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Vicinal Dinitridoruthenium‐Substituted Polyoxometalates γ‐[XW 10 O 38 {RuN} 2 ] 6− (X=Si or Ge)
Author(s) -
Besson Claire,
Musaev Djamaladdin G.,
Lahootun Vanina,
Cao Rui,
Chamoreau LiseMarie,
Villanneau Richard,
Villain Françoise,
Thouvenot René,
Geletii Yurii V.,
Hill Craig L.,
Proust Anna
Publication year - 2009
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200900965
Subject(s) - crystallography , polyoxometalate , chemistry , bond length , vicinal , cyclic voltammetry , metal , raman spectroscopy , yield (engineering) , crystal structure , materials science , electrochemistry , catalysis , biochemistry , physics , organic chemistry , electrode , optics , metallurgy
Reaction of the divacant polyoxometalate K 8 [γ‐XW 10 O 36 ] (X=Si, Ge) with two equivalents of the metal‐nitrido precursor Cs 2 [Ru VI NCl 5 ], at room temperature in water, produces K 2 (Me 2 NH 2 ) 2 H 2 [γ‐XW 10 O 38 {RuN} 2 ], X=Si ( DMA ‐ 1 a ) or Ge ( DMA ‐ 1 b ). The X‐ray crystal structures of both complexes show monomeric complexes with highly unusual vicinal terminal metal‐nitrido units. The RuN bond lengths are 1.594(10) and 1.612(11) Å in 1 a and 1 b , respectively. EXAFS studies confirmed the key structural assignments from X‐ray crystallography. The XANES spectrum of DMA‐1 a , diamagnetism, NMR ( 29 Si and 183 W) chemical shifts, voltammetric behavior, reductive titrations with [PW 12 O 40 ] 4− , and computational data are all consistent with d 2 Ru VI centers in these complexes. The FT‐IR and Raman spectra show the expected vibrational modes of the {γ‐XW 10 } unit and the RuN stretch at 1080 cm −1 , respectively. Interestingly, reduction of DMA‐1 a by 4 equivalents of [PW 12 O 40 ] 4− produces NH 3 in nearly quantitative yield. Cyclic voltammetry versus pH and calculations provide the energetics for the possible two‐electron reduction and two‐proton addition processes in this reaction.