Dithioether Ligands Research Articles

Silver-based coordination polymers assembled by dithioether ligands: potential antibacterial materials despite received ideas.

We report on the first examples on the antibacterial activity towards Gram-negative and Gram-positive bacteria of 2D silver-based coordination polymers obtained by self-assembly with acetylenic dithioether ligands. Their structure imparts a good stability that allows a sustainable release of Ag+ in the media.

One new copper iodide coordination polymer directed by 4-pyridyl dithioether ligand: Syntheses, structures, and photocatalysis

One new compound consisting of 1,1-bis(4-pyridylthio)methylene ([Bpytm]) ligand, namely [Bpytm]CuI (1), has been prepared and characterized by IR spectroscopy, solid Uv-visible diffuse reflectance spectrum, and X-ray Powder Diffraction (PXRD). Compound 1 is a 2D MOF and ligand [Bpytm] coordinate with metal ions to form tetrahedral configuration. For compound 1: Crystal system: Monoclinic, Space group: C2/c, a = 13.6671(11), b = 11.6075(11), c = 17.1225(12), α= 90°, β= 93.707(3)°, γ= 90°, V = 2710.6(4) Å3, Z = 8, Dcalc = 2.082 g cm–3. The photocatalytic properties and thermal stability have been researched.

From Short-Bite Ligand Assembled Ribbons to Nanosized Networks in Cu(I) Coordination Polymers Built Upon Bis(benzylthio)alkanes (BzS(CH2)nSBz; n = 1-9).

With the objective to establish a correlation between the spacer distance and halide dependence on the structural features of coordination polymers (CPs) assembled by the reaction between CuX salts (X = Cl, Br, I) and dithioether ligands BzS(CH2)nSBz (n = 1-9; Bz = benzyl), a series of 26 compounds have been prepared and structurally investigated. A particular attention has been devoted to the design of networks with extremely long and flexible methylene spacer units between the SBz donor sites. Under identical conditions, CuI and CuBr react with BzSCH2Bz (L1) affording respectively the one-dimensional (1D) CPs {Cu(μ2-I)2Cu}(μ-L1)2]n (CP1) and {Cu(μ2-Br)2Cu}(μ-L1)2] (CP2), which incorporate Cu(μ2-X)2Cu rhomboids as secondary building units (SBUs). The hitherto unknown architecture of two-dimensional (2D) layers obtained with CuCl (CP3) differs from that of CP1 and CP2, which bear inorganic -Cl-Cu-Cl-Cu-Cl- chains interconnected through bridging L1 ligands, thus forming a 2D architecture. The crystallographic characterization of a 1D CP obtained by reacting CuI with 1,3-bis(benzylthio)propane (L2) reveals that [{Cu(μ2-I)2Cu}(μ-L2)2]n (CP4) contains conventional Cu2I2 rhomboids as SBUs. In contrast, unusual isostructural CPs [{Cu(μ2-X)}(μ2-L2)]n (CP5) and (CP6) are obtained with CuX when X = Br and Cl, respectively, in which the isolated Cu atoms are bridged by a single μ2-Br or μ2-Cl ion giving rise to infinite [Cu(μ2-X)Cu]n ribbons. The crystal structure of the strongly luminescent three-dimensional (3D) polymer [{Cu4(μ3-I)3(μ4-I)(μ-L3)1.5]n (CP7) issued from reacting 2 equiv of CuI with BzS(CH2)4SBz (L3) has been redetermined. CP7 features unusual [(Cu4I3)(μ4-I)]n arrays securing the 3D connectivity. In contrast, mixing CuI with an excess of L3 provides the nonemissive material [{Cu(μ2-I)2Cu}(μ-L3)2]n (CP8). Treatment of CuBr and CuCl with L3 leads to [{Cu(μ2-Br)2Cu}(μ-L3)2]n (CP9) and the 0D complex [{Cu(μ2-Cl)2Cu}(μ-L3)2] (D1), respectively. The crystallographic particularity for CP9 is the coexistence of two topological isomers within the unit cell. The first one, CP9-1D, consists of simple 1D ribbons running along the a axis of the unit cell. The second topological isomer, CP9-2D, also consists of [Cu(μ2-Br)2Cu] SBUs, but these are interconnected in a 2D manner forming 2D sheets placed perpendicular to the 1D ribbons. Four 2D CPs, namely, [{Cu4(μ3-I)4}(μ-L4)2]n (CP10), [{Cu(μ2-I)2Cu}(μ-L4)2]n (CP11), [{Cu(μ2-Br)2Cu}(μ-L4)2]n (CP12), and [{Cu(μ2-Cl)2Cu}(μ-L4)2]n (CP13), stem from the self-assembly process of CuX with BzS(CH2)6SBz (L4). A similar series of 2D materials comprising [{Cu4(μ3-I)4}(μ-L5)2]n (CP14), [{Cu(μ2-I)2Cu}(μ-L5)2]n (CP15), [{Cu(μ2-Br)2Cu}(μ-L5)2]n (CP16), and [{Cu(μ2-Cl)2Cu}(μ-L5)2]n (CP17) result from the coordination of BzS(CH2)7SBz (L5) on CuX. Ligation of CuX with the long-chain ligand BzS(CH2)8SBz (L6) allows for the X-ray characterization of the luminescent 2D [{Cu4(μ3-I)4}(μ-L6)2]n (CP18) and the isostructural 1D series [{Cu(μ2-X)2Cu}(μ-L6)2]n CP19 (X = I), CP20 (X = Br) and CP21(X = Cl). Noteworthy, BzS(CH2)9SBz (L7) bearing a very flexible nine-atom chain generated the crystalline materials 2D [{Cu4(μ3-I)4}(μ-L7)2]n (CP22) and the isostructural 1D series [{Cu(μ2-X)2Cu}(μ-L6)2]n CP23 (X = I), CP24 (X = Br), and CP25 (X = Cl), featuring nanometric separations between the cubane- or rhomboid-SBUs. This comparative study reveals that the outcome of the reaction of CuX with the shorter ligands BzS(CH2)nSBz (n = 1-4) is not predictable. However, with more flexible spacer chains BzS(CH2)nSBz (n = 6-9), a clear structural pattern can be established. Using a 1:1 CuX-to-ligand ratio, [{Cu(μ2-X)2Cu}(μ-L4-7)2] CPs are always formed, irrespectively of L4-L7. Employing a 2:1 CuX-to-ligand ratio, only CuI is able to form networks incorporating Cu4(μ3-I)4 clusters as SBUs. All attempts to construct polynuclear cluster using CuBr and CuCl failed. The materials have been furthermore analyzed by powder X-ray diffraction, Raman spectroscopy, and thermogravimetric analysis, and the photophysical properties of the emissive materials have been studied.

