The binary intermetallic clathrates K8-xSi46 (x = 0.4; 1.2), Rb6.2Si46, Rb11.5Si136 and Cs7.8Si136 were prepared from M₄Si₄ (M = K, Rb, Cs) precursors by spark-plasma route (SPS) and structurally characterized by Rietveld refinement of PXRD data. The clathrate-II phase Rb11.5Si136 was synthesized for the first time. Partial crystallographic site occupancy of the alkali metals, particularly for ...

Can cyclen (1,4,7,10-tetraazacyclododecane) bind alkali metal azides? This question is addressed by studying the geometric and electronic structures of the alkali metal azide-cyclen [M(cyclen)N3] complexes using density functional theory (DFT). The effects of adding a second cyclen ring to form the sandwich alkali metal azide-cyclen [M(cyclen)2N3] complexes are also investigated. N3(-) is found...

Black phosphorus (BP) exhibits thickness-dependent band gap and high electronic mobility. The chemical intercalation of BP with alkali metal has attracted attention recently due to the generation of universal superconductivity regardless of the type of alkali metals. However, both ultrathin BP, as well as alkali metal-intercalated BP, are highly unstable and corrode rapidly under ambient condit...

Porphyrins are a group of tetrapyrrole pigments. Physical and chemical properties of porphyrins are often related to their compositions and structures. We conducted 1H solution NMR and UV-visible spectral analysis to characterize the structural feature of a water-soluble, synthetic porphyrin i.e. tetrakis (p-sulfonatophenyl) porphyrin, TPPS4, and its interaction with different metal ions in aqu...

We describe an alkali-metal magnetometer for detection of weak magnetic fields in the radio-frequency (rf) range. High sensitivity is achieved by tuning the Zeeman resonance of alkali atoms to the rf frequency and partially suppressing spin-exchange collisions in the alkali-metal vapor. We demonstrate magnetic field sensitivity of 2 fT/Hz(1/2) at a frequency of 99 kHz with a resonance width of ...

The interaction of alkali metals-specifically, lithium-with polycyclic aromatic hydrocarbons (PAHs) was studied using a variety of electronic structure methods. Electron transfer from lithium to a PAH depends on the size and structure of the PAH and the electronic structure method used. In some cases, we observe an artificial transfer when using density functional theory (DFT) due to the self-i...

the kinetics of catalyst deactivation and coke formation during dehydrogenation of propane over supported pt–based catalysts and, in particular, the effect of alkali metal promoters on catalyst activity and stability were studied. the analysis of propane conversion data showed that there is an optimum level of alkali metal promoter loading for both catalyst activity and stability.a model based ...

Structural optimization for heteronuclear clusters consisting of one alkali-metal ion and of up to 79 neutral rare gas atoms has been carried out. The basin-hopping Monte Carlo minimization method of Wales and Doye is used. Rare gas atoms interact with the Lennard–Jones potential, whereas the interaction between a neutral atom and an ion impurity is given by the Mason–Schamp potential. Starting...

2.1.1. Syntheses of alkali metal ozonides 51 2.1.2. Crystal structures of alkali metal ozonides 53 2.1.2.1. Potassium ozonide 53 2.1.2.2. Rubidium ozonide 56 2.1.2.3. Cesium ozonide 57 2.1.3. Thermal properties and decomposition of K0 3 ,Rb0 3 , andCs03 57 2.1.4. Magnetic properties of K0 3 ,Rb0 3 , and Cs0 3 57 2.1.5. Spectroscopic properties of ionic ozonides 58 2.2. Further ozonides 59 2.2.1...