CuCl2 Solution Research Articles

Solution phase treatments of Sb2Se3 heterojunction photocathodes for improved water splitting performance.

Antimony selenide (Sb2Se3) is an auspicious material for solar energy conversion that has seen rapid improvement over the past ten years, but the photovoltage deficit remains a challenge. Here, simple and low-temperature treatments of the p-n heterojunction interface of Sb2Se3/TiO2-based photocathodes for photoelectrochemical water splitting were explored to address this challenge. The FTO/Ti/Au/Sb2Se3 (substrate configuration) stack was treated with (NH4)2S as an etching solution, followed by CuCl2 treatment prior to deposition of the TiO2 by atomic layer deposition. The different treatments show different mechanisms of action compared to similar reported treatments of the back Au/Sb2Se3 interface in superstrate configuration solar cells. These treatments collectively increased the onset potential from 0.14 V to 0.28 V vs. reversible hydrogen electrode (RHE) and the photocurrent from 13 mA cm-2 to 18 mA cm-2 at 0 V vs. RHE as compared to the untreated Sb2Se3 films. From SEM and XPS studies, it is clear that the etching treatment induces a morphological change and removes the surface Sb2O3 layer, which eliminates the Fermi-level pinning that the oxide layer generates. CuCl2 further enhances the performance due to the passivation of the surface defects, as supported by density functional theory molecular dynamics (DFT-MD) calculations, improving charge separation at the interface. The simple and low-cost semiconductor synthesis method combined with these facile, low-temperature treatments further increases the practical potential of Sb2Se3 for large-scale water splitting.

Novel, Green, and Scalable Aqueous Synthesis of Yellow–Green Emitting Cs3Cu2Cl5 Scintillator and its Application in High‐Resolution TFT Panel for X‐Ray Imaging Detector

AbstractCopper‐based metal halide scintillators have received increasing attention due to their high light yield and nontoxicity. However, the synthetic methods are still not feasible for actual commercialization for the difficulty in scaling up and the absence of green chemical footprint. Herein, we report a new, simple, aqueous synthetic method for the mass production of highly purified and crystallized Cs3Cu2Cl5 powder by a room‐temperature reaction between a saturated aqueous solution of CsCl and a saturated hydrochloric acid solution of CuCl. The product exhibits a photoluminence peak centering at 527 nm (FWHM = 106.7 nm) and a quantum yield (PLQY) of 97%. A prototype X‐ray imaging detector is fabricated by coupling a large area scintillation screen prepared by blade coating of Cs3Cu2Cl5 powder and a commercial thin‐film transistor (TFT) panel (16 cm × 13 cm, 125 µm pixel size) with readout circuit. The device exhibits a high spatial resolution of 4 lp mm−1, exceeding the theoretical limit of the TFT panel, and an excellent dynamic imaging ability. In short, this work demonstrates an efficient novel synthetic method of Cs3Cu2Cl5 and its application as X‐ray imaging device, providing an applicable solution for its future commercialization.

Bio-Based Electrospun Fibers from Chitosan Schiff Base and Polylactide and Their Cu2+ and Fe3+ Complexes: Preparation and Antibacterial and Anticancer Activities.

The Schiff base derivative (Ch-8Q) of chitosan (Ch) and 8-hydroxyquinoline-2-carboxaldehyde (8QCHO) was prepared and fibrous mats were obtained by the electrospinning of Ch-8Q/polylactide (PLA) blend solutions in trifluoroacetic acid (TFA). Complexes of the mats were prepared by immersing them in a solution of CuCl2 or FeCl3. Electron paramagnetic resonance (EPR) analysis was performed to examine the complexation of Cu2+(Fe3+) in the Ch-8Q/PLA mats complexes. The morphology of the novel materials and their surface chemical composition were studied by scanning electron microscopy (SEM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). The performed microbiological screening demonstrated that in contrast to the neat PLA mats, the Ch-8Q-containing mats and their complexes were able to kill all S. aureus bacteria within 3 h of contact. These fibrous materials had efficiency in suppressing the adhesion of pathogenic bacteria S. aureus. In addition, Ch-8Q/PLA mats and their complexes exerted good anticancer efficacy in vitro against human cervical HeLa cells and human breast MCF-7 cells. The Ch-8Q-containing fibrous materials had no cytotoxicity against non-cancer BALB/c 3T3 mouse fibroblast cells. These properties render the prepared materials promising as wound dressings as well as for application in local cancer treatment.

