Table 6.

Chemical shift in ppm and k_ex for CEST active protons of X-ray contrast agents, lanthanide-based and transition metal-based paraCEST agents shown in Figure 10.

	Functional group	δ_Η (ppm)	k_ex (s⁻¹)
Iopamidol¹²³	amide NH	4.10	2,560^a
Iomeprol²⁴⁴	amide NH	4.30	1,830^a
Iohexol²⁴⁴	Amide NH	4.30	1,610^a
Ioversol²⁴⁴	Amide NH	4.30	1,630^a
Iodixanol²⁴⁴	Amide NH	4.30	1,210^a

Tb-DOTA-4AmCE¹²¹	Water co-ligand	−600	32,300
Dy-DOTA-4AmCE¹²¹	Water co-ligand	−720	58,800
Yb-HPDO3A²⁴⁵	Alcohol OH	71^b, 99^b	N/D
Tm-DOTAM-Gly²⁴⁶	Amide NH	−51^c	3,450
Ho- DOTAM-Gly²⁴⁶	Amide NH	39^c	2,500
Dy- DOTAM-Gly²⁴⁶	Amide NH	77^c	2,500
Eu-DOTAM-EB²⁴⁷	Amide NH	53	12,300

Fe-TCMT²⁴⁸	Amide NH	69	240
Fe-AMPT²⁴⁸	Aminopyridine NH₂	6.5	N/D
Fe-BZT²⁴⁸	Benzothiazole -NH	53	N/D
Fe-STHP²⁴⁸	Alcohol OH	54	3,000
Fe-DOTAM²⁴⁸	Amide NH	50	400
Fe-TAPC¹³¹	Aminopyridine NH₂	−79	1,700^d
Fe-NOPE¹³³	Amide NH	92, 24^e	500
Co-TCMT²⁴⁸	Amide NH	32	890
Co-DOTAM²⁴⁸	Amide NH	45	300
Co-CCRM²⁴⁸	Amide NH	112	510
Co-TPT²⁴⁸	Pyrazole NH	135	9,200
Co-HINO¹²⁷	Imdazole NH	32	1020^a
Co-TAPC¹³¹	Aminopyridine NH₂	−118	N/D
Co-NOPE¹³³	Amide NH	59, −19^e	240
Co-L5¹³⁶	Alcohol OH	140	5,000^f
Ni-TCMT²⁴⁸	Amide NH	76	364
Ni-CCRM²⁴⁸	Amide NH	72	328
Ni-HINO¹²⁷	Imdazole NH	55	1020^a
Ni-NOPE¹³³	Amide NH	72, 11^e	240
Ni-DOTAM²⁴⁹	Amide NH	73	330
Ni- chxdedpam²⁵⁰	Amide NH	91.5^e,g	6,100
Cu₂(L)(P₂O₇)¹³⁸	Amide NH	29 ppm	420

pH 7.4

The two -OH resonances observed have been tentatively assigned to R and S form of Yb-HP-DO3A.

pH 8.1, 312K

pH 7.7

magnetically inequivalent NH from amide NH₂.

pH 7.0

pH 7.2