Water stable colloidal PVP coated spin crossover nanoparticles.

Stable aqueous dispersions of spin-crossover (SCO) doped [Fe(Htrz)(trz)](BF) nanoparticles (NPs) were prepared by using water-soluble polyvinylpyrrolidone (PVP) as protecting polymer. The metal or ligand substitution percentage regulated the ultra-small size and morphology of the NPs. At the same time, the colloidal dispersions showed a complete conversion of the LS state to the HS state of the Fe ion.

Development of Iron-Based Single Atom Materials for General and Efficient Synthesis of Amines.

Earth abundant metal-based heterogeneous catalysts with highly active and at the same time stable isolated metal sites constitute a key factor for the advancement of sustainable and cost-effective chemical synthesis. In particular, the development of more practical, and durable iron-based materials is of central interest for organic synthesis, especially for the preparation of chemical products related to life science applications. Here, we report the preparation of Fe-single atom catalysts (Fe-SACs) entrapped in N-doped mesoporous carbon support with unprecedented potential in the preparation of different kinds of amines, which represent privileged class of organic compounds and find increasing application in daily life.

A mononuclear Fe(III) complex showing thermally induced spin crossover and slow magnetic relaxation with reciprocating thermal behaviour.

AC susceptibility measurements of [Fe(L)(NCSe)] reveal a field supported slow magnetic relaxation. On cooling, the relaxation time of the high-frequency fraction decreases which is a sign of reciprocating thermal behaviour. The relaxation time for the low-frequency mode at = 2.

Observation of Two-Step Spin Transition in Graphene Oxide-Based Hybrids with Iron(II) 4-amino-1,2,4-triazole Spin Crossover Nanoparticles.

A novel experimental protocol based on a reverse micellar method is presented for the synthesis of graphene oxide (GO)-based hybrids with spin crossover nanoparticles (SCO NPs) of the 1D iron(II) coordination polymer with the formula [Fe(NHtrz)](Br). By introducing different quantities of 0.5% and 1.

Observation of two-step spin transition in iron(II) 4-amino-1,2,4-triazole based spin crossover nanoparticles.

A synthetically controllable two-step spin transition was observed in iron(II) spin crossover nanoparticles of the dehydrated one-dimensional coordination polymer [Fe(NHtrz)]Br (NHtrz = 4-amino-1,2,4-triazole) using the reverse micellar method. The change from two-step to one-step hysteretic characteristics succeeded by changing the reaction time.

Microwave-Enhanced Crystalline Properties of Zinc Ferrite Nanoparticles.

Two series of ZnFeO mixed cubic spinel nanoparticles were prepared by a coprecipitation method, where a solution of Fe and Zn was alkalised by a solution of NaOH. While the first series was prepared by a careful mixing of the two solutions, the microwave radiation was used to enhance the reaction in the other series of samples. The effect of the microwave heating on the properties of the prepared particles is investigated.

An effect of scandium substitution on the phase purity and structural, magnetic, and electrochemical features of ε-FeO nanoparticle systems.

A series of Sc-substituted ε-FeO nanoparticles embedded in a silica matrix were synthesized by a sol-gel process. It was found that the preparation of a pure ε-FeO phase without any other iron(III) oxide phases as admixtures was achieved for ε-ScFeO (5 at% of Sc) as documented by analyses of X-ray powder diffraction (XRD) results. Extensive physicochemical characterization of the ε-ScFeO sample was performed employing transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), magnetization measurements, Fe Mössbauer spectroscopy, and electrochemical impedance spectroscopy (EIS).

Iron Nitride Nanoparticles for Enhanced Reductive Dechlorination of Trichloroethylene.

Nitriding has been used for decades to improve the corrosion resistance of iron and steel materials. Moreover, iron nitrides (FeN) have been shown to give an outstanding catalytic performance in a wide range of applications. We demonstrate that nitriding also substantially enhances the reactivity of zerovalent iron nanoparticles (nZVI) used for groundwater remediation, alongside reducing particle corrosion.

High-Performance Luminescence Thermometer with Field-Induced Slow Magnetic Relaxation Based on a Heterometallic Cyanido-Bridged 3d-4f Complex.

