1449-68-9Relevant academic research and scientific papers
The Origin of Chalcogen-Bonding Interactions
Pascoe, Dominic J.,Ling, Kenneth B.,Cockroft, Scott L.
, p. 15160 - 15167 (2017)
Favorable molecular interactions between group 16 elements have been implicated in catalysis, biological processes, and materials and medicinal chemistry. Such interactions have since become known as chalcogen bonds by analogy to hydrogen and halogen bonds. Although the prevalence and applications of chalcogen-bonding interactions continues to develop, debate still surrounds the energetic significance and physicochemical origins of this class of σ-hole interaction. Here, synthetic molecular balances were used to perform a quantitative experimental investigation of chalcogen-bonding interactions. Over 160 experimental conformational free energies were measured in 13 different solvents to examine the energetics of O···S, O···Se, S···S, O···HC, and S···HC contacts and the associated substituent and solvent effects. The strongest chalcogen-bonding interactions were found to be at least as strong as conventional H-bonds, but unlike H-bonds, surprisingly independent of the solvent. The independence of the conformational free energies on solvent polarity, polarizability, and H-bonding characteristics showed that electrostatic, solvophobic, and van der Waals dispersion forces did not account for the observed experimental trends. Instead, a quantitative relationship between the experimental conformational free energies and computed molecular orbital energies was consistent with the chalcogen-bonding interactions being dominated by n → σ? orbital delocalization between a lone pair (n) of a (thio)amide donor and the antibonding σ? orbital of an acceptor thiophene or selenophene. Interestingly, stabilization was manifested through the same acceptor molecular orbital irrespective of whether a direct chalcogen···chalcogen or chalcogen···H-C contact was made. Our results underline the importance of often-overlooked orbital delocalization effects in conformational control and molecular recognition phenomena.
Stepwise enhancement on optoelectronic performances of polyselenophene via electropolymerization of mono-, bi-, and tri-selenophene
Hu, Faqi,Jian, Nannan,Liu, Ximei,Lu, Baoyang,Qu, Kai,Xu, Jingkun,Zhao, Guoqun
, (2020)
Although much progress have been made on polyselenophenes-based molecular systems, the poor optoelectronic performance of parent polyselenophene still hamper both the fundamental understanding and practical applications of such materials due to the monomer instability during the polymerization process and the lack of suitable monomeric precursors. In this work, we develop an effective method to improve the optoelectronic performances and stability of parent polyselenophene by stepwise increasing the initial monomeric chain length for electrochemical polymerization. We find that the chain length increment of the monomeric structures from selenophene to bi- and tri-selenophenes dramatically reduces the electropolymerization potential and thus enables the formation of high quality polyselenophene films with better conjugated structures and less structural defects. As-formed polyselenophene from tri-selenophene reveals lowered optical band gap (1.72 eV), better redox activity and stability, and significantly improved electrochromic nature of reversible and stable color changes between red and blue with high performance including superior optical contrast up to 75%, high coloration efficiency up to 450 cm2 C?1, and very fast switching time (0.7 s for oxidation and 0.4 s for reduction). These advantageous properties of as-prepared polyselenophene films afford the successful fabrication of patterned flexible electrochromic devices, which exhibit reversible and stable color changes upon both doping-dedoping and mechanical bending.
Asymmetric Heteroleptic Ir(III) Phosphorescent Complexes with Aromatic Selenide and Selenophene Groups: Synthesis and Photophysical, Electrochemical, and Electrophosphorescent Behaviors
Feng, Zhao,Wang, Dezhi,Yang, Xiaolong,Jin, Deyuan,Zhong, Daokun,Liu, Boao,Zhou, Guijiang,Ma, Miaofeng,Wu, Zhaoxin
, p. 11027 - 11043 (2018/09/14)
With the aim of evaluating the potential of selenium-containing groups in developing electroluminescent (EL) materials, a series of asymmetric heteroleptic Ir(III) phosphorescent complexes (Ir-Se0F, Ir-Se1F, Ir-Se2F, and Ir-Se3F) have been synthesized by using 2-selenophenylpyridine and one ppy-type (ppy = 2-phenylpyridine) ligand with a fluorinated selenide group. To the best of our knowledge, these complexes represent unprecedented examples of asymmetric heteroleptic Ir(III) phosphorescent emitters bearing selenium-containing groups. Natural transition orbital (NTO) analysis based on optimized geometries of the first triplet state (T1) have shown that the phosphorescent emissions of these Ir(III) complexes dominantly show 3π- π? features of the 2-selenophenylpyridine ligand with slight metal to ligand charge transfer (MLCT) contribution. In comparison with their symmetric parent complex Ir-Se with two 2-selenophenylpyridine ligands, these asymmetric heteroleptic Ir(III) phosphorescent complexes can show much higher phosphorescent quantum yields (φP) of ca. 0.90. Both the hole- and electron-trapping ability of these Ir(III) phosphorescent complexes can be enhanced by selenophene and fluorinated selenide groups to improve their EL efficiencies. The EL abilities of these asymmetric heteroleptic Ir(III) phosphorescent emitters fall in the order Ir-Se3F > Ir-Se2F > Ir-Se1F > Ir-Se0F. The highest EL efficiencies have been achieved by Ir-Se3F in the solution-processed OLEDs with external quantum efficiency (next), current efficiency (n L), and power efficiency (n P) of 19.9%, 65.6 cd A-1, and 57.3 lm W-1, respectively. These encouraging EL results clearly indicate the great potential of selenium-containing groups in developing high-performance Ir(III) phosphorescent emitters.
