- Unusual triplet-triplet annihilation in a 3D copper(i) chloride coordination polymer
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A new coordination polymer (CP) defined as [Cu2Cl2(EtS(CH2)4SEt)4]n (CP2) was prepared by reacting EtS(CH2)4SEt with CuCl in acetonitrile in a 1:2 stoichiometric ratio. The X-ray structure reveals formation of non-porous 3D material composed of parallel 2D-[Cu2Cl2S2]n layers of Cl-bridged Cu2(μ-Cl)2 rhomboids assembled by EtS(CH2)4SEt ligands. A weak triplet emission (Φe e of 0.93 (298 K) and 3.5 ns (77 K) as major components. CP2 is the only 2nd example of emissive thioether/CuCl-containing material and combined DFT/TDDFT computations suggest the presence of lowest energy M/XLCT excited states. Upon increasing the photon flux (i.e. laser power), a triplet-triplet annihilation (TTA) is induced with quenching time constants of 72 ps (kQ = 1.3 × 1010 s-1) and 1.0 ns (kQ = 7.1 × 108 s-1) at 298 and 77 K, respectively, proceeding through an excitation energy migration operating via a Dexter process. Two distinct (Io)1/2 (Io = laser power) dependences of the emission intensity are depicted, indicating saturation as the observed emission increases with the excitation flux. These findings differ from that previously reported isomorphous CP [Cu2Br2(μ-EtS(CH2)4SEt)4]n (CP1), which exhibits no TTA behaviour at 77 K, and only one (laser power)2 dependence at 298 K. The ~18-fold increase in kQ upon warming CP2 from 77 to 298 K indicates a temperature-aided TTA process. The significant difference between the presence (slower, CP2) and absence (CP1) of TTA at 77 K is explained by the larger unit cell contraction of the former upon cooling. This is noticeable by the larger change in inter-rhomboid Cu?Cu separation for CP2.
- Schlachter, Adrien,Bonnot, Antoine,Fortin, Daniel,Karsenti, Paul-Ludovic,Knorr, Michael,Harvey, Pierre D.
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- Novel dithioether-silver(I) coordination architectures: Structural diversities by varying the spacers and terminal groups of ligands
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An investigation into the dependence of the framework formation of coordination architectures on ligand spacers and terminal groups was reported based on the self-assembly of AgClO4 and eight structurally related flexible dithioether ligands, RS(CH2)nSR (L an, R = ethyl group, Lbn, R = benzyl group, n = 1-4). Eight novel metal-organic architectures, [Ag(L a1)3/2ClO4]n (1a), [Ag2(La2)2(ClO4) 2]2 (2a), [AgLa3ClO 4]n (3a), {[Ag(La4) 2]ClO4}n (4a), [AgLb 1ClO4]2 (1b), [Ag(Lb 2)2]ClO4 (2b), {[Ag(Lb 3)3/2(ClO4)1/2](ClO 4)1/2}n(3b) and [Ag(Lb 4)3/2ClO4]n (4b), were synthesized and structurally characterized by X-ray crystallography. Structure diversities were observed for these complexes: 1a forms a 2-D (6,3) net, while 2a is a discrete tetranuclear complex, in which the Ag1 ion adopts linear and tetrahedral coordination modes, and the S donors in each ligand show monodentate terminal and μ2-S bridging coordination fashions; 3a has a chiral helical chain structure in which two homo-chiral right-handed single helical chains (Ag-La3-)n are bound together through μ2-S donors, and simultaneously gives rise to left-handed helical entity (Ag-S-)n. In 4a, left- and right-handed helical chains formed by the ligands bridging Ag1 centers are further linked alternately by single-bridging ligands to form a non-chiral 2-D framework. 1b has a dinuclear structure showing obvious ligand-sustained Ag Ag interaction, while 2b is a mononuclear complex; 3b is a 3-D framework formed by ClO4- linking the 2-D (6,3) framework, which is similar to that of 1a, and 4b has a single, double-bridging chain structure in which 14-membered dinuclear ring units formed through two ligands bridging two Ag 1 ions are further linked by single-bridging ligands. In addition, a systematic structural comparison of these complexes and other reported AgClO4, complexes of analogous dithioether ligands indicates that the ligand spacers and terminal groups take essential roles on the framework formation of the Ag1 complexes, and this present feasible ways for adjusting the structures of such complexes by modifying the ligand spacers and terminal groups.
- Li, Jian-Rong,Ba, Xian-He,Jiao, Jiao,Du, Wen-Ping,Xu, Xiu-Hua,Zhang, Ruo-Hua
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p. 464 - 474
(2007/10/03)
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- Reactions of diorganyl disulfides with dihaloalkanes in basic reductive media. Synthesis of bis(organylthio)alkanes
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A convenient preparative synthesis of bis(organylthio)alkanes was developed. It is based on alkylation with dihaloalkanes of solutions of diorganyl disulfides in the basic reductive system hydrazine hydrate-alkali. The generation of organylthiolate anions
- Alekminskaya,Russavskaya,Korchevin,Deryagina
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- Synthesis of α-Halogeno-ω-alkylthioalkanes and α,ω-Bisalkylthioalkanes
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The reaction of α,ω-dihalogenated alkanes with alkylthiolates affords α-halogeno-ω-alkylthioalkanes 1 as well as α,ω-bisalkylthioalkanes 2.Products 1 (40 examples) and 2 (22 examples) are easily isolated in good yields by flash chromato
- Anklam, Elke
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p. 841 - 843
(2007/10/02)
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