Thiocyanate Research Articles

Structure, Thermodynamics, and Dynamics of Thiocyanate Ion Adsorption and Transfer across the Water/Toluene Interface

Molecular dynamics simulations are used to examine in detail the structure, thermodynamics, and dynamics involve in the adsorption and transfer of the thiocyanate ion (SCN-) across the water/toluene interface. Free energy, hydration structure, and several dynamical properties as a function of the ion location along the interface normal are calculated and contrasted with recent experiments. The free energy profile exhibits a local minimum near the interface corresponding to adsorption free energy relative to bulk water of -6 kJ/mol, in reasonable agreement with experiments. The simulations provide insight into the water surface fluctuations that are coupled to the ion transfer, demonstrating formation of water finger-like structures assisting the transfer process.

The bifunctional role played by thiocyanate anions on the active dissolution and the passive film of titanium in hydrochloric acid

ABSTRACT The electrochemical behaviour of titanium dissolution and passivation in HCl was examined with and without the SCN− anions using potentiodynamic polarisation, electrochemical impedance spectroscopy, and current transients techniques. The nature of the Ti oxide film was characterised by utilising XPS and SEM tools. The corrosion current i corr, the critical passivation current i cc, and the passive current i pass values increased significantly when the HCl concentration, scan rate, and temperature were raised. On the contrary, the addition of SCN− anions decreases the i corr value, indicating that the Ti dissolution was inhibited as a result of SCN− adsorption on the Ti surface. The inhibition efficiency increased with increasing the concentration of SCN−. However, SCN− anions lead to destabilised passivity in the passive zone. The formation of the Ti oxide film is a diffusion-controlled operation, as shown by the i–t curves. According to the XPS measurements, the passive oxide coating consists mainly of TiO2 and less of Ti2O3.

(Invited) Epitaxial Electrodeposition of Wide Bandgap Semiconductors for Transparent and Flexible Electronics

Single-crystal silicon is the bedrock of semiconductor devices due to the high crystalline perfection that minimizes electron-hole recombination, and the dense SiOx native oxide that minimizes surface states. One issue with the material is that it is both brittle and opaque. There is interest in moving beyond the planar structure of conventional Si-based chips to produce flexible and transparent electronic devices such as wearable solar cells, sensors, and flexible displays. In this talk we will discuss the electrodeposition of transparent, wide bandgap semiconductors such as ZnO, CuI, and CuSCN that can be produced as epitaxial films on single-crystal and single-crystal-like substrates. These epitaxial films have an orientation that is controlled by the substrate, with electronic properties that mimic those of single crystals. The talk will emphasize the electrodeposition of the wide bandgap hole conductors CuI and CuSCN. They are electrodeposited by electrochemically reducing Cu(II)EDTA to Cu(I) in the presence of either iodide or thiocyanate anions. Cubic CuI deposits as dense films on Si(111), and CuSCN deposits as nanowires on Au(111). The CuI is epitaxial on the Si(111) in spite of a 2.4 nm thick interfacial SiOx layer. The rectifying p-CuI/SiOx/n-Si heterojunction diode shows an ideality factor of 1.5, a built-in voltage of 0.67 V, and a barrier height of 0.91 eV. The crystal structure and morphology of the CuSCN nanowires can be controlled by varying the SCN-/Cu(II) ratio in solution (see Fig. 1). We also show that the epitaxial films can be removed by a simple lift-off procedure to produce single-crystal-like flexible foils of transparent semiconductors.Fig. 1 – Controlling the crystal structure and morphology of CuSCN nanowires through the SCN-/Cu(II) ratio in solution. Top micrographs are of rhombohedral CuSCN deposited using SCN-/Cu(II) = 4, and the bottom micrographs are of hexagonal CuSCN deposited using SCN-/Cu(II) = 2. The nanowires were both on Au(111), and were deposited at a potential of -0.4 V vs. Ag/AgCl. Figure 1

Syntheses, crystal structures and properties of tetra-kis-(3-methyl-pyridine-κN)bis-(iso-thio-cyanato-κN)manganese(II) and tetra-kis-(3-methyl-pyridine-κN)bis-(iso-thio-cyanato-κN)iron(II).

