Multifunctional ligands

Coordination behavior of 2,5-dimethyl-4-phosphino-[l,2,3]diazaphosphole as potential multifunctional ligand has been investigated for complexation with a variety of metal centers. Despite the presence of three possible coordination sites, coordination takes place via exocyclic phosphino phosphorus (Structure 5) [81-83, 115],... 

Chart 5. Multifunctional ligands for bismuth with sulfur donors. 

Multifunctional ligands are able to link nanoparticles, for example in small assemblies like extended architectures. In early reports, Osifchin et al. and Brust et al. reported the self-assembly of alkyl-thiol capped gold nanoparticles using dithiol ligands [163, 164]. 

Another type of cyclic thioether is l,3,5-tris(alkylthia)cyclohexane (7), which is related to the open-chain multifunctional ligands mentioned above. With R = Me, the formation of weak Cu11 complexes with this ligand has been observed.17... 

Fig. 7.13 Chemical structures and cartoons of multifunctional ligands containing both pyridine (blue) and terpyridine (red) coordi-...

Metal oxide colloids have been effectively coupled with multifunctional ligands containing carboxyl groups that bind to the surface of nanoparticles [46]. One can rationally design optimal photocatalysts by tailoring functional groups for selective adsorption of specific... 

Figure 1. Schematic representation of OMSs with modified by multifunctional ligands.

It is shown that OMSs and PMOs with multifunctional organic ligands possess a high capacity towards mercury ions, which is due to the accessible pore network and high concentration of multifunctional ligands. Especially... 

Arsenic-containing heterocyclic derivatives are multifunctional ligands. For example, arsole can form several types of complexes (a) one involving the lone electron pair on As (156), (b) as a two-electron donor to one metal atom and, at the same time, as a one-electron donor to the other transition element (157), (c) as a four-electron ligand of the 7t-butadiene type due to the presence of two double C=C bonds (158), and (d) as a five-electron elementacyclopentadienyl ligand (159-162). Each of these types of compounds have been characterized by mass spectrometry (Tables 9 and 10). Unfortunately a detailed discussion of their mass spectral behaviour is unavailable. 

The use of multifunctional ligands allows generation of multinuclear species which may be tested as molecular precursors of mixed metal oxides. For example, LH2 = salicylaldehyde generated Bi2M2L4(LH)4(OR)4 and L H = l,3-bis(dimethylamino)propan-2-ol generated SrTa2(OEt)6(At2-OEt)4(At2-0-L )2.305 306... 

Selection of vanadium complexes with multifunctional ligands including sulfur. See refs 57b-61. 

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