DFT study of isomers of the ruthenium dihydride complex RuH2(CO)2(AsMe2Ph)2

International audienceA density functional theory (DFT) study of cct-As, ccc, and cct-CO isomers of the ruthenium dihydride complex RuH2(CO)(2)(AsMe2Ph)(2) is reported (see Scheme for the labeling isomer 34 structures of RuH2(CO)(2)(AsMe2Ph)(2)). Complex geometries and relative energies of different isomers have been calculated with both B3LYP and M06-2X functionals. The results show that the B3LYP calculated Boltzmann populations of cct-As, ccc, and cct-CO isomers are 65.5, 34.2, and 0.3%, respectively. These are in better agreement with the experimental data than those calculated at the M06-2X level. However, the calculations of H-1 NMR chemical shifts were found to be better described with M06-2X than with B3LYP or with HF level of theories. In addition, a transition state between the two most stable isomers was determined through DFT/(B3LYP or M06-2X) calculations

DFT and Ab Initio calculations of spectroscopic properties of tetramethyltin and of its cation

International audienceDFT and ab initio calculations are performed on tetramethyltin (SnMe4, TMSn) and its cation. A set of spectroscopic constants for both species are derived. They include equilibrium geometries, rotational constants and vibrational wavenumbers. All quantities are in close agreement with the available experimental data. For the cation, our calculations confirm the C3v charge transfer structure proposed earlier through the analysis of electron paramagnetic resonance (EPR) experimental data. Using multi reference configuration interaction and time dependant density functional theory (TD-DFT) methodologies, the vertical electronic excitation energies of TMSn and TMSn+ are determined. For the singlet-singlet neutral molecule, our calculated transition energies are distinctly lower than those previously computed. For the TMSn ($\tilde X$1A1 ? 11T2) absorption transition, our computed excitation energy coincides, however, with the experimental value. Predictive data are also given for the TMSn triplets. At the best level of theory, the vertical and the adiabatic ionization energies of TMSn are computed 9.86 eV and 8.74 eV, respectively. (C) 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 201

Synthesis, crystal structure, vibrational, optical properties, thermal analysis and theoretical study of a new Sn(IV) complex (C5H14N2)2[SnCl6]2·5H2O

In this study, a new organic-inorganic hybrid metal compound (C5H14N2)2[SnCl6]2.5H2O was crystallized at room temperature in the orthorhombic system (space group P21 21 21) where the structure is determined by single crystal X-ray diffraction analysis. The examination of the structure shows the cohesion and stability of the atomic arrangement result from the establishment of N—H···Cl, O(W)—H(W)···Cl, N—H···O(W) and O(W)—H(W)···O(W) hydrogen bonds between 1-methylpiperazine-1,4-diium (C5H14N2)2+cations, isolated (SnCl6)2– anions and water molecules to form organic and inorganic layers parallel to the (a, c) plane and alternate along the b-axis. Hirshfeld surface analysis was used to investigate intermolecular interactions, as well 2D fingerprint plots were conducted to reveal the contribution of these interactions in the crystal structure quantitatively. The solid phase FTIR and FT-Raman spectra of this compound have been recorded in the regions 400–4000 and 100–500 cm−1, respectively. The vibrational frequencies were also predicted from the calculated intensities by DFT method and were compared with the experimental frequencies, which yield good agreement between observed and calculated frequencies. Besides, the optical proprieties were investigated by UV-visible and photoluminescence spectroscopy studies in the region 200–700 nm and the electronic properties HOMO and LUMO energies were measured by TD-DFT approach. Moreover, this compound was characterized by thermal analysis between 300 and 500 K which revealing two phase transitions. Finally, X-ray photoelectron spectroscopy (XPS) analysis is reported to determine the degree of oxidation of tin in this compound and analyzing the surface chemistry of (C5H14N2)2[SnCl6]2.5H2O

Synthesis, crystal structure, vibrational spectroscopy, DFT, optical study and thermal analysis of a new stannate(IV) complex based on 2-ethyl-6-methylanilinium (C9H14N)2[SnCl6]

The new organic-inorganic compound, (C9H14N)2[SnCl6], has been synthesized and characterized by single-crystal X-ray diffraction at room temperature. Structural analysis indicates that this compound crystallizes in the monoclinic system with C2/m space group. The NH⋯Cl hydrogen bonds between (C9H14N)+ cations and [SnCl6]2- dianions contribute to the cohesion and the stability of the atomic arrangement. Hirshfeld surface analysis was used to investigate intermolecular interactions, as well 2D finger plots were conducted to reveal the contribution of these interactions in the crystal structure quantitatively. Furthermore, the room temperature Infrared (IR) spectrum of the title compound was analyzed on the basis of data found in the literature. The optical properties of the crystal were studied using optical absorption UV–visible and photoluminescence (PL) spectroscopy, which were investigated at room temperature exhibited one band at 237 nm and a photoluminescence emission at 407 nm. Experimental room-temperature X-ray studies were supported by theoretical methods using the DFT/B3LYP methods with the LanL2DZ basis set. The X-ray powder is in agreement with the X-ray structure. To determine molecular electrical transport properties we studied the energy difference between Occupied, HOMO, and Lowest Unoccupied, LUMO orbitals. Moreover, this compound was characterized by thermal analysis between 300 and 750 K and shows that the compound remains stable up to the temperature 383 K. Finally, X-ray photoelectron spectroscopy (XPS) analysis is reported to determine the degree of oxidation of tin in this compound and analyze the surface chemistry of (C9H14N)2[SnCl6].Financial support from Spanish MINECO (MAT2016-78155-C2-1-R, MAT2013-40950-R, and FPI grant BES-2011-046948 to MSM.A.), GobiernodelPrincipado de Asturias (GRUPIN14-060), FEDER, and the Secretary of State for Scientific Research and Technology of Tunisia, are acknowledged

Synthesis, crystal structure, physico-chemical characterization and theoretical study of a new Pb(II) complex = C 10 H 22 N 2 3 ·PbCl 5 ·3Cl·3H 2 O

A novel hybrid material, [C10H22N2]3·PbCl5·3Cl·3H2O, has been synthesized and its structure was determined by single-crystal X-ray diffraction. In the atomic arrangement, the different entities are held together through NH⋯Cl, OH⋯Cl and OH⋯O hydrogen bonds to form a three-dimensional network. Intermolecular interactions were investigated by Hirshfeld surfaces. The powder XRD data confirms the phase purity of the crystalline sample. The resulting IR spectrum calculated by the DFT/B3LYP/LanL2DZ method, is similar to the experimental spectrum allowing a good correlation between the experimental and theoretical wavenumbers. The optical properties in the UV–visible region have been explored by the UV–visible absorption. The photoluminescence (PL) spectroscopy, which was investigated at room temperature, exhibited one emission at 426 nm. Thermal analysis discloses a phase transition at 435 K and the decomposition of the sample starts from 554 K.Financial support from Spanish MINECO (MAT2016-78155-C2-1-R, MAT2013-40950-R, and FPI grant BES-2011-046948 to MSM.A.), Gobierno del Principado de Asturias (GRUPIN14-060), FEDER, and the Secretary of State for Scientific Research and Technology of Tunisia, are acknowledged