Direct Bactericidal Comparison of Metal Nanoparticles and Their Salts against S. aureus Culture by TEM and FT-IR Spectroscopy.

We report the bactericidal effect of Ag and Cu NPs with different concentrations on methicillin-resistant S. aureus strain in comparison to the effect of AgNO3 and CuCl2 solutions, characterized by microbiological tests, TEM and Fourier-transform infrared spectroscopy. NPs were produced by nanosecond laser ablation in distilled water and characterized by scanning electron microscopy, UV-vis, energy dispersive X-ray, FT-IR spectroscopy, as well as X-ray diffraction, dynamic light scattering size and zeta-potential measurements. Microbiological tests showed antibacterial activity of NPs and metal ion-containing salts. Comparative FT-IR spectroscopy of bacteria, treated with metal NPs and salts, showed the broadening of amide I and II bands, a CH2-related peak and its frequency decrease, indicating the increase of membrane fluidity. The main mechanisms of the antibacterial effect were proposed: Ag and Cu NPs release ions and ROS, which result in lipid peroxidation; AgNO3 forms precipitates on the cell surface, which lead to the mechanical rupture of the membrane and subsequent possible penetration of the precipitates in the emerged damaged spots, complete destruction of the membrane and bacterial death; Cu ions from the CuCl2 solution cause damage to phosphorus- and sulfur-containing biomolecules, which leads to disruption of intracellular biochemical processes. The theories were confirmed by FT-IR spectroscopy and TEM.

Ion Exchange Conversion of Na-Birnessite to Mg-Buserite for Enhanced and Preferential Cu2+ Removal via Hybrid Capacitive Deionization.

Layered manganese oxides (LMOs) have recently been demonstrated to be one of the most promising redox-active material platforms for electrochemical removal of heavy metal ions from solution via capacitive deionization (CDI). However, the impact of interlayer spacing of LMOs on the deionization performance of electrodes in a hybrid capacitive deionization (HCDI) system with an LMO cathode and a carbon anode (i.e., LMO/C electrodes), and their phase transformation behaviors, particularly during the desalination operations, have yet to be extensively evaluated. In this study, we thoroughly evaluate Mg-buserite obtained by ion exchange of fresh Na-birnessite and Na- and K-birnessite as HCDI electrodes to remove copper ions (Cu2+) from saline solutions. Among the three LMO/C electrodes, the Mg-buserite/C (MgB/C) electrodes demonstrate the best deionization performance in terms of salt adsorption capacity (SAC), electrosorption rate, and cycling stability, followed by K-birnessite/C (KB/C) and Na-birnessite/C (NaB/C). More importantly, MgB/C exhibits the highest Cu2+ ion adsorption capacity (IAC) of 89.3 mg Cu2+ per gram electrode materials at a cell voltage of 1.2 V in 500 mg L-1 CuCl2 solution, with an IAC retention as high as 96.3% after 60 charge/discharge cycles. Given that electrosorption of Cu2+ ions is often competed by alkali and alkaline earth metal ions, our data reveal that the MgB/C electrodes demonstrate selectivities of 4.7, 7.7, and 8.1 for Cu2+ over Na+, Ca2+, and Mg2+, respectively. Moreover, X-ray diffraction and spectroscopic analyses show that the enhanced deionization performance and preference for Cu2+ are mainly attributed to the expanded interlayer spacing of LMO minerals. This study provides a promising strategy for tailoring LMO minerals for improving their electrosorption capacity and preference for copper ions from a multivalent-ion solution via an HCDI platform.

