Structure-Directing Effect of Organic Cations in the Assembly of Anionic In(III)/Diazinedicarboxylate Architectures
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- 作者：Javier Cepeda ; Garikoitz Beobide ; Oscar Castillo ; Antonio Luque ; Sonia P茅rez-Y谩帽ez ; Pascual Rom谩n
- 刊名：Crystal Growth & Design
- 出版年：2012
- 出版时间：March 7, 2012
- 年：2012
- 卷：12
- 期：3
- 页码：1501-1512
- 全文大小：1155K
- 年卷期：v.12,no.3(March 7, 2012)
- ISSN：1528-7505
文摘
We report herein the synthesis and physicochemical characterization of seven new indium鈥損yrazine-2,5-dicarboxylato (pzdc) and pyridazine-3,6-dicarboxylato (pddc) compounds: (dma)6[In6(渭-pzdc)12]路xH2O (1), (dea)6[In6(渭-pzdc)12]路xH2O (2), {(tma)[In(渭-pzdc)2]路2H2O}n (3), {(dea)[In(渭-pzdc)2]路2H2O}n (4), {(dma)[In(渭-pddc)2]路xH2O}n (5), {(dma)[In(渭-pddc)2]}n (6), and (dma)4[In8(渭-pddc)12(H2O)8(OH)4]路xH2O (7) (where dma = dimethylammonium, dea = diethylammonium, tma = tetramethylammonium). Two types of In(III)/pzdc structures have been obtained. The first one (1 and 2) is comprised of discrete hexanuclear anionic assemblies held together by hydrogen bonding interactions through the organic cations generated by the thermal hydrolysis of the amide solvents. The second one (3 and 4) consists of an anionic three-dimensional (3D) framework with channels that are occupied by the counterions and solvent molecules. The first type of structure seems to be the kinetically preferred one since it is obtained when using relatively soft solvothermal conditions (120 掳C) and counterions that are able to establish relatively strong hydrogen bonding interactions. The 3D frameworks crystallize when the organic counterion is unable to establish hydrogen bonding interactions or when employing a higher temperature (150 掳C). The metal鈥搊rganic assemblies obtained in the In(III)/pddc system range from two-dimensional (2D) sheets (5 and 6) to discrete octameric entities (7) depending on the amount of water in the reaction mixture. It is worth noting that the open lamellar crystal structure of compound 5 undergoes a solid state transformation accompanied by the release of water molecules, rendering the solvent free 2D architecture of 6 that exhibits a different connectivity. Surprisingly, a prolonged exposure of 6 to a water saturated atmosphere does not revert to 5 but promotes a partial and reversible transformation to give a new unidentified In-pddc compound.