The Molecular Structure and NMR Properties of P-Phosphinoylmethyl Aminophosphonium Salts

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• 作者：Ló ; pez Leonardo ; Carmen ; Alajarí ; n ; Mateo ; Llamas Lorente ; Pilar ; Bautista ; Delia ; Jimeno ; Marí ; a Luisa ; Alkorta ; Ibon ; Elguero ; Jos&eacute
• 关键词：Coupling constants ; intramolecular hydrogen bonds ; 15N ; labeled derivatives ; aminophosphonium salts
• 刊名：Structural Chemistry
• 出版年：2003
• 出版时间：2003
• 年：2003
• 卷：14
• 期：4
• 页码：391-397
• 全文大小：84 KB

文摘

The molecular structures of two aminophosphonium salts (bromide and tetrafluoroborate) have been determined by X-ray analysis. They have similar conformations and hydrogen bond (HB) networks: the N–H acid proton is bonded to the anion and, in the case of the fluoroborate, to the oxygen atom of the phosphine oxide, forming a pseudo six-membered ring closed by a weak N–H⋅⋅⋅O intramolecular hydrogen bond (IMHB). These compounds have been studied by multinuclear NMR in solution, including the ¹⁵N-labeled derivatives, to determine a complete set of coupling constants. A coupling of ∣1.5∣ Hz between the ¹⁵N and the ³¹P nuclei, separated by three bonds, was observed experimentally for the bromide in CDCl₃ solution, which appears to be a classical ³J_N-P across the covalent bonds and not a ^3hJ_N-P across the IMHB.