Pt–Sn/Al2O3 catalyst for the selective hydrodeoxygenation of esters

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Synthesis and molecular structures of tris(thio- and selenophenyl)stannyl complexes of cyclopentadienylcarbonylnitrosylmanganese and their reaction products with tungsten carbony

Reactions of CpMn(CO)(NO)SnCl₃ (I) with sodium benzenethiolate and sodium benzenesele-nolate gave orange crystals of the complexes CpMn(CO)(NO)Sn(EPh)₃, where E = S (II) or Se (III). Treatment of complex II with photochemically generated W(CO)₅(THF) yielded the adduct CpMn(CO)(NO)Sn(SPh)₃ · W(CO)₅ (IV). A similar treatment of complex III resulted in the formation of the ditungsten complex W₂(CO)₄(SePh)₆ (V) with transfer of all chalcogenate groups from tin to tungsten. In reactions of complexes II and III with a Pt₀ complex with phosphine and acetylene, (PPh₃)₂Pt(Ph₂C₂), the chalcogenate groups are transferred from tin. Only the known Pt(II) complexes (PPh₃)₂Pt(EPh)₂), where E= S (VI) or Se (VII). Molecular structures IV and V were characterized by X-ray diffraction. It has been found that the Mn-Sn bond in complex IV (2.5479(9) Å) is nearly the same length as that found earlier for complex II (2.5328(17) Å) and is substantially shorter than the sum of the covalent radii of Mn and Sn (2.78 Å). The Sn-S bond is noticeably lengthened (2.5217(11) Å) only for the S atom bound to tungsten (W-S, 2.5696(12) Å), while the other Sn-S bonds (2.4413(12) and 2.4291(12) Å) are virtually the same as in complex II (on average, 2.441 Å). Complex V contains the direct W-W bond (2.8153(16) Å) supplemented with four benzeneselenolate bridges in which the W-Se bonds (on average, 2.642(2) Å) are longer than the two terminal W-SePh bonds (2.571(2) Å). All the W-Se bonds are much shorter than the sum of the covalent radii of W and Se (2.82 Å).     

(Dicarbonyl)(π-cyclohexadienyl)iron iodide,trichlorostannate, and tris(cymantrenecarboxylato)stannate: Synthesis and molecular structures

A reaction of [(η⁵-C₆H₇)Fe(CO)₃]BF₄ with KI in acetone gave brown crystals of the complex [(η⁵-C₆H₇)Fe(CO)₂]I (I), which was treated with SnCl₂ in THF to form orange crystals of the complex [(η⁵-C₆H₇)Fe(CO)₂]SnCl₃ (II). A reaction of complex II with potassium cymantrenecarboxylate ((CO)₃MnC₅H₄COOK, or CymCOOK) in THF yielded yellow crystals of the complex [(η⁵-C₆H₇)Fe(CO)₂]Sn(CymCOO)₃ (III). Structures I–III were identified using X-ray diffraction. The fragment (η⁵-C₆H₇)Fe(CO)₂ in complexes I–III remains virtually unchanged. The Fe-I bonds in complex I (2.6407(3) Å) and the Fe-Sn bonds in complexes II and III (2.4854(3) and 2.4787(4) Å, respectively) are appreciably shorter than the sum of the covalent radii of the corresponding elements, probably because of an additional dative interaction of the d electrons of iron with the vacant d orbitals of iodine or tin.     

Neutral and monocationic dinuclear (carbonyl)(cyclopentadienyl)(phenylchalcogenate) iron complexes of the general formulas [(RC5H4)Fe(CO)EPh]2 and [(RC5H4)Fe(CO)EPh]2PF6 (E = S or Te; R = H or Me): Synthesis, molecular structures, and EPR spectra

Heating of the compounds (RC₅H₄)Fe(CO)₂TePh (R = H (I) and Me (II)) in heptane afforded the dinuclear complexes [(RC₅H₄)Fe(CO)TePh]₂ (III and IV, respectively). By oxidation with Fc⁺PF ₆ ^? , these complexes were transformed into the paramagnetic cationic complexes [(RC₅H₄)Fe(CO)TePh]₂PF₆ (V and VI, respectively). Structures III–V and [(C₅H₅)Fe(CO)SPh]₂PF₆ (VII) were characterized by X-ray diffraction.     

ChemInform Abstract: The Ground-State Potential Energy Surface of Diazene

has been studied by using a complete active space MCSCF wave function generated by distributing eight electrons among eight orbitals.