Flexible Disulfoxides as Bridging Ligands for Copper(II) Coordination Architectures:  Fine Tuning the Complex Structures by Ligand Modifications

Abstract

Ten disulfoxide−CuII coordination architectures, {[Cu(meso-L b )2(ClO4)](ClO4)} n (1B), [Cu(meso-L b )2(ClO4)2] n (2B), [Cu(rac-L b )2(ClO4)2] n (3B), {[Cu(meso-L b 3 )3](ClO4)2} n (3B‘), [Cu(meso-L c 1 )2(ClO4)2] n (1C), [Cu(meso-L c 2 )2(ClO4)]2(ClO4)2(CHCl3)2 (2C), {[Cu(meso-L c 3 )2(ClO4)](ClO4)} n (3C), [Cu(meso-L d 1 )2(ClO4)2] n (1D), {[Cu2(rac-L d 2 )4(ClO4)2](ClO4)2(CHCl3)} n (2D), and [Cu(rac-L d 3 )2(ClO4)2] n (3D), were obtained by the reaction of Cu(ClO4)2 with nine structurally related flexible disulfoxide ligands, RS(O)(CH2) n S(O)R (n = 2−4; R = −CH2CH3, −CH2CH2CH3, −CH2CH2CH2CH3 for L b n - 1 , L c n - 1 , and L d n - 1 , respectively) in the presence of dehydrating reagent (diethoxyethane) in acetone/chloroform. The X-ray crystal structural analyses of the complexes revealed that all of them display a 2-D network structure, except for 2B and 2C, which display a one-dimensional and a dinuclear cage structure, respectively. All 2-D systems have a (4,4) topological arrangement with different conformations, except for 3B‘, which has a (3,6) structure. It is noteworthy that complexes 3B and 3B‘, with different structures, are obtained in the same reaction system, being a relatively rare case. In all of the complexes the ligands react in the bis-monodentate coordination mode, acting as linkage bridges: this feature is important for the assembly of the polymeric complexes. In addition, the configuration inversion of some disulfoxide ligands has been observed when reacting with CuII ions. In combination with other reported disulfoxide−CuII complexes, a systematic structural comparison was performed so as to summarize some general relationships among the spacer lengths, terminal groups of related ligands, and structures of the complexes. The magnetic behavior of three complexes, 1B−3B, as examples, was investigated.

catena-Poly[[bis(tetrafluoroborato)copper(II)]bis[μ-1,3-bis(ethylsulfinyl)propane-κ2O:O′]]

“…IR (cm À1 ): 3430 (m), 2934(m), 1635 (w), 1449 (m), 1411 (w), 1382 (w), 1060 (s), 982 (s), 952 (s), 522 (m). In the IR spectrum, the strong S O stretching vibration at 982 cm À1 is lower than that of the free ligand (1019 cm À1 ) (Li et al, 2005), indicating that O atoms of L coordinate to metal ions.…”

“…In recent years, we have been focusing on the investigation of flexible disulfoxide metal complexes (Li et al, 2004(Li et al, , 2005. As part of these efforts, we report here the crystal structure of a copper(II) complex [Cu(L) 2 (BF 4 ) 2 ] n , (I), where L is 1,3-bis (ethylsulfinyl)propane, which is isostructural with the perchlorate analog reported by us (Li et al, 2005), having a double-bridging one-dimensional chain structure containing sixteen-membered macrocyclic units (Fig. 1).…”

Structural Diversity and Modulation of Coordination Architectures with Flexible Dithioether or Disulfoxide Ligands

“…Generally, the influence of the metal ions on the complex structures can be attributed to the differences in their affinity, geometry, and ionic radius. Complex {[Cu( L ) 2 (ClO 4 )](ClO 4 )} n [ 23 , L = 1,2‐bis(ethylsulfinyl)ethane]13l has a polymeric 2D layer structure of (4,4) topology (Figure 7), in which the coordination geometry of Cu II is square‐pyramidal with four sulfoxide O donors in the equatorial plane and one O atom of ClO 4 – in the apical position. Each ligand links two Cu II ions through the O atoms of the sulfoxide groups to form a 2D framework.…”

“…Owing to the presence of long bridging ligands in all the complexes with paramagnetic ions, one could expect the lack of any noticeable magnetic coupling between the metal ions. The magnetic behavior of three selected Cu II –disulfoxide complexes, 14 , 17 , and 18 , was studied 13l. Figure 12 shows the temperature dependence of χ m T for those complexes.…”

Synthesis, Crystal Structure, Solution Study and In Silico ADME Profiling of Various Asymmetric Functionalized Triazenes

“…In this regard, the organic ligands play an important role in adjusting the architectures of their metal complexes, so proper selection of ligands is the key issue in construction of supramolecular networks [21,22]. However, the crystal engineering with desired topologies and specific properties still remains as a difficult challenge since there are a variety of factors influencing the self-assembly processes such as the coordination geometry and the oxidation state of the metal ions [23], metal-to-ligand ratio [24], nature of the ligands [25], solvents [26] and/or counter-anions [27], even the reaction temperature and pH value.…”