Fém-ligandum kölcsönhatás vizsgálata gázfázisú molekulaspektroszkópiai módszerekkel = Investigation of transition metal complexes by gas phase molecular spectroscopic methods

- Új kvantumkémiai eljárást dolgoztunk ki az átmenetifém-származékok fotoelektron (pe) színképének értelmezéséhez. - UPS vizsgálatok alapján meghatároztuk a CS és CSe ligandumok CO-hoz viszonyított donor-akceptor sajátságát. - Előállítottuk a Co(CO)2(N | Novel quantumchemical method has been worked out for the interpretation of the photoelectron (pe) spectra of transition metal derivatives.-Donor-acceptor properties of CS and CSe related to CO have been determined on the basis of UPS investigations.-New compound of Co(CO)2(NO)(t-BuNC) has been prepared and investigated by HeI UPS and threshold PEPICO methods. From the PEPICO measurements energetic and thermochemical data were derived.-Trimethyl phosphane, -arsane, and –stibane derivatives of CpMnCO3 and CoCO3NO have been investigated by HeI and HeII UPS methods and conclusions were drawn concerning the ?-acceptor and ?-donor ability of the ligands.-A new series of isonitrile-substituted cobalt tricarbonyl nitrosyl (Co(CO)2(NO)CNR, R= Me, Et, nPr, iPr, nBu, nPe, CH2SiMe3) has been synthesized and studied by HeI UPS. The relative importance of electronic and steric effects of the isonitrile ligands, as a function of the size of group –R were determined. Metallocene ions (Cp2M+, M=Cr,Co,Ni) were studied by TPEPICO spectroscopy to investigate the mechanism, energetics and kinetics of the ionic dissociation processes.-Me3Si and Me3Ge radicals were generated by the gas phase thermolysis of (Me3Si/Ge)2Hg. The HeI pe spectra were recorded and assigned.-Electronic structure determination of precursors (diiodofuroxan and thiadiazoles) of some exotic molecules has been performed. Pyrolizer/ reactor directly attached to the pe spectrometer has been constructed

Next-generation technologies for the electrosynthesis of ammonia from renewables

Ammonia is an important fertiliser for the agriculture, feedstock for the chemical industry, and an emerging high-energy-density carbon-free fuel. One such promising approach is to produce ammonia is the electrochemical synthesis of ammonia from dinitrogen and either dihydrogen or water under close-to-ambient conditions powered by renewable electricity. Replacing the mediator in the nitrogen reduction reaction system might improve the energy efficiency of this technology and facilitate the development of the green ammonia synthesis industry

Biosensors for Non-Invasive Detection of Celiac Disease Biomarkers in Body Fluids

Celiac disease is a chronic gluten-initiated autoimmune disorder that predominantly damages the mucosa of the small intestine in genetically-susceptible individuals. It affects a large and increasing number of the world’s population. The diagnosis of this disease and monitoring the response of patients to the therapy, which is currently a life-long gluten-free diet, require the application of reliable, rapid, sensitive, selective, simple, and cost-effective analytical tools. Celiac disease biomarker detection in full blood, serum, or plasma offers a non-invasive way to do this and is well-suited to being the first step of diagnosis. Biosensors provide a novel and alternative way to perform conventional techniques in biomarker sensing, in which electrode material and architecture play important roles in achieving sensitive, selective, and stable detection. There are many opportunities to build and modify biosensor platforms using various materials and detection methods, and the aim of the present review is to summarize developments in this field

Carbon Nanomaterial Based Biosensors for Non-Invasive Detection of Cancer and Disease Biomarkers for Clinical Diagnosis

The early diagnosis of diseases, e.g., Parkinson’s and Alzheimer’s disease, diabetes, and various types of cancer, and monitoring the response of patients to the therapy plays a critical role in clinical treatment; therefore, there is an intensive research for the determination of many clinical analytes. In order to achieve point-of-care sensing in clinical practice, sensitive, selective, cost-effective, simple, reliable, and rapid analytical methods are required. Biosensors have become essential tools in biomarker sensing, in which electrode material and architecture play critical roles in achieving sensitive and stable detection. Carbon nanomaterials in the form of particle/dots, tube/wires, and sheets have recently become indispensable elements of biosensor platforms due to their excellent mechanical, electronic, and optical properties. This review summarizes developments in this lucrative field by presenting major biosensor types and variability of sensor platforms in biomedical applications

Carbon Microsphere-Supported Metallic Nickel Nanoparticles as Novel Heterogeneous Catalysts and Their Application for the Reduction of Nitrophenol

Nickel nanoparticles are gaining increasing attention in catalysis due to their versatile catalytic action. A novel, low-cost and facile method was developed in this work to synthesize carbon microsphere-supported metallic nickel nanoparticles (Ni-NP/C) for heterogeneous catalysis. The synthesis was based on carbonizing a polystyrene-based cation exchange resin loaded with nickel ions at temperatures between 500 and 1000 °C. The decomposition of the nickel-organic framework resulted in both Ni-NP and carbon microsphere formation. The phase composition, morphology and surface area of these Ni-NP/C microspheres were characterized by powder X-ray diffraction, Raman spectroscopy, scanning electron microscopy and BET analysis. Elemental nickel was found to be the only metal containing phase; fcc-Ni coexisted with hcp-Ni at carbonization temperatures between 500 and 700 °C, and fcc-Ni was the only metallic phase at 800–1000 °C. Graphitization and carbon nanotube formation were observed at high temperatures. The catalytic activity of Ni-NP/C was tested in the reduction of 4-nitrophenol to 4-aminophenol by sodium borohydride, and Ni-NP/C was proved to be an efficient catalyst in this reaction. The relatively easy and scalable synthetic method, as well as the easy separation and catalytic activity of Ni-NP/C, provide a viable alternative to existing nickel nanocatalysts in future applications

Understanding the Factors Determining the Faradaic Efficiency and Rate of the Lithium Redox-Mediated N₂Reduction to Ammonia

The lithium mediated reduction of N2 is one of the only available approaches to electrochemical ammonia production at significant yields under ambient conditions. However, much remains to be investigated about the various electrochemical processes and side reactions that are involved. Herein, we have examined the effects of parameters including electrode potential, convection, N2 pressure, and water content to refine and control the process. We demonstrate that a closely linear ammonia yield can be maintained during experiments up to 60 h in length, with approximately constant faradaic efficiency. This steady state operation appears to be preceded by a coating of the electrode surface with the products of the reductive electrolyte decomposition, such as LiF. We demonstrate ammonia yield rates above 1 nmol s-1 cm-2 and faradaic efficiencies as high as 60% through the improved control of the reaction conditions. </p

Photolysis of Dimethylcarbamoyl Azide in an Argon Matrix: Spectroscopic Identification of Dimethylamino Isocyanate and 1,1‑Dimethyldiazene

The UV photolysis of dimethylcarbamoyl azide has been investigated in an argon matrix at cryogenic temperatures. The products of the photolysis were identified by infrared spectroscopy supported by quantum-chemical calculations. Sequential formation of dimethylamino isocyanate (Me₂N–NCO), 1,1-dimethyldiazene (Me₂NN), and ethane was established. Therefore, the major decomposition channel is identified as Me₂NC­(O)­N₃ → Me₂N–NCO → Me₂NN → Me–Me, via consecutive N₂, CO, and N₂ eliminations. Ground-state geometries, vibrational frequencies, IR intensities, and UV excitation energies of the transient dimethylamino isocyanate and 1,1-dimethyldiazene have been computed using the B3LYP and SAC-CI methods and the aug-cc-pVTZ basis set