Related Experiment Video
Updated: Jun 27, 2025

Amide Coupling Reaction for the Synthesis of Bispyridine-based Ligands and Their Complexation to Platinum as Dinuclear Anticancer Agents
Published on: May 28, 2014
Supramolecular Solid Complexes between Bis-pyridinium-4-oxime and Distinctive Cyanoiron Platforms
Igor Picek1, Dubravka Matković-Čalogović2, Goran Dražić3
1Department of Chemistry and Biochemistry, School of Medicine, University of Zagreb, Šalata 3, HR-10000 Zagreb, Croatia.
Abstract:
The structural features and optical properties of supramolecular cyanoiron salts containing bis-pyridinium-4-oxime Toxogonin® (TOXO) as an electron acceptor are presented. The properties of the new TOXO-based cyanoiron materials were probed by employing two cyanoiron platforms: hexacyanoferrate(II), [Fe(CN)6]4- (HCF); and nitroprusside, [Fe(CN)5(NO)]2- (NP). Two water-insoluble inter-ionic donor-acceptor phases were characterized: the as-prepared microcrystalline reddish-brown (TOXO)2[Fe(CN)6]·8H2O (1a) with a medium-responsive, hydrochromic character; and the dark violet crystalline (TOXO)2[Fe(CN)6]·3.5H2O (1cr). Complex 1a, upon external stimulation, transforms to the violet anhydrous phase (TOXO)2[Fe(CN)6] (1b), which upon water uptake transforms back to 1a. Using the NP platform resulted in the water-insoluble crystalline salt TOXO[Fe(CN)5(NO)]·2H2O (2). The structures of 1cr and 2, solved by single-crystal X-ray diffraction, along with a comparative spectroscopic (UV-vis-NIR diffuse reflectance, IR, solid-state MAS-NMR, Mössbauer), thermal, powder X-ray diffraction, and microscopic analysis (SEM, TEM) of the isolated materials, provided insight for the supramolecular binding, electron-accepting, and H-bonding capabilities of TOXO in the self-assembly of these functionalized materials.
Related Concept Videos
Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
Valence Bond Theory
Formation of Complex Ions
Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
Complexation Equilibria: The Chelate Effect
Stereoisomerism
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
![Solid-phase Synthesis of [4.4] Spirocyclic Oximes](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58508.jpg&w=3840&q=50)
