A simple, efficient, and mild procedure for a solvent-free one-step synthesis of various 4,4'-diaminotriarylmethane derivatives in the presence of antimony trichloride as catalyst is described. Triarylmethane derivatives were prepared in good to excellent yields and characterized by elemental analysis, FTIR, (1)H and (13)C NMR spectroscopic techniques. The structural and vibrational analysis we...

Ab initio calculations of a chemical shift at the HF/6-31G(d,p)//B3LYP/6-31G(d) level on a model system representing the interaction between Zn++ and the thiazoline ring of Bacitracin A is used for studying the binding mode between the metal ion and the ring system. The simulations show that a reinterpretation of the shift effects seen in the NMR spectra of the zinc–Bacitracin A complex may be ...

Gaussian-3 ground-state total electronic energies have been approximated using single point 6-31G(d) basis set Harteee±Fock self-consistent-®eld (HF-SCF) total energies and partial charges based on our earlier rapid estimation of correlation energy from partial charges method. Sixty-®ve closed-shell neutral molecules (composed of H, C, N, O, and F atoms) of the G2/97 thermochemistry database we...

The HF/6-31G level of theory was used to calculate relaxed potential energy surfaces for 12 analogs of disaccharides. The analogs were made by replacing glucose with tetrahydropyran and fructose with 2-methyltetrahydrofuran. Molecules had zero, one or two anomeric carbon atoms, and di-axial, axial-equatorial, and di-equatorial linkages. Despite the absence of hydroxyl groups, the surfaces accou...

Flephedrone is an analogue of cathinone - chemically similar to ephedrine, cathine and other amphetamines. Conformations of all isomers of flephedrone have been studied at the quantum-chemical level. Calculations have been performed using DFT and MP2 methods with two basis sets - 6-31G and 6-31G(d,p). Results show that there are low energy conformers for the ortho, meta, and para isomers that a...

N,N-dioctyl-azepanium, -piperidinium and -pyrrolidinium bromides 1-3, have been obtained and characterized by FTIR and NMR spectroscopy. DFT calculations have also been carried out. The optimized bond lengths, bond angles and torsion angles calculated by B3LYP/6-31G(d,p) approach have been presented. Both FTIR and Raman spectra of 1-3 are consistent with the calculated structures in the gas pha...

The catalytic asymmetric thiazolium- and triazolium-catalyzed benzoin condensations of aldehydes and ketones were studied with computational methods. Transition-state geometries were optimized by using Morokuma's IMOMO [integrated MO (molecular orbital) + MO method] variation of ONIOM (n-layered integrated molecular orbital method) with a combination of B3LYP/6-31G(d) and AM1 levels of theory, ...

The antharquinone-based chromophore of 11-hydroxyaklavinone is present in the structure of an anticancer agent, daunomycin. On the other hand, aklavinone is the parent aglycone of certain anthracycline antibiotics that possess anti-cancer activity too. The structures of aklavinone and its 11-hydroxy derivative have many -OH groups, and two keto groups which may take place in certain tautomeric ...

The different configurations (linear, zig-zag, and cyclic) of formamide dimers have been studied at the level of both Hartree–Fock (HF) and second order Møller–Plesset perturbation theory (MP2). The widely used a posteriori Boys–Bernardi “counterpoise” (CP) correction scheme has been compared with our a priori methods utilizing the “chemical Hamiltonian approach” (CHA). The appropriate interact...