Superatomic icosahedral-C(n)B(12-n) (n = 0, 1, 2) Stuffed mononuclear and binuclear borafullerene and borospherene nanoclusters with spherical aromaticity

Boron and boron-based nanoclusters exhibit unique structural and bonding patterns in chemistry. Extensive density functional theory calculations performed in this work predict the mononuclear walnut-like C(i) C(50)B(54) (1) (C(2)B(10)@C(48)B(44)), C(1) C(50)B(54) (2) (CB(11)@C(49)B(43)), and S(10) C(50)B(54) (3) (B(12)@C(50)B(42)) which contain one icosahedral-C(n)B(12-n) core (n = 0, 1, 2) at the center following the Wade’s skeletal electron counting rules and the approximately electron sufficient binuclear peanut-like C(s) C(88)B(78) (4) ((C(2)B(10))(2)@C(84)B(58)), C(s) C(88)B(78) (5) ((CB(11))(2)@C(86)B(56)), C(s) C(88)B(78) (6) ((B(12))(2)@C(88)B(54)), C(s) B(180) (7) ((B(12))(2)@B(156)), C(s) B(182) (8) ((B(12))(2)@B(158)), and C(s) B(184) (9) ((B(12))(2)@B(160)) which encapsulate two interconnected C(n)B(12-n) icosahedrons inside. These novel core–shell borafullerene and borospherene nanoclusters appear to be the most stable species in thermodynamics in the corresponding cluster size ranges reported to date. Detailed bonding analyses indicate that the icosahedral B(12)(2−), CB(11)(−), and C(2)B(10) cores in these core–shell structures possess the superatomic electronic configuration of 1S(2)1P(6)1D(10)1F(8), rendering spherical aromaticity and extra stability to the systems. Such superatomic icosahedral-C(n)B(12-n) stuffed borafullerenes and borospherenes with spherical aromaticity may serve as embryos to form bulk boron allotropes and their carbon-boron binary counterparts in bottom-up approaches.