Journal article
Synthesis and structural diversity of barium (N,N-dimethylamino)diboranates
Inorganic chemistry, Vol.51(12), pp.6449-6459
06/18/2012
DOI: 10.1021/ic2016879
PMID: 22667984
Abstract
The reaction of a slurry of BaBr(2) in a minimal amount of tetrahydrofuran (THF) with 2 equiv of Na(H(3)BNMe(2)BH(3)) in diethyl ether followed by crystallization from diethyl ether at -20 °C yields crystals of Ba(H(3)BNMe(2)BH(3))(2)(Et(2)O)(2) (1). Drying 1 at room temperature under vacuum gives the partially desolvated analogue Ba(H(3)BNMe(2)BH(3))(2)(Et(2)O)(x) (1') as a free-flowing white solid, where the value of x varies from <0.1 to about 0.4 depending on whether desolvation is carried out with or without heating. The reaction of 1 or 1' with Lewis bases that bind more strongly to barium than diethyl ether results in the formation of new complexes Ba(H(3)BNMe(2)BH(3))(2)(L), where L = 1,2-dimethoxyethane (2), N,N,N',N'-tetramethylethylenediamine (3), 12-crown-4 (4), 18-crown-6 (5), N,N,N',N'-tetraethylethylenediamine (6), and N,N,N',N",N"-pentamethylethylenetriamine (7). Recrystallization of 4 and 5 from THF affords the related compounds Ba(H(3)BNMe(2)BH(3))(2)(12-crown-4)(THF)·THF (4') and Ba(H(3)BNMe(2)BH(3))(2)(18-crown-6)·2THF (5'). In addition, the reaction of BaBr(2) with 2 equiv of Na(H(3)BNMe(2)BH(3)) in the presence of diglyme yields Ba(H(3)BNMe(2)BH(3))(2)(diglyme)(2) (8), and the reaction of 1 with 15-crown-5 affords the diadduct [Ba(15-crown-5)(2)][H(3)BNMe(2)BH(3)](2) (9). Finally, the reaction of BaBr(2) with Na(H(3)BNMe(2)BH(3)) in THF, followed by the addition of 12-crown-4, affords the unusual salt [Na(12-crown-4)(2)][Ba(H(3)BNMe(2)BH(3))(3)(THF)(2)] (10). All of these complexes have been characterized by IR and (1)H and (11)B NMR spectroscopy, and the structures of compounds 1-3, 4', 5', and 6-10 have been determined by single-crystal X-ray diffraction. As the steric demand of the Lewis bases increases, the structure changes from polymers to dimers to monomers and then to charge-separated species. Despite the fact that several of the barium complexes are monomeric in the solid state, none is appreciably volatile up to 200 °C at 10(-2) Torr.
Details
- Title: Subtitle
- Synthesis and structural diversity of barium (N,N-dimethylamino)diboranates
- Creators
- Scott R Daly - University of Illinois Urbana-ChampaignBrian J Bellott - University of Illinois Urbana-ChampaignMark A Nesbit - University of Illinois Urbana-ChampaignGregory S Girolami - University of Illinois Urbana-Champaign
- Resource Type
- Journal article
- Publication Details
- Inorganic chemistry, Vol.51(12), pp.6449-6459
- DOI
- 10.1021/ic2016879
- PMID
- 22667984
- NLM abbreviation
- Inorg Chem
- ISSN
- 0020-1669
- eISSN
- 1520-510X
- Publisher
- United States
- Language
- English
- Date published
- 06/18/2012
- Academic Unit
- Chemistry
- Record Identifier
- 9983985993302771
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