Reaction of the lithium salt of 1-(2′-pyridyl)-ortho-carborane, Li[1-R-1,2-C2B10H10]
(R = 2′-NC5H4), with sulfur, followed by hydrolysis, gave the mercapto-o-carborane, 1-R-2-SH-1,2-C2B10H10 which forms chiral crystals containing helical chains of molecules linked by intermolecular S–H⋯N hydrogen bonds. The cage C(1)–C(2) and exo C(2)–S bond lengths (1.730(3) and 1.775(2)
Å, respectively) are indicative of exo S
C π bonding. The tin derivative 1-R-2-SnMe3-1,2-C2B10H10, prepared from Li[1-R-1,2-C2B10H10] and Me3SnCl, crystallises with no significant intermolecular interactions. The pyridyl group lies in the C(1)–C(2)–Sn plane, oriented to minimise the N⋯Sn distance (2.861(3)
Å). The tin environment is distorted trigonal bipyramidal with axial N and Me. The gold derivative 1-R-2-AuPPh3-1,2-C2B10H10, prepared from Li[1-R-1,2-C2B10H10] and AuCl(PPh3), reveals no N⋯Au interaction in its crystal structure.