A facile and almost HF-free synthesis of Ti3C2@CuCl composite for supercapacitors

This work demonstrates a distinctive almost HF-free route of etching Ti3AlC2 MAX phase by metal displacement reaction at room temperature. The Ti3AlC2 particles are directly etched by CuCl2 solutions in different concentrations instead of HF. The etchant is reduced to nano CuCl particles, adhering to the surface of Ti3C2 layers to form the Ti3C2@CuCl composite which is evaluated as working electrodes for supercapacitors. Due to the synergistic effect between CuCl and Ti3C2 matrix, the appropriate amount of CuCl enhances the specific capacitance to 508.7 F·g−1 at 1A·g−1 in 6 M KOH electrolyte solution, which is much higher than pure Ti3C2 electrode. This work shows the possibility of synthesis of various Mxene-based frameworks by other metallic cations with lower metal activity.

Elution of Hg-containing substances from CeO2-MnO2/TiO2 adsorbent in H2S atmosphere by CuCl2 solution

Mercury (Hg) pollution in syngas has received increasing attention. The adsorbent can effectively remove Hg from syngas, and the removal of Hg-containing substances before the landfill of spent adsorbent can avoid Hg secondary pollution effectively. H2S was the main resource for the generation of stable and insoluble HgS in syngas. In this work, the elution of Hg-containing substances from the spent CeO2-MnO2/TiO2 (Ce-Mn/Ti) adsorbent in H2S atmosphere by CuCl2 solution was studied. The optimum temperature for Ce-Mn/Ti to remove Hg0 in H2S atmosphere was 160 °C. The Hg-containing substances were HgS (black), HgS (red), and HgO (yellow), in which both the proportion and elution difficulty followed the descending order of HgS(black) > HgS(red) > HgO(yellow). The elution was basically completed within 2 min with excellent efficiency of 98.38 %. Higher concentration, higher temperature, and lower pH were conducive to the elution, and the optimum concentration and temperature were 1.0 mol/L and 45 °C respectively. The elution followed the first-order two-domain model, in which HgO and HgS were the rapid and slow part respectively. The elution not only retained the favorable mesoporous structure, but also enabled the eluted Ce-Mn/Ti adsorbent to have a higher efficiency and a better stability on Hg removal by loading the active component of CuCl2. This study demonstrated that CuCl2 could be a good eluent for the elution of Hg-containing species and the reutilization of metal oxide-based adsorbent.

Facile Approach to the Fabrication of Highly Selective CuCl-Impregnated θ-Al2O3 Adsorbent for Enhanced CO Performance.

We have developed a facile and sustainable method to produce a novel θ-Al2O3-supported CuCl adsorbent through impregnation methods using CuCl2 as the precursor. In an easy two-step process, θ-Al2O3 was impregnated with a known concentration of CuCl2 solutions, and the precursor was calcined to prepare CuCl oversupport. The developed novel θ-Al2O3-supported CuCl adsorbent was compared with an adsorbent prepared through the conventional method using CuCl salt. The adsorbents were characterized via X-ray diffraction (XRD), thermal gravimetric analysis (TGA) and temperature-programmed reduction (H2-TPR). Overall, the adsorbent indicates a high CO adsorption capacity, high CO/CO2 and CO/N2 selectivity, and remarkable reusability performance. This process is operated at ambient temperature, which minimizes operation costs in CO separation processes. In addition, these results indicate that the systematic evaluation of alumina-supported CuCl adsorbent can provide significant insight for designing a realistic PSA process for selective CO separation processes.

Shared Hydrogen Atom Location and Chemical Composition in Picolinic Acid and Pyridoxal Hydrochloride Derivatives Determined by X-ray Crystallography.

