught or assessed on their professional behavioral skills as a scientist until late in the undergraduate course. By assessing the professional skills of students in first-year chemistry practical classes, this innovation commenced the development of students’ professional identity from the beginning of their university experience. The skills that were assessed included preparedness, cooperation in the group activities, working safely in the laboratory, and time management. By engaging students with professional behaviors and what it means to be a scientist during their first semester, students can potentially carry this through their whole undergraduate degree. This task was received positively by students and staff with over 50% of ...

The data presented here is related to the article titled, “Using handwriting to infer a writer's country of origin for forensic intelligence purposes” (Agius et al., 2017) [1]. This article reports original writer, spatial and construction characteristic data for thirty-seven English Australian11 In this study, English writers were Australians whom had learnt to write in New South Wales (NSW). writers and thirty-seven Vietnamese writers. All of these characteristics were coded and recorded in Microsoft Excel 2013 (version 15.31). The construction characteristics coded were only extracted from seven characters, which were: ‘g’, ‘h’, ‘th’, ‘M’, ‘0’, ‘7’ and ‘9’. The coded format of the writer, spatial and construction characteristics is made available in this Data in Brief in order to allow others to perform statistical analyses and modelling to investigate whether there is a relationship between the handwriting features and the nationality of the writer, and whether the two nationalities can be differentiated. Furthermore, to employ mathematical techniques that are capable of characterising the extracted features from each participant.

© 2017 The Chartered Society of Forensic Sciences Traditionally, forensic science has predominantly focused its resources and objectives on addressing court related questions. However, this view restricts the contribution of forensic science to one function and results in lost opportunities as investigative and intelligence roles are often overlooked. A change of perspective and expansion of the contributions of forensic science is required to take advantage of the benefits of abductive and inductive thought processes throughout the investigative and intelligence functions. One forensic discipline that has the potential to broaden its traditional focus is handwriting examination. Typically used in investigations that are focused on both criminal and civil cases, the examination procedure and outcome are time consuming and subjective, requiring a detailed study of the features of the handwriting in question. Traditionally, the major handwriting features exploited are characteristics that are often considered individual (or at least highly polymorphic) and habitual. However, handwriting can be considered as an information vector in an intelligence framework. One such example is the recognition of key elements related to the author's native language. This paper discusses the traditional method generally used around the world and proposes a theoretical approach to expand the application of handwriting examination towards gaining additional information for intelligence purposes. This concept will be designed and tested in a future research project.

© 2019 The Chartered Society of Forensic Sciences Gunshot residues (GSR) are an important forensic trace in firearm-related events. Currently, routine GSR analyses focus on the detection and characterisation of the inorganic components (IGSR). The increasing prevalence of heavy metal-free ammunition challenges these current protocols and there is an increasing interest in how the organic components of GSR (OGSR) can provide complementary information. Similar to the situation with IGSR, OGSR compounds originally deposited on the shooter during the firing process may further be transferred onto another individual or surface. Hence, the aim of this study was to provide additional information regarding the risk of a secondary transfer of OGSR. Two scenarios were investigated, the first one related to the arrest process and the possibilities of a secondary transfer arising between a shooter onto a non-shooter (e.g. between a police officer and a person of interest (POI)). The second scenario concerned the transfer of OGSR onto the non-shooter after handling a firearm for few minutes without discharging it. One calibre was chosen, the .40 S&W calibre, used by several Australian State police forces. A secondary transfer was observed in all cases for the two scenarios investigated, for three compounds of interest: ethylcentralite (EC), diphenylamine (DPA), N-nitrosodiphenylamine (N-nDPA). The firearm handling scenario resulted in a larger secondary transfer to that of the arrest scenario. Overall, the amounts of OGSR detected on the non-shooter were generally lower than that detected on the shooter and controls after the arrest scenario. The results of this study provide complementary knowledge about OGSR, which can be further used to improve the current practice and the interpretation of OGSR evidence. In particular, it highlights that the secondary transfer proposition must be considered during the interpretation of forensic findings, especially when small amounts of OGSR target compounds are detected.

