tetradecapotassium [[(phosphonatomethyl)imino]bis[ethylene[(phosphonatomethyl)imino]ethylenenitrilobis(methylene)]]tetrakisphosphonate

[[[[Di(potassiooxy)phosphinyl]methyl]imino]bis[2,1-ethanediyl[[[di(potassiooxy)phosphinyl]methyl]imino]-2,1-ethanediylnitrilobis(methylene)]]tetrakis[phosphonic acid dipotassium] salt