12
J. Oliver–Meseguer and A. Leyva–Pérez
Fig. 1.12 Top: Single-crystal X-ray diffraction of a Pd 4 cluster stabilized by perylene ligands (Pd
atoms are represented as yellow spheres) and within a MOF structure (Pd atoms are represented as
purple spheres (Fig. extracted from Ref. [48]. Copyright © 2003 by American Chemical Society)
Bottom: Perspective view along the b crystallographic axis of two portions (left) of the crystal
structure of the MOF enclosing the two crystallographic not equivalent ligand-stabilized quasilinear [Pd 4 ] clusters and DFT optimized structures (right). (Fig. adapted from Ref. [20] Copyright
© 2017 by Nature Publishing Group)
advances of the technique allow the determination of the size and charge in soluble
sub-nanometer metal clusters, down to a limiting resolution of 0.4 nm. Generally,
polar solvents such as water, alcohols or amide solvents (N, N–dimethyl formamide,
DMF, or N–methyl pyrrolidone, NMP) must be employed. Indeed, cationic Au 3–7 ,
Pd 3–4 and Pt 3–5 clusters have been satisfactorily determined with this technique [17,
37, 49, 53]. The somehow related diffusion-ordered spectroscopy (DOSY) technique,
which seeks to separate NMR signals of the clusters according to their diffusion
coefficients, is also a valuable tool for organic-stabilized Au clusters but not for
ligand-free metal clusters since a signal of the organic ligand must be monitored in
the experiments [9, 21].
J. Oliver–Meseguer and A. Leyva–Pérez
Fig. 1.12 Top: Single-crystal X-ray diffraction of a Pd 4 cluster stabilized by perylene ligands (Pd
atoms are represented as yellow spheres) and within a MOF structure (Pd atoms are represented as
purple spheres (Fig. extracted from Ref. [48]. Copyright © 2003 by American Chemical Society)
Bottom: Perspective view along the b crystallographic axis of two portions (left) of the crystal
structure of the MOF enclosing the two crystallographic not equivalent ligand-stabilized quasilinear [Pd 4 ] clusters and DFT optimized structures (right). (Fig. adapted from Ref. [20] Copyright
© 2017 by Nature Publishing Group)
advances of the technique allow the determination of the size and charge in soluble
sub-nanometer metal clusters, down to a limiting resolution of 0.4 nm. Generally,
polar solvents such as water, alcohols or amide solvents (N, N–dimethyl formamide,
DMF, or N–methyl pyrrolidone, NMP) must be employed. Indeed, cationic Au 3–7 ,
Pd 3–4 and Pt 3–5 clusters have been satisfactorily determined with this technique [17,
37, 49, 53]. The somehow related diffusion-ordered spectroscopy (DOSY) technique,
which seeks to separate NMR signals of the clusters according to their diffusion
coefficients, is also a valuable tool for organic-stabilized Au clusters but not for
ligand-free metal clusters since a signal of the organic ligand must be monitored in
the experiments [9, 21].