© 2016, Springer Science+Business Media Dordrecht. Forensic science and its influence on policing and the criminal justice system have increased since the beginning of the twentieth century. While the philosophies of the forensic science pioneers remain the pillar of modern practice, rapid advances in technology and the underpinning sciences have seen an explosion in the number of disciplines and tools. Consequently, the way in which we exploit and interpret the remnant of criminal activity are adapting to this changing environment. In order to best exploit the trace, an interdisciplinary approach to both research and investigation is required. In this paper, nine postdoctoral research fellows from a multidisciplinary team discuss their vision for the future of forensic science at the crime scene, in the laboratory and beyond. This paper does not pretend to be exhaustive of all fields of forensic science, but describes a portion of the postdoctoral fellows’ interests and skills.

The need for law enforcement agencies to obtain results more rapidly has driven the increased use of field-deployable technology in the field. Currently used in a case-by-case approach, the potential of these new technologies, could go beyond the traditional objective of forensic science (i.e. characterisation and identification) and provide timely information about criminal phenomena (i.e. multi-case approach). The use of portable instrumentation could for instance provide rapid information to law enforcement agencies about drug prevalence and drug smuggling if used in a systematic manner. This paper outlines the potential of using portable instrumentation to gather information related to illicit drugs rapidly. An innovative concept is proposed to screen surfaces of passports for the detection of remnants of illicit substances using rapid equipment already deployed at border controls. An experimental procedure was built to determine if powdered drugs could be detected on the surface of contaminated passports. Various scenarios were tested, including transfer, activity and persistence parameters. Experiments were conducted employing two different instruments, i.e. Ion Mobility spectroscopy (IMS) and Atmospheric Pressure Chemical Ionisation coupled to an Ion Trap Mass Spectrometer (APCI-ITMS). Promising results were obtained with the proposed method notably with the APCI-ITMS instrument as drugs were detected in minute amounts even after one hour of activity. High rates of false positives were obtained with the IMS contrary to APCI-ITMS. As a result, APCI-ITMS allows for the detection of remnants of illicit substances on passports’ surfaces and the approach employed in this proof of concept can be deployed in a real environment such as in airports.

© 2018, © 2018 Australian Academy of Forensic Sciences. Physical Developer (PD) is an underutilized technique for the development of latent marks on porous surfaces that have been wet, or as a subsequent technique in a development sequence. It is a multistep technique that works by selectively reducing silver ions to silver metal at nucleating sites in fingermark residue. Its use is associated with a plethora of issues, largely surrounding the inherent instability of the working solution. Recently, one of the components of the working solution, Synperonic N, has ceased production, and the recommended replacement is Tween 20. This article addresses factors during PD processing using Tween 20, other than reagent formulations that should be considered when using the technique.

© 2018 Elsevier B.V. The primary aims of fingermark detection research are to improve the quality and increase the rate of detection of identifiable impressions. This is usually performed through the development of new methods and technologies to provide alternatives to or improve current procedures. While research of this nature is important to pursue, it fails to address the underlying question related to the factors that affect the detection of a latent fingermark. There has been significant research that has examined the differences between techniques, donors and fingermark age, as well as the composition of latent fingermarks. However, they tend not to focus on determining how these factors influence the quality of the developed mark. This study involved the development and evaluation of over 14,000 natural fingermarks deposited on a variety of surfaces to examine the effect of substrate, age, donor variability (both inter- and intra-), depletions and type of finger on fingermark development. Fingermarks were deposited on four substrates (two non-porous and two porous) and developed with either indanedione-zinc (IND-Zn) or cyanoacrylate followed by rhodamine 6G staining (CA + R6G). Three independent assessors graded each mark on the quality of development using an absolute scale proposed by the UK Centre for Applied Science and Technology (CAST). The data generated from these assessments were then analysed for trends or other useful insights. The results from this work reaffirm that individual substrate characteristics (and the choice of development technique) play a significant role in determining the number and quality of marks developed. It was found that fingermarks were more likely to be detected on porous substrates and to also be of a higher quality than on non-porous. The effect of fingermark donor variability was also explored, with significant differences observed between donors and within donors. This research shows that current detection techniques do not detect all available fingermarks, reinforcing the need for further research into the fundamentals of fingermark detection in order to gain a better understanding of the techniques currently used. The study has identified considerations for the development of novel techniques and how we need to account for variability when designing fingermark research experiments.

