1,721,025 research outputs found
Ab initio molecular orbital calculations on lithium phosphenite and lithium chlorite charge-transfer complexes: geometries and vibrational frequencies
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Ab-initio SCF Study of the BO ion and the NaBO and HBO molecules
No full textThe results of ab initio MO calcns. on the BO2- anion and on the NaBO2 and HBO2 mols. are presented and discussed. NaBO2 is a linear mol. of Cv symmetry and its transition state corresponds to a cyclic structure with a bent BO2- group. Preference for an angular structure of Cs symmetry is suggested for HBO2. The results of this study are compared with previous theor. and vibrational spectroscopy investigations. Limited pseudopotential calcns. are also reported for BO2- and the linear structure of NaBO2
Ab initio study on the beryllium fluoride (Be2F4), magnesium fluoride (Mg2F4) dimers, on the mixed dimers beryllium magnesium fluoride (BeMgF4) and lithium sodium fluoride (LiNaF2) and on the lithium beryllium fluoride (Li2BeF4), lithium boron chloride (LiBCl4) and lithium aluminum chloride (LiAlCl4) ion-pairs
No full textBonding in and spectroscopic properties of gaseous triatomic molecules. Part II. Group IIB metal dihalides
No full textGroup electronegativities from benzene ring deformations: a quantum chemical study
No full textWe propose a new scale of group electronegativities, derived from benzene ring deformations in Ph-X molecules. A recent analysis of such deformations (Campanelli, A. R.; Domenicano, A.; Ramondo, F. J. Phys. Chem. A 2003, 107, 6429) has shown that two orthogonal linear combinations of the internal ring angles, termed SE and SR, are directly related to the electronegativity and resonance effects of the substituent, respectively. In the present paper, we show that SE increases linearly with the electronegativity of X within each of the first two rows of the periodic table, acting as a sensitive indicator of the polarity of the Ph-X bond. By using SE values from ab initio quantum chemical calculations, we have derived the electronegativities of 100 organic and inorganic groups. Nonbonded interactions with the ortho hydrogens and carbons may fictitiously alter the electronegativity of a group; in most cases, however, they are easily eluded by changing the conformation of the substituent with respect to the benzene ring. Although the atom directly linked to the ring tends to dominate the electronegativity of a group, the role of its adjacent atoms is also important. Their effect depends markedly on the nature of chemical bonding and electron density distribution within the grou
Study of the hydrogen-bonded urea-water [(NH2CONH2)(H2O)2] and urea-hydrogen fluoride [(NH2CONH2)(HF)2] complexes and of the interaction of H2O with metal cations and anions
No full textmolecular conformations and harmonic force field of 1,3,5-benzenetriol molecule from ab initio and density functional theory investigations.
No full textthe molecular structure of N,N'-diformohydrazide from ab initio studies (MP2 and density functional theory) and FTIR matrix spectroscopy
No full textHydrogen bonding in barbituric and 2-thiobarbituric acids: a theoretical and FT-IR study
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