Molecular dipole, dye structure and electron lifetime relationship in efficient dye sensitized solar cells based on donor-π-acceptor organic sensitizers
Climent, Clàudia,Cabau, Lydia,Casanova, David,Wang, Peng,Palomares, Emilio
, p. 3162 - 3172 (2015/02/19)
In this work we report the synthesis and characterization of two new push-pull organic dyes (LC95 and LC107) to be employed as sensitizers in solar cells. Both molecules contain the bis(4-hexyloxyphenylamino)styril unit as the donor group, the cyanoacrylate acid as the acceptor, and the selenophene-thiophene (LC95 dye) and thiophene-selenophene (LC107 dye) moieties as the conjugated linkers. Dye sensitized solar cells employing these two photosensitizers and the cobalt(II/III) redox electrolyte exhibit good solar to energy conversion efficiencies of 6.3% and 6.5% measured under the 100 mW cm-2simulated AM1.5 sunlight. The efficiencies are slightly lower with the iodine/iodide electrolyte. The performance of these two dyes has been discussed and compared to three closely related sensitizers, i.e. C214, C216 and C218, by means of experimental measurements and quantum chemistry computations, with special attention to differences on their geometries, molecular dipoles and electron recombination lifetimes.
Base-catalyzed halogen dance reaction and oxidative coupling sequence as a convenient method for the preparation of dihalo-bisheteroarenes
Getmanenko, Yulia A.,Tongwa, Paul,Timofeeva, Tatiana V.,Marder, Seth R.
supporting information; experimental part, p. 2136 - 2139 (2010/08/05)
Figure presented A one-pot preparation of the 2,2′-dibromo-1, 1′-bisheteroarenes 3a-d from bromo-heteroarenes utilizing the sequence of the base-catalyzed halogen dance (BCHD) reaction and CuCl2-promoted oxidative coupling of the in situ formed α-lithio-β-halo-heteroarenes 2a-d provides a convenient access to precursors for the preparation of tricyclic heteroaromatic cores. The structures of 3a,b,d, 6, and 9 were confirmed by single-crystal X-ray analysis, and dibromides 3a and 3b were used for the preparation of dithieno-[2,3-b:3′,2′-d]-pyrrole 10a and its selenophene analogue 10b, respectively.
Electron-Conjugated Organic Silane Compound and Production Method Thereof
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Page/Page column 20-21, (2009/01/24)
The present invention provides a π-electron-conjugated organice silane compound that give an organic thin film superior in peeling restance, orientation, crystallinity and eletroconductive properties, and a production method thereof. A π-electron-conjugated organice silane compound represented by General Formula: R1-SiX1X2X3 (R1 represents an organic group having a particular monocyclic heterocyclic unit; and X1 to X3 are a group giving a hydroxyl group by hydrolysis). A method of producing the organic silane compound, comprising allowing a compound represented by General Formula: R1-Li (R1 is the same as above) or a compound represented by General Formula: R1-MgX5 (R1 is the same as above; and X5 represents a halogen atom) with a compound represented by General Formula: X4-SiX1X2X3 (X1 to X3 are the same as above; and X4 represents a hydrogen or halogen atom or a lower alkoxy group). A π-electron-conjugated organic silane compound represented by General Formula; Z-(R11)m-SiR12R13R14 (Z represents a organice group derived froma particular fused polycyclic heterocyclic compound; R11 represents a bivalent organic group; m is 0 to 10; and R12 to R14 represents a halogen atom or an alkoxy group). A method of producing the organic silane compound, comprising allowing a compound represented by General Formula: Z-(R11)m-MgX30 (Z, R11 and m are the same as above; and X30 represents a halogen atom) to react with a compound represented by General Formula: X31-SiR12R13R14 (X31 represents a hydrogen or halogen atom or an alkoxy group; and R12 to R14 are the same as above).
Carbon-sulfur bond formation from 2-halochalcogenophenes via copper catalyzed thiol cross-coupling
Zeni, Gilson
, p. 2647 - 2651 (2007/10/03)
We present herein our results of the thiol coupling reaction of 2-halochalcogenophenes with Cu(I) and establish the first route to prepare (2-sulfides)-chalcogenophenes in good yields. The reaction performed with both electron donating and electron withdrawing substituents on thiol in the absence of any supplementary additives. In addition, the reaction proceeded cleanly under mild reaction conditions and was sensitive to nature of catalyst, base, and solvent.
