TY - JOUR
T1 - Tris(borane) adducts of diphosphanylmethanides
T2 - The [H3BCH(PPh2BH3)2]- anion and its alkali metal complexes
AU - Langer, Jens
AU - Geitner, Robert
AU - Görls, Helmar
PY - 2014
Y1 - 2014
N2 - The reactivity of lithium complexes that contain the borane-modified diphoshanylmethanide ligand [CH(PPh2BH3)2]- towards different Lewis base adducts of BH3 was studied to gain further insight into the mechanism of the isomerization of this derivative, which formally proceeds through a shift of one BH3 group from the phosphorus atom to the carbon atom. Whereas the use of BH3·THF in THF only resulted in the thf adduct of the starting material, [Li{CH(PPh2BH3)2}(thf)2] (1), the application of BH3·SMe2 in toluene resulted in the formation of the novel compound [(Li{H3BCH(PPh2BH3)2})∞] (2). The subsequent addition of ethereal ligands led to the isolation of [Li{H3BCH(PPh2BH3)2}(Me4thf)] (3) and [Li{H3BCH(PPh2BH3)2}(thf)3] (4). Treatment of these complexes with stronger Lewis bases such as N,N,N',N'-tetramethylethane-1,2-diamine (tmeda) results in the removal of one phosphorus-bound BH3 molecule and the formation of the [Ph2PCH(BH3)PPh2BH3]- anion. These results indicate that the isomerization of [CH(PPh2BH3)2]- requires an additional BH3 source and a rather strong Lewis base. Complexes 1-4 and the related derivatives [Li{CH(PPh2BH3)2}(Me4THF)] (5) and [K{H3BCH(PPh2BH3)2}(dme)2] (6; dme = 1,2-dimethoxyethane) were characterized by multinuclear NMR spectroscopy and by single-crystal X-ray diffraction analysis.
AB - The reactivity of lithium complexes that contain the borane-modified diphoshanylmethanide ligand [CH(PPh2BH3)2]- towards different Lewis base adducts of BH3 was studied to gain further insight into the mechanism of the isomerization of this derivative, which formally proceeds through a shift of one BH3 group from the phosphorus atom to the carbon atom. Whereas the use of BH3·THF in THF only resulted in the thf adduct of the starting material, [Li{CH(PPh2BH3)2}(thf)2] (1), the application of BH3·SMe2 in toluene resulted in the formation of the novel compound [(Li{H3BCH(PPh2BH3)2})∞] (2). The subsequent addition of ethereal ligands led to the isolation of [Li{H3BCH(PPh2BH3)2}(Me4thf)] (3) and [Li{H3BCH(PPh2BH3)2}(thf)3] (4). Treatment of these complexes with stronger Lewis bases such as N,N,N',N'-tetramethylethane-1,2-diamine (tmeda) results in the removal of one phosphorus-bound BH3 molecule and the formation of the [Ph2PCH(BH3)PPh2BH3]- anion. These results indicate that the isomerization of [CH(PPh2BH3)2]- requires an additional BH3 source and a rather strong Lewis base. Complexes 1-4 and the related derivatives [Li{CH(PPh2BH3)2}(Me4THF)] (5) and [K{H3BCH(PPh2BH3)2}(dme)2] (6; dme = 1,2-dimethoxyethane) were characterized by multinuclear NMR spectroscopy and by single-crystal X-ray diffraction analysis.
KW - Boranes
KW - Lithium
KW - Phosphanes
KW - Potassium
KW - X-ray diffraction
UR - http://www.scopus.com/inward/record.url?scp=84913580399&partnerID=8YFLogxK
U2 - 10.1002/ejic.201402845
DO - 10.1002/ejic.201402845
M3 - Article
AN - SCOPUS:84913580399
SN - 1434-1948
VL - 2014
SP - 5940
EP - 5947
JO - European Journal of Inorganic Chemistry
JF - European Journal of Inorganic Chemistry
IS - 34
ER -