Ya-Bo Xie

Syntheses and crystal structures of the copper(I) complexes with quinoline-based monothioether ligands

The reactions of three structurally related quinoline-based monothioether ligands, 8-(2-pyridylsulfanylmethyl)quinoline (L1), 8-(4-pyridylsulfanylmethyl)quinoline (L2) and 5-methyl-2- (8-quinolylmethylsulfanyl)-1,3,4-thiadiazole (L3) with CuI, lead to the formation of three novel complexes: {[Cu4I4(L1)2](CH2Cl2)} (1), [Cu3I3L2(CH3CN)]n (2) and [Cu4I4(L3)2]n (3), which have been characterized by elemental analyses, IR spectroscopy, and X-ray crystallography. Single-crystal X-ray analyses show that complex 1 is a tetranuclear structure with a distorted chair-like Cu4I4 skeleton, and 2 is a two-dimensional (2-D) network containing merlon-like 1-D double-stranded (CuI)n chains and CuI2Cu units, and 3 is a 1-D structure with a double-stranded stair CuI-chain. In 2 and 3, the 1-D (CuI)n skeletons are also built by chair-like Cu4I4 units.

Formation of novel discrete silver(I) coordination architectures with quinoline-based monothioethers: adjusting the intramolecular Ag⋯Ag distances and complex structures by ligands modifications and variations of counter anions

In our efforts to design discrete polynuclear metal complexes with tailored structures, four structurally related quinoline-based new monothioether ligands, 8-(2-pyridylsulfanylmethyl)quinoline (L1), 8-(4-pyridyl- sulfanylmethyl)quinoline (L2), 8-(2-pyrimidylsulfanylmethyl)quinoline (L3), 5-methyl-2-(8-quinolylmethyl- sulfanyl)-1,3,4-thiadiazole (L4) have been designed, and six new AgI complexes with these ligands, {[AgL1](ClO4)(CHCl3)}21, [Ag2L1(NO3)2]22, {[AgL1(CH3CN)](PF6)}23, [AgL2(NO3)]24, {[AgL3(CH3OH)](ClO4)}25 and {[AgL4](ClO4)}26 have been synthesized and characterized by single-crystal X-ray diffraction analysis. All six complexes adopt discrete structures, with 1,3,4,5 and 6 being dinuclear and 2 being tetranuclear, and Ag–Ag interactions were found to exist in complexes 1,2,3 and 6, as well as π–π stacking in 1–4. Furthermore, the Ag⋯Ag distances in 1–6 were compared. In the six complexes, the sulfur atoms of the ligands adopt quite different coordination modes: bridging in 1,2 and 3, chelating in 5 and non-coordination in 4 and 6. In addition, the structural differences of 1,2 and 3 indicate that the change in the counter anion greatly influences the coordination modes of the ligands and the coordination geometries of AgI ion, which consequently affects the resulting frameworks of such complexes.

New Coordination Architectures of Dithioether Ligand with Silver Salts: Effect of Anions on Complex Structures

Reactions of a flexible dithioether ligand, 2,3-bis(5-methyl-1,3,4-thiadiazole-2-thiomethyl)quinoxaline (L), with AgX (X = ClO4ˉ or PF6ˉ) lead to the formation of two new one-dimensional (1D) silver(i) complexes: {[AgL](ClO4)}∞ 1 and {[Ag2L(CH3OH)](PF6)2(CH3OH)}∞ 2, which have been characterized by elemental analysis, IR spectroscopy, and X-ray crystallography. Although 1 and 2 are synthesized under the same conditions, they take different structures due to the difference in anions in the silver salts. In 1, each ligand supplies three N-donors to bridge two silver atoms to result in a chain structure, and all silver atoms in the chain possess the same coordination geometry. In 2, each ligand gives six N-donors to coordinate to two silver atoms of different geometries, forming a 1D chain. The changes in counteranions affect the coordination mode of the ligand and the geometry of the Ag(i) centre, and consequently give rise to complexes with different structures. The coordination features of the ligand have also been primarily investigated through density functional theory calculations.