© 2018 Elsevier B.V. Fingermarks can be exploited for both their ridge detail and touch DNA. One-step luminescent cyanoacrylate (CA) fuming techniques used for fingermark enhancement, such as PolyCyano UV (Foster + Freeman Ltd) and Lumicyano™ (Crime Science Technology), claim to be compatible with DNA analysis as they reduce the need for post‐staining to increase contrast of the developed fingermark. The aim of this study was to determine the impact that these one-step luminescent cyanoacrylates have on DNA analysis and how they compare to conventional CA techniques. Four donors each deposited five sets of natural fingermarks, to which a known amount of washed saliva cells was dispensed onto half of each set of fingermarks. Each set was treated with either a conventional CA technique or a one‐step luminescent CA technique prior to collection and processing of DNA, with one set left as a non-fumed control. It was found that DNA was still recoverable and detectable following each of the treatments. Lumicyano™ had a similar impact on DNA profiles as conventional CA fuming and with post‐stain, however, the degradation effect of PolyCyano UV on DNA was greater than the conventional treatments. For quantities of DNA such as that from touch DNA, the use of PolyCyano UV to enhance fingermarks may impact subsequent DNA analysis by causing allele drop out at larger fragment sizes.

Forensic science has traditionally focused the majority of its resources and objectives towards addressing Court-related questions. However, this view restricts the contribution of forensic science to one process and results in a loss of information as the investigative and intelligence roles are largely neglected. A forensic science discipline suffering from this imbalance is handwriting examination, which may be characterised as a time consuming and subjective process that is mostly carried out towards the end of the investigation for the purpose of judicial proceedings. Individual and habitual characteristics are the major handwriting features exploited, however alternate information concerning the author's native language could potentially be used as a key element in an intelligence framework. This research focussed on the detection of characteristics that differentiate Vietnamese and English Australian writers based on their English handwriting. The study began with the extraction of handwriting characteristics from the writing of people from the two populations. The data was analysed using a logistic regression model and a classification and regression tree (CRT). Each recognised four class characteristics that were capable of distinguishing between the two nationalities. The logistic regression and CRT models were both capable of correctly predicting 93% of cases. Their predictive capabilities were then tested and supported using blind exemplars in order to mirror casework settings. It appeared that when using their respective class characteristics, the two models were capable of differentiating English Australians from Vietnamese in the data set. This proof of concept research demonstrated the plausibility of exploiting this additional information from a handwriting trace and taking advantage of it in an intelligence-led framework.

© 2014 Elsevier Ireland Ltd. An oil-in-water microemulsion containing a luminescent dye, nile red, has been synthesised using a solvent-diffusion method. This has been demonstrated to be effective in developing fresh latent fingermarks on porous surfaces. The working solution is made using a binary surfactant solution to create a lactescent dual organic-aqueous phase intermediate, which subsequently results in a transparent microemulsion after the organic solvent has evaporated. The solution is non-toxic and performs comparatively with a previously published methanolic formulation but at a much lower cost and with an extended shelf life. The microemulsion outperforms a previously reported aqueous nile blue formulation for the development of both charged and natural fresh fingermarks, and requires lower exposure times for image recording.

