作者:Eric A. Bruton、Lee Brammer、F. Christopher Pigge、Christer B. Aakeröy、Destin S. Leinen
DOI:10.1039/b301045g
日期:——
Despite their established hydrogen bonding capability, oxime functional groups (–C(R′)NOH) have received far less attention in supramolecular chemistry than their carboxyl and amide counterparts. Here we report a series of dioximes (R′H, CH3, NH2) for which hydrogen bonding patterns have been examined in the solid state to establish the reliability of hydrogen-bonded synthons available for use in supramolecular syntheses using oximes. In all cases, network structures were formed, most frequently propagated through oxime–oxime O–H⋯N hydrogen-bonded dimer formation [R22(6) graph set] and less often using C(3) chain or R44(12) ring arrangements. Even in the systems where R′ = NH2, robust and dominant oxime–oxime hydrogen bonding prevails, with amino groups playing a supporting role in network construction primarily via weaker N–H⋯O hydrogen bonds. The compounds studied are aromatic dioximes 1,3-C6H4(C(R′)NOH)21–3 and 1,4-C6H4(C(R′)NOH)24–6
(R′ = H, CH3, NH2), and aliphatic dioximes fumaramide dioxime 7
(R′ = NH2) and succinamide dioxime 8
(R′ = NH2).
尽管肟的官能团(–C(R′)NOH)具有已知的氢键形成能力,但在超分子化学中它们受到的关注远不及羧基和酰胺。我们报道了一系列肟(R′= H、CH3、NH2),这些肟在固态下的氢键模式已被研究,以确立在超分子合成中可以使用肟的氢键合成单元的可靠性。在所有情况下,都形成了网络结构,大多数情况下通过肟-肟 O–H⋯N 氢键二聚体形成(R22(6)图集)进行传播,较少情况下使用 C(3)链或 R44(12)环排列。即使在 R′= NH2 的系统中,强健且占主导地位的肟-肟氢键也占优势,氨基主要通过较弱的 N–H⋯O氢键在网络构建中起辅助作用。所研究的有机化合物包括芳香族肟1,3-C6H4(C(R′)NOH)21–3和1,4-C6H4(C(R′)NOH)24–6 (R′= H、CH3、NH2),以及脂肪族肟富马酰胺肟7 (R′= NH2)和琥珀酰胺肟8 (R′= NH2)。