Introduction.-The elements of the fourth group of the periodic system (not including titanium) form compounds of the type RsM. MR3, where M is an element of the fourth group and R is an organic group or hydrogen. In these compounds the stability of the bond between the atoms of the element M depends upon the nature of the central element as well as upon that of the substituent groups R. In general, the more electronegative the central element M, ...