Synthesis and catalytic activity of cationic dinuclear palladium (II) complexes supported by thioether ligands containing two di-(2-picolyl) amine arms

The design, synthesis and characterization of a series of dithioether ligands featuring two di-(2-picolyl)amine arms (2a–2d) and their corresponding cationic dinuclear palladium (II) complexes (3a–d) are reported. Crystal structures of ligand 2b and complexes 3b and 3d were determined by X-ray diffraction studies. The molecular structures of 3b and 3d display each of the two di-(2-picolyl)amine fragments coordinated to one palladium(II) atom in a (κ3-N,N,N) tridentate fashion and with the cationic metal centers displaying square-planar geometries. Weak interactions between the metal centers and the thioether fragments are observed. All bimetallic complexes 3a–d were tested as catalytic precursors in the Suzuki couplings of different o- or p-substituted iodo- or bromoaryls with boronic acids. The overall catalytic results indicate that complex 3b is the best precursor of the series demonstrating even more efficient performance compared to commercial palladium sources such as Pd(OAc)2 and the Nájera Catalysts.

Metallosupramolecular Compounds Based on Copper(II/I) Chloride and Two Bis-Tetrazole Organosulfur Ligands

The present work assesses the ability of two flexible bis-tetrazole organosulfur ligands to build up different metallosupramolecular compounds based on the analysis of the different supramolecular interactions. The reaction of copper(II) chloride dihydrate with the N,N’-donor dithioether ligands bis(1-methyl-1H-tetrazole-5-ylthio)methane (BMTTM) and 1,2-bis(1-methyl-1H-tetrazole-5-ylthio)ethane (BMTTE) was investigated using different synthetic methods. Four compounds have been obtained as single crystals: two pseudopolymorphic 1D Cu(II) coordination polymers with the ligand BMTTM, a 2D Cu(II) coordination polymer and a discrete Cu(I) tetramer with the BMTTE ligand. The effects of the weak interactions on the crystal packing and the Hirshfeld surfaces of the structures were analyzed to clarify the nature of the intermolecular interactions.

1,3-Dithianes as Assembling Ligands for the Construction of Copper(I) Coordination Polymers. Investigation of the Impact of the RC(H)S2C3H6 Substituent and Reaction Conditions on the Architecture of the 0D-3D Networks.

