1 ESP Thieno[2,3-B]pyridine-2-carboxamidine 1.000 2 ESX Benzo[B]thiophene-2-carboxamidine 0.846 3 ESI 4-iodobenzo[B]thiophene-2-carboxamidine 0.786 4 KTW 4-chloranyl-1-benzothiophene-2-carboximidamide 0.786 5 LFB 7-methoxy-1-benzothiophene-2-carboximidamide 0.733