The reaction of Mn(NCS)2 or Fe(NCS)2 with 3-methyl-pyridine (C6H7N) leads to the formation of two isostructural compounds with compositions [Mn(NCS)2(C6H7N)4] (1) and [Fe(NCS)2(C6H7N)4] (2). IR spectroscopic investigations indicate that only terminally coordinated thio-cyanate anions are present. This is confirmed by single-crystal structure analysis, which shows that their crystal structures consist of discrete centrosymmetric complexes, in which the metal cations are octa-hedrally coordinated by two N-bonded thio-cyanate anions and four 3-methyl-pyridine ligands. X-ray powder diffraction (XRPD) proves that pure samples have been obtained. Thermogravimetric measurements show that decomposition starts at about 90°C and that the two coligands are removed in one step for 1 whereas for 2 no clearly resolved steps are visible. XRPD measurements of the residue obtained after the first mass loss of 1 show that a new and unknown crystalline compound has been formed.

Novel natural exudate as a stabilizing agent for fabrication of copper nanoparticles as a colourimetric sensor to detect trace pollutant

Detection of trace pollutants in water has become one of the most interesting issues due to its direct relation to human health. This work exploits a simple, novel, cost-effective, and environmentally friendly method to fabricate optical copper nanoparticles (Cu NPs) as an efficient colourimetric sensor using tree gum as a stabilising and capping agent. The localised surface plasmon resonance (LSPR) band of almond gum Cu NPs (ACuNPs) is monitored using ultraviolet-visible (UV-vis) spectroscopy. With an average size of 33 nm, the ACuNPs, which were uniformly spherical, are assessed using high resolution-transmission electron microscopy (HR-TEM). The formation of pure metallic-phase crystalline ACuNPs is illustrated using x-ray diffractometry. The Cu nanostructure determines the thiocyanate (SCN−) ions in an aqueous medium as a colourimetric sensor. The ACuNPs demonstrated sensitive and selective colourimetric detection of SCN− ions based on the decrease in LSPR intensity, as monitored by a UV-vis spectrophotometer. The developed sensor is simple, rapid, and inexpensive compared to those based on precious noble metal nanoparticles and is sensitive to SCN− ions with a detection limit of 0.226 mg/l. This work presents the development of a highly effective and rapid sensor to detect SCN− ions without complex apparatuses.

Thiocyanate Ions Form Antiparallel Populations at the Concentrated Electrolyte/Charged Surfactant Interface.

Anions play significant roles in the separation of lanthanides and actinides. The molecular-scale details of how these anions behave at aqueous interfaces are not well understood, especially at high ionic strengths. Here, we describe the interfacial structure of thiocyanate anions at a soft charged interface up to 5 M bulk concentration with combined classical and phase-sensitive vibrational sum frequency generation (PS-VSFG) spectroscopy and molecular dynamics (MD) simulations. At low concentrations thiocyanate ions are mostly oriented with their sulfur end pointing toward the charged surfactants. The VSFG signal reaches a plateau at around 100 mM bulk concentration, followed by significant changes above 1 M. At high concentrations a new thiocyanate population emerges with their sulfur end pointing toward the bulk liquid. The -CN stretch frequency is different for up and down oriented SCN- ions, indicating different coordination environments. These results provide key molecular-level insights for the interfacial behavior of complex anions in highly concentrated solutions.

Synthesis, crystal structure and magnetic properties of coordination compounds of Mn(NCS)2 with the 3-bromopyridine ligand

Abstract Reactions of Mn(NCS)2 with 3-bromopyridine in acetonitrile lead to the formation of Mn(NCS)2(3-bromopyridine)4 (1) and Mn(NCS)2(3-bromopyridine)2(MeCN)2 (2) that were characterized by single crystal X-ray diffraction. Compounds 1 and 2 consist of discrete complexes, in which the Mn(II) cations are octahedrally coordinated by two trans-N-bonding thiocyanate anions and four pyridine (1) or two pyridine and two acetonitrile ligands (2). Thermoanalytical measurements on 1 and 2 have shown that upon heating half of the 3-bromopyridine co-ligands from 1 or both acetonitrile ligands from 2 are removed leading to a crystalline phase with the composition [Mn(NCS)2(3-bromopyridine)2] n (3-II). From dry n-butanol a phase with the same composition was obtained (3-I) that corresponds to a polymorphic or isomeric form of 3-II. Crystal structure analysis of 3-I shows that in this form the Mn cations are linked by pairs of anionic ligands into linear chains. The results of magnetic measurements on 3-I show antiferromagnetic interactions along the chains and the analysis of the magnetic susceptibility using the Fisher model for chains gave a J value of −5.76(5) K.

