Iron monocarbide has been investigated between 12 000 and 18 100 cm in a supersonic expansion by resonant two-photon ionization spectroscopy. Six new electronic states have been identified for which origins relative to the ground state have been determined. Three of these possess V853, one possesses V854, and two possess V852. The V853 state with an origin near 13 168 cm is likely a D3 state an...

The first optical spectroscopic investigation of MoC has revealed a complicated vibronic spectrum consisting of about 35 bands between 17 700 and 24 000 cm. Analysis has shown the ground state to be the V50 spin–orbit component of a S state that derives from a 10s11s5p2d configuration. The X S01 2 rotational constant for MoC was determined to be B050.553 640 60.000 055 cm, giving r051.687 71960...

Several gold +I and +III complexes are investigated computationally spectroscopically, focusing on the d-configuration physical oxidation state of metal center. Density functional theory calculations reveal non-negligible electron-sharing covalent character metal-to-ligand σ-bonding framework. The bonding scenarios gold(III) shown to be isoelectronic formal copper(III) complex [Cu(CF3)4]1-, in ...

It has recently been argued that the barrier to rotation around the C C bond in ethane is not to be explained by the generally accepted picture of steric hindrance between vicinal C H bonds in the eclipsed conformation but is caused by more favorable orbital interaction in the staggered conformation. In that conformation the C H bonds at opposite ends of the molecule have an in-plane trans conf...

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Sulfur is unique among the elements in consisting in its standard state of octatomic molecules. It is interesting that the stability of the S8 molecule can be understood by consideration of the forces determining the orientation around the sulfur-sulfur single bond. Let us consider a molecule such as H2S2, in which each sulfur atom forms a single bond with the other sulfur atom and a single bon...

The regioselectivity of 1,3-dipolar cycloaddition reactions between mesoionic compounds with singly-tethered substituents is examined. The results with propitiate dipolarophiles are compared with other singly and doubly-tethered examples according to a model using an asynchronous, concerted transition state. The isolation and reaction of a novel, nonaryl substituted mesoionic compound 7 is repo...

A two state (2-MO) model for the low-lying long axis-polarised excitations of poly(p-phenylene) oligomers and polymers is developed. First we derive such a model from the underlying PariserParr-Pople (P-P-P) model of π-conjugated systems. The two states retained per unit cell are the Wannier functions associated with the valence and conduction bands. By a comparison of the predictions of this m...

Abstract Density functional theory (DFT) was performed in the gas phase to investigate tautomerization and transitions efavirenz. The amide imidic tautomers' geometrical parameters are using B3LYP/6-31++G** M06-2X/ cc-pVTZ (-F). results showed that tautomer is more stable than phase. non-linear optical (NLO) properties of tautomers computed. Interestingly, forms may be an attractive compound en...

The influence of the insertion/addition of a benzene ring to the natural nucleic acid bases on the local aromaticity of the so-called size-expanded (xN, with N being adenine, guanine, cytosine, and thymine) bases is examined. To this end, the local aromaticity of the six- and five-membered rings in both the natural bases and their benzoderivatives is determined using HOMA, NICS, aromatic fluctu...