Originally Posted By: rudolphna
I'm mature enough to admit I was wrong. We were simply taught that. In hindsight, I can see how they would simplify it for the high school course. By the way we were taught it WAS wrong, but if moly can bond molecularly, then I guess it would be moly disulfide.
I do believe Mo and sulfur covalently bond (don't forget that bonds can have both ionic and covalent characteristics). From the looks of it one Mo(IV) center bonds with 6 sulphide ligands and forms "sheets" of sorts (like graphite) that are loosely held together by van der Waals forces. This is what allows moly to lubricate, the sheets slide away from each other.