Enhancements (ε), polarization levels (P) and relaxation times (T₁) for (¹⁵N) (¹⁴N)₂-azide 7–9 by d-DNP^a.

Cmpd	Molecular structure	ε	P/%	T 1/min
				Nαb	Nβ	Nγ
7		76 000	2.6	—	—	(3.2 ± 0.3)
8		121 500	4.2	—	—	(7.6 ± 0.3)
9		28 600	1.0	—	—	(5.6 ± 0.6)

^aEach experiment repeated twice. Measurements performed at B = 1 T. Enhancements and polarization levels measured for ¹⁵Nγ sites. T₁ lifetimes derived by fitting the experimental data to a single exponential decay function and then compensating the effect of using the small flip angle pulses (see ESI for details).

^bSignal to noise ratio too low for Nα.