zinc(II)

zinc(II)
Name	Zinc(II)
Systematic name	Zinc(II) ion
Other names	Zn2+, divalent zinc, zinc(II) cation
Oxidation states	+2
Electron configuration	[Ar]3d10
Ionic radius	74 pm (octahedral)
Category	d-block metal ion

zinc(II)

Zinc(II) is the doubly charged cation of the element zinc, a closed-shell d10 species that plays a central role in inorganic chemistry, coordination complexes, biochemistry, and industrial applications. It is characterized by a filled 3d subshell, a lack of accessible d–d transitions, and versatile coordination behavior that underpins its presence in enzymes, metalloproteins, alloys, and catalysts. Research on zinc(II) spans structural biology, materials science, environmental chemistry, and pharmacology, with contributions from laboratories and institutions worldwide.

Nomenclature and Electronic Structure

IUPAC nomenclature designates the ion as zinc(II); systematic naming conventions appear in texts from the International Union of Pure and Applied Chemistry and are used by researchers at institutions such as Massachusetts Institute of Technology, University of Oxford, and Max Planck Society. The electronic configuration is [Ar]3d10, which confers closed-shell stability analogous to the noble-gas-like behavior discussed in reviews from Royal Society of Chemistry journals and monographs by authors at California Institute of Technology and ETH Zurich. The +2 oxidation state is the predominant and nearly exclusive stable state under normal conditions, a point emphasized in treatises from National Institute of Standards and Technology and textbooks used at Harvard University chemistry departments. Spectroscopically, the filled 3d manifold results in weak ligand-field splitting and absence of spin-pairing changes, a subject of analyses from groups at University of Cambridge and École Normale Supérieure.

Occurrence and Production

Zinc(II) appears naturally as dissolved species in seawater sampled by expeditions from institutions like Scripps Institution of Oceanography and as mineralogical Zn2+-bearing phases in ores mined by corporations such as Rio Tinto Group and Glencore. Major zinc ore minerals include sphalerite, whose processing is documented by engineering programs at Stanford University and Imperial College London. Global production statistics and smelting technologies are tracked by agencies including the United States Geological Survey and commodity reports used by World Bank analysts. Industrial extraction typically involves froth flotation, roasting, and hydrometallurgical leaching, producing zinc(II) solutions that are electrorefined at facilities run by firms like Nyrstar and Teck Resources.

Coordination Chemistry and Compounds

Zinc(II) forms coordination complexes across coordination numbers from four to six; classical examples include tetrahedral zincates and octahedral aquo complexes characterized in structural studies from Brookhaven National Laboratory and crystallography centers at Carnegie Mellon University. Common ligands include water, ammonia, halides, phosphines, and chelators such as ethylenediaminetetraacetate (EDTA), with coordination motifs analyzed by researchers at University of California, Berkeley and University of Tokyo. Organometallic species such as diorganozinc compounds were developed by synthetic chemists at Bell Labs and in methodologies taught at University of Illinois Urbana–Champaign. Zinc(II) carboxylates and alkoxides serve as precursors in materials chemistry explored at Oak Ridge National Laboratory and Lawrence Berkeley National Laboratory.

Physical and Chemical Properties

As an ion, zinc(II) is colorless in most solution contexts because of its filled 3d shell; optical properties are discussed in spectroscopy literature from Argonne National Laboratory and academic groups at University of Chicago. Ionic radii and hydration enthalpies appear in compilations by International Union of Crystallography and thermochemical data sets maintained by National Institute of Standards and Technology. Zinc(II) undergoes ligand exchange kinetics that are generally fast relative to many transition-metal ions, a kinetic behavior characterized in kinetic studies at University of Michigan and University of California, San Diego. Redox chemistry typically involves conversion to metallic zinc via electrochemical reduction; electrorefining and galvanostatic processes are industrially optimized by researchers at Fraunhofer Society and metallurgical departments at McGill University.

Biological Roles and Toxicology

Zinc(II) is an essential micronutrient incorporated into numerous enzymes and transcription factors, including metalloproteins studied at Max Planck Institute for Biophysical Chemistry and structural biology facilities such as European Molecular Biology Laboratory. Iconic zinc-dependent enzymes include carbonic anhydrase and alcohol dehydrogenase, with regulatory zinc-finger motifs characterized in genomic research from National Institutes of Health and protein structure projects at European Bioinformatics Institute. Cellular zinc homeostasis involves transporters and metallothioneins investigated by teams at Johns Hopkins University and Cold Spring Harbor Laboratory. Toxicological profiles—acute and chronic—are monitored by public health agencies including the World Health Organization and Environmental Protection Agency; excess zinc(II) exposure can disrupt metal homeostasis and cause gastrointestinal and neurological effects documented in clinical reports from Mayo Clinic and Cleveland Clinic.

Applications and Industrial Uses

Zinc(II) is central to galvanizing processes pioneered in industrial history by firms in the Industrial Revolution and currently applied by manufacturers such as ArcelorMittal to protect steel from corrosion. Zinc salts like zinc sulfate and zinc oxide are produced at scale for use in agriculture, rubber vulcanization, and pharmaceuticals, industries connected to research at Bayer AG and product development labs at Johnson & Johnson. Zinc(II)-based catalysts and reagents underpin organic syntheses in academic groups at Massachusetts Institute of Technology and chemical companies including BASF. In materials science, zinc oxide and related Zn2+-derived compounds are integral to electronics and photonics research at IBM and Intel Corporation, while biomedical applications—nutritional supplements and topical formulations—are evaluated in clinical trials overseen by institutions such as World Health Organization and Food and Drug Administration.

Category:Zinc compounds Category:Metal ions