. Author manuscript; available in PMC: 2018 Jun 14.

Published in final edited form as: J Am Chem Soc. 2017 May 30;139(23):7761–7767. doi: 10.1021/jacs.7b00569

Table 1.

Synopsis of experimental conditions, enhancements and polarization levels. Substrates are ¹⁵N labelled, solvent is D₂O unless otherwise specified. Concentrations of liquid substrates are determined at the time of the experiment using ¹H spectroscopy. T = 75 °C.

Substrate	Activation time [h]	c_substrate /c_catalyst	c_Substrate [mM]	Enhancement 8.45 T (P [%])	Enhancement 1 T (P [%])	Enhancement ratio (1 T/8.45 T)
(2) pyridine	12	3.3	16.5^[b]	1100	-^[c]	-^[c]
(3) benzonitrile	0.25	20	50^[a,^b]	90	-^[c]	-^[c]
(4) CHCA	12	10	50	440 (0.13)	3700 (0.13)	8.4
(5) diazirine	6	10	16.3	560 (0.16)	4700 (0.17)	8.4
(6) nicotinamide	12	20	100	520(0.16)	6100 (0.21)	8.9
(6) nicotinamide H₂O	12	20	100	630 (0.2)	10500 (0.37)	28

^[a]

Signal maximum obtained 30 min. after activation, subsequent substrate loss due to evaporation.

^[b]

Initial concentration 100 mM.

^[c]

Insufficient SNR.