A Frustrated Phosphane–Borane Lewis Pair and Hydrogen: A Kinetics Study

The energy profile of a frustrated Lewis pair (FLP) dihydrogen splitting system was determined by a combined experimental kinetic and DFT study. A trimethylene‐bridged phosphane–borane FLP was converted into its endothermic H₂‐cleavage product by sequential H⁺/H^? addition. The system could be handled at low temperature, and the kinetics of the H₂ elimination were determined to give a rate constant of k_HH,exp(299 K)=(2.87±0.1)×10^?4 s^?1 in solution. The primary kinetic isotope effects were determined; for example, (k_HH/k_DD)_exp=3.19. The system was accurately analyzed by DFT calculations.     

Cycloaddition Reactions of an Active Cyclic Phosphane/Borane Pair with Alkenes,Alkynes, and Carbon Dioxide

The active six-membered cyclo-FLP 6 undergoes a rapid P/B addition reaction to carbon dioxide. At elevated temperature, the resulting heterobicyclo[2.2.2]octane derived product 7 undergoes ring opening and equilibrates with the cyclotetramer (7)₄ . In the large macrocyclic structure, four monomeric six-membered cyclo-FLP units are connected by four CO₂ molecules to form the supramolecular ring system. The P/B cyclo-FLP 6 undergoes a variety of additional cycloaddition reactions.     

Correction to: convergence rates for Kaczmarz-type algorithms

Numerical Algorithms - We will refer to the paper “Convergence rates for Kaczmarz-type algorithms”, published in Numerical Algorithms, 79(1)(2018), 1-17. It was observed by Dr. Mokhtar...     

On The Cut-off Parameters in the Bosonization Technique

Jordan's boson representation and cut-off repolarization for the one-dimensional two-fermion model (TFT) is used to get the equivalence of the model with the two-dimensional Coulomb gas and sine-Gordon model. The scaling equations for the coupling constants are thereby obtained up to the third order.     

Speciation Studies of Iron (III) with (Poly)phosphonate Ligands: The Case of EDTMP (EthylenediamineTetramethylene Phosphonic Acid)

The complex formation equilibrium of ethylenediaminetetramethylenephosphonic acid (EDTMP, H₈L) with iron (III) has been studied potentiometrically at 25°C and an ionic strength of 0.2 M (NaCl). The successive protonation constants of ligand EDTMP and the complex formation constants were determined with the PSEQUAD program. Keeping in view the biological studies, the speciation in the system Fe (III)—EDTMP was calculated and drawn with the HySS computer program, and pFe values are compared.