Tungsten-tungsten triple bond. 10. Ditungsten hexapivalate
Hydrocarbon solutions of W/sub 2/(O-t-Bu)/sub 6/ react with pivalic acid, t-BuCOOH (6 equiv), to give W/sub 2/(O/sub 2/C-t-Bu)/sub 6/ and t-BuOH. W/sub 2/(O/sub 2/C-t-Bu)/sub 6/ crystallizes from hexane as yellow cubic crystals. (Crystal data at -156/sup 0/C: a = 16.730 (5) A, b = 10.588 (2) A, c = 22.860 (8) A, ..beta.. = 107.26 (1)/sup 0/, Z = 4, d/sub calcd/ = 1.674 g cm/sup -3/, space group = P2/sub 1//c.) Each tungsten atom is coordinated to five oxygen atoms that lie roughly in a pentagonal plane, to the other tungsten atom by a W identical with W bond (2.292 (1) A), and weakly to an additional oxygen atom along an extension of the W-W axis (W-O (axial) = 2.54 A (averaged)). The molecule has a pair of cis-bridging pivalate groups that impose a near-eclipsed geometry for the two WO/sub 5/ pentagonal units. /sup 1/H NMR studies reveal that in toluene-d/sub 8/ solution W/sub 2/(O/sub 2/C-t-Bu)/sub 6/ exists as a mixture of two isomers, each having a C/sub 2/ axis of symmetry. These observations are compared with previous findings and in particular with those for W/sub 2/(O/sub 2/CNMe/sub 2/)/sub 6/. It is proposed that most, if not all, compounds of formula W/sub 2/(O/sub 2/CX)/sub 6/ will adopt a structure related to either W/sub 2/(O/sub 2/C-t-Bu)/sub 6/ or W/sub 2/(O/sub 2/CNMe/sub 2/)/sub 6/, which are closely related, differing only in the arrangement of the chelate ligands about a common W/sub 2/O/sub 10/O'/sub 2/ template. 15 references, 2 figures, 4 tables.
- Research Organization:
- Indiana Univ., Bloomington
- OSTI ID:
- 6213074
- Journal Information:
- Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 24:20; ISSN INOCA
- Country of Publication:
- United States
- Language:
- English
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360102* -- Metals & Alloys-- Structure & Phase Studies
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
400301 -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
BOND ANGLE
BOND LENGTHS
CARBOXYLIC ACIDS
CHEMICAL BONDS
CHEMICAL REACTIONS
CRYSTAL STRUCTURE
DATA
DIMENSIONS
DISPERSIONS
EXPERIMENTAL DATA
HYDROCARBONS
INFORMATION
LENGTH
LIGANDS
MIXTURES
MOLECULAR STRUCTURE
MONOCARBOXYLIC ACIDS
NMR SPECTRA
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PIVALIC ACID
REFRACTORY METAL COMPOUNDS
SOLUTIONS
SPECTRA
TRANSITION ELEMENT COMPOUNDS
TUNGSTEN COMPOUNDS