Ligands, chemical

Figure 3. Effect of Adjuvax-ligand chemical crosslinking on ligand sustained release rate.

Recently, nonpeptide compounds have been developed for many peptide receptor systems. These compounds, which usually are discovered through screening of chemical files, generally do not resemble the corresponding peptide ligands chemically. Nevertheless, they act as specific and... 

Ligand Chemical Database, GenomeNet WWW Server, Institute for Chemical Research, Kyoto University, http //www.genome.ad.jp/dbget-bin/www bget ligand+1.6.6.9... 

Bjerrum, J., Schwarzenbach, G., Sillen, L. G., Stability Constants, Spec. Pub. 6, Part I, Organic Ligands, Chemical Society, London, 1957. 

While DFT may or may not be more accurate than MP2 for absolute shielding calculations is debatable, the strength of the DFT method in calculations of shieldings is in the ability of DFT to provide a consistent picture over a wide range of chemical systems, since calculations can be done at a very modest computational cost compared to MP2. Among the successes of the method is in ligand chemical shifts in transition metal complexes. For example, 13C, 170,31P and H chemical shifts for oxo (12,14,15), carbonyl (16-19), interstitial carbide (20), phosphine (21,22), hydride (23), and other ligands have been successfully reproduced to within tens of ppm in... 

Schreckenbach et al. [92-94] investigated ligand chemical shifts in uranium compounds (ZORA DFT). Nonhybrid ZORA DFT computations were not able to reproduce the trends for 19F shifts of UF6 C1 though the correct magnitudes between 750 and 790 ppm were obtained. Spin-orbit effects were found to be of minor importance for the 19 F shifts. ZORA DFT computations were successfully... 

Bergbreiter, D.E., Using Soluble Polymers To Recover Catalysts and Ligands, Chemical Reviews, 102, 3345-3384 (2002). 

Bisalkyne d4 monomers, with N = 3 by symmetry, exhibit proton and carbon chemical shifts at higher fields than those of monoalkynes with N = 4. The proton chemical shift of 10.45 ppm for Mo(PhC=CH)2-(S2CNEt2)2 (52) falls nicely between the four-electron donor Mo(CO)-(PhC=CH)(S2CNEt2)2 case (12.6 ppm) and the two-electron donor (7r-C5H5)2Mo(HC=CH) case [7.68 ppm (Table II)]. Additional data for bisalkyne complexes, including pyrrole-N-carbodithioate derivatives, support a correlation of H chemical shifts with alkyne ttj donation, with three-electron donors typically near 10.0 0.5 ppm. Similar H values are found for cyclopentadienyl bisalkyne complexes with terminal alkyne ligands. Chemical shifts between 8.5 and 10.5 ppm characterize all the neutral and cationic bisalkynes listed in Table V except for [CpMo-(RC=CH)2(MeCN)]+ where one isomer has S near 11 ppm for the acetylenic proton (72). 

Other Compounds with Mono- or Bidentate Ligands Chemical and Physical Properties of Ca, Sr, and Ba Compounds of Type MXmLlt (X =... 

Other Compounds with Polydentate Ligands Chemical and Physical... 

LIGAND GenomeNet Ligands (chemicals) for different enzymes... 

Interaction of the analyte molecules with the adsorbent surface is the driving force of HPLC separations. The surface of HPLC packing material should have specific interactions with different analytes, and at the same time the packing material itself should be mechanically and chemically stable. Variation of the adsorbent surface chemistry is achieved via chemical modification of the base material surface—that is, chemical bonding of the specific ligands. Chemical modification of the surface has two purposes (a) shielding of the surface of base material and (b) introduction of the specific surface interactions. 

Zhou, Y, Hong, M., and Wu, X. (2006) Lanthanide-transition metal coordination polymers based on multiple N and O-donor ligands. Chemical Communications, (2), 135-143. 

Figure 6.3 The metal-oxygen core structure of Ln5( X5-0)( JL3-0Pr )4( x-0Pr )4(0Pr )5- (Ln = Eu, Nd, Gd, Er, Yb) [16]. (Redrawn from W.J. Evans, M.A. Greci and J.W. ZUler, The utility of N-methylimidazole and acetonitrile as solvents for the direct reaction of enropium with alcohols inclnd-ing the first example of acetonitrile as a p. — r l r 1-bridging ligand, Chemical Communications, 2367-2368, 1998.)...

Figure 6.27 The crystal structure of Sm(Tp )2(OH) where is tris(dimethylpyrazolyl)borate, a sterically cumbersome ligand [100]. (Redrawn from N. Marques, A. Sella and J. Takats, Chemistry of the lanthanides using pyrazolylborate ligands, Chemical Reviews, 102, 2137-2160, 2002.)...

Schumann, H., Meese-Marktscheffel, J.A., and Esser, L. (1995) Synthesis, structure, and reactivity of organometallic Jt-complexes of the rare earths in the oxidation state Ln + with aromatic ligands. Chemical... 

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