Carbon-rich nanomaterials

Tetraethynylethene (20) and its differentially protected derivatives are versatile building blocks for two-dimensional all-carbon networks and carbon-rich nanomaterials [1]. In addition, they attract interest for their fully cross-conjugated 7c-electron system [33], The first tetraethynylethene derivative, 21a, was reported in 1969 by Hori and co-workers [34], and the persilylated and peralkylated derivatives 21b-d were prepared in the mid-1970 s by Hauptmann [35]. In 1991, Hopf et al. [36] summarized this early synthetic work (Scheme 13-5) and reported the X-ray crystal structure of 21a the authors also suggested in their paper the potential of substituted tetraethynylethenes as monomers for new polymers. Also In 1991, Rubin et al. [37] reported the first synthesis of the parent compound 20 by a synthetic route, which, after suitable modifications, provided access to tetraethynylethenes with any desired substitution and protection pattern. These transformations are the subject of this Section the application of these compounds as precursors to two-dimensional all-carbon networks tmd carbon-rich nanomaterials will be discussed in the following sections. 

Modem acetylene chemistry plays a critical role in the current world-wide efforts to synthesize new molecular and polymeric carbon allotropes as well as carbon-rich nanomaterials. It is rapidly becoming clear that the preparative challenges in this interdisciplinary research area at the interface between materials science and chemistry are formidable and rival those in the more established synthesis of natural products and biologically active compounds. Modern materials research strongly relies on advanced synthetic methodology, and it is hoped that the field will attract many synthetically oriented chemists into its ranks their efforts will be rewarded by the development of materials with unique properties and unprecedented applications. 

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