Disclosed herein are compounds of the formula:
(R)
x
—Sn—(R′)
4-x
wherein x is 1 or 2; R is alkyl of from 1 to 12 carbon atoms; and R′ is a moiety selected from the group consisting of:
and mixtures thereof, wherein y is 1, 2, 3, or 4; and z is 1, 2, 3, or 4, and processes for forming such compounds. The compounds are excellent stabilizers for halogen-containing resins, such as PVC.