The quantum-chemical calculations on the conformational properties of 2-flouro-2-oxo- 1,3,2-dioxaphosphorinane (1), 2-choloro-2-oxo-1,3,2-dioxaphosphorinane (2) and 2-bromo- 2-oxo-1,3,2-dioxaphosphorinane (3) have been investigated by means of ab initio molecular orbital (HF/6-311+G**) and hybrid density functional theory (B3LYP/6-311+G**) based methods and Natural Bond Orbital (NBO) interpreta...

In the mol-ecule of the title compound, [FeCl(2)(C(25)H(19)N(3))], the three N atoms span the axial-equatorial-axial sites of the trigonal-bipyramidal coordination polyhedron; the geometry of the Fe(II) atom is 32% distorted from trigonal-bipyramidal (towards square-pyramidal along the Berry pseudorotation pathway). One of the Cl atoms is disordered over two positions in a 0.938 (11):0.062 (11)...

In the mol-ecule of the title compound, [MnCl(2)(C(25)H(19)N(3))], the three N atoms span the axial-equatorial-axial sites of the trigonal-bipyramidal coordination polyhedron; the geometry of the Mn(II) atom is 34% distorted from trigonal-bipyramidal (towards square-pyramidal along the Berry pseudorotation pathway). One of the Cl atoms is disordered over two positions in a 0.82 (3):0.18 (3) rat...

Dimers of ethylene carbonate and propylene carbonate are created in supersonic jet expansions and characterized by FTIR spectroscopy. Fermi resonances are switched on and off by dimerization. There is a unique centrosymmetric dimer of ethylene carbonate in a pronounced case of complementary chirality synchronization, contributing to its energy storage capacity at melting. Two chiral propylene c...

In this paper, the plastic limit load of cylindrical shells with opening subject to combined bending moment and axial force are found by finite element method using ANSYS suite of program. The effect of various parameters such as the geometrical ratios of shell and the shape, size, axial and angular position of the opening on the limit load of cylindrical shells under various loading conditions...

In the title complex, [Co(C(18)H(18)N(2)O(4))(C(2)H(3)O(2))(H(2)O)]·2CH(3)OH, the Co(III) atom is hexa-coordinated by water and acetate groups in the axial positions and by the tetra-dentate Schiff base occupying equatorial positions. These axial bonds are longer than the equatorial bonds to the tetra-dentate Schiff base. Two mol-ecules form a dimer through strong hydrogen bonds from the coordi...

In the title compound, [Cu(C(6)H(9)N(2)O(3)S)(2)](n), the copper(II) ion sits on an inversion center and is chelated by the imidazole N and sulfonate O atoms of two ligands in equatorial positions. O atoms of adjacent mol-ecules coordinate in the axial positions. Jahn-Teller tetra-gonal distortion is evident in the coordination geometry [Cu-N and Cu-O equatorial distances of 1.971 (3) and 2.045...

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...

As proporções dos confôrmeros axial-equatorial do N,N-dimetilcarbamato de cicloexila foram determinadas, pela primeira vez, pelo método de Eliel, pela ressonância magnética nuclear dinâmica(RMND) de 1H e de 13C e foram comparados com resultados obtidos através de cálculos teóricos. Pelo método de Eliel foram utilizados pelo menos cinco parâmetros experimentais independentes, em CCl4, CDCl3 e CD...

Characterized by microwave spectroscopy after their formation in a supersonic jet, the axial and equatorial hydrogen bond conformers of the title complex were studied. The axial form--shown in the picture--has been found to be the most stable one. The experimental data are consistent with a C(s) symmetry for both conformers, in which linear hydrogen bonds lying in the symmetry plane bisect the ...