Three new single-crystal structures were isolated for picolinic acid (2), the trifluoroacetate salt of picolinic acid (1), and pyridoxal hydrochloride (3). These compounds displayed unconventional crystallographic features that must be considered when structural refinements are carried out. Thus, the generated Fourier differences map obtained with the diffraction data collected at 100 K was crucial to visualize electron densities, which were balanced by either one hydrogen atom or a hydrogen atom with an occupancy factor of 1/2 located between either two carboxylate moieties, two phenolic oxygen atoms, or two pyridinic nitrogen atoms. Moreover, NMR studies were conducted to analyze the bulk chemical composition of single crystals of 2-pyridinecarboxylic acid obtained from the gem-diol/hemiacetal forms and the polymerization products after the treatment of 2-pyridinecarboxaldehyde with TFA:H2O (1) or a diluted Cu(NO3)2 solution (2). The quantitative yield of the pyridoxal hydrochloride crystalline material (3) obtained from a diluted CuCl2 solution was exhaustively characterized by solid-state NMR methods. These methods allowed the resolution of the signals corresponding to the protons of the hydroxyl moiety of the intramolecular hemiacetal group and the phenolic hydrogen. Theoretical calculations using DFT methods were done to complement the atomic location of the hydrogen atoms obtained from the X-ray analysis.

Controlled p-Type Doping of MoS2 Monolayer by Copper Chloride.

Electronic devices based on two-dimensional (2D) MoS2 show great promise as future building blocks in electronic circuits due to their outstanding electrical, optical, and mechanical properties. Despite the high importance of doping of these 2D materials for designing field-effect transistors (FETs) and logic circuits, a simple and controllable doping methodology still needs to be developed in order to tailor their device properties. Here, we found a simple and effective chemical doping strategy for MoS2 monolayers using CuCl2 solution. The CuCl2 solution was simply spin-coated on MoS2 with different concentrations under ambient conditions for effectively p-doping the MoS2 monolayers. This was systematically analyzed using various spectroscopic measurements using Raman, photoluminescence, and X-ray photoelectron and electrical measurements by observing the change in transfer and output characteristics of MoS2 FETs before and after CuCl2 doping, showing effective p-type doping behaviors as observed through the shift of threshold voltages (Vth) and reducing the ON and OFF current level. Our results open the possibility of providing effective and simple doping strategies for 2D materials and other nanomaterials without causing any detrimental damage.

CO2 capture and conversion: A homemade experimental approach

During the SARS-2-Covid pandemic our institution sought to continue the teaching and learning of experimental laboratories by designing, assembling, and delivering a microscale chemistry kit to the students´ homes. Thanks to this approach students were able to perform ~25 experiments during each one of the Fall 2020 and Spring 2021 semesters in an elective Electrochemistry and Corrosion course offered to Chemical Engineering undergraduates. In addition to performing traditional experiments, students were encouraged to design some of their own and have the entire group reproduce them. One of such student-designed experiments involved the capture of CO2 and its reduction with a readily available active metal (i.e., Al foil) in aqueous media to generate potentially useful products. The highly negative standard potential of Al is exploited for the reduction of lab-generated CO2, and the products are chemically tested. Al as a foil has been reported to be electrochemically inactive for carbon dioxide reduction. However, encouraged by an earlier report of the reduction of CO2 to CO, the Al surface is activated in the present experiment by removal of its natural oxide layer with a solution of CuCl2 produced in an electrochemical cell. This procedure enables Al to react with CO2 and yield useful chemistry. This experiment turned to be a discovery trip. The detailed procedure is discussed here, as well as the teaching methodology, grading scheme, and student outcomes.

Formation of Arrays of 1D Copper(II) Oxide Nanocrystals on the Nickel Surface upon Its Galvanic Replacement in a CuCl2 Solution and Their Electrocatalytic Properties in the Hydrogen Evolution Reaction during Water Splitting in an Alkaline Medium

Formation of Arrays of 1D Copper(II) Oxide Nanocrystals on the Nickel Surface upon Its Galvanic Replacement in a CuCl2 Solution and Their Electrocatalytic Properties in the Hydrogen Evolution Reaction during Water Splitting in an Alkaline Medium

Effect of CuCl2 treatment on RF magnetron-sputtered CdSe thin films for potential photovoltaic usage

