Spectral, thermal and electronic properties of a new class of hydrocarbon-based materials diamondoid oligomers was investigated. The methods for the selective functionalization of lower and higher diamondoids were developed. Methods of association lower diamondoids in lower oligomers have been developed. X-ray diffraction and thermogravimetric spectra of lower diamondoid oligomers were made. We propose a model that adequately accounts the effects of dispersion interactions in diamondoid oligomers for their physicochemical characteristics.