A theoretical study of the kinetic and mechanism of intramoleccha cychcation of (1)-undeca-7,8-dien-2-yne was performed using MT methods at B3LYP and B3PW91 levels of theory using 6-311g, 6-311C.6-31 IGs*, 6-31I+G, 6-31 I4-SG and 6-3114H-Gs* basis seo. Equilibrium molecular geometries andharmonic vibrational frequencies of the reaccint, transition state and product wens calculated. Theconsidere...

the results of mndo, am1 and pm3 semi-empirical calculations and hf/6-31g*, mp/6-31g*, mp2/6-311+g**, and b3lyp/6-311g** and qcisd/6-31g* ab initio methods for angle strain and conjugation effects in twist-boat, boat, and half-chair geometries of (z,z,z)-cycloocta-1,3,5-triene indicate that all methods, except pm3, predict wrong ordering of the conformations.

Both glycine and water exhibit a high affinity towards the hydroxyapatite HA surfaces. What happens when they are co-adsorbed at the HA (001) surface? B3LYP periodic calculations reveal that glycine displaces the pre-adsorbed water interacting directly with the HA surface.

Symmetrical and non-symmetrical diimines derived from dimedone were synthesized by the reaction of their corresponding enaminothiones with primary amines. The synthesized compounds were characterized using micro analytical data and NMR spectroscopy. Theoretical calculations by B3LYP/6-31G(d,p) level of theory show that the enolic form is the most stable within the possible tautomeric forms of t...

For metal-based compounds, the ground- and excited-state dipole moments and the difference thereof are, for the first time, obtained both experimentally and theoretically using solvatochromic equations and DFT/B3LYP/QZVP calculations. The approach is suggested to be promising and easily accessible, and can be universal to elucidate the electronic properties of metal-based compounds.

It has been established from experiments that stable medium-sized ionic clusters Si15-Si20 are prolate in shape. Density-functional theories (DFTs) also predict that nearly all low-lying neutral clusters in this size range are prolate in shape. Moreover, most of them are built onto two generic structural motifs, either the tricapped-trigonal-prism (TTP) Si9 motif or the six/six Si6Si6 (sixfold-...

[Cu4(mu-dppm)4(mu4-eta1,eta2-C[triple bond]C-)]2+ has been shown by 31P and 1H NMR studies to undergo two fluxional processes in solution, the oscillation of the C[triple bond]C2- unit inside the copper rectangle and the flipping of the diphosphines, and this has been supported by DFT(B3LYP) calculations.

A computational modeling of the protonation of corannulene at B3LYP/6-311G(d,p)//B3LYP/6-311G(d,p) and of the binding of lithium cations to corannulene at B3LYP/6-311G(d,p)//B3LYP/6-31G(d,p) has been performed. A proton attaches preferentially to one carbon atom, forming a sigma-complex. The isomer protonated at the innermost (hub) carbon has the best total energy. Protonation at the outermost ...

Density-functional theory ~DFT! calculations of indirect nuclear magnetic resonance spin–spin coupling tensors J, with the anisotropic but symmetric parts being the particular concern, are carried out for a series of molecules with the linear response ~LR! method. For the first time, the anisotropic components of J are reported for a hybrid functional. Spin–spin tensors calculated using the loc...

The structures and properties of [n]sila-acenes (n=2-4) were investigated by density functional theory method. The results of calculations were obtained at B3LYP/6-311G (d,p) level on model species. Energetic criteria suggest that 2-1b (n=2), 3-1b (n=3), and 4-1b (n=4) isomers enjoy stabilization. By frontier orbital analysis, these systems are among the most stable of the family. Also, calcula...