Diurnal Oxidation for Manganese Minerals in the Arctic Ocean

The relative abundance of different oxidation states for this important micronutrient varies on the basis of how much available sunlight there is.

Ti(IV)-exchanged nano-ZIF-8 and nano-ZIF-67 for Enhanced Photocatalytic Oxidation of Hydroquinone

The metal centres of nano-ZIF-8(Zn) and nano-ZIF-67(Co) were partially exchanged with titanium centres to form bimetallic nZIF-8(Zn/Ti) (52% Ti4+) and nZIF-67(Co/Ti) (38% Ti4+) respectively, for enhanced photocatalytic performance. A morphological and structural analysis by SEM, EDS-Mapping and PXRD showed that the particle size, distribution, and the structural integrity of the Sodalite frameworks of the parent ZIFs were retained during the exchange process to form the new bimetallic Ti-ZIFs. FTIR confirmed that no additional chemical bonds were formed during the process. XPS binding energies confirmed the preservation of the Zn(II), Co(II) and Ti(IV) oxidation states, as well as the Ti-content, consistent with ICP-OES and EDS measurements. The Ti-exchanged ZIFs showed higher activity during the photocatalytic oxidation of hydroquinone in comparison with their parent ZIFs. Their kinetic rates were nearly five times faster than those of the parent ZIFs, with the first-order rate constants k = 0.189 min-1 for nZIF-8(Zn/Ti) and k = 0.139 min-1 for nZIF-67(Co/Ti). These catalysts are efficient, stable, and reusable for three photocatalytic cycles without a significant loss of catalytic activity.

Recent advances and perspectives in ruthenium-catalyzed cyanation reactions

The cyanation reaction has achieved rapid progress in recent times. The ability to exhibit multiple oxidation states increased the demand of ruthenium in the field of catalysis. These cyanation reactions have wide application in pharmacological and biological fields. This review gives an overview of the ruthenium-catalyzed cyanation reactions covering literature up to 2021.

Potassium at the Origins of Life: Did Biology Emerge From Biotite in Micaceous Clay?

Intracellular potassium concentrations, [K+], are high in all types of living cells, but the origins of this K+ are unknown. The simplest hypothesis is that life emerged in an environment that was high in K+. One such environment is the spaces between the sheets of the clay mineral, mica. The best mica for life’s origins is the black mica, biotite, because it has a high content of Mg++ and it has iron in various oxidation states. Life also has many of the characteristics of the environment between mica sheets, giving further support for the possibility that mica was the substrate on and within which life emerged.

In defence of oxidation states

In this Perspective, some of the criticisms which have been made concerning the use of oxidation states are addressed, particularly in the context of the teaching of inorganic chemistry.

Acid/base responsive assembly / dis-assembly of a family of zirconium(IV) clusters with a cyclic imide-dioxime ligand

The hydrolytically stable dioxime ligand (2Ζ-6Ζ)-piperidine-2,6-dione (H3pidiox), acts as a strong chelator mainly with hard metals in high oxidation states, a pre-requisite for potential applications in metal sequestering processes from...

Reply to the ‘Comment on “In Defence of Oxidation States”’ by J. C. Green, Dalton Transactions, 2022, 51, DOI: 10.1039/D1DT02930D

A Reply to the comment by J. C. Green on our article “In Defence of Oxidation states”.

Comment on “In Defence of Oxidation States” by N. C. Norman and P. G. Pringle, Dalton Transactions, 2022, 51, DOI: 10.1039/D0DT03914D

A comment on “In defence of oxidation states” by N. C. Norman and P. G. Pringle: a historical perspective on the Covalent Bond Classification and the use of Valency Number in this context.