The parent compound 1,3-dithiane (L1) was reacted with CuI providing the 1D coordination polymer [{Cu(μ2-I)2Cu}(μ2-L1)2] n (CP1), an isostructural compound [{Cu(μ2-Br)2Cu}(μ2-L1)2] n (CP2) was isolated upon treatment of CuBr with L1. In contrast, treatment of L1 with CuCl results in the formation of 2D polymeric [{Cu(μ2-Cl)2Cu}(μ2-L1)] n (CP3), in which each sulfur atom acts as a 4-electron donor. The 1D compounds [{Cu(μ2-X)2Cu}(μ2-L2)2] n (CP7, X = Br, and CP8, X = Cl) resulting from treatment of 2-methyl-1,3 dithiane (L2) with CuBr and CuCl are isostructural with their CuI homologue [{Cu(μ2-I)2Cu}(μ2-L2)2] n (CP5), reported previously. Using CuCN, a 2D CP of composition [{Cu(μ2-CN)2Cu}(μ2-L2)2] n (CP9) has been isolated. Complexation of 2-isobutyl-1,3-dithiane (L3) on CuI generates a 2D material [{Cu3(μ3-I)(μ2-I)2(μ2-L3)2}] n (CP10), incorporating the usual trinuclear μ3-I-capped Cu clusters as SBUs, whereas 2D-polymeric compounds [{Cu(μ2-Br)2Cu}(μ2-L3)2] n (CP11) and [{Cu(μ2-Cl)2Cu}(μ2-L3)2] n (CP12) were obtained with CuBr and CuCl. Treatment of 2-Me3Si-1,3-dithiane (L4) with CuX yields the series [{Cu2(μ4-X)(μ2-X)}(μ2-L4)] n (CP13-CP15). With 2-phenyl-1,3-dithiane (L5), the outcome of the reaction with CuI depends on the reaction conditions. Reaction with CuI in MeCN provides a 1D ribbon [{Cu(μ2-I)2Cu}(MeCN)2(μ2-L5)2] n (CP16), whereas treatment of CuI with L5 in hot EtCN yields 2D-polymeric[{Cu3(μ3-I)(μ2-I)2(μ2-L5)2}] n (CP17). A reversible phase transition from triclinic P1̅ to monoclinic P21/ m is observed when recording the structure of CP16 at five different temperatures in the 100-300 K range. Ligand L6 containing a ferrocenyl function at the 2-position was also probed as organometallic dithioether ligand. Reaction of L6 with 1 equiv of CuI produces the 0D dinuclear complex [{Cu(μ2-I)2Cu}(η1-L6)2(MeCN)2] (D1), whereas treatment with 2 equiv of CuI affords the novel 1D CP [{Cu(μ3-I)2Cu}(μ-L6)] n (CP18), in which both S atoms of one L6 molecule span two copper centers of the infinite (CuI) n ribbon. Some selected results of thermal analyses and luminescence measurements are also presented.

Five novel copper halide/thiocyanate coordination compounds directed by 4-pyridyl dithioether ligands: syntheses, structures, and photocatalytic properties

The reactions of three structurally related flexible 4-pyridyl dithioether ligands, 1,2-bis(4-pyridylthio)ethane (Bpyte), 1,3-bis(4-pyridylthio)propane (Bpytp) and 1, 4-bis(4-pyridylthio)butane (Bpytb) with CuI (CuBr and CuSCN) led to form five new complexes: {[Bpyte](CuI2)2} (1), {[Bpytp]CuI2} (2), {[Bpytp]3(CuBr2)3} (3), {[Bpytp]Cu(SCN)2(CH3CN)} (4) and {[Bpytb]Cu(SCN)2(DMF)} (5), which have been characterized by IR, SEM-EDS (energy dispersive spectrometer), ultraviolet–visible absorption spectrum and thermogravimetric analysis. Single-crystal X-ray analyses showed that compounds 1–5 possess 1-D chain. Furthermore, compounds 2–5 demonstrated good photocatalytic degradation for methyl orange (MO) irradiated by visible light.

