氨基金刚烷-十一氟-闭式-十二硼酸盐（1-）的合成与表征。新型超弱阴离子。

Synthesis and characterization of ammonioundecafluoro-closo-dodecaborates(1-). New superweak anions.

作者信息

Ivanov Sergei V, Davis Jennifer A, Miller Susie M, Anderson Oren P, Strauss Steven H

机构信息

Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA.

出版信息

Inorg Chem. 2003 Jul 28;42(15):4489-91. doi: 10.1021/ic0344160.

DOI:10.1021/ic0344160

PMID:12870929

Abstract

The ammonioborane monoanion H(3)NB(12)H(11)(-) was per-B-fluorinated with elemental fluorine in liquid hydrogen fluoride to yield the first member of a new class of weakly coordinating anions, H(3)NB(12)F(11)(-) (isolated as N(n-Bu)(4)[H(2)NB(12)F(11)] in 41% yield). The pK(a) of the H(3)NB(12)F(11)(-) anion is 9.6. Several salts of the tri-N-alkylated anions Me(3)NB(12)F(11)(-) and Dd(3)NB(12)F(11)(-) (Dd = n-C(12)H(25)) were also prepared. The structure of [CPh(3)][Me(3)NB(12)F(11)] was determined by single-crystal X-ray diffraction: monoclinic, space group P2(1)/c, a = 18.053(3) A, b = 33.139(5) A, c = 9.600(2) A, beta = 91.459(4) degrees, V = 5742(2) A(3), Z = 8, T = 173(2) K, R(1) = 0.045. It revealed that the only direct interactions between the undecafluoroammonioborate monoanions and the trityl cations in the two independent ion pairs were long and weak BF...CPh(3) interactions of 2.992(6) and 2.942(6) A. Salts of the new anions were chemically, electrochemically, and thermally stable. The conductivity of Li(Me(3)NB(12)F(11)) in dimethoxyethane was comparable to that of LiPF(6) but less than half the value of Li(1-Me-CB(11)F(11)).

摘要

氨硼烷单阴离子H₃NB₁₂H₁₁⁻在液态氟化氢中用元素氟进行全硼氟化，生成一类新型弱配位阴离子的首个成员H₃NB₁₂F₁₁⁻（以[N(n-Bu)₄]₂[H₂NB₁₂F₁₁]形式分离得到，产率为41%）。H₃NB₁₂F₁₁⁻阴离子的pKₐ为9.6。还制备了三-N-烷基化阴离子Me₃NB₁₂F₁₁⁻和Dd₃NB₁₂F₁₁⁻（Dd = n-C₁₂H₂₅）的几种盐。通过单晶X射线衍射确定了[CPh₃][Me₃NB₁₂F₁₁]的结构：单斜晶系，空间群P2(1)/c，a = 18.053(3) Å，b = 33.139(5) Å，c = 9.600(2) Å，β = 91.459(4)°，V = 5742(2) Å³，Z = 8，T = 173(2) K，R(1) = 0.045。结果表明，在两个独立离子对中，十一氟氨硼酸盐单阴离子与三苯甲基阳离子之间唯一的直接相互作用是长且弱的BF...CPh₃相互作用，键长分别为2.992(6) Å和2.942(6) Å。新阴离子的盐在化学、电化学和热方面都很稳定。Li(Me₃NB₁₂F₁₁)在二甲氧基乙烷中的电导率与LiPF₆相当，但不到Li(1-Me-CB₁₁F₁₁)值的一半。