By reaction of tungsten(VI) chloride with the trisilanolic silsesquioxane (C6H11)(7)Si7O9(OH)(3) (1), the bis(silsesquioxane)tungsten [(C6H11)(7)Si7O9(O)(3)](2)W (3) complex is formed. This is evidenced by proton and carbon NMR and X-ray diffraction. Compound 3 crystallizes in the orthorhombic space group Cmca with a = 19.407(7) Angstrom, b = 25.163(6) Angstrom, c = 22.176(3) Angstrom, V = 10829(5) Angstrom(3), and Z = 4. In addition, the analysis of silsesquioxanes by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF), a technique initially developed for the characterization of biomolecules, has been successfully applied.