ZLA Controller described a loss of separation event due to an emergency descent and attempted to clear restricted airspace.

Narrative

Aircraft X at FL450 was eastbound just south of R2501. Aircraft Y was westbound at FL430. When the aircraft were approximately ten miles apart I applied merging target procedures. When the aircraft were approximately four miles apart Aircraft X made a transmission that I could not understand. I then saw Aircraft X descend from the assigned altitude of FL450. I told Aircraft X to maintain FL450. Aircraft X made another transmission; also difficult to understand; but I understood that he was in an emergency descent. I issued an immediate 30 degree left turn to and advised Aircraft Y that Aircraft X was descending. Aircraft Y advised Aircraft X was in sight. Aircraft X then began a left turn while descending. I asked Aircraft X to what altitude he was descending. Aircraft X replied FL250. I issued a clearance to fly heading 030 to keep Aircraft X clear of R2501; which was released to ATC at or above FL270. Aircraft X refused. I then issued FL270 which Aircraft X accepted. With the help of Sector 37; we able to keep other aircraft from being involved. Aircraft X was routed direct to a nearby airport. I transferred RADAR and communication to Sector 37.