CuCl2 solutions of various molarities were used to treat CdSe thin films produced by RF magnetron sputtering. In-depth investigation on the impacts of this treatment on CdSe thin films were studied. The structural investigation revealed that all as-grown films exhibited the hexagonal phase peak at the (101) plane. The crystalline and grain sizes increased with CuCl2 treatment, reaching 114 nm for 0.1 M CuCl2-treated CdSe thin film. A granule-like morphology was seen on the treated films. Opto-electric study revealed that CuCl2 treatment improved CdSe film properties and tailored structural restrictions. The 0.30 M CuCl2 treatment was shown to be an important process parameter for the CdSe thin films, indicating its potential as a photovoltaic material.

Enhancement of the Water Affinity of Histidine by Zinc and Copper Ions.

Histidine (His) is widely involved in the structure and function of biomolecules. Transition-metal ions, such as Zn2+ and Cu2+, widely exist in biological environments, and they are crucial to many life-sustaining physiological processes. Herein, by employing density function calculations, we theoretically show that the water affinity of His can be enhanced by the strong cation–π interaction between His and Zn2+ and Cu2+. Further, the solubility of His is experimentally demonstrated to be greatly enhanced in ZnCl2 and CuCl2 solutions. The existence of cation–π interaction is demonstrated by fluorescence, ultraviolet (UV) spectroscopy and nuclear magnetic resonance (NMR) experiments. These findings are of great importance for the bioavailability of aromatic drugs and provide new insight for understanding the physiological functions of transition metal ions.

Surface functionalization with copper endows carbonate apatite honeycomb scaffold with antibacterial, proangiogenic, and pro-osteogenic activities.

Osteomyelitis is a potentially devastating inflammatory bone disease that leads to bone destruction and loss. Treatment of osteomyelitis requires the removal of residual bacteria as well as osteogenesis with angiogenesis at the site of treatment. Use of an appropriate amount of copper (Cu) in treatment scaffolds may achieve these goals without the risk of toxicity. In this study, the surface of the carbonate apatite honeycomb scaffold was functionalized with Cu through a dissolution-precipitation reaction. The resulting scaffolds retained the honeycomb structure after immersion in CuCl2 solution, and Cu was precipitated on the surface as libethenite [Cu2(OH)PO4]. The surface Cu concentration was controlled by the concentration of the CuCl2 solution. Scaffolds with a surface Cu concentration of 23.8wt% exhibited antibacterial and cytotoxic effects, whereas those with concentrations of ≤4.6wt% exerted antibacterial effects without negatively affecting the cellular adhesion, proliferation, differentiation, and calcification of osteoblast-like cells. Furthermore, scaffolds with a surface Cu concentration of 4.6wt% Cu inhibited bacterial growth for at least 28days and displayed proangiogenic and pro-osteogenic activities in vivo. These data confirm the success in functionalizing scaffolds with Cu that may be utilized as an innovative osteomyelitis therapy.

Separation of Chitin from Shrimp and Application in Heavy Metal Wastewater Treatment

In this research work natural bio polymer “chitosan” was extracted using locally available shrimp shells and absorption of copper by chitosan was studied. Synthesis of chitosan involved four main stages as preconditioning, demineralization, deproteinization and deacetylation. Chitosan was characterized using Fourier Transform Infrared Spectroscopy (FTIR). The affinity of chitosan for cupper was studied using anhydrous CuCl2 solution as the heavy metal solution containing Cu (II) ions

A feasibility study of the therapeutic application of a mixture of 67/64 Cu radioisotopes produced by cyclotrons with proton irradiation.

