Isomerization and aggregation of 2-(2-(2-hydroxy-4-nitrophenyl)hydrazono)-1-phenylbutane-1,3-dione: Recent evidences from theory and experiment

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SUPPLEMENTARY INFORMATION

Isomerization and aggregation of 2-(2-(2-hydroxy-4-nitrophenyl)hydrazono)-1-phenylbutane-1,3-dione: recent evidences from theory and experiment

Silvia Hristova1_{, Fadhil S. Kamounah}2,3_{, Aurelien Crochet}4_{, Poul Erik Hansen}3_{, Katharina M.}

Fromm4_{, Daniela Nedeltcheva}1_{, Liudmil Antonov}1*

1_{Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences,}

Acad. G. Bonchev str., bldg. 9, 1113 Sofia, Bulgaria

2_{Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100}

Copenhagen Ø, Denmark

3_{Department of Science and Environment, Roskilde University, DK-4000, Roskilde, Denmark} 4_{Department of Chemistry, University of Fribourg, Chemin du Musée 9, 1700 Fribourg,}

Switzerland

*_{Corresponding author.}

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Table S1. Experimental [1] and predicted (B3LYP/6-311+G(2d,p)//M06-2X/TZVP) 1_{H chemical}

shifts (in ppm) of the major and minor forms of 1 and 3 in DMSO-d6.

Heavy atoms (see Scheme 4) 1 major form 1 minor form 3 major form 3 minor form * ** * ** * ** * ** 1 29.27 2.51 29.27 2.57 29.27 2.5 29.27 2.57 3´ 23.80 7.68 23.80 7.7 23.69 7.93 23.68 7.91 5´ 23.75 7.7 23.52 7.83 23.70 7.91 23.47 8.02 6´ 24.24 7.18 23.64 7.76 24.24 7.26 23.65 7.86 2" 23.66 7.9 23.92 7.7 23.67 7.91 23.93 7.72 3" 24.08 7.54 24.16 7.5 24.08 7.55 24.17 7.52 4" 23.92 7.67 23.98 7.64 23.92 7.68 23.98 7.66 NH 17.63 14.14 19.25 11.65 17.65 14.11 19.23 11.58 OH / OCH3 26.71 11.51 26.74 11.5 27.81 4.08 27.83 4

* predicted nuclear shieldings; ** experimentally measured chemical shifts.

Table S2. Linear equations between experimental (Y) and predicted (X) values from Table S1.

Compound Isomer Slope Intercept R2

1* major -1.00 31.64 0.998

minor -0.91 29.24 0.997

3 major -0.99 31.41 0.999

minor -0.90 29.23 0.997

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Figure S1. 1_{H NMR spectrum of 1. The spectrum shows both major and minor species. The}

major species has the following assignment: 7.90, H-2”; 7.72, H-5´; 7.70, H-3´; 7.76, H-4”; 7.53, H-3”, 7.20, H-6´; 2.51, CH3 all in ppm. For numbering see Scheme 4.

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E E’

Z Z’

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Figure S3. H-bonds motifs of 1, H-bonds are draw as blue dash lines, Symm.: #1: 1/2+x, 3/2-y, 1/2+z; #2: -1/2+x, 3/2-y, -1/2+z.

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Figure S6. Deprotonation as a function of the content of water in DMSO: dry DMSO (black solid like), increasing water content (from dashes to red solid line).

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References

[1] S. Hristova, F.S. Kamounah, N. Molla, P.E. Hansen, D. Nedeltcheva, L. Antonov, The possible tautomerism of the potential rotary switch

2-(2-(2-Hydroxy-4-nitrophenyl)hydrazono)-1-phenylbutane-1,3-dione, Dyes and Pigments. 144 (2017) 249– 261. doi:10.1016/j.dyepig.2017.05.021.

[2] A. Lyčka, 15 N NMR study of ( E )- and ( Z )-2-(2-(2-hydroxy-4-nitrophenyl)hydrazono)-1-phenylbutane-1,3-diones. A suitable method for analysis of hydrazone isomers, Dyes and Pigments. 150 (2018) 181–184. doi:10.1016/j.dyepig.2017.10.023.