1,3-Dithiolane and 1,3-Ferrocenyl-dithiolane as Assembling Ligands for the Construction of Cu(I) Clusters and Coordination Polymers

The parent compound 1,3-dithiolane L1 reacts with CuI providing the 2D coordination polymer (CP) [{Cu(μ2-I)2Cu}(μ2-L1)2] n (CP1). The Cu⋯Cu distance within the Cu(μ2-I)2Cu rhomboid is temperature-dependent and shrinks from 2.9081(7) (294 K) to 2.8743(5) (100 K). The 1D polymeric compound [{Cu(μ2-Br)}(μ2-L1)] n (CP2) was isolated upon treatment of CuBr with L1 in MeCN solution. Likewise, treatment of L1 with CuCl in a 1:1 ratio results in formation of the unusual 1D CP [{Cu(μ2-Cl)}(μ2-L1)] n (CP3). In contrast to CP1 incorporating dinuclear Cu(μ2-I)2Cu units as connection nodes, the isolated Cu atoms of CP2 and CP3 are bridged by a single μ2-Br or μ2-Cl ligand giving rise to infinite [Cu(μ2-X)Cu] n ribbons. Reaction of ferrocenecarbaldehyde with 1,2-ethanedithiol affords the crystallographically characterized ferrocenyl-dithiolane Fc-C(H)S2C2H4 (L2). L2 was used as organometallic dithioether ligand to assemble, upon treatment with CuI, the original luminescent 1D CP [{Cu2(μ4-I)(μ2-I)}(μ2-L2)] n (CP4), in which both S atoms of one L2 molecule span two copper centers of a meander-shaped infinite (CuI) n ribbon. Upon reaction of L2 with CuBr in a 1:2 ratio, the discrete tetranuclear cluster [{Cu4(μ2-Br)2(μ3-Br)2}(μ2-L2)2(MeCN)2] (CL1) is formed.

New Heterocyclic Dithioether Ligands for Highly Selective Separation and Recovery of Pd(II) from Acidic Leach Liquors of Spent Automobile Catalyst

The solvent extraction behavior of Pd(II) from a hydrochloric acid solution with heterocyclic dithioether ligands, namely, 1,2-bis((5-methyl-1,3,4-thiadiazol-2-yl)thio)ethane (BMDTE) and 1,2-bis((5-(methylthio)-1,3,4-thiadiazol-2-yl)thio)ethane (BMTDTE) were investigated, for the first time, as potential extractants by using chloroform as diluent. Various experimental parameters such as effects of the concentration of hydrochloric acid, extractant concentration, hydrogen ion, chloride ion, and diluents on the extraction of Pd(II) was also investigated in detail. By comparing the extraction time, BMDTE exhibits a more rapid and quantitative extraction of Pd(II) even within 5 min than BMTDTE (30 min). The loading experiments indicated that the maximum loading capacity of BMDTE and BMTDTE for Pd(II) was determined to be 124 and 118 ppm, respectively. The stoichiometry of the extracted species during extraction was confirmed by 1H NMR and Job’s method analysis. Both of the two extractants exhibit high extract...

Anion exchange coupled with the reduction and dimerisation of a copper(ii) nitrate complex of tripyridyl dithioether via a single-crystal-to-single-crystal transformation.

It is a challenge to develop methodologies involving multiple transformations for preparing new materials that cannot be obtained via direct synthesis. Herein, we report an anion exchange process accompanying cation reduction and dimerisation via a single-crystal-to-single-crystal transformation. First, a direct reaction of the flexible tripyridyl dithioether ligand L with CuI afforded a mixture of four bis(ligand) complexes (1a-1d). To avoid the formation of undesired mixed products, a copper(ii) nitrate complex-mediated approach involving anion exchange and cation reduction was employed to generate a monomeric complex, [CuII(L)NO3]NO3·toluene (2). When the dark blue crystals of 2 were immersed in an aqueous NaI solution, the crystals were transformed to a pale yellow dimeric copper(i) iodide complex, [(μ-CuI2I2)(L)2] (3). The observed anion exchange promotes the reduction of copper(ii) to copper(i) at the expense of I-/I3- oxidation as well as dimerisation via the formation of a Cu2I2 cluster. This result corresponds to the synthesis of a compound that otherwise was not able to be prepared via a direct synthetic procedure.

Can a highly flexible copper(i) cluster-containing 1D and 2D coordination polymers exhibit MOF-like properties?

