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), Vol. 24:20
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ORGANIC COMPOUNDS
CHEMICAL REACTIONS
CRYSTAL STRUCTURE
MOLECULAR STRUCTURE
OXYGEN COMPOUNDS
PIVALIC ACID
TUNGSTEN COMPOUNDS
CHEMICAL BONDS
BOND ANGLE
BOND LENGTHS
EXPERIMENTAL DATA
HYDROCARBONS
LIGANDS
NMR SPECTRA
SOLUTIONS
CARBOXYLIC ACIDS
DATA
DIMENSIONS
DISPERSIONS
INFORMATION
LENGTH
MIXTURES
MONOCARBOXYLIC ACIDS
NUMERICAL DATA
ORGANIC ACIDS
REFRACTORY METAL COMPOUNDS
SPECTRA
TRANSITION ELEMENT COMPOUNDS
360102* - Metals & Alloys- Structure & Phase Studies
400201 - Chemical & Physicochemical Properties
400301 - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)