Synthesis, Characterization, and Preliminary Study of [Co(2- aminopyridine)2(NCS)2] or bis(2-aminopyridine)dithiocyanato cobalt(II) as An Antibacterial

This study aims to synthesize complex compounds from the Co(II) ion with mixed ligands of 2-aminopyridine and thiocyanate ions. The complexes obtained have Co(II) : 2-aminopyridine: thiocyanate ratio of 1:2:2 based on preliminary analysis by SEM-EDX, DHL, and FTIR. The complex in the form of a blue needle crystal is stable at room temperature and melts at 169 °C. Characterization shows that the complex formed is neutral. The antibacterial activity test was carried out using the diffusion method and show that the resulting complex compounds could inhibit the growth of S. typhi and S. aureus bacteria better than 2-aminopyridine.

Pseudohalide Anions to Suppress Oxidative Degradation for Efficient Formamidinium-Based Sn-Pb Halide Perovskite Solar Cells.

Although binary Sn-Pb perovskites possess optimal band gap approaching to the Shockley-Queisser limit efficiency, the enhancement on power conversion efficiency (PCE) of Sn-Pb perovskite solar cells (PSCs) is impeded by the detrimental oxidation of Sn2+. Herein, a novel and effective strategy is developed to introduce pseudohalide anion thiocyanate (SCN-) with similar ionic radius to iodide to occupy the X-site of the perovskite lattice, thus restraining the rapid oxidation of Sn2+ to Sn4+. The incorporation of SCN- into perovskite stabilizes the perovskite crystal structure thermodynamically and increases the adsorption-energy-barrier of oxygen molecules. The coordination between Sn2+ and SCN- can reduce the defect density by healing the undercoordinated Sn2+ and suppressing the Sn and I vacancies. With the incorporation of SCN-, the ion migration behavior and lattice strain associated with the defects are remarkably relaxed. The study on carrier dynamics based on steady-state and time-resolved photoluminescence suggests that the carrier lifetime and non-radiative recombination rate of SCN- PSCs can be remarkably prolonged and depressed, respectively. As a result, FASn0.5Pb0.5I3-based PSCs achieve a 14.5% increase in PCE, reaching 13.74% under AM 1.5G illumination. This strategy takes a noteworthy step toward high efficiency and high stability FA-based Sn-Pb PSCs.

Synthesis and structure of сopper(II) thiocyanate and nitrate complexes with 1-tert-butyl1H-1,2,4-triazolе

Complexes [Сu(NCS)2L3], [Сu(NO3)2L4] and [Cu(NCS)2L4]·L have been prepared by direct synthesis involving the interaction of metallic copper, ammonium salts NH4X (Х = NCS, NO3) and 1-tert-butyl-1H-1,2,4-triazole (L). Their composition and structure were determined by elemental analysis, single crystal X-ray analysis, and IR spectroscopy (range of 4000–500 cm–1). All the complexes showed mononuclear structure. In them triazole acts as a monodentate ligand, being coordinated by the N4 atom of the heterocycle. The NCS– and NO–3 anions display monodentate N- and O-coordination, accordingly. In [Сu(NCS)2L3], copper(II) cation has square-pyramidal environment of nitrogen atoms of two ligands L and two thiocyanate anions in the basal sites, and one nitrogen atom of ligand L in the apical position. In complexes [Сu(NO3)2L4] and [Cu(NCS)2L4]·L, copper(II) cations are octahedrally surrounded by nitrogen atoms of ligand L in the equatorial sites and by O or N atoms of corresponding anions in the axial positions.

Computational hints for the simultaneous spectroscopic detection of common contaminants in water

In this work, we present a reliable computational methodology with the capability to aid in the identification of ionic water contaminants, such as nitrite, nitrate, and thiocyanate ions, based on the use of Resonance Raman (RR) spectroscopy. The method combines an exhaustive configurational sampling that fully captures the structural complexity inherent to aqueous solutions with state–of–the–art computational techniques that accurately simulate the response properties originating Resonance Raman signals of molecules in solution. Our computational findings show that it is possible to limit the quantum mechanical treatment to only a few explicit water molecules in order to capture the relevant interactions, and thus reproduce the available experimental spectra for NO2- and NO3-. Once validated, the methodology is applied to the prediction of the RR spectrum of aqueous SCN−. Our results indicate that by using an incident wavelength of 210 nm, the three emerging contaminants can be simultaneously detected in an aqueous matrix, thus avoiding the laborious indirect measurements used in current protocols. The designed protocol offers generalized explicit benefits: simultaneous detection of pollutants whose absorption spectra overlap, and because of the very nature of RR, pushes detection limits to lower concentrations.

