Synthesis and characterization of synthetically useful salts of the weakly-coordinating dianion [B12Cl12]2-
Synthesis and characterization of synthetically useful salts of the weakly-coordinating dianion [B12Cl12]2-
复制标题
DOI：
10.1039/b821030f
复制
发表时间：
2009-01-01
影响因子：
4
通讯作者：
Uzun, Rabiya
中科院分区：
文献类型：
--
作者：
Geis, Vanessa;Guttsche, Kristin;Uzun, Rabiya
以廉价易得的Na[BH 4]和I-2为原料，在二甘醇二甲醚（diethylene glycol dimethyl ether）中，通过改进的合成方法，在实验室规模上合成了封闭十二氢十二硼酸酯[NEt 3 H]（2）[B12 H12]。随后在常压下与元素氯在水溶液中氯化产生全氯化弱配位[B12 Cl 12]（2-）阴离子。通过简单的复分解反应，可以得到各种有用的盐[阳离子]（2）[B12 Cl 12]（阳离子= [NEt 3 H]（+），[NBu 4]（+），Li+，Na+，K+，Cs+）。这些盐是有用的起始材料，其具有打开[B12 Cl 12]（2-）作为弱配位二价阴离子的化学的潜力。示例性地，它们用于进一步的反应以制备[NO]（2）[B12 Cl 12]、[PPN]（2）[B12 Cl 12]和[CPh 3]（2）[B12 Cl 12]。测定了Cs-2[B_（12）Cl_（12）]中心点SO_2、[CPh_3]（2）[B_（12）Cl_（12）]中心点2C_（2）H_（4）Cl_（2）和[CPh_3]（2）[B_（12）Cl_（12）]中心点2SO_（2）的晶体结构以及[NO]（2）[B_（12）Cl_（12）]中心点SO_2和[PPN]（2）[B_（12）Cl_（12）]中心点CH_2Cl_2的初步晶体结构。SO2溶剂化物Cs2[B12 Cl 12]中心点SO2的晶体结构与无溶剂Cs2 [B12 Cl 12]的晶体结构有关。[CPh 3]（2）[B_（12）Cl_（12）]中心点2C（2）H（4）Cl（2）和[CPh 3]（2）[B_（12）Cl_（12）]中心点2SO（2）在固态下具有非常相似的结构。在这两种情况下，[CPh 3]（+）阳离子分别与[B12 Cl 12]（2-）阴离子和SO2或C2 H4 Cl 2溶剂分子仅形成非常弱的接触。[B12 Cl 12]（2-）中的平均实验B-B（178.7 pm）和B-Cl（178.9 pm）键长在所有确定的结构中基本上不变，并且通过PBE 0/TZVPP量子化学计算（B-B 178.6 pm，B-Cl 179.3 pm）很好地再现。结果表明，[B12 Cl 12]（2-）是一种易接近的弱配位阴离子。
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 I-2 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 Cs-2[B12Cl12]center dot SO2, [CPh3](2)[B12Cl12]center dot 2C(2)H(4)Cl(2), and [CPh3](2)[B12Cl12]center dot 2SO(2) and preliminary crystal structures of [NO](2)[B12Cl12] center dot SO2 and [PPN](2)[B12Cl12]center dot CH2Cl2 were determined. The crystal structure of the SO2 solvate Cs2[ B12Cl12] center dot SO2 is related to the crystal structure of solvent free Cs-2[ B12Cl12]. [ CPh3] (2)[ B12Cl12] center dot 2C(2)H(4)Cl(2) and [CPh3](2)[ B12Cl12]center dot 2SO(2) 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 C2H4Cl2 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.