The reaction of CuI with the highly flexible dithioether ligand p-TolS(CH2)8STol-p affords both in MeCN or in EtCN the 2D coordination polymers [Cu8I8{p-TolS(CH2)8STol-p}3(solvent)2]n (1·MeCN and 1·EtCN) containing octanuclear Cu8I8 clusters as connection nodes. In contrast, treatment of CuI with p-tBuC6H4S(CH2)8SC6H4But-p in EtCN solution leads to the formation of the luminescent 1D CP [Cu4I4{tBuC6H4S(CH2)8SC6H4-tBu}2(EtCN)2]n (2·EtCN) incorporating Cu4(μ3-I)4 clusters of the closed cubane type as secondary building units (SBUs). The 2D coordination polymers 1·MeCN and 1·EtCN demonstrate the ability to lose their solvent crystallisation molecules under vacuum and readsorb the same or a new one using vapor as monitored by powder X-ray diffraction, thermogravimetric, IR, chromaticity, emission spectra and emission lifetime measurements. Conversely, the 1D material 2·EtCN does not readsorb EtCN, likely due to the collapse of the macrocycles formed by the metal cluster nodes and flexible long-chained ArSC8SAr ligands but absorbs a smaller substrate such as CO2.

CuX (X = Cl, Br, I) Containing Coordination Polymers Built Upon Isomeric RSCH2C≡CCH2SR (R = p-Tolyl, Benzyl) Dithioether Ligands: First Example of a Luminescent (CuCl)n/Dithioether Network

The CuBr salt reacts with the acetylenic dithioether 1,4-bis(p-tolylthio)but-2-yne (L1) to generate the 1D [{Cu(μ2-Br)2Cu}(μ-p-MeC6H4SCH2C≡CCH2SC6H4Me-p)2] n coordination polymer (1), contrasting with the previously reported reaction with CuI, which provided a 2D network [{Cu4(μ3-I)4}(μ-p-MeC6H4SCH2C≡CCH2SC6H4Me-p)2] n . (JIOPM, 2014, 24, 190-200). The ribbons of 1 incorporate two different types of alternating centrosymmetric Cu(μ2-Br)2Cu rhomboids displaying loose Cu···Cu contacts of 2.9306(14) and 2.9662(14) A. The reaction of CuI and CuBr with the isomeric dithioether ligand 1,4-bis(benzylthio)but-2-yne (L2) yields the isomorphous dinuclear 0D complexes [{Cu(μ2-X)2Cu}(μ-PhCH2SCH2C≡CCH2SCH2Ph)2] (2a: X = I; 2b: X = Br). These species represent the first examples of dinuclear [S2{Cu(μ2-X)2Cu}S2] complexes spanned by a dithioether ligand. In contrast, treatment of CuCl with L2 gives rise to the formation of an unusual 2D coordination polymer [{Cu2(μ2-Cl)(μ3-Cl)}(μ-PhCH2SCH2C≡CCH2SCH2Ph)] n (3), in which the layers are assembled both by dative Cu–S thioether bonds and organometallic Cu-π-acetylenic interactions via the triple bond of the L2 ligand. Furthermore, the Cu(I) centers are interconnected through μ2- and μ3-bound chloro ligands. Finally, thermal stability and photophysical proprieties were studied. This investigation demonstrated the interesting luminescent behavior of CuCl-containing coordination polymer (3).

Copper(I) Halides (X = Br, I) Coordinated to Bis(arylthio)methane Ligands: Aryl Substitution and Halide Effects on the Dimensionality, Cluster Size, and Luminescence Properties of the Coordination Polymers

