| Autor: |
Geis, Vanessa, Guttsche, Kristin, Knapp, Carsten, Scherer, Harald, Uzun, Rabiya |
| Předmět: |
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| Zdroj: |
Dalton Transactions: An International Journal of Inorganic Chemistry; 4/21/2009, Issue 15, p2687-2694, 8p |
| Abstrakt: |
The closo-dodecahydrododecaborate [NEt3H]2[B12H12] has been prepared on a lab scale by an improved synthesis from cheap and readily available starting materials Na[BH4] and I2 in diglyme (diethylene glycol dimethyl ether). Subsequent chlorination with elemental chlorine in aqueous solution at normal pressure yielded the per-chlorinated weakly coordinating [B12Cl12]2- anion. By simple metathesis reaction a variety of useful salts [cation]2[B12Cl12] (cation = [NEt3H]+, [NBu4]+, Li+, Na+, K+, Cs+) is available. These salts are useful starting materials, which have the potential to open up the chemistry of [B12Cl12]2- as a weakly coordinating dianion. Exemplarily, they were used in further reactions to prepare [NO]2[B12Cl12], [PPN]2[B12Cl12], and [CPh3]2[B12Cl12]. The crystal structures of Cs2[B12Cl12].SO2, [CPh3]2[B12Cl12].2C2H4Cl2, and [CPh3]2[B12Cl12]·2SO2 and preliminary crystal structures of [NO]2[B12Cl12]·SO2 and [PPN]2[B12Cl12]·CH2C12 were determined. The crystal structure of the SO2 solvate Cs2[B12Cl12]·SO2 is related to the crystal structure of solvent free Cs2[B12Cl12]· [CPh3]2[B12Cl12].2C2H4Cl2 and [CPh3]2[B12Cl12]·2SO2 have very similar structures in the solid state. In both cases the [CPh3]+ cations form only very weak contacts to the [B12Cl12]2- anion and SO2 or C2H4C12 solvent molecules respectively. The averaged experimental B-B (178.7 pm) and B-Cl (178.9 pm) bond lengths within [B12Cl12]2- are essentially unchanged in all determined structures and are reproduced well by PBE0/TZVPP quantum chemical calculations (B-B 178.6 pm, B-Cl 179.3 pm). All results indicate that [B12Cl12]2- is a readily accessible weakly-coordinating dianion. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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