Design of Carborane Molecular Architectures via Electronic Structure Computations
Figure 7
Several examples of carborane single and dimeric biradical with almost degenerate singlet and triplet electronic states. (a) -(3,6) biradical derived from hydrogen abstraction on positions 3 and 6 in 1,2-C2B10H12 or -carborane: adiabatic singlet-triplet energy gap for this system = 0.06 eV. (b) -(2,4) biradical derived from hydrogen abstraction on positions 2 and 4 in 1,7-C2B10H12 or -carborane: adiabatic singlet-triplet energy gap for this system = 0.04 eV. (c) -(2,4) biradical derived from hydrogen abstraction on positions 2 and 4 in 1,12-C2B10H12 or p-carborane: adiabatic singlet-triplet energy gap for this system = 0.04 eV. The dots on each system represent “unpaired” electrons. Geometries and energies are computed with CASSCF and CASPT2 methods, respectively [13].
