N3-NOtBu2

N3-NOtBu2

N3-DOtBu3

Spermine-NOTA

Spermine-DOTA

[1,4,7]Triazonan-1-yl-acetic acid tert-butyl ester

1,4-bis(tert-butoxycarbonylmethyl)-1,4,7-triazacyclononane NO2A-(t-Bu ester)

NOTA-bis(t-Bu)ester

NH2-PEG4-DOTA

NH2-PEG3-DOTA

"4-(4,10-bis(2-(tert-butoxy)-2-oxoethyl)-7-(2-ethoxy-2-oxoethyl)

-1,4,7,10-tetraazacyclododecan-1-yl)-5-(tert-butoxy)-5-oxopentanoic acid"

5-benzyl-1-tert-butyl-2-(4,10-bis(2-(tert-butoxy)-2-oxoethyl)-7-(2-ethoxy-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)pentanedioate