1 YKG [(5-bromo-7-methyl-2-oxo-2h-1-benzopyran-4-yl)methyl]phosphonic acid 1.000 2 GTV [(5,7-dimethyl-2-oxo-2h-1-benzopyran-4-yl)methyl]phosphonic acid 0.895 3 TWB [(6,7-dimethyl-2-oxo-2h-1-benzopyran-4-yl)methyl]phosphonic acid 0.895 4 XJE [(5-methoxy-7-methyl-2-oxo-2h-1-benzopyran-4-yl)methyl]phosphonic acid 0.850 5 7SX [(5,7-dimethyl-2-oxo-1,2-dihydroquinolin-4-yl)methyl]phosphonic acid 0.800 6 FUJ [(7-methoxy-2-oxo-2h-1-benzopyran-4-yl)methyl]phosphonic acid 0.800 7 L8J [(5,7-dibromo-2-oxo-1,2-dihydroquinolin-4-yl)methyl]phosphonic acid 0.800 8 P9T [(5,7-difluoro-2-oxo-2h-1-benzopyran-4-yl)methyl]phosphonic acid 0.800 9 KED [(2-oxo-1,2-dihydroquinolin-4-yl)methyl]phosphonic acid 0.789 10 VKE [(6-oxo-2h,6h-[1,3]dioxolo[4,5-G][1]benzopyran-8-yl)methyl]phosphonic acid 0.762 11 T6Z [(1-methyl-2-oxo-1,2-dihydroquinolin-4-yl)methyl]phosphonic acid 0.750 12 I59 Hydroxy(1-naphthyl)methylphosphonic acid 0.700