Aluminum cluster structure

The isolation methods and the structures of the metalloid aluminum clusters discussed here have shown the particular suitability of the ligand N(SiMe3)2 for... 

Giant Aluminum Clusters with Shell Structures Consisting of Nested Polyhedra Pieces of Icosahedral Quasicrystals... 

Fig. 2.3-12. Molecular structures of 59, 60, 60a, and topological relationships of 59 and 60 to the corresponding sections from the solid-state structure of elemental aluminum, and structural similarities of the clusters Ali2R6 and In Rs- In the latter cluster the octahedral sections are highlighted.

It was mentioned above that the cluster modeling of the surface sites of highly coordinated oxide lattices faces certain difficulties. This is probably the reason why only a few computations were performed for such systems. The aluminum oxide structure is just of this type. 

Rexer EF, Jellinek J, Krissinel EB, Parks EK, Riley SJ (2002) Theoretical and experimental studies of the structures of 12-, 13-, and 14-atom bimetallic nickel/aluminum clusters. J Chem Phys 117 82... 

Kuznetsov et al. have shown that the basic aluminum square structure is preserved when the Al cluster reacts to form some bimetallic systems with chemical compositions MA14" and M2A14 (where M = Li+,Na+, and Cu+), and the... 

Pellaiin M, Baguenard B, Broyer M et al (1993) Shell structure in photoionization spectra of large aluminum clusters. J Chem Phys 98 944—950... 

Aluminum clusters have been investigated using a variety of experimental techniques, providing abundance spectra [164, 165], spin multiplicities [166], IPs [164, 167], EAs, and static polarizability [105]. Reactivity studies have been reported for size-selected A1 clusters in contact with a variety of small molecules (see, for instance, [167]), and the presence of different isomers in a population of clusters has been investigated by measuring the mobility of clusters in a buffer gas [168]. Finally, the electronic structure of these clusters has been probed by photoelectron spectroscopy on the anion species Al [169, 170]. As mentioned above, bulk aluminum is remarkably close to a nearly... 

L. Hanley, S.A. Ruatta, and S.L. Anderson, Collision-Induced Dissociation of Aluminum Cluster Ions Fragmentation Patterns, Bond Energies, and Structures for A1 -A1+ , J. Chem. Phys. 87, 260 (1987). 

The structure of AI4H7 is shown below. Write a semitopological diagram for this aluminum cluster anion. 

G.A. Breaux, C.M. Neal, B. Cao, M.F. Jarrold, Melting, premelting, and structural transitions in size-selected aluminum clusters with around 55 atoms. Phys. Rev. Lett. 94(17), 173401 (2005)... 

The tetrahedral Al incorporated in mesoporous silica reduces considerably the quantity of amorphous carbon, increasing the MWCNTs selectivity, due to the formation of strong Bronsted acidic sites, which allow a better dispersion of iron metallic clusters. The Fe/Al-MCM41 (10) showed the best results in CNT purity and yield. This indicates that the aluminum content and its tetrahedral structural incorporation play an important role in the CNT syntheses. 

Although the structure of MAO was analyzed by different methods, such as IR and NMR spectroscopy, mass spectroscopy and lots more, the exact composition and structure of MAO are still not entirely clear or well-understood [27, 28], It is assumed that the structures of MAO include one-dimensional linear chains, cyclic rings that contain triscoordinated A1 centers, and three-dimensional clusters with tetracoordinated aluminum [24] (Fig. 8). 

An important result of the multinuclear NMR investigations of 23— 25, 27, 28, and 31-35 is that the structures, in contrast to aggregates of monometalated secondary phosphanes and arsanes, are retained in solution. Thus, the phosphandiide derivatives here discussed show resonance signals in their 31P NMR spectra that are independent of concentration and temperature (see Table III). The 31P and 27A1 NMR chemical shifts of 23-25, 27, and 31-35 differ with respect to ring size of the clusters and electronic influences by the substituents at phosphorus and aluminum. 

This section will focus on homonuclear neutral or anionic clusters of the elements aluminum, gallium, indium, and thallium, which have an equal number of cluster atoms and substituents. Thus, they may clearly be distinguished from the metalloid clusters described below, which in some cases have structures closely related to the allotropes of the elements and in which the number of the cluster atoms exceeds the number of substituents. The compounds described here possess only a single non-centered shell of metal atoms. With few exceptions, their structures resemble those of the well-known deltahedral boron compounds such as B4(CMe3)4 [30], B9CI9 [31] or [B H ]2 [32]. The oxidation numbers of the elements in these... 

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