Ligands coordination bonds

Metal-ligand coordination bond, which is the most significant part of MOF, is hydrolyzed with water, resulting in the displacement of ligand bond and as a consequence, the whole structure... 

Coordination chemistry is particularly amenable to DCC. The labile nature of most metal-ligand coordination bonds assures facile and reversible connections among the constituents, which enables quick thermodynamic equilibration of the system. Furthermore, metals may assume a wide variety of coordination stoichiometries and geometries, thereby yielding highly diverse DCLs. It is therefore not surprising that some of the first DCC systems were based on coordination complexes,... 

This chapter will cover the synthetic, structural, and solution chemistry of rare earth complexes with carboxylic acids, polyaminopolycarboxylic acids, and amino acids, with an emphasis on their structural chemistry. As the carboxylate groups play the key roles in the metal-ligand coordination bonding in these complexes, we will start the chapter with the coordination chemistry of rare earth-carboxylic acid complexes, followed by rare earth-polyaminopolycarboxylic acid and rare earth-amino acid coordination chemistry. Owing to length limitations, an exhaustive citation of the large amount of research activities on the subjects is not possible. Instead, only selected examples are detailed to highlight the key features of this chemistry. 

Fraunfelder and co-workers [65-68] have found the same relationship in the reduction kinetics of CO and O2 ligand coordination bonds with the complex-forming Fe ions of the heme group myoglobin upon photodissociation of these bonds induced by laser photolysis of 10 s duration. The formation of Fe-CO and Fe-02 bonds after photolysis was registered with a spectrophotometer by restoration of the mother compound absorption spectrum in the wide range of times (10 -10 s) and temperatures (2-300 K). Before photolysis the six-coordinate Fe ion is in the heme plane. The coordination bond break causes not only the ligand shift but also... 

Polar, anionic Surfaces of variable-charge minerals L Metal-ligand coordination bond (Strong)... 

The dotted lines indicate that some kind of non-covalent bond between the molecular thread and the macrocycle is established. As shown in the examples developed later on, these interactions are either hydrophobic in nature, or n-donor/rr-acceptor interactions between aromatic nuclei, or hydrogen bonds or metal-ligand coordination bonds. Their effect is to shift the equilibrium of scheme 2 towards the formation of the threaded species, which can thus be obtained quantitatively from the separated... 

Metal centers can typically be included in the core or as the core of a dendrimer via metal-ligand coordination bonds. Complexes (M(L) ) of metals (M) containing ligands (L) that can readily be replaced are generally employed for synthesizing these metallodendrimers. Due to its remarkable ability to form stable coordination compounds, Ru(II) metal ion is an excellent candidate for such a build-up process. One of the first examples of Ru(II)-based metallodendrimers was prepared by reacting... 

Groote R, Szyja M, Pidko EA, Hensen EJM, Sijbesma RP (2011) Unfolding and mechano-chemical scission of supramolecular polymers containing a metal-ligand coordination bond. Macromolecules 44 9187-9195... 

In (Ti -Cp)Rh(Ti -C2H4)2, two alkene proton signals are observed at 233 K (the dilferent H environments are red and black respectively in 24.55). At 373 K, the proton environments become equivalent on the NMR spectroscopic timescale as each alkene ligand rotates about the metal-ligand coordinate bond. 

Theoretical data supported quite well the vibrational IR and RAIRS data and allowed an interpretation of the energetic process of the complex-surface interaction. The variation observed in the Wiberg index values for the metal-ligand coordination bond suggests an important tc electronic redistribution around the cation by surface effect Table 14.7. 

Fig. 1 Formation of coordination polymers from metal ions and bisligands. Note that the polymeric chain is held together by metal-ligand coordination bonds so that metal ions are an integral part of the chain...

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