Ligand common

A simple NMR technique, and arguably the most widely used and effective for hit validation, is the chemical shift perturbation method. In this approach, a reference spectrum of isotopically labeled target is recorded in absence and presence of a given test ligand (or a mixture of test ligands). Commonly, differences in chemical shift between free and bound protein target are observed in 2D [15N, 1H and/or 2D [13C, H] correlation spectra of a protein (or nucleic acid) upon titration of a ligand... 

Abstract During the past decade, atom transfer radical polymerization (ATRP) has had a tremendous impact on the synthesis of macromolecules with well-defined compositions, architectures, and functionalities. Structural features of copper and copper(II) complexes with bidentate, tridentate, tetradentate, and multidentate nitrogen-based ligands commonly utilized in ATRP are reviewed and discussed. Additionally, recent advances in mechanistic understanding of copper-mediated ATRP are outlined. 

Scheme 7 Nitrogen-based ligands commonly used in copper-catalyzed ATRA and ATRP...

Although ligands commonly coordinate to vacant metal d orbitals (i.e., n —s-dvi1 interactions), such coordination is also possible with the unfilled metal s orbital (i.e., hl->-Sm interactions) for metal ions with completely filled d shells. An example is Zn2+(d10s°), where the vacant 4s orbital serves as the acceptor orbital for donor-acceptor interactions of ni s/+ type. 

In particular, Diels-Alder adducts from the enantioselective reaction of 2-bromo-acrolein and 2-chloroacrolein with a variety of dienes are of exceptional synthetic versatility. Readers are advised to consult the review article by Corey and Guzman-Perez.54 For the purpose of quick reference, chiral ligands commonly used in Diels-Alder reactions are listed in Table 5-6. 

Cyanide and Thiocyanate Complexes Among other unidentate anionic ligands commonly encountered, cyanide forms stable complexes with both Cu(II) and Cu(I) however, the CuCN salt is so insoluble (p gp = 19.5)[169] that only the reduced complex has been characterized, that is, the addition of cyanide to an aqueous solution initially containing Cu(II) results in autoreduction to Cu(I). The overall equilibrium constant ( 34) for the reaction of Cu(I) with four cyanide ions was determined as early as 1904 by Kunschert [170] and subsequent measurements have yielded virtually identical values ... 

Considering homoleptic organolanthanide species the reader will get a rough overview of the ligands commonly examined. Figs. 7-10 classify structurally characterized complexes according to their shortest intramolecular Ln-X contact [155], Figs. 7-9 show derivatives of Ln(III) in the upper half and... 

Many organometallic compounds of group 13 are formed by n bonds. The n ligands commonly used are olefins, cyclopentadiene, or their derivatives. 

Figure 12 Molecular structures of four bischelating ligands commonly used to form octahedral Ru- and Rh-complexes for attachment to DNA phenanthrenequinone diimine (phi), dipyridophenazine (dppz), 5-(amido-glutaric acid)-l,10-phenanthroline (phen ), and 2,2 -bipyridine (bpy).

Figure 2. The ligand common to all molybdenum and tungsten enzymes, MPT, is shown here in several formats (a) in common stick notation (b) as a ball and stick (c) an orientation rotated 90° from view (b) to emphasize the spacial relationship between the pterin plane and the dithiolene-pyran ring portion (d) MGD in common stick notation and for comparison, (e ) FAD, a common electron-transfer prosthetic group. Coordinates for the views in (b) and (c) are taken from the data deposited in the Protein Data Bank (PDB) for the 1.3-A resolution structure of DMSO reductase from Rhodobacter sphaeroides.

B.S. Jensen, Complex Formation of Selected Radionuclides with Ligands Commonly Found in Groundwater Low Molecular Organic Acid., CEC. 

In common with other platinum metals, an important area of ruthenium chemistry involves trialkyl- and triarylphosphines, and the corresponding phosphites. An extremely wide range of complexes is known, mainly of the II state, although compounds in the 0, III, and less commonly, IV state are known other ligands commonly associated with the PR3 group are halogens, alkyl and aryl groups, CO, NO, and alkenes as well as H and H2. Similar chemistry is found for osmium. 

Ligands commonly bridge two or more metal atoms in coordination modes not seen for monometallic complexes. 

Redox processes between metal complexes are divided into outer-sphere processes and inner-sphere processes that involve a ligand common to both coordination spheres. The distinction is fundamentally between reactions in which electron transfer takes place from one primary bond system to another (outer-sphere mechanism) and those in which electron transfer takes place within a primary bond system (inner-sphere mechanism) (Taube, 1970). 

Cationic hydro complexes have been obtained by the replacement of a coordinated anionic ligand (commonly a halide) with a neutral ligand in the presence of a noncoordinating anion. A representative example is the synthesis of [PtH(C0)(PEtg)2]C104 from PtHCl(PEt3)2 in the presence of CO and sodium perchlorate (86) ... 

Table 7.6 Ligands Commonly Used to Study Different Opioid Receptor Types ...

Catalysts based on salicylaldiminato ligands (commonly referred to as phenoxy-imine ligands) were introduced for ethylene polymerization in 1998.1126 This remarkable class of highly active catalysts can lead to an unique variety of linear PEs.1121,1127-1144 Several reviews have been dedicated to these systems.1140 1145-1149 The performances of some of these bis(phenoxy-imine) systems are reported in Table 18. The most typical and most widely investigated systems in this class are complexes 135-138. 

Reaction cycles are further distinguished by the number of static ligands common to each chiromer. In both of the cycles of Chart IV, ligands 1, 2 and 3 are common to each chiromer, and ligands 4, 5 and 6 change. A reaction cycle in which three ligands are static is termed a triligostat. 

Apparent violations of this rule are encountered in diligostatic cycles (two static ligands common to all chiromers), in monoligostatic (one static ligand) and in aligostatic cycles (no static ligands). 

One of the most successful routes for SMM synthesis is the reaction between a pre-formed Mn cluster and (a) solvent, (b) reductant/oxidant, and/or (c) flexible organic bridging ligand. Commonly the metal complexes used are the triangular species [64] [Mn30(02CR)6(py)3] , but all Mn x > 2) clus-... 

A second strategy investigated by Stang et al. [79,83] is the use of a C2h diaza-bisheterocycle as linker ligand, such as 2,6-diazaanthracene (DAA) 43 and 2,6-diazaanthracene-9,10-dione (DAAD) 44, as opposed to the D2d or D2h symmetrical ligands commonly used in molecular squares. 

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