Chemical bonding models are developed for the titanocarbohedrenes Ti14C13 and Ti8C12 by assuming that the Ti atoms use a six-orbital sd(5) manifold and there is no direct Ti-Ti bonding. In the 3 x 3 x 3 cubic structure of Ti14C13, the 8 Ti atoms at the vertices of the cube are divided into two tetrahedral sets, one Ti(III) set and one TI(IV) set, and the 6 Ti atoms at the midpoints of the cube faces exhibit square planar TiC4 coordination with two perpendicular three-center four-electron bonds. The energetically unfavorable Ti, dodecahedral structure for Ti8C12 has 8 equivalent TI(III) atoms and C-2(4-) units derived from the complete deprotonation of ethylene. In the more energetically favorable T-d tetracapped tetrahedral structure for Ti8C12, the C-2 units are formally dianions and the 8 Ti atoms are partitioned into inner tetrahedra (Ti-i) bonded to the C-2 units through three-center Ti-C-2 bonds and outer tetrahedra (Ti degrees) bonded to the C-2 units through two-center Ti-C bonds. The Ti atoms in one of the Ti-4 tetrahedra are Ti(0) and those in the other Tis tetrahedron are Ti(III). Among the two such possibilities, the lower energy form has the (Ti-0)degrees(4)(Ti-III)(4)(i) configuration, corresponding to dicarbene C-2 ligands with two unpaired electrons in the carbon-carbon pi-bonding similar to the multiple bond in triplet O-2. This contrasts with the opposite (Ti-III)degrees(4)(TiO)(4)(i) configuration in the higher energy form of Th-Ti8C12, corresponding to ethynediyl ligands with full C drop C triple bonds and unpaired electrons in the C sp hybrid orbitals for sigma-bonding to Ti.