Addition compounds formed between silicon tetrachloride and some amines have been prepared and analyzed. Molecular ratios of 4/1, 2/1, and 1/1 were established for amine to silicon tetrachloride in these compounds. It is suggested that these molecular compounds use 4s, 3d, 4p orbitals only, in forming the coordinate bonds that establish the compound, and that the configuration of the silicon tetrachloride remains essentially undisturbed. Use of these assumptions permits definite structural predictions to be made about the compounds.