© 2016 American Chemical Society. First-year general chemistry classes at large universities typically enroll students with diverse backgrounds. The vast majority of these students are not chemistry majors. NMR instrumentation was introduced to this class to engage these students in their learning and to represent modern chemistry to students for whom this course might be their only chemistry experience. We have incorporated NMR spectroscopy into the general chemistry laboratory experiments at the University of Technology Sydney in Sydney, Australia. Benchtop NMR spectrometers now mean that students can have close and frequent access to instrumentation. This chapter describes the use of the picoSpin-45 NMR spectrometer in the introductory laboratory, the types of experiments performed, quiz and survey results, and implementation challenges and successes.

In current casework, most post-cyanoacrylate stains rely on luminescence emission in the visible region (400-700 nm). While traditional stains such as rhodamine 6G work well under most circumstances, some surfaces may generate background luminescence under the same conditions. Detection in the near-infrared region (NIR > 700 nm) has shown to be effective in minimizing the interferences from such surfaces. The laser dye styryl 11 generated strongly luminescent fingermarks when applied after cyanoacrylate fuming on all surfaces tested. When compared to rhodamine 6G, the dye was superior only when viewed in the NIR. Styryl 11 was subsequently combined with rhodamine 6G, and the mixed stain formulation (named StaR 11 by the authors) induced stronger luminescence compared with styryl 11 alone with an ability to visualize in both the visible and NIR regions. Reliable and consistent results were obtained when using either styryl 11 alone or the STaR 11 mixture. The enhancement achieved did not otherwise vary depending on the source of the fingermark secretions. With visualization possible in both the visible and NIR regions, the styryl 11/rhodamine 6G mixture showed significant potential as a post-cyanoacrylate stain.

© 2015 Elsevier Ireland Ltd. Physical developer (PD) is a fingermark development technique that deposits silver onto fingermark ridges. It is the only technique currently in routine operational use that gives results on porous substrates that have been wet. There is a reasonable understanding of the working solution chemistry, but the chemical constituent(s) contained in fingermark residue that are specifically targeted by PD are largely unknown. A better understanding of the PD technique will permit a more informed selection of alternative or complementary detection methods, and greater usage in operational laboratories. Recent research by our group has shown that PD does not selectively target the lipids present in the residue.This research investigated the hypothesis that PD targets the eccrine constituents in fingermark residue. This was tested by comparison of PD and indanedione-zinc (Ind-Zn) treated natural fingermarks that had been deposited successively, and marks that had been deposited with a ten second interval in between depositions. Such an interval allows for the regeneration of secretions from the pores located on the ridges of the fingers. On fingermark depletions with no time interval between depositions, PD and Ind-Zn treated depletions successively (and comparatively) decreased in development intensity as the amount of residue diminished. Short time intervals in between successive depletions resulted in additional secretions from the pores intermittently occurring, the increased development of which was visualised by treatment with both PD and Ind-Zn. The changes in development intensity were seen with both techniques on the same split depletions in a series, comparably and proportionately. These results indicate that the components targeted by PD are contained in the material excreted by the friction ridge pores through its mirrored development with Ind-Zn.Repetition of the experiments on marks that only contained eccrine material showed good Ind-Zn development but poor results with PD. This indicates that there are other constituents contained in "natural" fingermarks that are required to be present for PD to be able to target constituents in the eccrine sweat. It may be that the required constituents in the natural residues are non-water soluble, and that these protect the eccrine constituents from solubilisation in the aqueous washes employed in the PD method.Further research is being undertaken to determine whether PD is targeting specific compounds in the pore secretions, or a mixture of compounds consisting of the eccrine material, epidermal lipids and sebaceous lipids typically present in latent fingermark residues.

