Coordination compounds complex ions

Many complexes and coordination compounds exist as isomers, compounds that contain the same numbers of the same atoms but in different arrangements. For example, the ions shown in (13a) and (13b) differ only in the positions of the Cl ligands, but they are distinct species, because they have different physical and chemical properties. Isomerism is of more than academic interest for example, anticancer drugs based on complexes of platinum are active only if they are the correct isomer. The complex needs to have a particular shape to interact with DNA molecules. 

These products differ widely in their behaviour, particularly in water and, though there is no general agreement on what constitutes a complex or coordination compound the following definition is sufficient for the present purpose a complex molecule or ion is one in which an atom (A) is attached to other atoms (B) or groups of atoms (C) to a number in excess of the charge or oxidation number of the atom (A). 

Azido complexes are coordination compounds with azide ions as inner-sphere ligands and may be cationic, such as azidopentaaquocobalt(III) (d) or anionic, such as hexaazidocuprate (e) or neutral, such as dipyridine diazidozinc (0- There are mixed-ligand complexes, such as (d) and (f), and all-azido... 

Uranium, tetrathiocyanatotetrakis[tris-(dimethylamino)phosphine oxidc]-structure, 87 Uranium(VI) complexes liquid-liquid extraction of, 541 Uranyl complexes six-coordinate compounds structure, 53 stereochemistry, 74 Uranyl ions photoreactivity, 408 Urea... 

The zinc group does not display the variable valence associated with transition metal ions. However the group does have the transition-like property of forming many complexes or coordination compounds, such as [Zn(NH3)4] and [Hg(CN]]4]2-. 

An inorganic molecule that contains several atoms, including one or more metal atoms, is called an inorganic complex or coordination compound. An example is nickel tetracarbonyl, Ni(CO)4. An inorganic complex with an electric charge is called a complex ion. Familiar examples of complex ions are the ferrocyanide ion, Fe(CN)e - the ferricyanide ion, Fe(CN)e the hydrated aluminum ion, A1(H20)6, and the deep blue cupric ammonia complex ion, Cu(NH3)4 +, which is formed by adding ammonium hydroxide to a solution of cupric salt. Complex ions are important in the methods of separation used in qualitative and quantitative chemical analysis and in various industrial processes. 

Far and away the most common coordination number is 6, with the ligands arranged at the corners of an octahedron. For metals from atomic number 11 (sodium) upward, more complex ions and compounds contain six-coordinate metal ions than not. Examples of ions are [Cr(NCS)6] , where the underlining of the N indicates that it is this constituent of the ligand, rather than the sulfur atom, that is directly attached to the metal, [SnCl6]2-, [Ni(H2NCH2CH2NH2)3]2+, [Ru(bipy)3]2+, and miSshf-. 

Complex Ions Coordination Numbers, Geometries, and Ligands 744 Formulas and Names of Coordination Compounds 745... 

A complex ion is a metal ion with Lewis bases attached to it through coordinate covalent bonds. A complex (or coordination compound) is a compound consisting either of complex ions and other ions of opposite charge (for example, the compound K4[Fe(CN)g] of the complex ion Fe(CN)g and four ions) or of a neutral complex species (such as cisplatin). 

A metal complex, or coordination compound, consists of a metal atom or ion bonded to several neutral or anionic ligands. Carbon monoxide, CO, is a neutral unidentate ligand, which forms a four-coordinate complex with Ni it coordinates through the carbon atom and the complex, Ni(CO)4, is tetrahedral. 

Zirconium [7440-67-7] is classified ia subgroup IVB of the periodic table with its sister metallic elements titanium and hafnium. Zirconium forms a very stable oxide. The principal valence state of zirconium is +4, its only stable valence in aqueous solutions. The naturally occurring isotopes are given in Table 1. Zirconium compounds commonly exhibit coordinations of 6, 7, and 8. The aqueous chemistry of zirconium is characterized by the high degree of hydrolysis, the formation of polymeric species, and the multitude of complex ions that can be formed. 

The chemistry of Cr(III) in aqueous solution is coordination chemistry (see Coordination compounds). It is dominated by the formation of kineticaHy inert, octahedral complexes. The bonding can be described by Ss]] hybridization, and HteraHy thousands of complexes have been prepared. The kinetic inertness results from the electronic configuration of the Cr ion (41). This type of orbital charge distribution makes ligand displacement and... 

---