Linear hybrid aminoborane/phosphinoborane chains: synthesis, proton-hydride interactions, and thermolysis behavior.
Linear hybrid aminoborane/phosphinoborane chains: synthesis, proton-hydride interactions, and thermolysis behavior.
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线性杂化氨基硼烷/膦基硼烷链：合成、质子-氢化物相互作用和热解行为。
DOI：
10.1021/ic034938f
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发表时间：
2004
影响因子：
4.6
通讯作者：
I. Manners
中科院分区：
文献类型：
--
作者：
C. Jaska;A. Lough;I. Manners
锂化膦-硼烷加合物Li[PPhR.BH(3)]或Li[CH(2)-PR(2).BH(3)]与Me(2)NH.BH(2)Cl反应，得到杂化线性物种Me(2)NH-BH(2)-PPhR-BH(3)(1，R=Ph；2，R=H)或Me(2)NH-BH(2)-CH(2)-PR(2)-BH(3)(3，R=Ph；4，R=Me)。1和3的单晶X射线衍射研究证实了预期的四配位N-B-P-B和N-B-C-P-B骨架。此外，质子N-H和氢化B-H氢原子之间的相互作用导致1的分子间H…H接触很短，而3的分子内H…H距离非常短，为1.95 A。溶液和固体红外光谱研究也表明，即使在稀溶液中，这些二氢相互作用也保持不变。氢键强度在7.9~10.9kJ摩尔(-1)范围内，表明存在较弱的相互作用。考察了1-4的热和催化脱氢偶联反应活性。在130℃下，观察到1和2的裂解反应生成了Me(2)NH.BH(3)，[Me(2)N-BH(2)](2)，PhPRH.BH(3)(R=Ph，H)，PhPRH(R=Ph，H)，Ph(2)PH-BH(2)-PPh(2)-BH(3)，以及低分子量多膦硼烷[PhPH-BH(2)](N)(M(W)约5000)。在尝试的催化脱氢偶联反应中也观察到了类似的产物，但在较温和的反应条件下(50摄氏度)。3在130℃热分解得到六元环[BH(2)-CH(2)-PPh(2)](2)(5)，这可能是Me(2)NH.BH(3)从3解离的结果。4在90℃热分解得到Me(2)NH.BH(3)和Me(3)P.BH(3)，此外还有一个暂定为[BH(2)-CH(2)-PME(2)](2)(6)的产物。
The reaction of the lithiated phosphine-borane adducts Li[PPhR.BH(3)] or Li[CH(2)-PR(2).BH(3)] with Me(2)NH.BH(2)Cl afforded the hybrid linear species Me(2)NH-BH(2)-PPhR-BH(3) (1, R = Ph; 2, R = H) or Me(2)NH-BH(2)-CH(2)-PR(2)-BH(3) (3, R = Ph; 4, R = Me). Single-crystal X-ray diffraction studies on 1 and 3, the first for linear hybrid aminoborane/phosphinoborane adducts, confirmed the expected four-coordinate N-B-P-B and N-B-C-P-B frameworks. In addition, interactions between the protic N-H and hydridic B-H hydrogen atoms resulted in short intermolecular H...H contacts for 1, whereas 3 was found to possess an exceptionally short intramolecular H...H distance of 1.95 A. Solution and solid state infrared studies on 3 and 4 also suggest that these dihydrogen interactions were maintained even in dilute solution. Hydrogen bond strengths in the range of 7.9 to 10.9 kJ mol(-1) indicate the presence of a relatively weak interaction. The thermal and catalytic dehydrocoupling reactivities of 1-4 were also investigated. Chain cleavage reactions were observed for 1 and 2 upon thermolysis at 130 degrees C to afford species such as Me(2)NH.BH(3), [Me(2)N-BH(2)](2), PhPRH.BH(3) (R = Ph, H), PhPRH (R = Ph, H), Ph(2)PH-BH(2)-PPh(2)-BH(3), and also the low molecular weight polyphosphinoborane [PhPH-BH(2)](n) (M(w) approximately 5000). Similar products were observed for the attempted catalytic dehydrocoupling reactions but under milder reaction conditions (50 degrees C). Thermolysis of 3 at 130 degrees C yielded the six-membered ring [BH(2)-CH(2)-PPh(2)](2) (5), which presumably results from the dissociation of Me(2)NH.BH(3) from 3. Thermolysis of 4 at 90 degrees C afforded Me(2)NH.BH(3) and Me(3)P.BH(3), in addition to a product tentatively assigned as [BH(2)-CH(2)-PMe(2)](2) (6).