Purpose 64Cu and 67Cu radioisotopes have nuclear characteristics suitable for nuclear medicine applications. The production of 64Cu is already well established. However, the production of 67Cu in quantities suitable to conduct clinical trials is more challenging as it leads to the coproduction of other Cu isotopes, in particular 64Cu. The aim of this study is to investigate the possibility of using a CuCl2 solution with a mixture of 67/64Cu radioisotopes for therapeutic purposes, providing an alternative solution for the cyclotron production problem.MethodsCopper radioisotopes activities were calculated by considering proton beam irradiation of the following targets: (i) 70Zn in the energy range 70–45 MeV; (ii) 68Zn in the energy range 70–35 MeV; (iii) a combination of 70Zn (70–55 MeV) and 68Zn (55–35 MeV). The contribution of each copper radioisotope to the human‐absorbed dose was estimated with OLINDA/EXM software using the biokinetic model for CuCl2 published by ICRP 53. The total absorbed dose generated by the 67/64CuCl2 mixture, obtained through different production routes, was calculated at different times after the end of the bombardment (EOB). A simple spherical model was used to simulate tumors of different sizes containing uniformly distributed 67/64Cu mixture and to calculate the absorbed dose of self‐irradiation. The biological damage produced by 67Cu and 64Cu was also evaluated through cellular dosimetry and cell surviving fraction assessment using the MIRDcell code, considering two prostate cancer cell lines with different radiosensitivity.ResultsThe absorbed dose to healthy organs and the effective dose (ED) per unit of administered activity of 67CuCl2 are higher than those of 64CuCl2. Absorbed dose values per unit of administered activity of 67/64CuCl2 mixture increase with time after the EOB because the amount of 67Cu in the mixture increases. Survival data showed that the biological damage caused per each decay of 67Cu is greater than that of 64Cu, assuming that radionuclides remain accumulated in the cell cytoplasm. Sphere model calculations demonstrated that 64Cu administered activity must be about five times higher than that of 67Cu to obtain the same absorbed dose for tumor mass between 0.01 and 10 g and about 10 times higher for very small spheres. Consequently, the 64CuCl2‐absorbed dose to healthy organs will reach higher values than those of 67CuCl2. The supplemental activity of the 67/64CuCl2 mixture, required to get the same tumor‐absorbed dose produced by 67CuCl2, triggers a dose increment (DI) in healthy organs. The waiting time post‐EOB necessary to keep this DI below 10% (t 10%) depends on the irradiation methods employed for the production of the 67/64CuCl2 mixture.ConclusionsA mixture of cyclotron produced 67/64Cu radioisotopes proved to be an alternative solution for the therapeutic use of CuCl2 with minimal DI to healthy organs compared with pure 67Cu. Irradiation of a 70Zn+68Zn target in the 70–35 MeV proton energy range for 185 h appears to be the best option from among all the production routes investigated, as it gives the maximum amount of activity, the shortest t 10% (10 h), and less than 1% of 61Cu and 60Cu impurities.

Video-Based Teaching on Electrolysis Using Simple Copper Media to Vocational School Students

Abstract: The purpose of this study was to present learning the concept of electrolysis using simple copper media to vocational high school students in grade 3. This research was conducted by making a sample of well water with CuCl₂ solution which has a concentration of 1g / L and voltage variation (1.5; 3; 4.5; 6,0; 7.5; and 9,0 V). The test was carried out by electrolysis and water quality tests consisting of solute level testing, water pH test, and water temperature test. This research was also conducted by providing pre-test questions, learning videos, and post-tests. The results showed that the most effective electrolysis method occurred in variations with a voltage of 9V. This is indicated by the value of the decrease in concentration and the increase in mass of solutes after electrolysis. Meanwhile, the test results of vocational high school students show that video-based teaching can improve students 'understanding, as indicated by the students' post-test scores that are higher than the pretest scores. This research is expected to assist in the selection of instructional media for students and to find out which electrolysis method is effective for reducing Cu levels. Keywords: CuCl₂, electrolysis, learning media, simple copper.

