Amine-Templated Open-Framework Zinc Arsenates of Varying Dimensionalities: Synthesis, Structure, Polymorphism, and Transformation Reactions

Rao, Koteswara V and Chakrabarti, Sandip and Natarajan, Srinivasan (2007) Amine-Templated Open-Framework Zinc Arsenates of Varying Dimensionalities: Synthesis, Structure, Polymorphism, and Transformation Reactions. In: Inorganic Chemistry, 46 (25). pp. 10781-10790.

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Abstract

Eight new open-framework zinc arsenates, encompassing the entire hierarchy of open-framework structures, have been prepared hydrothermally. The structures include zero-dimensional, one-dimensional chains, two-dimensional layers, and three-dimensional structures formed through the transformation of the molecular zinc arsenates. The structure of $[C_6N_4H_{21}]$$[Zn(HAsO_4)_2$$(H_2AsO_4)]$, I, is composed of $ZnO_4$ and $H_2AsO_4$ units connected through the vertices forming four-membered rings with $HAsO_4$ units hanging from the Zn center. The four-membered rings are connected through the corners forming the one-dimensional chain structures in $[C_4N_2H_{12}]$$[Zn(HAsO_4)_2].H_2O$, II, and $[C_5N_2H_{14}]$ $[Zn(HAsO_4)_2].H_2O$, III. $ZnO_4$ and $AsO_4$ units form a fully four-connected two-dimensional structure in $[C_4N_2H_{12}]$$[Zn-(AsO_4)]_2$, IV. One-dimensional zigzag ladders are connected through $HAsO_4$ units forming two-dimensional layers in $[C_4N_2H_{12}]$1.5$[Zn_2(AsO_4)(HAsO_4)_2].H_2O$, V, while the similar building units form a layer with hanging $HAsO_4$ units in the layered arsenate $[C_6N_4H_{21}]_6$$[Zn_{12}(HAsO_4)_{21}]$, VI. Hanging $HAsO_4$ units are also observed in the polymorphic structures of $[C_6N_3H_{20}][Zn_2(AsO_4)(HAsO_4)_2].2H2_O$, VII and VIII. Formation of zero-dimensional monomer, I, a fully four-connected layer, IV, and the polymorphic structures, VII and VIII, are important and noteworthy. The transformation reactions of I indicate that the monomer is reactive and gives rise to structures of higher dimensionalities, indicating a possible Aufbau-type building-up process in these structures.

Item Type:	Journal Article
Publication:	Inorganic Chemistry
Publisher:	American Chemical Society
Additional Information:	Copyright of this article belongs to American Chemical Society.
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	09 Jun 2008
Last Modified:	19 Sep 2010 04:45
URI:	http://eprints.iisc.ac.in/id/eprint/14240

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