Bis(phenylthio)methane (L1) reacts with CuI to yield the 1D-coordination polymer [{Cu4(μ3-I)4}(μ-L1)2]n (1) bearing cubane Cu4I4 clusters as connecting nodes. The crystal structures at 115, 155, 195, and 235 K provided evidence for a phase transition changing from the monoclinic space group C2/c to P21/c. The self-assembly process of CuI with bis(p-tolylthio)methane (L2), bis(4-methoxyphenylthio)methane (L3), and bis(4-bromo-phenylthio)methane (L4) affords the 1D-coordination polymers [{Cu4(μ3-I)4}(μ-Lx)2]n (x = 2, 3, or 4). Compounds 2 and 4 are isostructural with C2/c low temperature polymorph of 1, whereas the inversion centers and 2-fold axes are lost in 3 (space group Cc). The use of bis(m-tolylthio)methane (L5) has no impact on the composition and overall topology of the resulting 1D ribbon of [{Cu4(μ3-I)4}(μ-L5)2]n (5). Even the coordination of the sterically crowded dithioether bis(5-tert-butyl-2-methylphenylthio)methane (L8) does not alter the network topology generating the 1D polymer [{Cu4(μ3-I)4}(μ-L8)2]n (8). The 1D polymer [{Cu(μ2-Br)2Cu}(L1)2] (9) results from the coordination of L1 with CuBr in a 1:1 metal-to-ligand ratio. In contrast to the mean Cu···Cu distances, which are <2.8 Å noted for the Cu4(μ3-I)4 clusters in the 1D polymers 1–8, the Cu···Cu contact within the Cu(μ2-Br)2Cu rhomboids of 9 [2.9194(8) Å] is above the sum of the van der Waals radii of two Cu atoms. The structural arrangement of 1D polymer [{Cu(μ2-Br)2Cu}(L3)2]n (11) is quite similar to that of 9. While the reaction of CuBr with L5 results in a similar 1D polymer [{Cu(μ2-Br)2Cu}(L5)2]n (12), the reaction of CuBr with L2 leads to the dinuclear complex [{Cu(μ2-Br)2Cu}(η1-L2)4] (10) ligated by four pendent bis(p-tolylthio)methane ligands. The ligation of bis(o-tolylthio)methane, L6, on CuBr also yields a discrete complex [{Cu(μ2-Br)2Cu}(MeCN)2(η1-L6)2] (13) bearing MeCN and dangling dithioether ligands. A strong luminescence is detected for all CuI polymers, all exhibiting emission lifetimes in the microsecond time scale (i.e., phosphorescence). The polymers containing the Cu4I4 core (1–8) exhibit the typically observed low-energy band and sometimes a weaker high-energy band. The nature of the low-energy band was proposed based on literature DFT and TDDFT computations and is predicted to be a mixture of cluster-centered (CC*) and metal/halide-to-ligand charger transfer (M/XLCT). An approximate relationship between the Cu···Cu distance and the emission maxima corroborates the CC* contribution to the nature of the excited states. The emission of the rhomboid-containing materials is assigned to M/XLCT based on literature works on similar motifs.

Metallosupramolecular compounds based on Cu(ii)/oxalate/twisted NSSN ligands showing a new in situ S–C bond cleavage

Four new complexes, [Cu2(C2O4)2(SCS)]·3H2O (1), [Cu2(C2O4)3(SCSH)2]·H2O (2), [Cu(C2O4)(SS)2]·3H2O (3) and [Cu(C2O4)(SS)]·6H2O (4) [where SCS = bis(4-pyridylthio)methane and SS = 4,4′-dipyridyldisulfide], have been synthesized by the reaction of the SS and SCS ligands with the corresponding copper(II) oxalate salt. The different synthetic conditions allowed control of the preparation of a 3D open metal–organic framework in 1, a dinuclear zwitterionic molecular compound in 2 and one- and two-dimensional (1D and 2D) coordination polymers in 3 and 4, respectively. Compound 4 was also obtained by in situ transformation of the dithioether ligand (SCS) to the disulfide ligand (SS) under hydrothermal conditions at 150 °C. The topology of the structures has been studied and 1 is a new 3D MOF with a binodal 4-connected node in a scarcely known network topology. Different numbers and topologies of water molecules are hosted in the crystal lattices of the compounds. The integrity of the frameworks after dehydration has been validated and discussed. The magnetic properties of compounds 1, 2 and 4 have also been investigated. Strong antiferromagnetic behaviour was found in 1 and weak antiferromagnetic coupling was observed in 2 and 4. The magneto-structural correlations that govern these interactions are discussed in detail.

Construction of (CuX)2n Cluster-Containing (X = Br, I; n = 1, 2) Coordination Polymers Assembled by Dithioethers ArS(CH2)mSAr (Ar = Ph, p-Tol; m = 3, 5): Effect of the Spacer Length, Aryl Group, and Metal-to-Ligand Ratio on the Dimensionality, Cluster Nuclearity, and the Luminescence Properties of the Metal–Organic Frameworks