Syntheses, crystallographic characterization, and structural relations of Rb[SCN

Abstract Colorless rubidium thiocyanate was synthesized by three different approaches. DCS-TGA measurements allowed for extraction of phase transition, melting, and decomposition temperatures. Single-crystal X-ray diffraction showed Rb[SCN] to crystallize in the low-temperature LT-K[SCN] crystal structure type (Pbcm, oP16). Above its phase-transition temperature (432.1 K) the title compound crystallizes with the high-temperature HT-K[SCN] crystal structure type (I4/mcm, tI28) with head-to-tail disordered thiocyanate anions. Both modifications are related to one another and to the LT/HT-Cs[SCN] structure types, and the relation has been studied in detail employing the Bärnighausen formalism. Phase purity and bulk phase transition were confirmed by temperature-dependent PXRD.

Studi Karakterisasi dan Aktivitas Antibakteri Senyawa Kompleks dari Zink(II) Klorida, Kalium Tiosianat dan 2-Aminopiridina

The development of complex compounds as antibacterial continues to be carried out to overcome cases of microbial resistance. One of them is the development of complex compounds with thiocyanate and aminopyridine ligands which show good potential as antibacterial. Complex compound of zinc(II) chloride with thiocyanate and 2-aminopyridine ligands was successfully synthesized. The synthesis was carried out by mixing the reactants with ratio of Zn2+: 2-aminopyridine: SCN 1:2:2 under heating and stirring continuously for 6 hours. The Obtained beam-shaped colorless crystals were characterized using melting point, electrical conductivity, thiocyanate ion qualitative, FTIR, SEM-EDX, XRD powder and antibacterial activity against Salmonella typhi and Staphylococcus aureus test. The crystals melt at 160-165 0C. The results of the electrical conductivity test, qualitative test of thiocyanate ion, FTIR and SEM-EDX analysis indicate the presence of Zn2+, thiocyanate and 2-aminopyridine with ratio 1: 2: 2. Based on XRD powder spectral data and theoritical analysis, the complex synthesized compounds had high crystallinity and predicted has tetrahedral structure. Antibacterial test showed that against S.aureus, the compound had higher antibacterial activity than free ligands, but lower than chloramphenicol. Therefore, the antibacterial activity of the complex compound was classified as moderate.

Testing diverse strategies for ruthenium catalyst removal after aqueous homogeneous olefin metathesis

Traditionally, olefin metathesis (OM) is carried out in organic solvents such as dichloromethane or toluene. Due to the development of water-resistant or even water-soluble ruthenium catalysts in the last two decades, considerable progress on OM in aqueous media has been made. However, the removal of ruthenium from the product of OM reactions performed in water remains a substantial challenge. In the present work, selected approaches to purify the reaction mixtures after aqueous homogeneous olefin metathesis (AHOM) reactions have been probed to address this shortcoming. It was found that elimination of a water-soluble Ru catalyst after AHOM conducted in neat water can be achieved via addition of thiocyanate ions (with or without support of charcoal additive). The developed purification method can make the aqueous metathesis methodology more practical, allowing easier separation of a spent water-soluble catalyst from the water-soluble metathesis products. Unfortunately, this methodology did not provide satisfactory results in the case of AHOM reactions performed in water/alcohol mixtures. To allow separation of a Ru catalyst in the latter case, a method utilizing a stimuli-responsive polymer was tested, leading however to limited success.

A monomeric iron(III) compound containing N-(2-pyridylmethyl)iminodiisopropanolate and thiocyanato ligands: structure, magnetic and catalytic properties

The reaction of Fe(NO3)3·9H2O, sodium thiocyanate, and N-(2-pyridylmethyl)iminodiisopropanol (H2pmidip) in methanol/water mixture solution leads to the formation of a mononuclear iron(III) compound of [FeIII(Hpmidip)(NCS)2] (1). The iron ion of 1 has a distorted octahedral structure that is bonded by two thiocyanate anions and one Hpmidip- ligand. One of the two hydroxyl moieties in H2pmidip is deprotonated, while the other is involved in hydrogen bonding interactions to form a dimeric structure. The magnetic properties of 1 reveal a very weak antiferromagnetic interaction within the dimer with parameters J = -0.75 cm−1 and g = 2.068. 1 showed that the catalytic oxidations for a variety of olefins are selective and effective with moderate yields using meta-chloroperoxybenzoic acid (m-CPBA). For the identification of the mechanism for olefin epoxidation in 1, the OO bond cleavage of peroxyphenylacetic acid (PPAA) and competitive experiments of cis- and trans-2-octene have been investigated.

