The reaction of tetraethylammonium metavanadate, （Et4N）VO3, with isovanillin semithiocarbazone（VSTC）, HOC6H3（OCH3）CH=NNHCSNH2, in a mixed solvent of ethanol, water and DMSO yields the mononuclear dioxovanadate（...The reaction of tetraethylammonium metavanadate, （Et4N）VO3, with isovanillin semithiocarbazone（VSTC）, HOC6H3（OCH3）CH=NNHCSNH2, in a mixed solvent of ethanol, water and DMSO yields the mononuclear dioxovanadate（V） complex, [（C2H5）4N][V（V）O2 （OC6H3- （OCH3）CHNNCSNH2）](H2O （C17H31N4O5SV, Mr = 454.5） and its single-crystal structure has been determined by X-ray diffraction. The crystal belongs to orthorhombic space group P212121 with unit cell parameters a = 12.940（3）, b= 15.414（3）, c = 10.703（2） ?, V = 2134.8（11） ?3, Z=4, Dcalc = 1.414 Kg/m3, ( = 0.597 mm-1, and F（000） = 960. The final agreement factors are R = 0.076 and Rw=0.096 for 1600 observed independent reflections with F ≥4.0(（F）. The structure revealed that the vanadium atom is bound to two terminal oxygen atoms and one tridentate donor ligand in a distorted square pyramidal arrangement. The sulphur-nitrogen-oxygen donor Schiff-base ligand in the thiol form rather than the thione form is coordinated to the vanadium via the mercapto sulphur, the (-nitrogen and the hydroxylate oxygen.展开更多
The goal of the present work was to optimize the phase-structural composition and microstructure of binary Ti0.8-0.9V0.2-0.1 alloys with respect to their hydrogen sorption properties. Application of these alloys is fo...The goal of the present work was to optimize the phase-structural composition and microstructure of binary Ti0.8-0.9V0.2-0.1 alloys with respect to their hydrogen sorption properties. Application of these alloys is for hydrogen absorption from gaseous mixtures containing substantial amounts of carbon monoxide （CO） at high temperatures. Irrespective of alloy composition, both α（HCP） and β（BCC） phases in Ti0.8-0.9V0.2-0.1 formed single phase FCC hydrides upon hydrogenation in pure H2. An in situ synchrotron X-ray diffraction study showed that only the β-phase transformed to the corresponding hydride when the alloy was hydrogenated in a mixture of H2＋10%CO. Rapid solidification （RS） of the alloy resulted in refined grain sizes both in the Ti0.8V0.2 and Ti0.9V0.1 alloys. Furthermore, RS was found to increase the β-phase fraction in Ti0.9V0.1, being twice larger than that of the as-cast alloy. Ti0.9V0.1 had a platelike microstructure as observed by scanning electron microscopy （SEM）, the plates were about 300 nm thick. The microstructure refinement resulted in a faster kinetics of H desorption as observed by temperature desorption spectroscopy （TDS）.展开更多
The new oxovanadium (V) complex, [PyH][VO2(L)] 1 (salicyladehyde 5-bromo salicyloylhydrazone is abbreviated as H2L; Hpy is protonated pyridine) was obtained from a refluxed solution of VOSO4 and H2L in acetonitrile-me...The new oxovanadium (V) complex, [PyH][VO2(L)] 1 (salicyladehyde 5-bromo salicyloylhydrazone is abbreviated as H2L; Hpy is protonated pyridine) was obtained from a refluxed solution of VOSO4 and H2L in acetonitrile-methanol-pyridine. Similarly, another new complex, [VO(L)(OCH3)] 2 was synthesized by refluxing VOSO4 and H2L in methanol-pyridine. Crystal data for 1: C19H15N3O5BrV, Mr= 496.2, monoclinic, P21/n, a = 7.1885(3), b = 9.2718(3), c = 28.803(1) A, β = 96.185(1)°, Z = 4 and V = 1908.6(1) A3; for 2: C15H12N2O5BrV, Mr= 431.1, monoclinic, P2,/n, a = 12.202(2), b = 8.045(2), c = 16.604(3) A, β = 101.29(3)°, Z = 4 and V = 1598.4(2) A3. The structures of 1 and 2 have been determined by X-ray analyses and reveal that the coordination environments of V atoms in both complexes are of square-based pyramid. Three of the four based donor atoms are from the tridentate 'ONO' donor ligand while the fourth is one terminal oxygen atom with the V(1) - O(3) distance 1.646(4) A for 1 and one -OCH3 group with the V(1)-O(3) distance 1.753(3) A for 2. The V(1)-O(4) terminals occupy the axial sites in both cases. The complexes are also characterized by IR and 1H NMR spectroscopies.展开更多
