Restriction of CaCO3 polymorph by NH⋯O hydrogen-bonded poly(methacryloylaminocarboxylate) ligands: induced polymorph change by strength and/or formation manner of hydrogen bond
作者:Kazuyuki Takahashi、Atsuko Kobayashi、Mototsugu Doi、Seiji Adachi、Takahisa Taguchi、Taka-aki Okamura、Hitoshi Yamamoto、Norikazu Ueyama
DOI:10.1039/b415692g
日期:——
Novel poly(methacryloylaminocarboxylate) ligands were synthesized as models for an acidic peptide in CaCO3 biominerals. Syndiotactic poly[3-methyl-2-(methacryloylamino)butyrate], isotactic-rich poly[3-(methacryloylamino)propionate], and syndiotactic poly[4-(methacryloylamino)butyrate] form 5-, 6-, and 7-membered-ring intra-side-chain NHâ¯O hydrogen bonds, respectively, between a carboxylate oxyanion and the neighboring amide NH proton, while syndiotactic poly[3-(methacryloylamino)propionate] forms intermolecular NHâ¯O hydrogen bonds. These polymer ligands strongly bind to CaCO3 crystals because of the NHâ¯O hydrogen bonds. In polymer ligandâCaCO3 composites, the strength and/or mode of hydrogen bonding in the polymer ligands affects the CaCO3 polymorphs. Five-membered-ring intra-side-chain and intermolecular hydrogen-bonded polymers have weak hydrogen bonds and produce calcite crystals, whereas other ligands with 6- and 7-membered-ring intra-side-chain hydrogen bonds have strong hydrogen bonds and yield vaterite crystals. Polymorph change of CaCO3 crystal is induced by differences of strength and/or mode of the NHâ¯O hydrogen bond.
作为 CaCO3 生物矿物中酸性肽的模型,合成了新型聚(甲基丙烯酰氨基羧酸盐)配体。半乳聚[3-甲基-2-(甲基丙烯酰氨基)丁酸酯]、富含等轴的聚[3-(甲基丙烯酰氨基)丙酸酯]和半乳聚[4-(甲基丙烯酰氨基)丁酸酯]分别形成 5、6 和 7 个元环内侧链 NHâ¯O 氢键、而辛二酸聚[3-(甲基丙烯酰氨基)丙酸]则形成分子间 NHâ¯O 氢键。由于 NHâ¯O 氢键的作用,这些聚合物配体能与 CaCO3 晶体紧密结合。在聚合物配体与 CaCO3 复合材料中,聚合物配体中氢键的强度和/或模式会影响 CaCO3 的多晶型。五元环侧链内氢键和分子间氢键聚合物的氢键较弱,可生成方解石晶体,而其他具有六元环和七元环侧链内氢键的配体的氢键较强,可生成长石晶体。CaCO3 晶体的多晶型变化是由 NHâ¯O 氢键的强度和/或模式差异引起的。