Metal alkoxides - models for metal oxides. 1. Preparations and structures of hexadecaalkoxytetatungsten compounds, W/sub 4/(OR)/sub 16/, where R = Me and Et, and octaoxotetraisopropoxytetrapyridinotetramolybdenum, Mo/sub 4/(O)/sub 4/(. mu. -O)/sub 2/(. mu. /sub 3/-O)/sub 2/(O-i-Pr)/sub 2/(. mu. -O-i-Pr)/sub 2/(py)/sub 4/

Journal Article · Wed Oct 07 04:00:00 EDT 1981 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00410a018· OSTI ID:5690026

Chisholm, M H; Huffman, J C; Kirkpatrick, C C; Leonelli, J; Folting, K

In hydrocarbon solvents, W/sub 2/(NMe/sub 2/)/sub 6/ (M = M) and each of the alcohols, MeOH and EtOH, react to give tetranuclar compounds, W/sub 4/(OR/sub 16/ (R = Me and Et), by alcoholysis and oxidation of tungsten, 3+ to 4+. These new compounds have been characterized by a variety of physicochemical techniques including, for the ethoxide, a single-crystal x-ray diffraction study. By the formation of alkoxy bridges, each tungsten atom attains an octahedral coordination. The M/sub 4/O/sub 16/ skeleton is akin to those found in the anion W/sub 4/O/sub 16//sup 8 -/ and the neutral alkoxide (Ti(OEt)/sub 4/)/sub 4/, but the eight electrons associated with the four W(4+)d/sup 2/ atoms lead to cluster-W/sub 4/ bonding as evidenced by a comparison of M-M distances. From the reaction between Mo/sub 2/(O-i-Pr)/sub 6/ (M = M) and molecular oxygen in pyridine, a minor product, formed in ca. 15% yield based on Mo, is shown to be Mo/sub 4/O/sub 8/(O-i-Pr)/sub 4/(py)/sub 4/ by a complete x-ray diffraction study. The central Mo/sub 4/O/sub 8/O/sub 4/N/sub 4/ moiety is closely related to those mentioned above. The average oxidation state of molybdenum is +5, and the four electrons available for M-M bonding form two localized M-M single bonds. These observations lead us to propose that (1) metal alkoxides provide hydrocarbon-soluble models for metal oxides and (2) there should be a large class of structurally related M/sub 4/X/sub a/Y/sub b/Z/sub c/ cluster compounds (a + b + c = 16) in which the metal atoms achieve an octahedral environment and by appropriate variations of ligands and metals, have 0 through 12 electrons for M-M bonding. Crystal data are presented for W/sub 4/(OEt)/sub 16/.

• Research Organization: Indiana Univ., Bloomington
• OSTI ID: 5690026
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 103:20; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400301 -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ALCOHOLS
AMINES
AMMONIUM COMPOUNDS
AZINES
BOND ANGLE
BOND LENGTHS
COHERENT SCATTERING
CRYSTAL STRUCTURE
DATA
DIFFRACTION
DIMENSIONS
ETHANOL
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
INFORMATION
LENGTH
METHANOL
MOLYBDENUM COMPOUNDS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANOMETALLIC COMPOUNDS
PYRIDINES
PYRIDINIUM COMPOUNDS
QUATERNARY COMPOUNDS
SCATTERING
TRANSITION ELEMENT COMPOUNDS
TUNGSTEN COMPOUNDS
X-RAY DIFFRACTION