© 2015 Elsevier Ireland Ltd. Physical developer (PD) is a fingermark development technique that involves the selective reduction of silver onto fingermark residue. PD can develop marks on porous substrates even if they have been wet, leading to the logical, long held belief that the reagent targets the water insoluble constituents in the fingermark residue. The present research has tested this hypothesis as part of a broader study that aims to identify the targets of physical developer. Spot tests of some fatty acids, cholesterol and squalene, treated with PD, showed that only cholesterol produced significant silver deposition. PD is known to be particularly effective on aged marks, however cholesterol degrades over time. These observations indicate that PD reactivity with fingermarks cannot solely be due to the presence of cholesterol.Fingermarks were deposited on paper and washed with various organic solvents before being treated with PD. PD effectiveness was intermittent on both solvent washed and unwashed sides of both natural and groomed marks; however, it was seen to effectively develop groomed samples that had been exposed to common lipid extraction solvents, shown to have removed the lipids by visualisation using the lipid stain Nile red. PD effectiveness was most affected by exposure of samples to solvents that could dissolve water soluble components, showing that the removal of these constituents (by either water, or other solvents) decreases the amount of silver deposited on the fingermark residue by the working solution.Close observation of PD developed samples showed variation in silver deposition uniformity when comparing a developed ridge to a pore site located on that ridge. Some samples showed an absence of silver, and other showed an increase of silver at pore locations. This indicates that the material excreted by the pores on the finger has an effect on silver deposition, suggesting that PD may be specifically targeting eccrine constituents that are present along the ridges but are more concentrated at the pore locations.These findings indicate that PD is not targeting the lipids in the fingermark residue per se, and may instead be targeting eccrine constituents or a more complex mixture of both eccrine and lipid constituents. Further investigation is underway within our group to investigate the components targeted by PD to gain a better understanding of what is a notoriously sensitive and hard to employ technique in the hope that it can be improved or simplified, or alternatives identified.

The solvation and ligation tendencies of alkali metal thiolates and selenolates in relation to metal and donors were investigated by synthesizing a family of target compounds, and analysing their structural features in solution and the solid state. The target compounds were synthesized utilizing hydrogen elimination, involving treatment of the chalcogenol with either sodium or potassium hydride in the presence of various donors. The separated ions were [Na(18-crown-6)(THF)2][SMes*] 1, (Mes* = 2,4,6-tBu3C6H2), [K(18-crown-6)(THF)2][SMes*] 3, and [K(18-crown-6)(THF)2][SeMes*] 4, and K(dibenzo-18-crown-6)(SMes*)·THF 2, displayed potassium–sulfur contacts. Compounds 1–4 were characterized using X-ray crystallography, NMR and IR spectroscopy. Cyclic voltammetry studies were carried out on 1–3, Na(dibenzo-18-crown-6)(SMes*) 5 and K(dibenzo-18-crown-6)(STrip)· THF 6 (Trip = 2,4,6-iPr3C6H2). A concentration dependent equilibrium reaction, which leads to an increase in free thiolate at higher concentrations, was observed for all complexes. NMR experiments using solutions of 5 (8.5 and 0.085 mM, THF-d8) and trimethyl phosphate confirmed the presence of free thiolate at higher concentration.

The synthesis and structural characterization of two magnesium thiolate complexes are described. Both compounds were prepared by analogous reactions routes, namely, alkane elimination and transamination, but using differently sized ligands. Utilization of the smaller HSCPh3, resulted in the formation of [Mg(15-crown-5)(SCPh3)2], 1, displaying a seven-coordinate magnesium center with two magnesium−sulfur bonds. Employment of the sterically more encumbered HS-2,4,6-tBu3C6H2 yielded a separated cation and anions as displayed in [Mg(15-crown-5)(THF)2][S-2,4,6-tBu3C6H2]2, 2. Compound 2 exhibits a seven-coordinate cation, completing its coordination environment with five metal−crown-ether interactions in addition to two tetrahydrofuran (THF) contacts. The compounds were characterized by IR and NMR spectroscopy in addition to X-ray crystallography. Crystal data with Mo Kα (λ = 0.710 73 A) are as follows: 1, C48H50MgO5S2, a = 8.4785(4) A, b = 9.3595(5) A, c = 13.8306(6) A, α = 87.332(1)°, β = 85.929(1)°, γ = 68....

