Many carborane derivatives, first synthesized during the rapid development of this field of chemistry in the 60s of the last century, remained completely uncharacterized by modern spectral and structural methods. In this work, a series of C-mercuro derivatives of ortho-carborane 1-PhHg-2-Ph-1,2-C2B10H10 and (2-R-1,2-C2B10H10)2Hg (R = H, Me, Ph) were newly synthesized and characterized by NMR spectroscopy. The molecular crystal structure of bis(2-phenyl-ortho-carboran-1-yl)mercury was determined by single crystal X-ray diffraction.