1,11-Diphenyl-5,7-bis(1-(2-pyridinyl)ethylidene)-2,10-dithia-4,5.lambda.~5~,7.lambda.~5~,8-tetraaza-6.lambda.~2~-stannaundeca-3,8-diene-3,9-dithiol compound with butane (1:2) AIDS-133826 AIDS133826 NSC630457