Interactions of guanidinium with benzene-sulphonic, -phosphonic and -arsonic acids and several of their nitro-derivatives

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• 作者：Kay Latham^a ; ^{kay.latham@rmit.edu.au} ; James E. Downs^a ; Colin J. Rix^a ; Jonathan M. White^b ; ¹ ; ^{whitejm@unimelb.edu.au}
• 关键词：Guanidinim cation ; Benzenesulphonate ; Benzenephosphonate ; Benzenearsonate ; H-bonding ; Supramolecular
• 刊名：Journal of Molecular Structure
• 出版年：2011
• 出版时间：22 February 2011
• 年：2011
• 卷：987
• 期：1-3
• 页码：74-85
• 全文大小：1750 K

文摘

The supramolecular interactions of the planar guanidinium cation () with benzenesulphonate (1), -phosphonate (2) and -arsonate (3) anions, and several of their 3- and 4-nitro-substituted derivatives is reported. In all cases well-defined crystalline materials, containing hydrogen-bonded networks with quasi-hexagonal sheet lattices were formed. However, the unsubstituted sulphonate (1) formed a 1:1 guanidinium:sulphonate bilayer structure, whilst the unsubstituted phosphonate (2) and arsonate (3) formed 2:1 guanidinium:phosphonate/arsonate single-layer structures with water occluded within the crystal voids. The additional H-bonding interactions resulting in distortion of the crystal voids in (2)/(3) as compared to the symmetrical hexagonal-form in (1). In the case of the nitro-substituted sulphonate derivatives, the 1:1 bilayer structure of the parent (1) was retained for the 3-nitrobenzenesulphonate (4), but transformed to a 1:1 single-layer system for the 4-nitrobenzenesulphonate (6). The reverse was observed for the nitrated phosphonic acids, whereby the 4-nitrobenzenephosphonate anion in (5) caused little disruption to the 2:1 single-layered structure and quasi-hexagonal sheet seen in (2), but the 3-nitrobenzenephosphonate caused a breakdown of the network forming a new, complex ribbon system (7). The greater complexity of the P/As (−2) structures compared to the S (−1) structure is attributed to the higher charge on the former anions providing additional opportunities for H-bonding. The observation of such interactions clearly indicates the likelihood of such species interacting with biologically-important arginine residues in vivo with concomitant unintended, but likely, toxic consequences.