The synthesis and characterization of a family of magnesium thiolates [Mg(SR)2(donor)n]m (R = C6H5, C6F5, -2-NC5H4; n = 1−4; m = 1, 3) and the first magnesiate thiolate [cat]2[Mg(SC6F5)4] are descr...

The synthesis and characterization of a family of sodium and potassium thiolates [A(donor)S(Trip)]n (A = Na, K; Trip = 2,4,6-i-Pr3C6H2, n = 1−∞) is described. [Na(PMDTA)S(Trip)]2, 1 (PMDTA = N,N,N‘,N‘‘,N‘‘-pentamethyldiethylenetriamine), [(NaS(Trip))2(Na(Et2O)S(Trip))4]·0.5 solvent, 2, [Na(TMEDA)S(Trip)]∞, 3 (TMEDA = N,N,N‘,N‘-tetramethylethylenediamine), [Na(THF)S(Trip)]n, 4 (n = 6 or ∞), [K(dibenzo-18-crown-6)(THF)S(Trip)]·THF, 5, [(KS(Trip))2(K(THF)S(Trip))2(K(THF)2S(Trip))2], 6, [K(THF)S(Trip)]∞, 7, [(K(THF)S(Trip))2(K(TMEDA)S(Trip))2(KS(Trip))2]·THF, 8, and [K(PMDTA)S(Trip)]∞, 9, were synthesized by treatment of HS(Trip) with NaH or KH along with the addition of various donors. The target molecules were characterized by IR, 1H NMR, and depending on solubility, 13C NMR spectroscopy and melting point. Compounds 1−3 and 5−9 were also characterized by single-crystal X-ray crystallography. Analysis of structural data clearly indicates that the structural chemistry of the target molecules can be influenced...

The synthesis and structural identification of a family of crown-ether-coordinated and crown-ether-free potassium thiolates are described. [Li(15-crown-5)(SCPh3)] (1), [K(18-crown-6)(SCPh3)(C6H6)0....

Conventional fingermark powders rely on contrast induced by absorption/reflection (e.g. black powder) or luminescence in the visible region (e.g. Blitz Green(®)). In most cases, these powders provide sufficient contrast; however, in some circumstances surface characteristics can interfere with the visualisation of powdered fingermarks. Visualisation in the near infra-red (NIR) region, however, has been shown to eliminate interferences commonly encountered in the visible region. In this study, a mixture of rhodamine 6G and the NIR laser dye styryl 11 (STaR 11) was coated onto an aluminium oxide nanopowder and then mixed with silver magnetic powder to develop and visualise fingermarks in the NIR. When compared to Blitz Green(®), it was determined that the STaR 11 magnetic powder was better suited for marks deposited on textured surfaces and for older marks, whereas Blitz Green(®) performed better on smooth glossy surfaces. The ability of the STaR 11 mixed dye formulation to be visualised in both the visible and NIR regions also provides a significant advantage over conventional luminescent fingermark powders.

A side reaction leads to the product. In the synthesis of [{Be(SPh)2 (py)(NH3 )}2 {[18]crown-6}] (1, py=pyridine) from [Be{N(SiMe3 )2 }2 ] and HSPh, the coordinated ammonia molecules (see the structure of 1 in the picture) are formed in a competing reaction between liberated hexamethyldisilazane and the thiol.

Eine Nebenreaktion fuhrt zum Produkt: Bei der Synthese von [{Be(SPh)2(py)(NH3)}2([18]krone-6)] 1 (py=Pyridin) aus [Be{N(SiMe3)2}2] und HSPh entstehen die beiden koordinierenden Ammoniakmolekule (siehe Struktur von 1 im Kristall) in einer Konkurrenzreaktion durch eine N-Si-Bindungsspaltung aus freigesetztem Hexamethyldisilazan und nichtumgesetztem Thiol.

