Effect of A-site cation radius on thermodynamic properties of ARuO3 (A = Ca, Sr, and Ba)

The thermodynamic properties of alkaline earth ruthenate ARuO₃ (A?=?Ca, Sr, and Ba) perovskites have been investigated for the first time by means of a modified rigid ion model at temperature 1 K?≤?T?≤?300 K. As strong electron–phonon interactions are present in these compounds, the lattice contribution to the specific heat deserves proper attention. The values of specific heat calculated by us have shown remarkably good agreement with corresponding experimental data. We have found that in ARuO₃ (A?=?Ca, Sr, and Ba) ruthenate family, Debye temperature increases inversely with the ionic radius of the alkaline earth A cations. In addition, the results on the temperature dependence of thermal expansion coefficient (α), cohesive energy (?), molecular force constant (f), Reststrahlen frequency (υ), Debye temperature (θ _D), and Grüneisen parameter (γ) are also reported.     

A homometallic tricapped cubane cluster: [(Cp*Mo)4B4H4(μ4-BH)3] (Cp* = η5-C5Me5)

The reaction of [Cp*MoCl(4)] with an excess of LiBH(4), followed by thermolysis with tellurium powder in toluene, afforded a tricapped cubane cluster, [(Cp*Mo)(4)B(4)H(4)(μ(4)-BH)(3)] (1), which represents an unprecedented metal-rich metallaborane cluster with a cubane core containing 58 cluster valence electrons (cve) and three metal-metal bonds.     

Synthesis, characterization and coordination properties of bis(alkyl)selenosalen ligands

New bis (alkyl) selenosalen podand ligands having Se2N2 donor sites have been synthesized by the condensation of unsymmetrical o-formylphenyl alkyl selenide (1-3) with ethylenediamine. The reaction of bis(alkyl)selenosalen podands with Pd(II) and Pt(II) afforded selenoether-selenolate coordination complexes 7-10via cleavage of one of the two Se-C(alkyl) bonds of bis(alkyl)selenosalen podands upon complexation. DFT calculations revealed that the cleavage of Se-C(alkyl) bonds occurred possibly via S(N)2 mechanism instead of a sequence of oxidative addition and reductive elimination reactions. The spectral data and elemental analyses confirmed the formation of selenoether-selenolate complexes. The structures of the podands N,N'-bis[(2-methylseleno)phenylmethylene]-1,2-ethanediamine (4), N,N'-bis[(2-decylseleno)phenylmethylene]-1,2-ethanediamine (5) and the selenoether-selenolate complex 8 have been determined by single crystal X-ray diffraction analysis. The crystal structure of 5 showed SeH interaction with a ladder like 3D supramolecular arrangement via interdigitation of long alkyl chains. Comparison of crystal packing of podands 4 and 5 indicates that the alkyl chain length has significant impact on the crystal packing. The platinum selenolate complex 8 shows a square planar arrangement around the Pt centre, where the Se atoms in the selenolate and the selenoether have nearly equal Pt-Se bond length.     

Diode laser spectrum and analysis of the 882-cm−1 band of s-tetrazine

A high-resolution diode laser spectrum of the 882-cm^?1 band of s-tetrazine has been obtained. A complete rotational analysis of this band, incorporating quartic and sextic centrifugal distortion coefficients, has been carried out. The rotational constants A, B, and C have been determined with an accuracy better than 10^?5 cm^?1. The analysis has shown the band to be A-type and, on this basis, the vibrational assignment of this band has been revised from ν₁₂ to ν₁₄.     

Microwave Induced Bismuth Trichloride Catalysed Beckmann Rearrangement of Oximes

A new and efficient method for the rearrangement of oximes 1 has been achieved by a simple reaction of a ketoximes with bismuth trichloride under microwave irradiation in the solid state.