Ligand Isomer Effect on the Formations of Supramolecular Lead(II), Mercury(II), and Copper(II)/Mercury(II) Complexes of Bis-O₂S₂-Macrocycle

Abstract

In addition to ortho-isomer (o-bis-L) and metaisomer (m-bis-L) of bis-O 2 S 2 -macrocycle obtained previously, its para-isomer (p-bis-L) was newly isolated, and the complete isomer series were structurally characterized by single crystal X-ray analysis. In complexations, borderline (Pb 2+ ) and soft (Hg 2+ and Cu + ) metal salts were employed to investigate the isomer effect on the coordination modes and topologies of the supramolecular complexes. Lead(II) perchlorate afforded an infinite one 2), both of which are based on the endocyclic binuclear complexes mainly due to the oxophilicity of the lead(II) ion. Meanwhile, mercury(II) halides showed an endocyclic dinuclear complex [Hg 2 (o-bis-L)I 2 ][Hg 3 I 8 ] (3) and an exocyclic 1-D coordination polymer [Hg 3 (m-bis-L)Br 6 ] n (4) because the differences of sulfur-to-sulfur separation in the free ligand isomers might induce the different coordination modes. When a mixture of mercury(II) iodide and copper(I) iodide was used in the reaction with m-bis-L, a heterometallic 1-D coordination polymer [Cu 2 Hg 2 (m-bis-L)(μ-Cu 2 I 2 )(CH 3 CN) 2 I 6 ] n (5) was obtained. In 5, exocyclic dicopper(I) complex units are linked by −Hg-Cu 2 I 4 -Hg− segments to form an infinite zigzag chain. Consequently, unlike the borderline metal, the soft metal ions show the sulfur-to-sulfur separation dependent coordination modes. These results demonstrate how small differences in the ligand isomers impact their self-assembled coordination products in terms of coordination mode and topological structure including dimensionality.

2,2′-Ethylenebis(1,3-dithiane) as a polydentate μ2-, μ4- and μ5-assembling ligand for the construction of sulphur-rich Cu(i), Hg(ii) and heterometallic Cu(i)/Hg(ii) coordination polymers featuring uncommon network architectures

“…64,65 The most reminiscent is that of [(μ-7,10,21,24-tetraoxa-4,13,18,27-tetrathiatricyclo[14.12.1.12,15]triaconta-1(29),2(30),15-triene)-hexakis(μ-I)-bis(MeCN)-diiodo-tetra-copper( i )-di-mercury( ii )], in which a macrocyclic tetrathioether ligand is coordinated through two S -donor sites to a CuI(MeCN) fragment, which in turn is linked to mononuclear Hg( ii ) centres via shared μ-I bridges (refcode JIBLEO). 66…”

“…64,65 The most reminiscent is that of [(μ-7,10,21,24-tetraoxa-4,13,18,27-tetrathiatricyclo[14.12.1.12,15]triaconta-1(29),2(30),15triene)-hexakis(μ-I)-bis(MeCN)-diiodo-tetra-copper(I)-di-mercury(II)], in which a macrocyclic tetrathioether ligand is coordinated through two S-donor sites to a CuI(MeCN) fragment, which in turn is linked to mononuclear Hg(II) centres via shared μ-I bridges (refcode JIBLEO). 66 Reaction of CP1 with HgBr 2 in MeCN solution in a 1 : 1 ratio. Encouraged by these unexpected findings, we attempted also to react CP1 with HgBr 2 in a 1 : 1 molar ratio in MeCN solution (Scheme 9).…”

The crystal structures, Hirshfeld surface analyses and energy frameworks of two hexathiapyrazinophane regioisomers; 2,5,8,11,14,17-hexathia-[9.9](2,6,3,5)-pyrazinophane and 2,5,8,11,14,17-hexathia-[9.9](2,5,3,6)-pyrazinophane

“…Ligands with mixed hard and soft binding characters, such as O, N and S donor atoms, are known to display diverse coordination modes by binding selectively to metal centres giving rise to unusual coordination geometries (Kim et al, 2018;Klinga et al, 1994;Lockhart et al, 1992). Three regioisomers, o, m and p, of a bis-dioxadithia-benzenophane (L, O 4 S 4 ) have been reported on by the group of Shim Sung Lee (Kim et al, 2018).…”

“…Ligands with mixed hard and soft binding characters, such as O, N and S donor atoms, are known to display diverse coordination modes by binding selectively to metal centres giving rise to unusual coordination geometries (Kim et al, 2018;Klinga et al, 1994;Lockhart et al, 1992). Three regioisomers, o, m and p, of a bis-dioxadithia-benzenophane (L, O 4 S 4 ) have been reported on by the group of Shim Sung Lee (Kim et al, 2018). The structures of a number of metal complexes have also been described; for example, both o-bis L and m-bis L form one-dimensional coordination polymers with AgPF 6 (Siewe et al, 2014), while with lead(II) perchlorate a binuclear complex was obtained with o-bis L and a one-dimensional coordination polymer with m-bis L (Kim et al, 2018).…”

“…Three regioisomers, o, m and p, of a bis-dioxadithia-benzenophane (L, O 4 S 4 ) have been reported on by the group of Shim Sung Lee (Kim et al, 2018). The structures of a number of metal complexes have also been described; for example, both o-bis L and m-bis L form one-dimensional coordination polymers with AgPF 6 (Siewe et al, 2014), while with lead(II) perchlorate a binuclear complex was obtained with o-bis L and a one-dimensional coordination polymer with m-bis L (Kim et al, 2018). In all four complexes the metal atoms coordinate to both the O and S atoms.…”