((1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetrayl)tetrakis(methylene))tetraphosphonic acid

((1R – 3R – E)-5-((E)-2-((1R – 3As – 7Ar)-1-((2R – 5R – E)-5 – 6-Dimethylhept-3-En-2-Yl)-7A-Methyldihydro-1H-Inden-4(2H – 5H – 6H – 7H – 7Ah)-Ylidene)Ethylidene)-4-Methylenecyclohexane-1 – 3-Diyl)Bis(Oxy)Bis(Tert-Butyldimethylsilane)