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Title: Ditechnetium heptoxide revisited: Solid-state, gas-phase, and theoretical studies

Here, ditechnetium heptoxide was synthesized from the oxidation of TcO 2 with O 2 at 450 °C and characterized by single crystal X-ray diffraction (SCXRD), electron impact mass spectrometry (EI-MS) and theoretical methods. Refinement of the structure at 100 K indicates that Tc 2O 7 crystallizes as a molecular solid in the orthorhombic space group Pbca (a = 7.312(3) Å, b = 5.562(2) Å, c = 13.707(5) Å, V = 557.5(3) Å 3). The Tc 2O 7 molecule can be described as corner-sharing TcO4 tetrahedra (Tc---Tc = 3.698(1) Å and Tc-O Bri-Tc = 180.0°). The EI-MS spectrum of Tc 2O 7 consists of both mononuclear and dinuclear species. The main dinuclear species in the gas-phase are Tc 2O 7 (100%) and Tc 2O 5 (56%), while the main mononuclear species are TcO 3 (33.9%) and TcO 2 (42.8%). The difference in the relative intensities of the M 2O 5 (M = Tc, Re) fragments (1.7% for Re) indicate that these Group 7 elements exhibit different gas phase chemistry. The solid-state structure of Tc 2O 7 was investigated by density functional theory (DFT) methods. The optimized structure of the Tc 2O 7 molecule is in good agreement with the experimental one.more » Simulations indicate that the more favorable geometry for the Tc 2O 7 molecule in the gas-phase is bent (Tc-O Bri-Tc = 156.5°), while linear (Tc-O Bri-Tc = 180.0°) is favored in the solid state.« less
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [2] ;  [2] ;  [1] ;  [1] ;  [2] ;  [3] ;  [1]
  1. Univ. of Nevada, Las Vegas, NV (United States)
  2. Univ. of Zurich, Zurich (Switzerland)
  3. Univ. of Nevada, Las Vegas, NV (United States); Argonne National Lab. (ANL), Lemont, IL (United States)
Publication Date:
Grant/Contract Number:
AC02-06CH11357; NA0003180
Type:
Accepted Manuscript
Journal Name:
Inorganic Chemistry
Additional Journal Information:
Journal Volume: 55; Journal Issue: 20; Journal ID: ISSN 0020-1669
Publisher:
American Chemical Society (ACS)
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States); Univ. of California, Berkeley, CA (United States). Nuclear Science and Security Consortium
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1339618
Alternate Identifier(s):
OSTI ID: 1405177