The present invention relates to silane sulfide modifier compounds and methods of making them. The invention also relates to a silane sulfide modified macromolecular compound obtainable by reacting a living anionic elastomeric polymer and a silane sulfide modifier. The silane sulfide modified macromolecular compound may be provided in the form of a polymer composition, and the polymer composition may be vulcanized (cross-linked) by making use of and reaction with at least one vulcanization agent, resulting in a vulcanized polymer composition.