Dehydropolymerization of Amine Boranes using Bis(imino)pyridine Rhodium Pre-Catalysis: σ-Amine Borane Complexes, Nanoparticles, and Low Residual-Metal BN-Polymers that can be Chemically Repurposed

被引：2

作者：

Cross, Mathew J. ^{[1
]}

Brodie, Claire N. ^{[1
]}

Crivoi, Dana G. ^{[2
]}

Goodall, Joe C. ^{[1
]}

Ryan, David E. ^{[1
,2
]}

Martinez-Martinez, Antonio J. ^{[2
,3
,4
]}

Johnson, Alice ^{[2
,5
]}

Weller, Andrew S. ^{[1
]}

机构：

[1] Univ York, Dept Chem, York YO10 5DD, England

[2] Univ Oxford, Dept Chem, Oxford OX1 3TA, England

[3] Univ Huelva, CIQSO Ctr Res Sustainable Chem, Supramol Organometall & Main Grp Chem Lab, Campus El Carmen, Huelva 21007, Spain

[4] Univ Huelva, Dept Chem, Campus El Carmen, Huelva 21007, Spain

[5] Sheffield Hallam Univ, Dept Biosci & Chem, Howard St, Sheffield S1 1WB, England

来源：

CHEMISTRY-A EUROPEAN JOURNAL | 2023年 / 29卷 / 60期

基金：

英国工程与自然科学研究理事会;

关键词：

amine-borane; dehydropolymerization; mechanism; nanoparticle; rhodium; GEOMETRY OPTIMIZATION; HOMOGENEOUS CATALYSIS; DIMETHYLAMINE-BORANE; CRUCIAL ROLE; DEHYDROGENATION; POLYAMINOBORANES; MECHANISMS; BORONIUM; ADDUCTS; DEHYDROCOUPLING/DEHYDROGENATION;

D O I：

10.1002/chem.202302110

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The sigma amine borane complexes [Rh(L1)(eta(2):eta(2)-H3B center dot NRH2)][OTf] (L1= 2,6-bis-[1-(2,6-diisopropylphenylimino) ethyl]pyridine, R=Me, Et, Pr-n) are described, alongside [Rh(L1)(NMeH2)][OTf]. Using R=Me as a pre-catalyst (1 mol%) the dehydropolymerization of H3B center dot NMeH2 gives [H2BNMeH](n) selectively. Added NMeH2, or the direct use of [Rh(L1)(NMeH2)][OTf], is required for initiation of catalysis, which is suggested to operate through the formation of a neutral hydride complex, Rh(L1)H. The formation of small (1-5 nm) nanoparticles is observed at the end of catalysis, but studies are ambiguous as to whether the catalysis is solely nanoparticle promoted or if there is a molecular homogeneous component. [Rh(L1)(NMeH2)][OTf] is shown to operate at 0.025 mol% loadings on a 2 g scale of H3B center dot NMeH2 to give polyaminoborane [H2BNMeH](n) [M-n=30,900 g/mol, D = 1.8] that can be purified to a low residual [Rh] (6 mu g/g). Addition of Na[N(SiMe3)(2)] to [H2BNMeH](n) results in selective depolymerization to form the eee-isomer of N,N,N-trimethylcyclotriborazane [H2BNMeH](3): the chemical repurposing of a main-group polymer.

引用

页数：9