ISSN:
1572-8862
Keywords:
Tungsten
;
octanuclear cluster
;
oxo
;
alkoxide
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Abstract From the reaction between W4(p-tolyl)2(O-i-Pr)10 and H2, in hydrocarbon solvents, the compound [W4(O)2(O-i-Pr)8]2, 1, has been isolated in ca. 25% yield. Formation of 1 is traced to the decomposition of a compound of formula [W4O-i-Pr)10] n , which has been characterized only by1H NMR spectroscopy. The latter is formed by the stepwise hydrogenolysis of W4(p-tolyl)2(O-i-Pr)10 + H2 → W4(H)(p-tolyl)(O-i-Pr)10 + toluene; W4(H)(p-tolyl)(O-i-Pr)10 → [W4(O-i-Pr)10] n + toluene. In the presence of a small amount of H2O2 the previously characterized compound W4(O)(O-i-Pr)10, 2, is formed. The structure of 1 consists of two pseudo W4 tetrahedra linked through the agency of a pair of alkoxide bridges that bind two tungsten atoms that in turn cap triangles, W3(O)2(O-i-Pr)7, of tungsten atoms. At −176°C the cell dimensions werea=12.600(3),b=14.722(3),c=12.585(2),β=119.77(1),Z=1, andd calcd = 2.240 g cm−3 in the space group P1¯. The W-W distances within these triangles are ca. 2.9 Å whereas the capping W-W atom distances are ca. 2.5 Å. The1H NMR spectrum of 1 in benzene-d6 is consistent with the maintenance of the solid-state structure in solution.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01175841