The 1:1:1 reaction of DyCl·6HO, K[Co(CN)] and bpyO in HO has provided access to a complex with formula [DyCo(CN)(bpyO)(HO)]·4HO () in a very good yield, while [DyFe(CN)(bpyO) (HO)]·4HO () was also precipitated (also in a high yield) using K[Fe(CN)] instead of K[Co(CN)]. Their structures have been determined by single-crystal X-ray crystallography and characterized based on elemental analyses and IR spectra. Combined direct current (dc) and alternating current (ac) magnetic susceptibility revealed slow magnetic relaxation upon application of a dc field.

A facile approach to prepare silica hybrid, spin-crossover water-soluble nanoparticles as potential candidates for thermally responsive MRI agents.

A reverse micelle method was used for the synthesis of water-soluble silica hybrid, spin-crossover (SCO) nanoparticles (NPs). MRI experiments provided temperature dependent 2 values, indicating their potential use as smart MRI agents, while lyophilization of NP dispersions in water yielded powders with a preserved but modified thermal hysteretic magnetic profile.

Condensed Clustered Iron Oxides for Ultrahigh Photothermal Conversion and Multimodal Imaging.

Magnetic iron oxide nanocrystals (MIONs) are established as potent theranostic nanoplatforms due to their biocompatibility and the multifunctionality of their spin-active atomic framework. Recent insights have also unveiled their attractive near-infrared photothermal properties, which are, however, limited by their low near-infrared absorbance, resulting in noncompetitive photothermal conversion efficiencies (PCEs). Herein, we report on the dramatically improved photothermal conversion of condensed clustered MIONs, reaching an ultrahigh PCE of 71% at 808 nm, surpassing the so-far MION-based photothermal agents and even benchmark near-infrared photothermal nanomaterials.

2-D spin crossover materials at the nanometric scale: the effects of the size-reduction on the magnetic properties.

Spin Crossover (SCO) particles at the nanometric scale provide an alternative point of view and a new perspective concerning the development of a new generation of spintronic, electronic, photonic and mechanical devices. The coexistence of the SCO phenomenon with the accompanying hysteresis loop enhances the functionality of future devices for storing and processing information. Despite all promising facts, the SCO phenomena are greatly affected by cooperativity issues resulting in a direct relation between the decrease of the size of nanopatricle and the overall decrease of cooperativity towards more gradual spin transitions.

Hierarchical Porous Graphene-Iron Carbide Hybrid Derived From Functionalized Graphene-Based Metal-Organic Gel as Efficient Electrochemical Dopamine Sensor.

A metal-organic gel (MOG) similar in constitution to MIL-100 (Fe) but containing a lower connectivity ligand (5-aminoisophthalate) was integrated with an isophthalate functionalized graphene (IG). The IG acted as a structure-directing templating agent, which also induced conductivity of the material. The MOG@IG was pyrolyzed at 600°C to obtain MGH-600, a hybrid of Fe/FeC/FeO enveloped by graphene.

Core-Shell Fe/FeS Nanoparticles with Controlled Shell Thickness for Enhanced Trichloroethylene Removal.

Zero-valent iron nanoparticles (nZVI) treated by reduced sulfur compounds (i.e., sulfidated nZVI, S-nZVI) have attracted increased attention as promising materials for environmental remediation.

Formic Acid, a Ubiquitous but Overlooked Component of the Early Earth Atmosphere.

Terrestrial volcanism has been one of the dominant geological forces shaping our planet since its earliest existence. Its associated phenomena, like atmospheric lightning and hydrothermal activity, provide a rich energy reservoir for chemical syntheses. Based on our laboratory simulations, we propose that on the early Earth volcanic activity inevitably led to a remarkable production of formic acid through various independent reaction channels.

Light- and temperature-assisted spin state annealing: accessing the hidden multistability.

Among responsive multistable materials, spin crossover (SCO) systems are of particular interest for stabilizing multiple spin states with various stimulus inputs and physical outputs. Here, in a 2D Hofmann-type coordination polymer, [Fe(isoq){Au(CN)}] (isoq = isoquinoline), a medium-temperature annealing process is introduced after light/temperature stimulation, which accesses the hidden multistability of the spin state. With the combined effort of magnetic, crystallographic and Mössbauer spectral investigation, these distinct spin states are identified and the light- and temperature-assisted transition pathways are clarified.