Room-Temperature Cell Disruption and Astaxanthin Recovery from Haematococcus lacustris Cysts Using Ultrathin α-Quartz Nanoplates and Ionic Liquids

Ionic liquids (ILs) are new green solvents, which are widely used in lignocellulosic and microalgal biorefineries. However, high-temperature operating conditions limit their application in the extraction of heat-labile algal products, such as bioactive astaxanthin. In this study, we report the technical feasibility of room-temperature astaxanthin extraction from Haematococcus lacustris cysts with a thick and complex cell wall structure, by combining ultrathin α-quartz nanoplates (NPLs) with ethyl-3-methylimidazolium ([Emim])-based ILs. When four different [Emim]-based ILs with thiocyanate (SCN), diethylphosphate (DEP), HSO4, and Cl anions were applied to 90-day-old H. lacustris cysts at room temperature (~28 °C), the astaxanthin extraction efficiency was as low as 9.6–14.2%. Under sonication, α-quartz NPLs disrupted the cyst cell wall for a short duration (5 min). The astaxanthin extraction efficacies of a subsequent IL treatment improved significantly to 49.8% for [Emim] SCN, 60.0% for [Emim] DEP, 80.7% for [Emim] HSO4, and 74.3% for [Emim] Cl ions, which were 4.4, 6.1, 8.4, and 5.2 times higher than the extraction efficacy of only ILs, respectively. This finding suggests that α-quartz NPLs can serve as powerful cell-wall-disrupting agents for the room-temperature IL-mediated extraction of astaxanthin from robust algal cyst cells.

Counterintuitive Electrostatics upon Metal Ion Coordination to a Receptor with Two Homotopic Binding Sites.

The consecutive binding of two potassium ions to a bis(18-crown-6) analogue of Tröger’s base (BCETB) in water was studied by isothermal titration calorimetry using four different salts, KCl, KI, KSCN, and K2SO4. A counterintuitive result was observed: the enthalpy change associated with the binding of the second ion is more negative than that of the first (ΔHbind,2° < ΔHbind,1°). This remarkable finding is supported by continuum electrostatic theory as well as by atomic scale replica exchange molecular dynamics simulations, where the latter robustly reproduces experimental trends for all simulated salts, KCl, KI, and KSCN, using multiple force fields. While an enthalpic K+–K+attraction in water poses a small, but fundamentally important, contribution to the overall interaction, the probability of the collapsed conformation (COL) of BCETB, where both crown ether moieties (CEs) of BCETB are bent in toward the cavity, was found to increase successively upon binding of the first and second potassium ions. The promotion of the COL conformation reveals favorable intrinsic interactions between the potassium coordinated CEs, which further contribute to the observation that ΔHbind,2° < ΔHbind,1°. While the observed trend is independent of the counterion, the origin of the significantly larger magnitude of the difference ΔHbind,2° – ΔHbind,1° observed experimentally for KSCN was studied in light of the weaker hydration of the thiocyanate anion, resulting in an enrichment of thiocyanate ions close to BCETB compared to the other studied counterions.

Crystal structures of two Co(NCS)2 urotropine coordination compounds with different Co coordinations.

The reaction of Co(NCS)2 with urotropine in ethanol leads to the formation of two different compounds, namely, bis-(ethanol-κO)bis-(hexa-methyl-ene-tetra-mine-κN)bis-(thio-cyanato-κN)cobalt(II)-di-aqua-κ 2O-bis-(hexa-methyl-ene-tetra-mine-κN)bis-(thio-cyanato-κN)cobalt(II)-ethanol-hexa-methyl-ene-tetra-mine (1.2/0.8/1.6/4), [Co(NCS)2(C6H12N4)2(C2H6O)2]1.2·[Co(NCS)2(C6H12N4)2(H2O)2]0.8·1.6C2H6O·4C6H12N4, 1, and tris-(ethanol-κO)(hexa-methyl-ene-tetra-mine-κN)bis(thio-cyanato-κN)cobalt(II), [Co(NCS)2(C6H12N4)(C2H6O)3], 2. In the crystal structure of compound 1, two crystallographically independent discrete complexes are observed that are located on centres of inversion. In one of them, the Co cation is octa-hedrally coordinated to two terminal N-bonded thio-cyanate anions, two urotropine ligands and two ethanol mol-ecules, whereas in the second complex 80% of the coordinating ethanol is exchanged by water. Formally, compound 1 is a mixture of two different complexes, i.e. di-aqua-dithio-cyanato-bis-(urotropine)cobalt(II) and di-ethano-ldi-thio-cyanato-bis-(uro-trop-ine)cobalt(II), that contain additional ethanol and urotropine solvate mol-ecules leading to an overall composition of [Co(NCS)2(urotropine)2(ethanol)1.2(H2O)0.8·0.8ethanol·4urotropine. Both discrete complexes are linked by inter-molecular O-H⋯O and O-H⋯N hydrogen bonding and additional urotropine solvate mol-ecules into chains, which are further connected into layers. These layers combine into a three-dimensional network by pairs of centrosymmetric inter-molecular C-H⋯S hydrogen bonds. In the crystal structure of compound 2, di-thio-cyanato-(urotropine)tri-ethano-lcobalt(II), the cobalt cation is octa-hedrally coordinated to two terminal N-bonded thio-cyanate anions, one urotropine ligand and three ethanol mol-ecules into discrete complexes, which are located in general positions. These complexes are linked by inter-molecular O-H⋯N hydrogen bonding into layers, which are further connected into a three-dimensional network by inter-molecular C-H⋯S hydrogen bonding.

