Bortolus MR, Mercier HPA, Schrobilgen GJ, Brock DS. Noble-Gas Difluoride Complexes of MOF4 (M = Mo, W); Syntheses, Structures and Bonding of NgF2·MOF4 and XeF2·2MOF4 (Ng = Kr, Xe).
Chemistry 2021;
28:e202103729. [PMID:
34758160 DOI:
10.1002/chem.202103729]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Indexed: 11/09/2022]
Abstract
The NgF 2 ∙MOF 4 (Ng = Kr, Xe; M = Mo, W) and XeF 2 ∙2MOF 4 complexes were synthesized in anhydrous HF (aHF) solvent and melts, respectively. Their single-crystal X-ray diffraction (SCXRD) structures show NgF 2 ∙MOF 4 and XeF 2 ·2MOF 4 have F t -Ng-F b ---M arrangements, in which the NgF 2 ligands coordinate to MOF 4 through Ng-F b ---M bridges. The XeF 2 ligands of XeF 2 ·2MOF 4 also coordinate to F 3 OM-F b '---M'OF 4 moieties through Xe-F b ---M bridges to form F t -Xe-F b ---M(OF 3 )-F b '---M'OF 4 , where XeF 2 coordinates trans to the M=O bond and F b ' coordinates trans to the M'=O bond. The Ng-F t , Ng-F b , and M---F b bond lengths of NgF 2 ∙ n MOF 4 are consistent with MOF 4 and F 3 OM-F b '---M'OF 4 fluoride-ion affinity trends: CrOF 4 < MoOF 4 < WOF 4 ≈ F 3 OMo-F b '---Mo'OF 4 < F 3 OW-F b '---W'OF 4 . The [--(F 4 OMo)( µ 3 -F)H---H( µ -F)--] ∞ and [H 2 F][W 2 O 2 F 9 ] solvates were also synthesized in aHF and characterized by SCXRD. Quantum-chemical calculations show the M---F b bonds of NgF 2 ·MOF 4 and XeF 2 ·2MOF 4 are predominantly electrostatic, σ-hole type bonds.
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