Ligands, index

Mapping the indexed ligand set of a configuration onto the indexed skeletal sites with due accounting for skeletal symmetry affords a consistent nomenclatural description as well as a procedure for enumerating the conceivable configurations of a skeletal class. 

A ligand permutational reaction refers to a specific permutation of indexed ligand positions. For a six coordinate complex there are 6 or 720 such permutations including the identity, however, fortunately all do not yield distinguishable isomers. 

Ligand Formula Index Ligand Formula Index... 

In empirical formulas of inorganic compounds, electropositive elements are listed first [3]. The stoichiometry of the element symbols is indicated at the lower right-hand side by index numbers. If necessary, the charges of ions are placed at the top right-hand side next to the element symbol (e.g., S "). In ions of complexes, the central atom is specified before the ligands are listed in alphabetical order, the complex ion is set in square brackets (e.g., Na2[Sn(OH)+]). 

Figure 2-80. The permutation matrix oFthe reference isomer the second line gives the indices of the sites of the skeleton and the first line the indices of the ligands (e.g.. the ligand with index 3 is on skeleton site 3).

Fig. 2. Yellowness index vs two-roU mill heat stabiUty, where the mercaptide ligands, — SCH2COOR (A), —SCH2CH2COOR ( ), and —SCH2CH2C00R + HSCH2CH2C00R ( )) IT 9, and 6% Sn, respectively. R = CgH. R = H33. ...

The development of ligands selective for individual receptor subtypes relevant to a targeted disease could decrease these toxic effects thereby improving the therapeutic index. Two new arotinoids are already available for topical use in skin diseases. These are tazarotenic acid (tazarotene) and 6-[3-(l-adamanty 1)-... 

Index of Review Articles and Specialist Texts Table 3 Complexes According to Ligand... 

Entries where the oxidation state of a metal has been specified occur after all the entries for the unspecified oxidation state, and the same or similar entries may occur under both types of heading. Thus cyanide appears under Chromium complexes, Chromium(O) complexes, Chromium(I) complexes, etc. More specific entries, such as Chromium, hexacyano-, may also occur. Similar ligands may also occur in different entries. Thus a carboxylic acid-metal complex may occur under Carboxylic acid complexes, under entries for specific carboxylic acids, and under the specific metal. Coordination complexes may also be listed in the Cumulative Formula Index. 

The element symbols within each formula are arranged according to a modified Hill system in which the order is metal(s), C, H and then any remaining symbols arranged alphabetically. Compounds containing two (or more) different metals appear twice (or more), being listed under each metal. Common ligand abbreviations which appear in the text have also been used in the index. These include acac (acetylacetone), bipy (2,2 -bipyridyl), diars [o-phenylenebis(dimethyl-arsine)], dien (diethylenetriamine), etc. 

The idea of ligand efficiency was extended by considering other molecular descriptors. Abad-Zapatero and Metz [56] introduced a percentage efficiency index, a binding efficiency index and a surface-binding efficiency index by normalizing... 

Numerous modifications to the bis(aryl)-a-diimine ligand motif have been reported, especially in the patent literature. The review by Ittel includes an index of diimine and related ligands in proprietary publications up to the year 2000 [26]. Instead, this discussion will focus on academic reports of Ni(II) and Pd(II) polymerization catalysts bearing a-diimine or other closely related chelating neutral nitrogen ligands. 

Fig. 10. A SPR Detection realized in a BIAcore system. A fan of polarized light passes a prism and is focused at the interface to an aqueous phase under conditions of total reflection. An evanescent wave enters the solvent phase. If the prism is coated with a thin gold layer at the interface the free electrons in the metal absorb energy from the evanescent wave for a distinct angle, depending on the refractive index of the solvent near the interface. B The gold layer can be modified with, e.g., a carboxydextrane matrix, where catcher molecules can be immobilized by standard chemistry. If a ligand is applied with the aqueous phase it may interact with the catcher and accumulate in the matrix, causing a shift in the resonance angle. If no specific binding occurs the refractive index in proximity of the sensor is less affected...

F. Spindler, M. Studer, A. Togni, Topics in Catalysis 2002, 39, 3 and information on commercial ligands in http // www.solvias.com/english/products-and-services/chemicals/ligands/index.html... 

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