Copper(I) halide complexes with n,n’-diallylthiomorpholinium chloride: synthesis and crystal structure

By means of alternating current electrochemical technique, basing on ethanolic solutions of CuCl 2 ·2H 2 O or CuBr 2 and N,N’-diallylthiomorpholinium chloride, the two isostructural s-complexes of [C 4 H 8 NS(C 3 H 5 ) 2 Cu Hal 2 ] composition were obtained in a single crystal form and characterized by X-ray single crystal method: sp. gr. P 2 1 / c , Z = 4, Hal = Cl ( І ) – a = 7.7763(4), b = 13.1892(5), c = 13.1761(6) Å, β = 103.470(5)°, V = 1314.2(1) Å 3 , r calc. = 1.611 g/сm 3 , m (MoK a ) = 2.20 mm −1 , q max. = 28.8°, 10141 measured, 2659 used reflections, R ( F 2 ) = 0.032, S = 1.07; Hal = 1,04Br/0,96Cl ( ІІ ) – a = 7.9771(3), b = 13.2391(5), c = 13.1422(5) Å, β = 103.942(4), V = 1347.1(1) Å 3 , r calc. = 1.80 g/см 3 , m (MoK a ) = 5.02 mm −1 , q max. = 29.0°, 21269 measured, 2772 used reflections, R ( F 2 ) = 0.027, S = 1.08. In the crystal structure of the studied compounds, the trigonal-pyramidal coordination environment of Cu(I) includes sulfur atoms of the organic cation and three chloride anions (compound I ) or chloride/bromide mixture (compound II ). Atoms occupying position Hal (2) perform a bridging function and connect individual coordination polyhedrons into dimeric topological units {L 2 Cu 2 Hal 4 }. These dimers through hydrogen bonding are linked into a three-dimensional framework. None of the available allylic groups of the N,N’-diallylthiomorpholinium cation are coordinated to the copper(I) ion. In our opinion, this feature of the discussed crystal structure of [(C 4 H 8 NS(C 3 H 5 ) 2 )Cu Hal 2 ] compounds is explained by the influence of competition between the sulfur atom and the C=C bond of the allyl group of the cation during complexation in solution and the redistribution of electron density in the crystal structure of solid compounds due to hydrogen contacts C–H… Hal . Keywords : N,N’-diallylthiomorpholinium; copper(І); s-complexes; crystal structure.

Development of a biocrystallisation assay for examining effects of homeopathic preparations using cress seedlings

Background:
 
 A major challenge of homeopathic basic research is to develop test systems that yield consistent results. Outcome of plant bioassays is usually based on growth parameters (e.g. germination rate, seedling length, leaf area).
 
 
 
 Aims:
 
 We aimed to evaluate the potential of a crystallisation method with additives (“biocrystallisation”) as complementary outcome measure. This method used is based on the crystallographic phenomenon that when crystallising watery solutions of dihydrate CuCl2 in the presence of organic additives (juices/extracts), reproducible dendritic crystal structures are observed. The resulting biocrystallograms can be evaluated visually and/or by computerized image analysis.
 
 
 
 Methods:
 
 Cress seeds (Lepidium sativum L.) germinated and grew in vitro in either Stannum met. 30x or water 30x. Per experiment, six coded (blinded) 30x preparations were applied in randomized order, representing three independent replicates of the two treatments. Seedlings grew for 96 hours in darkness and were subsequently processed into a watery extract. Biocrystallisation was performed on circular glass plates in 6-fold replication per treatment group, yielding 36 biocrystallograms per experiment. A total of 15 independent experiments were performed at two independent laboratories. Biocrystallograms were scanned and analysed by computerized texture image analysis, using 15 second-order parameters as outcome measure. 3-way-ANOVA with the independent parameters treatment (n=2), internal replicate (n=3), and number of experiment (n=15) was used to analyse the data.
 
 
 
 Results:
 
 All 15 texture analysis variables yielded significant or highly significant results for the homeopathic treatment. Two variables yielded differences between the internal replicates, most probably due to a processing order effect. There were only minor differences between the results of the two laboratories.
 
 
 
 Conclusions:
 
 The texture of biocrystallograms of homeopathically treated cress exhibited specific characteristics, differentiating water 30x and Stannum met. 30x. Thus, the biocrystallisation method seems to be a promising complementary outcome measure for plant bioassays investigating effects of homeopathic preparations.