Nanoarchitecture
through Strained Molecules: Cubane-Derived
Scaffolds and the Smallest Carbon Nanothreads
Haw-Tyng Huang
Li Zhu
Matthew D. Ward
Tao Wang
Bo Chen
Brian L. Chaloux
Qianqian Wang
Arani Biswas
Jennifer L. Gray
Brooke Kuei
George D. Cody
Albert Epshteyn
Vincent H. Crespi
John V. Badding
Timothy A. Strobel
10.1021/jacs.9b12352.s002
https://acs.figshare.com/articles/dataset/Nanoarchitecture_through_Strained_Molecules_Cubane-Derived_Scaffolds_and_the_Smallest_Carbon_Nanothreads/11832942
Relative
to the rich library of small-molecule organics, few examples
of ordered extended (i.e., nonmolecular) hydrocarbon networks are
known. In particular, sp<sup>3</sup> bonded, diamond-like materials
represent appealing targets because of their desirable mechanical,
thermal, and optical properties. While many covalent organic frameworks
(COFs)extended, covalently bonded, and porous structureshave
been realized through molecular architecture with exceptional control,
the design and synthesis of dense, covalent extended solids has been
a longstanding challenge. Here we report the preparation of a sp<sup>3</sup>-bonded, low-dimensional hydrocarbon synthesized via high-pressure,
solid-state diradical polymerization of cubane (C<sub>8</sub>H<sub>8</sub>), which is a saturated, but immensely strained, cage-like
molecule. Experimental measurements show that the obtained product
is crystalline with three-dimensional order that appears to largely
preserve the basic structural topology of the cubane molecular precursor
and exhibits high hardness (comparable to fused quartz) and thermal
stability up to 300 °C. Among the plausible theoretical candidate
structures, one-dimensional carbon scaffolds comprising six- and four-membered
rings that pack within a pseudosquare lattice provide the best agreement
with experimental data. These diamond-like molecular rods with extraordinarily
small thickness are among the smallest members in the carbon nanothread
family, and calculations indicate one of the stiffest one-dimensional
systems known. These results present opportunities for the synthesis
of purely sp<sup>3</sup>-bonded extended solids formed through the
strain release of saturated molecules, as opposed to only unsaturated
precursors.
2020-02-10 19:04:09
covalent
carbon nanothread family
sp 3
solid
diamond-like
hydrocarbon
precursor
cubane
COF
Smallest Carbon Nanothreads
synthesis
Experimental measurements show
molecule