Spin-Crossover Phenomenon in Microcrystals and Nanoparticles of a [Fe(2-mpz)Ni(CN)] Two-Dimensional Hofmann-Type Polymer: A Detailed Nano-Topographic Study.

The diamagnetic two-dimensional Hofmann-type metal-organic framework [Zn(2-mpz)Ni(CN)] has been successfully synthesized along with its isostructural hysteretic spin-crossover Fe analogue in the form of both bulk microcrystalline powder and nanoparticles. Detailed atomic force microscopy topographic study revealed a nanogrowth relationship between the height and length of the nanoparticle.

Biotechnological applications of nanostructured hybrids of polyamine carbon quantum dots and iron oxide nanoparticles.

The combination of different nanomaterials has been investigated during the past few decades and represents an exciting challenge for the unexpected emerging properties of the resulting nano-hybrids. Spermidine (Spd), a biogenic polyamine, has emerged as a useful functional monomer for the development of carbon quantum dots (CQDs). Herein, an electrostatically stabilized ternary hybrid, constituted of iron oxide-DNA (the core) and spermidine carbon quantum dots (CQD, the shell), was self-assembled and fully characterized.

Knowledge, Attitudes, Practices and Health Beliefs toward Leptospirosis among Urban and Rural Communities in Northeastern Malaysia.

Background: Leptospirosis is a zoonotic disease with a worldwide distribution, especially in developing countries such as Malaysia. This study was designed to explore the knowledge, attitudes, beliefs and practices (KABP) toward leptospirosis among the communities in northeastern Malaysia and to determine the sociodemographic factors associated with the KABP toward leptospirosis. A cross-sectional study using a stratified sampling method was conducted among 214 individuals in four locales in northeastern Malaysia.

Economic benefit of leptospirosis prevention in Kelantan, Malaysia: Willingness-to-contribute approach.

Leptospirosis is an endemic disease in Malaysia. Despite the increasing incidence rate, knowledge on the economic assessment of preventing leptospirosis is still limited. This paper introduces the willingness-to-contribute (WTC) method for estimating the economic benefit of preventing leptospirosis.

Noncovalent Grafting of a Dy Single-Molecule Magnet onto Chemically Modified Multiwalled Carbon Nanotubes.

While synthetic methods for the grafting of nanoparticles or photoactive molecules onto carbon nanotubes (CNTs) have been developed in the last years, a very limited number of reports have appeared on the grafting of single-molecule magnets (SMMs) onto CNTs. There are many potential causes, mainly focused on the fact that the attachment of molecules on surfaces remains not trivial and their magnetic properties are significantly affected upon attachment. Nevertheless, implementation of this particular type of hybrid material in demanding fields such as spintronic devices makes of utmost importance the investigation of new synthetic protocols for effective grafting.

Development and validation of a new knowledge, attitude, belief and practice questionnaire on leptospirosis in Malaysia.

Background: In Malaysia, leptospirosis is considered an endemic disease, with sporadic outbreaks following rainy or flood seasons. The objective of this study was to develop and validate a new knowledge, attitude, belief and practice (KABP) questionnaire on leptospirosis for use in urban and rural populations in Malaysia.

Methods: The questionnaire comprised development and validation stages.

Seroprevalence of leptospiral antibodies among market workers and food handlers in the central state of Malaysia.

Objective: The high prevalence of leptospirosis in humans is of great public health concern, particularly in tropical and subtropical regions. This study aimed to determine the seroprevalence of leptospiral antibodies and distribution of serovars, and to assess the usefulness of enzyme-linked immunosorbent assay (ELISA) as a screening method for leptospiral antibodies in a high-risk healthy community.

Methods: Cross-sectional study of 231 market workers and food handlers in wet markets and food premises from two localities in central Malaysia.

Prevalence and molecular characterisation of Schistosoma haematobium among primary school children in Kebbi State, Nigeria.

Schistosomiasis is the major source of morbidity in Sub-Saharan Africa and Asia. It is estimated that 207 million people are infected, of which 97% are in Africa. The aim of this study was the determining of prevalence as well as the phylogeny of S.