Two new silver(I) complexes with different structures formed with two flexible multimethylene chain heterocyclic thioethers having different linker spacers

Abstract The formation of a dinuclear complex 1 and a one-dimensional chain complex 2, whose structures were determined by single-crystal X-ray diffraction analysis, was achieved by the reaction of AgNO3 and two similar N-containing heterocyclic thioether ligands, 2,2′-[1,5-pentanediylbis(thio)]bis(4,6-dimethylpyrimidine) (L1) and 2,2′-[1,6-hexanediylbis(thio)]bis(4,6-dimethylpyrimidine) (L2). In complex 1, L1 serves as a bidentate ligand and bridges two AgI centers with two nitrogens from different dimethylpyrimidine rings to form a 24-membered macrometallacycle. In complex 2, each AgI ion in the one-dimensional polymeric chain adopts a slightly distorted trigonal planar geometry comprised of a monodentate nitrate anion, an S atom of one ligand and an N atom of another ligand. There exists apparent Ag–Ag interaction in complex 2 but there are not such interactions in complex 1. The structural difference of the two complexes shows that the variation of the ligand spacers is an effective factor in controlling the structural topologies of such metal-organic supramolecular architectures.

Novel Bimetallic Macrocyclic Complexes Assembled from PdII and Flexible Pyridyl Dithioether Bridging Spacers

Two novel dimeric palladium(II) complexes with flexible pyridyl dithioether bridging ligands, [Pd(L1)Cl2]2 (1) and [Pd(L2)Cl2] (2), where L1=1,3-bis(2-pyridylthio)propane and L2=1,3-bis(4-pyridylthio)propane, have been synthesized and structurally characterized by X-ray diffraction analyses. In both complexes, each PdII center is four-coordinated in the trans-form by two chloride anions and two nitrogen donors from two distinct ligands. Complex 1 exhibits a unique 20-membered metallomacrocyclic structure with twisted conformation, while 2 shows a dinuclear 28-membered metallomacrocycle with planar conformation. In addition, there are weak C-H ⃛Cl or C-H ⃛S hydrogen bonding interactions in both complexes, resulting in different 3-D supramolecular architectures.

Polymeric silver(I) complexes with pyridyl dithioether ligands: experimental and theoretical investigations on the coordination properties of the ligands

The reactions of four flexible tetradentate ligands, 1,3-bis(2-pyridylthio)propane (L1), 1,4-bis(2-pyridylthio)butane (L2), 1,5-bis(2-pyridylthio)pentane (L3) and 1,6-bis(2-pyridylthio)hexane (L4) with AgX (X = BF4-, ClO4-, PF6-, or CF3SO3-) lead to the formation of seven new complexes: [AgL1(BF4)]2 (1), [[AgL2](ClO4)]infinity (2), [[AgL2(CH3CN)](PF6)]infinity (3), [[AgL3](BF4)(CHCl3)]2 (4), [[AgL3(CF3SO3)](CH3OH)(0.5)]infinity (5), [[Ag2L4(2)](BF4)2]infinity (6), and [[AgL4](PF6)]infinity (7), which have been characterized by elemental analyses, IR spectroscopy, and X-ray crystallography. Single-crystal X-ray analyses show that complexes 1 and 4 possess dinuclear macrometallacyclic structures, and complexes 2, 3 and 5-7 take chain structures. In all the complexes, the nitrogen atoms of ligands preferentially coordinate to silver atoms to form normal coordination bonds, while the sulfur atoms only show weak interactions with silver atoms and the intermolecular AgS weak contacts connect the low-dimensional complexes into high-dimensional supramolecular networks. Additional weak interactions, such as pi-pi stacking, F...F weak interactions, Ag...O contacts or C-H...O hydrogen bonds, also help to stabilize the crystal structures. It was found that the parity of the -(CH2)n- spacers (n = 3-6) affect the orientation of the two terminal pyridyl rings, thereby significantly influence the framework formations of these complexes. The coordination features of ligands and their conformation changes between free and coordination states have been investigated by DFT calculations.