. 2021 Apr 19;6(17):11266–11279. doi: 10.1021/acsomega.1c00111

Table 3. ¹³C NMR Parameters of Coal Samples and Carbon Assignment^a.

sample	f_a	f_a^c	f_a’	f_a^N	f_a^H	f_a^P	f_a^S	f_a^B	f_al	f_al*	f_al^H	f_al^O
XJ-1	0.50	0.15	0.35	0.23	0.13	0.12	0.05	0.06	0.49	0.13	0.36	0.11
GZ-2	0.69	0.11	0.58	0.34	0.24	0.10	0.10	0.14	0.31	0.10	0.21	0.08
SX-3	0.74	0.07	0.67	0.29	0.38	0.04	0.09	0.16	0.26	0.08	0.18	0.07
SX-4	0.75	0.06	0.69	0.26	0.43	0.02	0.05	0.19	0.25	0.11	0.14	0.06
LC-5	0.78	0.04	0.74	0.25	0.49	0.01	0.03	0.21	0.22	0.12	0.10	0.07

f_a : total aromatic carbon; f_a^c: carbonyl; f_a’:^,aromatic ring; f_a^N: non-protonated and aromatic; f_a^H: protonated and aromatic; f_a^P: hydroxyl or ether oxygen; f_a^S: alkylation aromatic; f_a^B: aromatic bridgehead; f_al: total aliphatic carbon; f_al*: CH₃ or non- protonated; f_al^H: CH or CH₂; f_al^O: bonded to oxygen.

Table 3. 13C NMR Parameters of Coal Samples and Carbon Assignmenta.

Table 3. ¹³C NMR Parameters of Coal Samples and Carbon Assignment^a.