Ligands trivial names

Some commonly used macrocycles. — The number in brackets indicates the size of the ring. The terms ane and ene denote saturated and unsaturated rings respectively. The number of ligating atoms is indicated by a subscript. A trivial name is often used (G. A. Melson in Coordination Chemistry of Macrocyclic Compounds, Ed. G. A. Melson, Plenum, New York, 1979, Chapter 1 Comprehensive Coordination Chemistry, Ed. G. Wilkinson, Pergamon, Oxford, 1987. Several chapters in Vol. 2 (Ligands)). 

The original concepts of metal-ligand bonding were essentially related to the dative covalent bond the development of organometallic chemistry has revealed a further way in which ligands can supply more than one electron pair to a central atom. This is exemplified by the classical cases of bis(benzene)chromium and bis(cyclopentadienyl)iron, trivial name ferrocene. These molecules are characterised by the bonding of a formally unsaturated system (in the organic chemistry sense, but expanded to include aromatic systems) to a central atom, usually a metal atom. 

To aid in identifying the significant features of the ligands listed in Table 2, trivial names have been assigned using the following conventions ... 

The size and shape of the binding cavity that they define and their rigidity or flexibility are determined by the nature of the structural subunits making up the branches of the graphical representations. Their overall shape and appearance has also led to the coining of a number of so-called trivial names that refer to a particular aspect of the structure. Proposals have been made to name and define different types of macrocyclic ligands and molecular receptors [2.12]. Without being ex-... 

This definition is framed to emphasise the metal-binding properties of the ligands and includes most cyclic polydentate ligands that can incorporate a metal ion into the middle of a bonding cavity. It is also worth noting that many macrocyclic ligands have trivial names. This reflects the unfriendly nature of the systematic names for example, the systematic names of 6.5 and 6.8 are 1,4,8,11-tetraazatetracyclodecane and 2,5,8,15,18,2l-hexaoxatricyclo[20.4.0.09 14]hexacosa-l(22),8,11,13,23,24-hexaene, respectively. 

The trivial names half-sandwich, piano-stool, milking stool and pogo-stick are given to complexes which have only one cyclopentadienyl (or other rf-CnR ) ligand. 

An example of the alternative cationic species is provided by [Ph2PCH2NMe3]+I . Baird and coworkers developed this theme in preparing the all-phosphorus cationic phosphoniumphosphines [Ph2P(CH2) PMe3]X (n = 2,3, 6, 10 X = NO3, Cl, PFe), to which they gave the trivial names II-, III-, VI-, and X-phosphos. These ligands form water-soluble transition metal complexes such as [(nbd)RhCl(II-phosphos)] [PFg]... 

Organic (and some inorganic) ligands are frequently named with older trivial names rather than with lUPAC (International Union of Pure and Applied Chemistry) names. The lUPAC names are more correct, but trivial names and abbreviations are still commonly used. Tables 9-2, 9-3, and 9-4 list some of the common ligands. Ligands with two or more points of attachment to metal atoms are called chelating ligands, and the compounds are called chelates (pronounced key-lates), a name derived from the... 

Because of so-called pyrrole redistribution reactions4 that are acid-promoted, use of monopyrroles (e.g., (3)) which do not have identical 3- and 4-substituents will result in a mixture of porphyrins. Thus, pyrrole (3) gives a mixture of trivially named etioporphyrins I IV (4)-(7) when it is cyclotetramerized under acidic conditions. Such a mixture of ligands, similar as they are, still makes the characterization of a subsequent metal complex almost impossible, and should therefore be avoided. 

Trivial Names Official Gene Name Natural Ligands... 

This simple group of rules clearly does not by any means cover the full set of naming rules that apply to deal with modern coordination chemistry. However, they go some of the way to allowing you to navigate around nomenclature for the relatively simple complexes you will likely meet. It is a difficult task to name complicated compounds - which is why, even in the chemical research literature, people sometimes choose to avoid it as much as possible. For some, nothing compares with a drawing of the complex molecule and a trivial name(s) for the ligand(s) involved ... 

Not only does chelation make the complex more stable, but it also forces the donor atoms to take up adjacent or cis sites in the resulting complex. Equation (2) shows how displacement of a chelating carbonate ion gives the unusual cis dichloride product instead of the thermodynamically more stable trans dichloride. Polydentate chelating ligands with three or more donor atoms also exist. Macrocyclic ligands, such as (4) and (5), confer an additional increment in the formation constant (the macrocyclic effect) they have been given trivial names, such as cryptates (4) and sepulchrates (5).i... 

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