This article presents a combined experimental and computational study of novel isothiochromene 2,2-dioxide derivatives, which were synthesized by the electrophilic substitution reactions. The compounds have been studied by NMR, IR spectroscopy and single-crystal X-ray analysis. According to X-ray diffraction data, the six-membered ring of 6 adopts a distorted half-chair conformation, but in case of compounds 7 and 8, we have a twist-boat conformation of the six-membered ring with deviation of the S1 and C8 atoms from the mean plane of the remaining atoms of the ring, respectively. Results of quantum-chemical calculations of possible isomers and tautomers of the isolated oxime 8 and azo compounds 10 at the B3LYP/aug-cc-pVDZ level indicate that the oxime-oxo tautomer (8a) is more stable than the nitroso-hydroxy tautomer (8b) in agreement with the crystal data and that the keto tautomer (II) is more stable than the hydroxyl tautomer (I) and zwitterion tautomer (III), because of a strong intramolecular hydrogen bond N–H···O.
Structural Chemistry - An X-ray diffraction study of (1S,2S,3S,4R,5R,8S)-diethyl 2,4-dicyano-3-(furan-2-yl)-8-morpholino-6-oxobicyclo[3.2.1]octane-2,4-dicarboxylate reveals the absence of strong... 相似文献
A one‐pot method for the synthesis of 3‐amino‐7‐nitro‐1,2‐dihydroisoquinoline‐4‐carbonitriles from 2‐chloro‐5‐nitrobenzylamines and malononitrile has been developed. 相似文献
The regioselectivity of the interaction between isomeric 4,5‐dihydro‐1,4‐benzothiazepin‐3(2H)‐one 1,1‐dioxide and 1,5‐dihydro‐4,1‐benzothiazepin‐2(3H)‐one 4,4‐dioxide derivatives with the Vilsmeier reagent and DMFDMA (N,N‐dimethylformamide dimethylacetal) has been investigated. The structures of synthesized compounds are confirmed by 1H, 13C NMR, elemental analysis, and X‐ray data. 相似文献
Searching for prospective luminescent materials, the series of new lanthanide coordination compounds CsLnL4 (Ln = La, Pr, Nd, Sm – Er, and Yb; L? = {C6H5CONPO(OCH3)2}-) was synthesized. X-ray diffraction studies of CsNdL4 and CsYbL4 have been performed establishing polymeric structures of the tetrakis-complexes built from [LnL4]? anions and cesium cations functioning as linkers. The IR, absorption, emission, excitation spectra, and decay time measurements at 298 and 77 K, as well as thermal gravimetric analyses, were used to characterize the complexes. 相似文献
Structural Chemistry - A reversible phase transition in 2-methyl-5-nitroanilinium dihydrogen phosphate, (H2m5na)H2PO4, has been found and characterized. Lattice parameters of (H2m5na)H2PO4 change... 相似文献