Salicylaldehyde (2-hydroxybenzaldehyde) and its derivatives are convenient carbonyl precursors for ligand systems to be noted fortheir light synthetic procedures, varied denticities, and also interesting pharmacological properties.The presence of suitable additional functional hydroxyl groups would increase the number of donor atoms of the resulting Schiff base and, as a consequence, its chelating ability and structural flexibility. Herein we report the synthesis, NMR characterization, and crystal structure of the novel organic salt with triethylamine with the formula (Et3NH)(H2L)·0.5(CH3)2CO (1), where H3Lis 2,3-dihydroxybenzaldehyde semicarbazone. Single crystals of the salt 1 were obtainedfrom acetone in the presence of triethylamine. Compound 1 crystallizes in the monoclinic space group C2/c, being of the ionic type. It includes protonated triethylamine as a cation, semicarbazone with a deprotonated hydroxyl group in the 2nd position as an anion (see picture), and theacetone molecule that is disordered over two positions. Its structure in DMSO-d6 solution was confirmed by 1H, 13C and 15N NMR spectroscopy, being compared with the NMR data for H3L. In the 1H NMR spectrum of 1 all signals of the protons from H3L are present, except hydroxyl protons. Most likely, the very broad signal at b 10.18 ppm, corresponding only to the amide proton in H3L, includes also the cationic proton of triethylamine and the hydroxyl group in the 3rd position of 1. The characteristic shape of this signal strongly confirms the existence of numerous hydrogen bonds in crystal packing of 1, which were established by X-Ray study as well. Proton chemical shifts of H3L moiety in 1 present insignificant difference, with respect to H3L. Signals at b 0.93 and 2.43 ppm demonstrate the presence of triethylamine fragment, while the crystallization acetone in the molecule of 1 is proved by the peak at b 2.08 ppm. 13C and 15N NMR data for the salt 1 were obtained by 1D and 2D HETCOR techniques totally validating its structure. Thus, the resonances for 13C and 15N nuclei in 1 practically remain unchanged, in comparison with H3L, while the signals for triethylamine (b 11.6 and 45.7 ppm) and acetone (b 30.6 and 206.3 ppm) in its 13C spectrum have additionally been attested. Cationic nitrogen was found by 1H/15N HMBC experience at b 47 ppm, while azomethine, amide and amine nitrogen atoms resonated at b314, 156 and 77 ppm, respectively.