“…[10] Attempts to synthesize cyclacenes were reported by the groups led by Stoddart, [11] Cory, [12] Schlüter, [13] PeÇa [14] and Wang, [15] who successfully constructed belt-shaped molecular frameworks mainly by Diels-Alder reactions,b ut failed to achieve the fully conjugated structures.T he first successful synthesis of zigzag carbon nanobelts has not been achieved until very recently on the basis of am odified design, [m]benzo-[n]cyclacene (m n), [16][17][18] which is more stable than [n]cyclacene because benzannulation increases the number of Clarsa romatic sextets.I tami and co-workers reported, in ap reprint format in May 2020 [19] and later in af ormal publication, [20] the synthesis of [12]benzo [18]cyclacene (Figure 1a)t hrough repetitive Diels-Alder cycloadditions followed by reductive aromatization;a nd af ew months later, Chi and co-workers published the synthesis of [8]benzo- [12]cyclacene (Figure 1a)u sing essentially the same strategy. [21] Herein we report new zigzag carbon nanobelts 1-3 (Figure 1b)o nt he basis of ad esign different from [n]cyclacene or [m]benzo[n]cyclacene.Carbon nanobelts 1 and 2 are apair of constitutional isomers,whose polycyclicframeworks represent two different cutouts from zigzag (16,0) SWCNT, and 3 is alarger analogue of 2 representing asidewall segment of (24,0) SWCNT.F igure 2c ompares the polycyclic frameworks of 1 and 2 with [16]cyclacene by mapping them on an unrolled honeycomb lattice of (16,0)SWCNT,s howing the alkoxylated benzenoid rings in 1 and 2 as grey hexagons and other six-membered rings as light blue hexagons.T he light blue hexagons in 1 and 2 compose the essential belt structures, while the grey hexagons are not necessary to keep the belt structure but allow expansion along the direction of the nanotube axis. [ 16]cyclacene represents ac omplete row of linearly arranged hexagons along the equator in the unrolled lattice of (16,0)SWCNT.I nc ontrast, the essential belt structures of 1 and 2 present aw ave-like arrangement of light blue hexagons across five and three rows,respectively,in the unrolled lattice of (16,0)SWCNT.Such wave-like arrangement of hexagons involves alarger number of Clarsaromatic sextets than the linear arrangement in [n]cyclacene.S pecifically,t he essential belt structures (shown in light blue) of 1 and 2 contain eight Clarsaromatic sextets,while the closedshell form of [16]cyclacene does not contain any Clars aromatic sextet.…”