Reaction of CuI with bis(phenylthio)propane in a 1:1 ratio yields the two-dimensional coordination polymer [{Cu(μ(2)-I)(2)Cu}{μ-PhS(CH(2))(3)SPh}(2)](n) (1). The 2D-sheet structure of 1 is built up by dimeric Cu(2)I(2) units, which are connected via four bridging 1,3-bis(phenylthio)propane ligands. In contrast, treatment of 2 equiv of CuI with 1,3-bis(phenylthio)propane in MeCN solution affords in a self-assembly reaction the strongly luminescent metal-organic 2D-coordination polymer [Cu(4)I(4){μ-PhS(CH(2))(3)Ph}(2)](n) (2), in which cubane-like Cu(4)(μ(3)-I)(4) cluster units are linked by the dithioether ligands. The crystallographically characterized one-dimensional (1D) compound [{Cu(μ(2)-Br)(2)Cu}{μ-PhS(CH(2))(3)SPh}(2)](n) (3) is obtained using CuBr. The outcome of the reaction of PhS(CH(2))(5)SPh with CuI also depends of the metal-to-ligand ratio employed. Mixing CuI and the dithioether in a 2:1 ratio results in formation of [Cu(4)I(4){μ-PhS(CH(2))(5)Ph}(2)](n) (4) in which cubane-like Cu(4)(μ(3)-I)(4) clusters are linked by the bridging dithioether ligand giving rise to a 1D necklace structure. A ribbon-like 1D-polymer with composition [{Cu(μ(2)-I)(2)Cu}{μ-PhS(CH(2))(5)SPh}(2)](n) (5), incorporating rhomboid Cu(2)I(2) units, is produced upon treatment of CuI with 1,5-bis(phenylthio)pentane in a 1:1 ratio. Reaction of CuBr with PhS(CH(2))(5)SPh produces the isomorphous 1D-compound [{Cu(μ(2)-Br)(2)Cu}{μ-PhS(CH(2))(5)SPh}(2)](n) (6). Strongly luminescent [Cu(4)I(4){μ-p-TolS(CH(2))(5)STol-p}(2)](n) (7) is obtained after mixing 1,5-bis(p-tolylthio)pentane with CuI in a 1:2 ratio, and the 2D-polymer [{Cu(μ(2)-I)(2)Cu}(2){μ-p-TolS(CH(2))(5)STol-p}(2)](n) (8) results from reaction in a 1:1 metal-to-ligand ratio. Under the same reaction conditions, 1D-polymeric [{Cu(μ(2)-Br)(2)Cu}{μ-p-TolS(CH(2))(5)STol-p}(2)](n) (9) is formed using CuBr. This study reveals that the structure of the self-assembly process between CuX and ArS(CH(2))(m)SAr ligands is hard to predict. The solid-state luminescence spectra at 298 and 77 K of 2 and 4 exhibit very strong emissions around 535 and 560 nm, respectively, whereas those for 1 and 5 display weaker ones at about 450 nm. The emission lifetimes are longer for the longer wavelength emissions (>1.0 μs arising from the cubane species) and shorter for the shorter wavelength ones (<1.4 μs arising from the rhomboid units). The Br-containing species are found to be weakly fluorescent.

Unexpected Reactivity and Coordination in Gallium(III) and Indium(III) Chloride Complexes With Geometrically Constrained Thio- and Selenoether Ligands

Reaction of GaCl(3) with 1 mol equiv of [14]aneS(4) in anhydrous CH(2)Cl(2) gives the exocyclic chain polymer [GaCl(3)([14]aneS(4))] (1) whose structure confirms trigonal bipyramidal coordination at Ga with a planar GaCl(3) unit. In contrast, using [16]aneS(4) and GaCl(3) or [16]aneSe(4) and MCl(3) (M = Ga or In) in either a 1:1 or a 1:2 molar ratio produces the anion-cation complexes [GaCl(2)([16]aneS(4))][GaCl(4)] (2) and [MCl(2)([16]aneSe(4))][MCl(4)] (M = Ga, 3 and M = In, 4) containing trans-octahedral cations with endocyclic macrocycle coordination. The ligand-bridged dimer [(GaCl(3))(2){o-C(6)H(4)(SMe)(2)}] (5) is formed from a 2:1 mol ratio of the constituents and contains distorted tetrahedral Ga(III). This complex is unusually reactive toward CH(2)Cl(2), which is activated toward nucleophilic attack by polarization with GaCl(3), producing the bis-sulfonium species [o-C(6)H(4)(SMeCH(2)Cl)(2)][GaCl(4)](2) (6), confirmed from a crystal structure. In contrast, the xylyl-based dithioether gives the stable [(GaCl(3))(2){o-C(6)H(4)(CH(2)SEt)(2)}] (8). However, replacing GaCl(3) with InCl(3) with o-C(6)H(4)(CH(2)SEt)(2) preferentially forms the 4:3 In:L complex [(InCl(3))(4){o-C(6)H(4)(CH(2)SEt)(2)}(3)] (9) containing discrete tetranuclear moieties in which the central In atom is octahedrally coordinated to six bridging Cl's, while the three In atoms on the edges have two bridging Cl's, two terminal Cl's, and two mutually trans S-donor atoms from different dithioether ligands. GaCl(3) also reacts with the cyclic bidentate [8]aneSe(2) to form a colorless, extremely air-sensitive adduct formulated as [(GaCl(3))(2)([8]aneSe(2))] (10), while InCl(3) gives [InCl(3)([8]aneSe(2))] (14). Very surprisingly, 10 reacts rapidly with O(2) gas to give initially the red [{[8]aneSe(2)}(2)][GaCl(4)](2) (11) and subsequently the yellow [{[8]aneSe(2)}Cl][GaCl(4)] (12). The crystal structure of the former confirms a dimeric [{[8]aneSe(2)}(2)](2+) dication, derived from coupling of two mono-oxidized {[8]aneE(2)}(+•) cation radicals to form an Se-Se bond linking the rings and weaker transannular 1,5-Se···Se interactions across both rings. The latter (yellow) product corresponds to discrete doubly oxidized {[8]aneSe(2)}(2+) cations (with a primary Se-Se bond across the 1,5-positions of the ring) with a Cl(-) bonded to one Se. Tetrahedral [GaCl(4)](-) anions provide charge balance in each case. These oxidation reactions are clearly promoted by the Ga(III) since [8]aneSe(2) itself does not oxidize in air. The new complexes have been characterized in the solid state by IR and Raman spectroscopy, microanalysis, and X-ray crystallography where possible. Where solubility permits, the solution characteristics have been probed by (1)H, (77)Se{(1)H}, and (71)Ga NMR spectroscopic studies.

