Discrete oligomers

A second metallacyclobutane [F] is formed via die reassociation of terminal olefin from discrete oligomers (or monomer) with the active methylidene, produced in [E] (see above). 

Each of the discrete oligomers was characterized by single-crystal X-ray diffraction, and the structures are shown in Fig. 6.1. The Sn-Sn bond lengths varied in the range 2.80-2.97 A, and each oligomer was shown to possess a trans-planar conformation. 

Much of the foundation for foldamer research has been generated by the physical organic community and has focused on discrete oligomers. However, progress in fields like protein stmcture, enzymology, organic chemistry. 

IniiMo4o062 (i. e. X = 0.1) was the first compound from this series of phases to be discovered [130] and despite its complex structure it is readily accessible. The structure of InnMo4o062 is formed from alternating layers which contain dusters built from four and five octahedra respectively. The interduster Mo-Mo distances are long enough to allow for a discussion of the clusters as discrete oligomer-... 

The relative ease of inducing alignment of discrete oligomer chains, rather than their polymeric counterparts may yet render the use of oligomer films particularly advantageous in certain applications, such as waveguided or microcavity electroluminescent devices. 

The self-association of planar d transition-metal complexes with the formation of weak metal-metal bonds is prominently featured for Rh. Discrete oligomers to infinite stacks have been isolated in the solid state. As discussed in the following sections, the stability of these ID Rh chain molecules has been attributed to weak metal-metal interactions. Vacancy in the Rh d-band results mixed-valent chain compound of rhodium. The ligand-ligand interactions have been invoked to rationalize the stability of chain compounds as well. 

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