Arkhipov Sergey G, Rychkov Denis A, Pugachev Alexey M, Boldyreva Elena V
REC-008, Novosibirsk State University, Pirogova str. 2, Novosibirsk 630090, Russian Federation.
Institute of Automation and Electrometry SB RAS, pr. Akademika Koptyuga 1, Novosibirsk 630090, Russian Federation.
Acta Crystallogr C Struct Chem. 2015 Jul;71(Pt 7):584-92. doi: 10.1107/S2053229615010888. Epub 2015 Jun 18.
Crystals of maleates of three amino acids with hydrophobic side chains [L-leucenium hydrogen maleate, C6H14NO2(+)·C4H3O4(-), (I), L-isoleucenium hydrogen maleate hemihydrate, C6H14NO2(+)·C4H3O4(-)·0.5H2O, (II), and L-norvalinium hydrogen maleate-L-norvaline (1/1), C5H11NO2(+)·C4H3O4(-)·C5H12NO2, (III)], were obtained. The new structures contain C2(2)(12) chains, or variants thereof, that are a common feature in the crystal structures of amino acid maleates. The L-leucenium salt is remarkable due to a large number of symmetrically non-equivalent units (Z' = 3). The L-isoleucenium salt is a hydrate despite the fact that L-isoleucine is a nonpolar hydrophobic amino acid (previously known amino acid maleates formed hydrates only with lysine and histidine, which are polar and hydrophilic). The L-norvalinium salt provides the first example where the dimeric cation L-Nva...L-NvaH(+) was observed. All three compounds have layered noncentrosymmetric structures. Preliminary tests have shown the presence of the second harmonic generation (SGH) effect for all three compounds.
获得了三种具有疏水侧链的氨基酸马来酸盐晶体[L-亮氨酸氢马来酸盐，C6H14NO2(+)·C4H3O4(-)，(I)；L-异亮氨酸氢马来酸盐半水合物，C6H14NO2(+)·C4H3O4(-)·0.5H2O，(II)；以及L-正缬氨酸氢马来酸盐-L-正缬氨酸(1/1)，C5H11NO2(+)·C4H3O4(-)·C5H12NO2，(III)]。这些新结构包含C2(2)(12)链或其变体，这是氨基酸马来酸盐晶体结构中的一个共同特征。L-亮氨酸盐由于大量对称不等价单元（Z' = 3）而引人注目。L-异亮氨酸盐是一种水合物，尽管L-异亮氨酸是一种非极性疏水氨基酸（以前已知的氨基酸马来酸盐仅与赖氨酸和组氨酸形成水合物，而赖氨酸和组氨酸是极性和亲水的）。L-正缬氨酸盐提供了观察到二聚阳离子L-Nva...L-NvaH(+)的首个实例。所有三种化合物都具有层状非中心对称结构。初步测试表明这三种化合物都存在二次谐波产生（SHG）效应。
