Heteroatom containing diamondoids (i.e., "heterodiamondoids") are compounds that have a diamondoid nucleus in which one or more of the diamondoid nucleus carbons has been substitutionally replaced with a noncarbon atom. Diamondoid materials can serve as n- and p-type materials in electronic devices and can serve as optically active materials.
In U.S. Patent 7,649,056 Chevron U.S.A. Inc. (San Ramon, CA) inventors Shenggao Liu, Robert M. Carlson and Jeremy E. Dahl reveal a process to create heterodiamondoids and functionalized heterodiamondoids, The diamond nanoparticles are useful in for instance, nanotechnology, drugs, drug carriers, pharmaceutical compositions, precursors for the synthesis of biologically active compounds, photoresist materials and/or photoresist compositions for far UV lithography, synthetic lubricants, heat resist materials and solvent-resistant resins, and so on.
For example, these heterodiamondoid derivatives may have desirable lipophilic properties, which may improve the bioavailability of pharmaceutically active groups attached thereto. These heterodiamondoids and derivatives may also be useful as chemical intermediates for the synthesis of further functionalized heterodiamondoids to form a variety of useful materials.
Such materials include composite matrix resins, structural adhesives and surface files that are used for aerospace structural applications. Furthermore, coating layers or molded products with excellent optical, electrical or electronic and mechanical properties are produced for use in optical fibers, photoresist compositions, conduction materials, paint compositions and printing inks.
In addition, these heterodiamondoid derivative-containing materials will have high thermal stability making them suitable for use in environments requiring such stability including for example, devices such as semiconductors, coatings for refractory troughs or other high temperature applications.
In applications of particular importance, the heteroatom introduced into the triamantane of higher diamondoid nucleus are electron-donating or electron-accepting. The semiconducting heterodiamondoids that result have utility in a variety of transistor and other electronic and microelectronic settings.
In applications of particular importance, the heteroatom introduced into the triamantane of higher diamondoid nucleus are electron-donating or electron-accepting. The semiconducting heterodiamondoids that result have utility in a variety of transistor and other electronic and microelectronic settings.
These heteroatom substituents impart desirable properties to the diamondoid. In addition, the heterodiamondoids are functionalized affording compounds carrying one or more functional groups covalently pendant therefrom. Chevron also provides ,
The Chevron process provides heterotriamantanes and hetero higher diamondoids. Heteroatoms are selected from atoms of group III B elements such as B or Al; noncarbon group IV B elements such as Si; group V B elements such as N, P or As, and particularly N or P; and group VI B elements such as O, S, or Se. It will be noted that the group VB elements are generally classed as electron-donating (hole-accepting) or "electropositive" atoms and the group III B elements are generally classed as electron-accepting (hole-donating) or "electronegative" atoms.
These heterodiamondoids are a triamantane or a higher diamondoid nucleus with 1 or more (for example 1 to 20 and especially 1 to 6) of its cage carbons replaced by a heteroatom. The heterodiamondoids can also be substituted with up to 6 alkyl groups per diamondoid unit.
The Chevron inventors also crated functionalized heterodiamondoids. Heterotriamantanes and higher heterodiamondoids contain at least 1 and, preferably 1 to 6 functional group(s) covalently bonded to cage carbons.
In addition, when the heteroatoms in the heterodiamondoids are electron-donating, and particularly nitrogen, this gives rise to the possibility that the donated electrons can be excited from the normal valence bond through a bond gap into a conductive bond. When the excited electrons decay back to their base state, particularly if a vacancy is adjacent to the electron-donating heteroatom, a photon can be emitted. This suggests that these hetrodiamondoids could have properties to provide molecular size and crystallite-sized flouresent species, lasing species and photodetecting species.
Previously only adamantane and substituted adamantane are the only readily available diamondoids. Diamantane and triamantane and substituted diamantanes have been studied, and only a single tetramantane has been synthesized. The remaining diamondoids were provided for the first time by the inventors Dahl and Carlson, and are described for example, in U.S. patent application Ser. No. 60/262,842 filed Jan. 19, 2001 and PCT US02/00505 filed 17 Jan. 2002.
