1	476	3-butyl-1-(2,2-diphosphonoethyl)pyridinium	1.000
2	PB6	3-[(1e)-but-1-en-1-yl]-1-(2,2-diphosphonoethyl)pyridinium	1.000
3	QAF	{2-[3-(hex-1-yn-1-yl)pyridinium-1-yl]ethane-1,1-diyl}bis(phosphonate)	0.909
4	NI9	3-fluoro-1-(2-hydroxy-2,2-diphosphonoethyl)pyridinium	0.727