Table 5. LLIT ¹³C DNP enhancements polarized at 0.33 T for phenylacetylene/0.001 M and 0.14 M TEMPO45 and a_FCvia DFT modeling.

System	Nucleus	Absolute enhancement	a FC a
Phenylacetylene b	13C-β c	+1400 ± 210	3.281
	13C-α	+290 ± 44	0.871
	13C-ipso	–280 ± 42	0.277
	13C-ortho	–36 ± 5	0.579
	13C-meta	–32 ± 5	0.117
	13C-para	N/A d	0.181

^a a _FC is the Fermi contact HFC in units of MHz computed as described.

^bInverse gated ¹H decoupling was employed.

^cC-β results are based on measurements of 0.01 M TEMPO solution, while C-α and C-1–3 results are from 0.14 M TEMPO solution.

^dC-4 signal is close to zero.