A rare example of a double metamagnetic transition leading to 2D and 3D long-range order in the two-dimensional pyrazine- and azido-bridged cobalt(II) compound [Co(pyz)(N)].

The synthesis, characterization, crystal structure and detailed magnetic properties of a pyrazine (pyz) and azido (N) bridged cobalt(II) compound of formula [Co(N)(pyz)] (1) are reported. Compound 1 shows a layered structure formed by Co(II) chains with double μ-N(κN,N) bridges that are further connected by μ-(pyrazine-κN,N) bridges. The layers present weak van der Waals interactions between azido terminal groups.

Coordination chemistry beyond Werner: interplay between hydrogen bonding and coordination.

A tutorial review is presented dealing with the role of hydrogen bonding in coordination compounds. Examples are given for important intramolecular hydrogen bonding, and stabilising unusual coordination geometries, or reactive species. Also examples are discussed for intermolecular H-bonds between coordination entities and anions, and for stabilising crystal lattices, like in coordination polymers.

Fast and slow versus strong and weak metal-DNA binding: consequences for anti-cancer activity.

The binding of transition metal compounds to nucleic acids is discussed in the perspectives of kinetics and their anticancer activity. Kinetics of ligand exchange is primarily determined by the intrinsic properties of the metal ions, and to a lesser degree by the ligands coordinated already to the metal ion. Metal compounds having ligand-exchange rates of the same order of magnitude as cell-division processes, e.

Quinoxaline-2-carboxamide as a carrier ligand in two new platinum(II) compounds: Synthesis, crystal structure, cytotoxic activity and DNA interaction.

The search for platinum compounds structurally different from cisplatin has led to two new platinum(II) compounds containing quinoxaline-2-carboxamide as a carrier ligand, i.e. cis-[Pt(qnxca)(MeCN)Cl2] (1) and the [Pt(qnxca-H)(dmso)Cl] (2).

New clues for platinum antitumor chemistry: kinetically controlled metal binding to DNA.

From the metal ions and metal compounds that are known to bind to DNA, many anticancer Pt(II) and Ru(II)Ru(III) compounds are known to have ligand-exchange kinetics in the same order of magnitude as the division of tumor cells. The present article discusses this process in detail with special attention to cisplatin and related compounds and the cellular binding sites and processes of such compounds. Detailed platinated DNA structures are presented and discussed in light of the mechanistic studies of metal antitumor compounds.

Medicinal applications of heavy-metal compounds.

A brief summary of the key role for certain heavy-metal compounds in medicine is discussed, with a special focus on very recent findings in the following four topics: platinum anti-tumor compounds (novel mononuclear compounds, dinuclear compounds and trinuclear compounds with promising activity); ruthenium anti-tumor compounds (the first clinical trial for a Ru compound has begun); gadolinium NMR-imaging compounds (association with biomacromolecules is now possible); technetium compounds (the use of organometallic precursors opens a plethora of new species and enables the labeling of, for example, neurotransmitter molecules).