Synthesis and Characterization of Two Isomeric, Self-Assembled Arsenic−Thiolate Macrocycles

Abstract

The use of labile As-S bond formation in the self-assembly of discrete supramolecular structures is extended. Macrocyclic structures of chemical formula As2L2Cl2 (H2L=alpha,alpha'-dimercapto-p-xylene) were prepared and characterized. Diastereomeric syn and anti isomers of these macrocycles were selectively crystallized and characterized in the solid state using single-crystal X-ray diffraction. Both the syn and anti macrocycles show close contacts between the arsenic(III) ions and the aromatic carbons, consistent with intramolecular arsenic-pi interactions. The dynamic behavior of the isomers in solution is also investigated. anti-As2L2Cl2.AsCl3 crystallizes in monoclinic space group P2(1)/c (No. 14) with a=10.6194(5) A, b=16.7780(9) A, c=8.5725(4) A, beta=100.6830(10) degrees, and Z=2. syn-As2L2Cl2 crystallizes in orthorhombic space group Pnma (No. 62) with a=10.8881(8) A, b=19.3511(14) A, c=9.9524(7) A, and Z=4.

Mutual influence between anion–π and pnicogen bond interactions: The enhancement of P⋯N and P⋯O interactions by an anion–π bond

“…Pn-bond interactions are relevant in biological systems. For instance, the P···N interactions were found in protein β-sheets [30]. The Pn-bonds involving Sb atom also likely participate in the mechanism of inhibition of Sb-based drugs used to treat leishmaniasis [31].…”

Self-assembled antimony-thiolate Sb2L3and Sb2L2Cl2complexes

“…Both dinuclear complexes exhibit close contacts between antimony and arene rings in the solid state characteristic of antimony-p interactions [23]. Thus, antimony-arene interactions provide a novel additional stabilizing factor favoring formation of these discrete supramolecular structures [24,25].…”

Synthesis and characterization of a rare arsenic trithiolate with an organic disulfide linkage and 2-chloro-benzo-1,3,2-dithiastibole

“…Recent interest in arsenic thiolates as building blocks in self-assembled macrocycles [2,3] along with a lack of single crystal X-ray structural analysis of relatively simple arsenic thiolates has prompted our work on the synthesis and characterization of several arsenic dithiolates [4]. These are of the general formula RS 2 AsX where R is an organic group connecting the sulfurs and X = Cl or I.…”