Synthetic and spectroscopic investigations of N(4)-substituted isatin thiosemicarbazones and their copper(II) complexes

Bain, Gordon A.; West, Douglas X.; Krejci, Jacqueline; Valdés-s-Martinez, Jesús; Hernández‐Ortega, Simón; Toscano, Rubén A.

doi:10.1016/s0277-5387(96)00323-3

Cited by 84 publications

(62 citation statements)

References 11 publications

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“…These values are much larger than the barrier height for rotation around a single C-C bond (which is about 3 kcal/mol) supporting the idea of a restricted rotation along the N2 -C3 bond, at least for I-TSC and I-MTSC. This restricted rotation along the N2 -C3 bond suggests that the two isomers are structural isomers rather than conformers, and that the use of Z and E labels, which is consistent with the study of Bain et al [24], is justifiable. The barrier height for I-DMTSC (as well as the ones for I-TSC and I-DMTSC) is probably underestimated by the level of theory used in this study consid-ering that the calculated value would probably result in a relatively fast rotation on the NMR time scale in solution and therefore unique, averaged resonances for both isomers.…”

Section: Discussionsupporting

confidence: 81%

“…Table 2 Calculated energetic parameters for the Z → E isomerization process (kcal/mol), the calculated relative abundance of the two isomers at 298 K, and the calculated dipole moments (D) for the two isomers. [24], for MI-TSC are from reference [33], for MI-MTSC and MI-DMTSC are from reference [25], and for ALL-TSC, ALL-MTSC, and ALL-DMTSC are from reference [17]. All data is obtained in DMSO-d 6 .…”

Section: Resultsmentioning

confidence: 99%

“…b The calculated results are in gas phase. [24], for MI-TSC are from reference [33], for MI-MTSC and MI-DMTSC are from reference [25], and for ALL-TSC, ALL-MTSC, and ALL-DMTSC are from reference [17]. All data is obtained in DMSO-d 6 .…”

Section: Resultsmentioning

confidence: 99%

“…Figure 6 shows that only the Z configuration with respect to the C=N1 bond allow for an intramolecular hydrogen bond interaction between H A and O A . More recently, the study of Bain et al [24] on I-DMTSC and other thiosemicarbazones reported the existence of two isomers obtained by rotation around the N2 -C3 bond. This is formally a single bond and the two structures should be just conformers, but if the rotation around the N2 -C3 bond were impeded, the two structures can be considered as geometric isomers.…”

Section: 'mentioning

confidence: 99%

“…It was also found that isatin-based thiosemicarbazones protect mice against intracerebral vaccinia virus while isatin-based semicarbazones were inactive [23]. Bain et al [24] reported the synthesis and spectroscopic investigations of N4 -substituted isatin thiosemicarbazones and their copper(II) complexes. MI-MTSC, MI-DMTSC and their complexes with cobalt(II), nickel(II), and copper(II) ions were prepared and characterized by spectral methods [25].…”

Section: Introductionmentioning

confidence: 99%

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A theoretical investigation on the isomerism and the NMR properties of thiosemicarbazones

Silva

Albu

2007

Open Chemistry

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Hybrid density functional theory calculations at the mPW1PW91/6-31+G(d,p) level of theory have been used to investigate the optimized structures and other molecular properties of five different series of thiosemicarbazones. The investigated compounds were obtained from acenaphthenequinone, isatin and its derivatives, and alloxan. The focus of the study is the isomerism and the NMR characterization of these thiosemicarbazones. It was found that only one isomer is expected for thiosemicarbazones and methylthiosemicarbazones, while for dimethylthiosemicarbazones, two isomers are possible. All investigated thiosemicarbazones exhibit a hydrazinic proton that is highly deshielded and resonates far downfield in the proton NMR spectra. This proton is a part of a characteristic sixmembered ring, and its NMR properties are a result of its strong, intermolecular hydrogen bond. The relationships between the calculated 1 H and 13 C NMR chemical shifts and various geometric parameters are reported.

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Section: Discussionsupporting

confidence: 81%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: 'mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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A theoretical investigation on the isomerism and the NMR properties of thiosemicarbazones

Silva

Albu

2007

Open Chemistry

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Microwave‐assisted synthesis, spectroscopy and biological aspects of binuclear titanocene chelates of isatin‐2,3‐bis(thiosemicarbazones)

Banerjee

Pandey

Sengupta

2008

Applied Organom Chemis

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The reactions of bis(cyclopentadienyl)titanium(IV) chloride with a new class of bis(thiosemicarbazones) (H 2 L), derived by condensing isatin with different N(4)-substituted thiosemicarbazides, have been studied both by a conventional stirring method and also using microwave technology. Binuclear products of type [{(η 5 -C 5 H 5 ) 2 TiCl} 2 (L)] have been isolated in both cases. Tentative structural conclusions are drawn for the reaction products based upon analysis, electrical conductance, magnetic moment and spectral (UV-visible, IR, 1 H NMR and 13 C NMR) data. FAB mass spectra of these compounds were also recorded to confirm the binuclear structures. Studies were conducted to assess the growth inhibiting potential of the ligands and complexes against various fungal, viral and bacterial strains.

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Synthesis, structural characterization, biological activity and thermal study of tri‐ and diorganotin(IV) complexes of Schiff base derived from 2‐aminomethylbenzimidazole

Nath

Saini

Kumar

2009

Applied Organom Chemis

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This report deals with the synthesis and structural features of tri-and diorganotin(IV) complexes of the general formulae, R n Sn(L) m [n = 3, m = 1, R = Me, n-Bu and Ph; n = 2, m = 2, R = Me, n-Bu, n-Oct and Ph; HL = Schiff base derived from the condensation of 2-aminomethylbenzimidazole (ambmz) and salicylaldehyde (abbreviated as HL or Hsal-ambmz)]. The newly synthesized complexes were characterized by elemental analysis, molar conductance, electronic, infrared, far-infrared, 1 H NMR, 13 C NMR, 119 Sn NMR and 119 Sn Mössbauer spectral studies. Thermal studies of all of the synthesized complexes were also carried out using thermogravimetry-differential thermal analysis-derivative thermogravimetric (TG-DTA-DTG) techniques. The residues thus obtained were characterized by infrared and powder X-ray diffraction analysis. The bioassay results of anti-inflammatory activity (using the carrageenan-induced paw edema bioassay in rats) and acute toxicity (LD 50 ) of the synthesized derivatives indicated that diorganotin(IV) derivatives (19.75-22.23% inhibition) show better activity as compared with triorganotin(IV) derivatives (10.32-17.86% inhibition).

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Synthetic and spectroscopic investigations of N(4)-substituted isatin thiosemicarbazones and their copper(II) complexes

Cited by 84 publications

References 11 publications

A theoretical investigation on the isomerism and the NMR properties of thiosemicarbazones

A theoretical investigation on the isomerism and the NMR properties of thiosemicarbazones

Microwave‐assisted synthesis, spectroscopy and biological aspects of binuclear titanocene chelates of isatin‐2,3‐bis(thiosemicarbazones)

Synthesis, structural characterization, biological activity and thermal study of tri‐ and diorganotin(IV) complexes of Schiff base derived from 2‐aminomethylbenzimidazole

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