文摘The reaction of tetraethylammonium metavanadate, （Et4N）VO3, with isovanillin semithiocarbazone（VSTC）, HOC6H3（OCH3）CH=NNHCSNH2, in a mixed solvent of ethanol, water and DMSO yields the mononuclear dioxovanadate（V） complex, [（C2H5）4N][V（V）O2 （OC6H3- （OCH3）CHNNCSNH2）](H2O （C17H31N4O5SV, Mr = 454.5） and its single-crystal structure has been determined by X-ray diffraction. The crystal belongs to orthorhombic space group P212121 with unit cell parameters a = 12.940（3）, b= 15.414（3）, c = 10.703（2） ?, V = 2134.8（11） ?3, Z=4, Dcalc = 1.414 Kg/m3, ( = 0.597 mm-1, and F（000） = 960. The final agreement factors are R = 0.076 and Rw=0.096 for 1600 observed independent reflections with F ≥4.0(（F）. The structure revealed that the vanadium atom is bound to two terminal oxygen atoms and one tridentate donor ligand in a distorted square pyramidal arrangement. The sulphur-nitrogen-oxygen donor Schiff-base ligand in the thiol form rather than the thione form is coordinated to the vanadium via the mercapto sulphur, the (-nitrogen and the hydroxylate oxygen.
基金Project "Integrated Process for Hydrogen Production and Separation" supported by Norwegian Research Council and Statoil, Norway
文摘The goal of the present work was to optimize the phase-structural composition and microstructure of binary Ti0.8-0.9V0.2-0.1 alloys with respect to their hydrogen sorption properties. Application of these alloys is for hydrogen absorption from gaseous mixtures containing substantial amounts of carbon monoxide （CO） at high temperatures. Irrespective of alloy composition, both α（HCP） and β（BCC） phases in Ti0.8-0.9V0.2-0.1 formed single phase FCC hydrides upon hydrogenation in pure H2. An in situ synchrotron X-ray diffraction study showed that only the β-phase transformed to the corresponding hydride when the alloy was hydrogenated in a mixture of H2＋10%CO. Rapid solidification （RS） of the alloy resulted in refined grain sizes both in the Ti0.8V0.2 and Ti0.9V0.1 alloys. Furthermore, RS was found to increase the β-phase fraction in Ti0.9V0.1, being twice larger than that of the as-cast alloy. Ti0.9V0.1 had a platelike microstructure as observed by scanning electron microscopy （SEM）, the plates were about 300 nm thick. The microstructure refinement resulted in a faster kinetics of H desorption as observed by temperature desorption spectroscopy （TDS）.
基金The work was supported by the Chinese Academy of Sciences, the National Natural Science Foundation of China(20073048)the NSF of Fujian province for financial support
文摘The new oxovanadium (V) complex, [PyH][VO2(L)] 1 (salicyladehyde 5-bromo salicyloylhydrazone is abbreviated as H2L; Hpy is protonated pyridine) was obtained from a refluxed solution of VOSO4 and H2L in acetonitrile-methanol-pyridine. Similarly, another new complex, [VO(L)(OCH3)] 2 was synthesized by refluxing VOSO4 and H2L in methanol-pyridine. Crystal data for 1: C19H15N3O5BrV, Mr= 496.2, monoclinic, P21/n, a = 7.1885(3), b = 9.2718(3), c = 28.803(1) A, β = 96.185(1)°, Z = 4 and V = 1908.6(1) A3; for 2: C15H12N2O5BrV, Mr= 431.1, monoclinic, P2,/n, a = 12.202(2), b = 8.045(2), c = 16.604(3) A, β = 101.29(3)°, Z = 4 and V = 1598.4(2) A3. The structures of 1 and 2 have been determined by X-ray analyses and reveal that the coordination environments of V atoms in both complexes are of square-based pyramid. Three of the four based donor atoms are from the tridentate 'ONO' donor ligand while the fourth is one terminal oxygen atom with the V(1) - O(3) distance 1.646(4) A for 1 and one -OCH3 group with the V(1)-O(3) distance 1.753(3) A for 2. The V(1)-O(4) terminals occupy the axial sites in both cases. The complexes are also characterized by IR and 1H NMR spectroscopies.
