Amido core structures

Fig. 3.5-7. Schematic drawings of the core structures of the amido-imidoalanes 33 and 34.

The redox-active metalloligand [Ru(Cp) N=C-C(pz)3 ][PF6] reacts with [Ir(COD)Cl]2 giving a bimetaUic Ru -Ir complex [Ru(Cp) i-N=C-C(pz)3 Ir(COD)Cl2] [PFe] upon activation of the C=N moiety. This heterobimetaUic complex features an unprecedented metallacyclic alkyl-amido carbene core structure coordinated to an Ir center. A DFT study on structures, spin states, FMOs, and UV-VIS spectroscopic properties of [M(Tp)(CvH5N)(PPh3)(N3)] (M= Ru or Fe) has been carried out in order to understand whether Ru can be replaced by cheaper Fe in photosensitizers for DSSCs. ... 

A rare example of thiourea coordination to low-valent Co is of a disubstituted thiourea as bridging ligand, observed in the cluster Co3(CO)7(/i3-S)(/i- 72-PhNC(S)NHCH2Ph) which is formed by reaction of Co2(CO)8 with the thiourea.172 The crystal structure of the product defines a tetrahedral Co3S core with all carbonyls in terminal positions and the deprotonated thiourea bridging two Co centers via the S and an amido N. 

A first generation poly(amido amine) dendrimer has been functionalized with three calyx[4]arenes, each carrying a pyrene fluorophore (4) [30]. In acetonitrile solution the emission spectrum shows both the monomer and the excimer emission band, typical of the pyrene chromophore. Upon addition of Al3+ as perchlorate salt, a decrease in the excimer emission and a consequent revival of the monomer emission is observed. This can be interpreted as a change in the dendrimer structure and flexibility upon metal ion complexation that inhibits close proximity of pyrenyl units, thus decreasing the excimer formation probability. 1H NMR studies of dendrimer 4 revealed marked differences upon Al3+ addition only in the chemical shifts of the CH2 protons linked to the central amine group, demonstrating that the metal ion is coordinated by the dendrimer core. MALDI-TOF experiments gave evidence of a 1 1 complex. Similar results have been obtained for In3+, while other cations such as Ag+, Cd2+, and Zn2+ do not affect the luminescence properties of... 

Fig. 3. Structure of an MIM with a tetracarboxylic core. C polycarboxylic core of MIM GI first layer of triiodinated rings. I3 triiodinated aromatic ring G2 second layer of triiodinated rings. L amido-acetyl bond G3 third layer of triiodinated rings. AA amino alcohol...

It is interesting to note that in the reaction of (188) with [TcOCU] , the 0x0 group is replaced by a doubly deprotonated amino group. The mixed imido-amido Tc complex [Tc(app)Cl2(Happ)j (263) was synthesized and structurally characterized with Re. Neutral, mixed amino-phosphino ligands can stabilize the soft [Tc=N] + core in the expected way, whereas the harder [Tc=0] + core imposes subsequent acid/base reactions. Stabilization is then mainly achieved by deprotonation, in order to compensate for the relatively high charge. ... 

The phenylimido-bridged dimer [(C5H4CH2GH2GH2N(H)GMe3)Ti(NHPh)(/x-NPh)]2 is obtained by reaction of the Cp-amido complex (C5H4GH2GH2CH2NCMe3)/(NMe2)2 with aniline. Its molecular structure has been determined by X-ray diffraction and reveals a slightly asymmetric Ti(/x-NPh)2Ti core (Scheme 281, Section 4.05.3.4).616... 

FIGURE 49 Structure of Yb4(THF)4(/i- 7 7 -PhNNPh)4(/t3-NPh)2 (left) with its tetranuc-lear core featuring two triply bridging amido ligands (right) (redrawn after Emel yanova et al., 1994 Trifonov et al., 1991). 

Proteins, on the other end of the scale of molecular complexity, act as emulsifiers but behave differently from the small molecules, because of their individual molecular structures, and, indeed, it is the particular proteins present which give many food emulsions their characteristic properties. Most, if not all, proteins in their native states possess specific three-dimensional structures which are maintained in solution, unless they are subjected to dismptive influence such as heating (6). When they adsorb to an oil-water interface, it is unlikely that the peptide chains of proteins dissolve significantly in the oil phase, as they are quite hydro-philic as a result of the presence of carboxyl or amido groups it is more likely that the major entities penetrating the interface are the side chains of the amino acids (Table 1). It is possible, for example, for an a-helical portion of a protein to have a hydrophobic side, created by the hydrophobic side chains which lie outside the peptide core of the helix. However, even proteins lacking such regular structures possess amino acids with hydrophobic side chains which will adsorb to the oil-water interface. When a protein is adsorbed, the structure of the protein itself will... 

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