The synthesis and structural characterization of two magnesium thiolate complexes are described. Both compounds were prepared by analogous reactions routes, namely, alkane elimination and transamination, but using differently sized ligands. Utilization of the smaller HSCPh(3), resulted in the formation of [Mg(15-crown-5)(SCPh(3))(2)], 1, displaying a seven-coordinate magnesium center with two magnesium-sulfur bonds. Employment of the sterically more encumbered HS-2,4,6-tBu(3)C(6)H(2) yielded a separated cation and anions as displayed in [Mg(15-crown-5)(THF)(2)][S-2,4,6-tBu(3)C(6)H(2)](2), 2. Compound 2 exhibits a seven-coordinate cation, completing its coordination environment with five metal-crown-ether interactions in addition to two tetrahydrofuran (THF) contacts. The compounds were characterized by IR and NMR spectroscopy in addition to X-ray crystallography. Crystal data with Mo Kalpha (lambda = 0.710 73 Å) are as follows: 1, C(48)H(50)MgO(5)S(2), a = 8.4785(4) Å, b = 9.3595(5) Å, c = 13.8306(6) Å, alpha = 87.332(1) degrees, beta = 85.929(1) degrees, gamma = 68.733(1) degrees, Z = 1, triclinic; 2, C(54)H(94)MgO(7)S(2), a = 13.6755(2) Å, b = 12.8045(6) Å, c = 32.7127(12) Å, beta = 97.87(1) degrees, Z = 4, monoclinic.

The exploration of synthetic methodologies toward heavy alkaline-earth chalcogenolates resulted in the preparation and structural characterization of a family of calcium thiolates, including [Ca(SC(6)F(5))(2)(py)(4)], 1 (py = pyridine), the separated ion-triple [Ca(18-crown-6)(NH(3))(3))][SMes](2).2THF, 2 (Mes = 2,4,6-tBu(3)C(6)H(2)), and the contact triple [Ca(18-crown-6)(SMes)(2)].THF, 3. Compound 1 was prepared by treating [Ca(N(SiMe(3))(2))(2)](2) with 4 equiv of HSC(6)F(5) under addition of pyridine. The thiolates 2 and 3 were synthesized by treatment of calcium metal dissolved in dry, liquid NH(3) under addition of 2 equiv of HSMes and crown ether or, alternatively, by the reduction of MesSSMes with calcium metal in dry, liquid ammonia. We also report two reaction products isolated during attempted calcium thiolate syntheses: [CaBr(4)(THF)(2)(mgr;(2)-Li)(2)(THF)(4)], 4, isolated as the product of a salt elimination reaction between CaBr(2) and 2 equiv of [Li(THF)(n)()S-2,4,6-(i)()Pr(3)C(6)H(2)](m)(). [(NH(4))(py)(SC(6)F(5))], 5, was obtained as the sole product in the reaction of metallic calcium with HSC(6)F(5) in liquid ammonia under addition of pyridine. All compounds were characterized by single-crystal X-ray crystallography in addition to IR and NMR spectroscopy.

A side reaction leads to the product. In the synthesis of [{Be(SPh)

© 2018 Institute for Innovation in Science and Mathematics Education. Inquiry-oriented approaches to learning have gradually entered science laboratory programs, aiming to deliver an authentic experience of doing science, enhance student engagement with the material, and bring greater emphasis on generic skills underpinning graduate attributes. Although such approaches have demonstrated pedagogical advantages and improved student engagement, it is not clear how the advantages should be weighted against other elements of what may be regarded as the laboratory program's cultural framework. We analysed two large-enrolment introductory tertiary programs: physics and chemistry at the University of Technology Sydney. The programs differed in the level of inquiry orientation but also in approaches to design, logistics and relevancy. We found that, based on student survey responses, the putative advantages of a deeper inquiry orientation in the physics laboratory were insufficient to compensate for the apparent advantages arising from the other elements of the cultural framework in the chemistry laboratory.