New copper(I) polymers assembled by dithioether ligands

New copper(I) polymers assembled by dithioether ligands

Synthesis, crystal structures and thermal analysis of two new coordination polymers

Abstract Two new silver(I) – dithioether coordination polymers based on the combination of the dithioether ligand L = CH3–S(CH2)3S–CH3 and AgX silver salts, where X = NO3− (1) and CF3CF2COO− (2), have been synthesized and characterized. In both coordination polymers, the dithioether building blocks propagated the silver (I) centers to build chains, in which the counteranions complete the coordination sphere of the metal centers. Furthermore, the tubular chains in 2 are, in turn, associated through weak C F…F C interactions into 3D-structures. The thermogravimetric investigation reveals that those complexes decompose in a single step respectively to metallic silver. The stoichiometries of the obtained polymers were found to be dependent of the starting metal-to-ligand ratio.

Syntheses, structures and bioactivities of silver(I) complexes with dithioether ligands that contain a di- or triethylene glycol chain and different terminal groups

A series of flexible dithioethyl ligands that contain ethyleneoxy segments were designed and synthesized, including bis(2-(pyridin-2-ylthio)ethyl)ether (L1), 1,2-bis(2-(pyridin-2-ylthio)ethoxy)ethane (L2), bis(2-(benzothiazol-2-ylthio)ethyl)ether (L3) and 1,2-bis(2-(benzothiazol-2-ylthio)ethoxy)ethane (L4). Reactions of these ligands with AgNO3 led to the formation of four new supramolecular coordination complexes, [Ag2L1(NO3)2]2 (1), [Ag2L2(NO3)2] (2), [AgL3(NO3)]∞ (3) and [AgL4(NO3)] (4) in which the length of the (CH2CH2O)n spacers and the terminal groups of ligands cause subtle geometrical differences. Studies of the inhibitory effect to the growth of Phaeodactylum tricornutum show that all four complexes are active and the compound 4 has the highest inhibitory activity.

Silver(I) Complexes with Dithioether Ligands: Syntheses, Crystal Structures, and Fluorescence Properties

AbstractTwo new dithioether ligands, 1,4‐bis[(phenylsulfanyl)methyl]naphthalene (L1), and 4,4′‐bis[(tert‐butylsulfanyl)methyl]biphenyl (L2) were synthesized and their silver(I) complexes were studied. Both AgI complexes, [AgL1(NO3)]n (1) and [AgL2(NO3)]2 (2), were synthesized at ambient temperature and characterized by elemental analysis, IR spectroscopy, and single‐crystal X‐ray diffraction analysis. Single‐crystal X‐ray analysis shows that complex 1 has a one‐dimensional helical chain structure with the neutral repeating unit [Ag(μ2‐L1)(NO3)], whereas complex 2 has a centrosymmetrical neutral dinuclear structure. Moreover, complexes 1 and 2 are further extended into three‐dimensional supramolecular frameworks by hydrogen bonding and π–π stacking interactions, respectively. In addition, complexes 1 and 2 display strong blue emission in the solid state at room temperature.