A comparative study on the formation of guest clusters induced by different shapes (or sizes) of exocyclic binding sites embedded in the bis-macrocyclic host isomers is reported. CuI reacts with two regioisomers of a bis-dithiamacrocycle, o-bis-L (W-shaped binding site) and m-bis-L (U-shaped binding site), to yield one-dimensional coordination polymers {[(μ4-Cu4I4)(o-bis-L)]·2CH3CN}n (1a) and [(μ4-Cu2I2)(m-bis-L)]n (2). In 1a, the o-bis-L ligand isomer is linked by a spacious cubane [Cu4I4] cluster, while the m-bis-L ligand in 2 is linked by a smaller rhomboid [Cu2I2] cluster because of the different exocyclic binding sites. The results observed illustrate the possibility for the metal clusters including [CunIn] (n = 2 or 4) to adopt a controlled formation through the binding site alternation or design. Because of the adaptive cluster formations, the products show different photophysical properties. Additionally, sliding of the one-dimensional chains in 1a was observed upon loss of the lattice solvent molecules in ambient condition.

Syntheses of the regioisomers of bis-dithiamacrocycle and the regioisomer-controlled endo- and exocyclic coordination behaviors are reported. Direct bis-cyclization reaction of 1,2,4,5-tetra(bromomethyl)benzene with 3,6-dioxa-1,8-octanedithiol led to a mixture of two bis-dithiamacrocycle regioisomers (ortho-type; o-bis-L and meta-type; m-bis-L) which were separated by recrystallization and column chromatography. When the two isomers were reacted with AgPF6, o-bis-L gave an endocyclic one-dimensional (1-D) coordination polymer {[Ag3(o-bis-L)2(CH3CN)](PF6)3·2CH3CN}n (1) with a 3:2 (metal-to-ligand) stoichiometry, while m-bis-L afforded an exocoordination-based 1-D polymeric complex {[Ag(m-bis-L)](PF6)}n (2) with a 2:2 stoichiometry. The observed endo- and exocoordination modes depending on the isomers were discussed in terms of the S···S distances in the bis-dithiamacrocycle isomers. Due to the closer S···S distance in each macrocyclic ring, o-bis-L is suitable for the endocoordination. However, m-bis-L forms an exocyclic complex because the S···S distance between two macrocyclic rings is shorter than that in one macrocyclic ring. NMR experiments also revealed that o-bis-L and m-bis-L form the endo- and the exocyclic complexes, respectively, in solution.

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.

An investigation of the coordination behavior of sulfur-containing mixed-donor tribenzo-macrocycles (5), giving an overall metal coordination geometry of eight with a square antiprism arrangement. From these results, the effects of the donor variation and the anioncoordination ability on the resulting topologies of the soft metal complexes are discussed.

Synthesis and structural characterization of mercury(II) halides and perchlorate complexes (1-4) of bis-OS 2 -macrocycle (L) are reported. L reacts with mercury(II) chloride and bromide to yield an isostructural 2D coordination polymers with type [Hg(L)X 2 ] n (1: X = Cl and 2: X = Br). In 1, each Hg atom which lies outside the cavity is six-coordinate with a distorted octahedral geometry, being bound to four adjacent ligands via monodentate Hg-S bonds and two remaining sites are occupied by two terminal chlorido ligands to form a fishnet-like 2D structure. When reacting with mercury(II) iodide, L afforded a 1D coordination polymer {[Hg 2 (L)I 4 ]·CHCl 3 } n (3) in which each exocyclic Hg atom is four-coordinate, being bound to two sulfur donors from different ligands doubly bridging the ligand molecules in a head-to-tail mode. The coordination sphere in 3 is completed by two iodo terminal ligands, adopting a distorted tetrahedral geometry. On reacting with mercury(II) perchlorate, L forms solvent-coordinated 1D coordination polymer {[Hg 2 (L)(DMF) 6 ](ClO 4 ) 4 ·2DMF} n (4) instead of the anion-coordination. In 4, the Hg atom is five-coordinate, being bound to two sulfur donors from two different ligands doubly bridging the ligand molecules in a side-by-side mode to form a ribbon-like 1D structure. The three remaining coordination sites in 4 are completed by three DMF molecules in a monodentate manner. Consequently, the different structures and connectivity patterns for the observed exocyclic coordination polymers depending on the anions used are influenced not only by the coordination ability of the anions but also by anion sizes.