The Effect of Cooking on the Goitrogenic (cyanogenic glycosides and glucosinolates) Content of Pumpkin Leaves (Telfairia occidentalis) and Spinach Leaves (Spinacia olairaceae)

Fresh ugwu (Telfairia occidentalis) and spinach (Spinacia olairaceae) leaves play important roles in human nutrition. Leafy vegetables including Telfairia occidentalis and Spinacia olairaceae are considered as agents of transmission of goitrogens which interfere with iodine uptake thus causing goiter. Cyanogenic glycosides are naturally occurring goitrogens found in staple foods in the tropics. Thiocyanate and isothiocyanate have been demonstrated as the goitrogenic principles of cyanogenic plants Thiocyanate ion acts as a goitrogen when present at high concentration especially when the iodine content of the diet is low. Thiocyanate inhibits the uptake of iodine by the iodide pump of the thyroid gland thus acting as a goitrogen which suppresses thyroid function leading to goiter. This study examined the effect of cooking on the goitrogenic potential of Ugwu and Spinach leaves. A total of (10g) of fresh/ andraw ugwu and spinach leaves were randomly collected and cooked. All samples were examined according to standard methods for detection of goitrogens. The cyanogenic glycosides content of rawand fresh ugwu leaves were 1. 6mg /kg - 1. 82mg/ kg while that of cooked leaves were 0. 004mg/ kg - 0. 0 l3mg/ kg. The glucosinolates content for raw and fresh Ugwu leaves were15.7mg/kg-17.28mg/kg, while that of cooked Ugwu leaves were 11.18mg/kg- 12.51mg/kg . For Spinach the cyanogenic glycosides content for raw and fresh were 0.24mg/kg-1.28mg/kg, while that of cooked spinach were 0.013mg/kg- 0.00Smg/kg. The glucosinolates content for raw and fresh spinach were 4.0mg/kg-2.64mg/kg while those of the cooked leaves were 2.52mg/kg-1.82mg/kg. there was a significant diference (P=0.085) in the level of reduction of glucosinolate content between raw and cooked Ugwu leaves and Spinach. There is also a significant difference (p=3.04) in the concentration of glucosinolates between Ugwu leaves and Spinach. Ugwu leaves had a higher concentration of glucosinolates than spinach in both fresh (raw) and cooked conditions respectively. These findings provide evidence that the risk of acquiring goiter from the consumption of ugwu and spinach leaves is reduced when cooked.&#x0D; Keywords: Ugwu leaves, Spinach leaves, Cooking, Goitrogens, Cyanogenic glycosides, Glucosinolates

Syntheses, crystal structures and spectral properties of two polymeric Cd(ΙΙ) complexes with 2-methyl-5-(2-pyridyl)-1,3,4-thiadiazole

Two polymeric Cd(ΙΙ) complexes of [Cd2L2(µ-Cl)4]n (1) and [Cd2L2(µ-SCN)4]n (2) were synthesized and characterized by single crystal X-ray diffraction, UV-Vis, fluorescence and TGA. Complex 1 crystallizes in monoclinic system with space group P21/c. Complex 2 crystallizes in triclinic system with space group p − 1. Both of 1 and 2 are double-bridged Cd(ΙΙ) polymeric complexes bridged by two chlorine atoms and two thiocyanate ions, respectively.