B 12 F n 0/- (n = 1-6) series: when do boron double chain nanoribbons become global minima?

We present an extensive density-functional and wave function theory study of partially fluorinated B12 Fn 0/- (n = 1-6) series, which show that the global minima of B12 Fn 0/- (n = 2-6) are characterized to encompass a central boron double chain (BDC) nanoribbon and form stable BF2 groups at the corresponding BDC corner when n ≥ 3, but the B12 F0/- system maintains the structural feature of the well-known quasi-planar C3v B12 . When we put the spotlight on B12 F6 0/- species, our single-point CCSD(T) results unveil that albeit with the 3D icosahedral isomers not being their global minima, C2 B12 F6 (6.1,1 A) and C1 B12 F6 - (12.1,2 A) as typical low-lying isomers are 0.60 and 1.95 eV more stable than their 2D planar counterparts D3h B12 F6 (6.7,1 A') and C2v B12 F6 - (12.7,2 A2 ), respectively, alike to B12 H6 0/- species in our previous work. Detailed bonding analyses suggest that B12 Fn 0/- (n = 2-5) possess ribbon aromaticity with σ plus π double conjugation along the BDC nanoribbon on account of their total number of σ and π delocalized electrons conforming the common electron configuration (π2(n+1) σ2n ). Furthermore, the simulated PES spectra of the global minima of B12 Fn - (n = 1-6) monoanions may facilitate their experimental characterization in the foreseeable future. Our work provides new examples for ribbon aromaticity and powerful support for the F/H/Au/BO analogy.