Fine Tuning of Metallaborane Geometries: Chemistry of Metallaboranes of Early Transition Metals Derived from Metal Halides and Monoborane Reagents
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Title |
Fine Tuning of Metallaborane Geometries: Chemistry of Metallaboranes of Early Transition Metals Derived from Metal Halides and Monoborane Reagents
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Creator |
BOSE, SK
GEETHARANI, K RAMKUMAR, V MOBIN, SM GHOSH, S |
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Subject |
cp-asterisk
structural-characterization electronic-structures molecular-structures crystal-structures complexes clusters reactivity tetrahydroborate eta(5)-c5me5 cluster compounds metallaboranes niobium tantalum vanadium |
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Description |
Reaction of [Cp(n)MCl(4-x)] (M=V: n=x=2; M=Nb: n=1, x=0) or [Cp*TaCl(4)] (CP=eta(5)-C(5)H(5), Cp*=eta(5)-C(5)Me(5)), with [LiBH(4)center dot thf] at -70 degrees C followed by thermolysis at 85 degrees C in the presence of [BH(3)center dot thf] yielded the hydrogen-rich metallaboranes [(CpM)(2)-(B(2)H(6))(2)] (1: M=V; 2: M=Nb) and [(Cp*Ta)(2)(B(2)H(6))(2)] (3) in modest to high yields. Complexes 1 and 3 are the first structurally characterized compounds with a metal-metal bond bridged by two hexahydroborate (B(2)H(6)) groups forming a symmetrical complex. Addition of [BH(3)center dot thf] to 3 results in formation of a metallaborane [(Cp*Ta)(2)B(4)H(8)(mu-BH(4))] (4) containing a tetrahydroborate ligand, [BH(4)](-), bound exo to the bicapped tetrahedral cage [(Cp*Ta)(2)B(4)H(8)] by two Ta-H-B bridge bonds. The interesting structural feature of 4 is the coordination of the bridging tetrahydroborate group, which has two B-H bonds coordinated to the tantalum atoms. All these new metallaboranes have been characterized by mass, (1)H, (11)B, and (13)C NMR spectroscopy and elemental analysis and the structural types were established unequivocally by crystallographic analysis of 1-4.
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Publisher |
WILEY-V C H VERLAG GMBH
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Date |
2011-09-01T16:27:59Z
2011-12-26T12:59:43Z 2011-12-27T05:52:27Z 2011-09-01T16:27:59Z 2011-12-26T12:59:43Z 2011-12-27T05:52:27Z 2009 |
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Type |
Article
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Identifier |
CHEMISTRY-A EUROPEAN JOURNAL, 15(48), 13483-13490
0947-6539 http://dx.doi.org/10.1002/chem.20090181.9 http://dspace.library.iitb.ac.in/xmlui/handle/10054/12821 http://hdl.handle.net/10054/12821 |
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Language |
en
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