(1R,2S,3R,5S)-3-{6-(2,2-Diphenyl-ethylamino)-2-[2-(1-ethyl-1H-imidazol-4-yl)-ethylamino]-purin-9-yl}-5-(4-ethyl-[1,2,3]triazol-2-yl)-cyclopentane-1,2-diol trifluoroacetate