105472-15-9Relevant articles and documents
Organotransition-metal metallacarboranes. 9. nido-2,3-dibenzyl-2,3-dicarbahexaborane(8) [(PhCH2)2C2B4H6], a versatile multifunctional nido-carborane: Iron-polyarene sandwich compounds and chromium tricarbonyl π-complexes
Spencer, James T.,Grimes, Russell N.
, p. 328 - 335 (2008/10/08)
The title carborane 1, a nearly nonvolatile air- and water-stable liquid, has been prepared in multigram quantities from dibenzylacetylene (1,4-diphenyl-2-butyne) and B5H9 in the presence of triethylamine. The multifunctional reactivity of 1 has been systematically explored via the preparation of a variety of mixed iron-carborane-polyarene complexes in which one or more of the three bonding rings in 1 (C2B3 and two C6) are coordinated to metals. Thus, 1 was bridge-deprotonated to give the (PhCH2)2C2B4H5 - anion which in turn was treated with FeCl2 and C8H82- ion to form the cyclooctatriene complex (η6-C8H10)Fe[(PhCH2) 2C2B4H4] (2). The C8H10 ligand in 2 is readily displaced by arenes on heating, affording sandwich complexes of general formula (arene)Fe[(PhCH2)2C2B4H4] where the arene is [2.2]paracyclophane (3), 9,10-dihydroanthracene (4), or fluorene (o,o′-diphenylenemethane) (6). The reaction of 4 with 2 at elevated temperature yielded the staggered triple-decker diiron species (η6,η6-C14H12)Fe 2[(PhCH2)2C2B4H 4]2 (5). Complexes 2-6 are air-stable orange crystalline solids. Treatment of 2 with chromium hexacarbonyl in refluxing butyl ether/tetrahydrofuran resulted in complexation of one phenyl ring with a Cr(CO)3 group, forming (2-[(CO)3Cr(η6-C6H5)CH 2]-3-PhCH2-2,3-C2B4H 4)Fe(η6-C8H10) (7); reaction of 7 with Cr(CO)6 gave the dichromium species (2,3-[(CO)3Cr(η6-C6H5)CH 2]2-2,3-C2B4H 4)Fe(η6-C8H10) (8) in which both of the phenyl rings and the carborane face are coordinated to metals. Complexes 7 and 8 are yellow, moderately air-and light-stable solids. Characterization of compounds 1-8 was achieved via 11B and 1H NMR, IR, and mass spectroscopy, supported by an X-ray diffraction analysis of a dichromium complex of 1 which is reported in the following paper.
