| Autor: |
Vlasenko MP; Department of Chemistry, Southern Federal University, Zorge Street 7, 344090 Rostov-on-Don, Russian Federation., Pozharskii AF; Department of Chemistry, Southern Federal University, Zorge Street 7, 344090 Rostov-on-Don, Russian Federation., Ozeryanskii VA; Department of Chemistry, Southern Federal University, Zorge Street 7, 344090 Rostov-on-Don, Russian Federation., Kletskii ME; Department of Chemistry, Southern Federal University, Zorge Street 7, 344090 Rostov-on-Don, Russian Federation., Lisovin AV; Institute of Physical and Organic Chemistry, Southern Federal University, Stachki Avenue 194/2, 344090 Rostov-on-Don, Russian Federation., Demidov OP; Department of Chemistry, North Caucasus Federal University, Pushkin Street 1, 355017 Stavropol, Russian Federation., Tkachuk AV; Department of Chemistry, Southern Federal University, Zorge Street 7, 344090 Rostov-on-Don, Russian Federation. |
| Abstrakt: |
Six previously unknown zwitterions with positively and negatively charged [NHN] hydrogen bonds were synthesized by acylation of 4,5-bis(dimethylamino)-1-tosylamino-8-aminonaphthalene with subsequent alkaline treatment of the resulting 8-acylamino derivatives. Using NMR and XRD measurements in conjunction with quantum chemical DFT/PBE1PBE/6-311++G(d,p) calculations, it was shown that the negatively charged [NHN] - bond in such compounds commonly differs from the [NHN] + bond by significantly lower linearity, higher asymmetry, and moderate to strong paramagnetic shift of the chelated NH proton signal. Among other remarkable findings, the most important are (1) unusually high polarity (μ = 21-26 D) of the obtained zwitterions, (2) sharp difference in structures of the solid 1,8-bis(tosylated) zwitterion (BTZ) grown from MeCN or DMF, and (3) registration for one of the stereoisomers of BTZ with the record short [NHN] - hydrogen bridge (N···N = 2.510 Å) almost reaching the theoretical limit (2.50 Å) for the [NHN] + hydrogen bond. |
