The invention provides a silicone composition which is rapidly, completely, and reliably radiation curable to an elastomer comprising an organopolysiloxane polymer having terminal groups which contain ethylenic unsaturation and in addition possess both hydrogen bond donor and acceptor capabilities. The invention also provides a composition which is curable to a pressure sensitive adhesive comprising the above polymer and a sufficient amount of tackifier. The invention also relates to silicone macromonomers additives for varying the properties of the composition. The invention further relates to fluorosilane compounds useful in the preparation of silicone macromonomers, their preparation and the preparation of silicone macromonomers.