Björn Hellquist

Effect of Steric Hindrance on kinetic and equilibrium data for substitution reactions of diaqua(N-substituted (ethylenediamine)- palladium(II) with chloride in aqueous solution

Abstract Kinetic and thermodynamic data are reported for the complex formation reactions: Pd(R4en)(H2O)22+Cl− Pd(R4en)(H2O)Cl++H2O and Pd(R4en)(H2O)Cl++Cl− Pd(R4en)Cl2+H2O, as a function of steric hindrance for RMe and Et. The reported rate constants for these reactions decrease drastically on increasing the steric hindrance. These findings along with strongly negative △S≠ values support the operation of an associative reaction mechanism. Values for the complex formation and acid-dissociation constants are reported, from which speciation plots are constructed. All the results are discussed in reference to the corresponding data for the unsubstituted en system and the cis-Pt(NH3)2(H2O)22+ species.

Beyond the borders of the local: How “instructional products” from learning study can be shared and enhance student learning

Purpose: The purpose of this paper is to present how experiences gained from a theory-informed lesson study – learning study (LrS) – in regard to a specific learning goal can be shared and used by ...

Solvent exchange and complex formation reactions of Pd(II) in aqueous solution: mechanistic information from high pressure studies

Abstract High pressure NMR and stopped-flow techniques have been employed to study a series of water exchange and complex formation reactions of Pd(II) outlined in (1) and (2). The volumes of activation show an interesting correlation with the partial molar volume of the entering ligand and underline the operation of an associative substitution mechanism in all cases.