A Highly Stable (4, 8)-Connected Tb-MOF Exhibiting Efficiently Luminescent Sensing towards Nitroimidazole Antibiotics

A robust 4,8-connected Tb-based metal-organic framework (Tb-MOF) with paddle wheel-shaped {Tb₂(COO)₄} subunits extended by C₃-symmetric 3,3',3''-[1,3,5-benzenetriyltris(carbonylimino)]tris-benzoate connector was hydrothermally synthesized, showing highly environmental stability, good dispersion and intense green emission in water system. Resulting critically from the well suppressed absorption towards the excitation energy, the Tb-MOF exhibits rapid and efficient fluorescent response towards nitroimidazole antibiotics with strong quenching constants and low detection limits of 1.59 × 10⁴ m ^–1 and 2.4 μM for metronidazole as well as 1.62 × 10⁴ m ^–1 and 2.9 μM for dimetridazole. Moreover, the sensitive and selective identification of the Tb-MOF has strong anti-interference and excellent regeneration ability, which endows the promising applications of the Tb-MOF as fluorescent sensing materials.     

An amphiphilic [2]biphenyl-extended pillar[6]arene: Synthesis,controllable self-assembly in water and application in cell-imaging

Synthesis and functionalization of novel macrocyclic host molecules are important topics in supramolecular chemistry. In this work, the first amphiphilic [2]biphenyl-extended pillar[6]arene (AM-[2]BP-ExP6) was designed and synthesized with poly(ethylene glycol) chains as the hydrophilic tails and a rigid cavity as the hydrophobic core. Due to its amphiphilic nature, AM-[2]BP-ExP6 could self-assemble to stable fibers in water. What's more, AM-[2]BP-ExP6 could associate with quaternary ammonium modified tetraphenylethylene guest (QTPE) to form a 2:1 host-guest complex, accompanied by significant enhanced fluorescence. Interestingly, different like AM-[2]BP-ExP6, AM-[2]BP-ExP6⊃QTPE host-guest complex self-assembled into fluorescent particles with diameter about 310 nm, the obtained fluorescent particles can be further employed in living cell imaging.     

一系列由柔性N,N''-双(3-吡啶甲基)胺构筑的螺旋配合物的合成、结构和性质

合成和表征了5个螺旋配位聚合物{[Cu(Hbpma)(H₂O)₄]₂(SO₄)₃·3.5H₂O}_n (1)、{[Ni(Hbpma)(H₂O)₄]₄(SO₄)₆·10.75H₂O}_n (2)、{[Mn(Hbpma)(H₂O)4](SO₄)_1.5·3H₂O}_n (3)、{[Zn(Hbpma)(H₂O)₄]₄(SO₄)₆·4H₂O·4CH₃OH}_n (4)和{[Cu(Hbpma)2(H₂O)₂](SO₄)2·9H₂O}_n (5),其中bpma代表N,N'-双(3-吡啶甲基)胺。晶体结构分析表明配合物1~4为一维链状结构,配合物5为二维层状结构,其中金属离子由质子化的bpma配体桥连。值得注意的是,采取反-反式构象的柔性bpma配体使得配合物1和2为假螺旋链结构,配合物3和4为螺旋链结构,配合物5为螺旋层结构。同时研究了配合物的磁性和热稳定性。     

基于5-磺酸基间苯二甲酸钠和双三唑烷烃的Cu(Ⅱ)配合物的合成、结构和性质

利用5-磺酸基间苯二甲酸钠(NaH₂sip)和双三唑烷烃,合成了3个配合物[Cu_0.5(btm)(H₂O)](H₂sip)·H₂O}_n(1,btm=双三唑甲烷),{[Cu(btp)₂(H₂sip)(H₂O)](NO₃)·4H₂O}_n(2,btp=双三唑丙烷)和{[Cu(btb)₂(Hsip)]_n(3,btb=双三唑丁烷)。化合物1为一维双链结构;化合物2为二维四方网络结构,多个二维层依次叠加形成三维超分子结构;化合物3也具有二维层状结构,其中金属铜离子和双三唑丁烷构成的一维双链结构经双齿μ₂-Hsip^2-配体连接构成了二维层状结构。同时对配合物的热稳定性和顺磁共振特性进行了讨论。     

Transition-metal-free trifluoromethylthiolation and difluoromethylthiolation of thiols with trifluoromethanesulfonyl chloride and difluoromethanesulfonyl chloride

Triphenylphosphine-mediated metal-free trifluoromethylthiolation and difluoromethylthiolation of thiols by CF₃SO₂Cl and CHF₂SO₂Cl to synthesize trifluoromethyl disulfides and difluoromethyl disulfides, respectively, was achieved at room temperature. Iodine generated in situ from iodide facilitated this reaction via the formation of iodotriphenylphosphonium iodide which could serve as a reducing agent in this transformation. Readily available reagents and mild reaction conditions without transition-metals allow this protocol to be more practical than traditional methods.     

Ferric chloride-promoted direct trifluoromethylselenolation of nitrogen-containing heterocyclic compounds by Se-(trifluoromethyl) 4-methylbenzenesulfonoselenoate in water

The ferric chloride-promoted direct trifluoromethylselenolation of indoles and other nitrogen-containing heterocyclic compounds in water was performed by employing TsSeCF₃ as a trifluoromethylselenolation reagent. The shelf-stable and readily accessible reagents, along with the environmentally friendly and mild reaction conditions make this method an effective alternative for the trifluoromethylselenolation of electron-rich aromatics.     

Cadmium(II)–Triazole Framework as a Luminescent Probe for Ca2+ and Cyano Complexes

A bidentate ligand, 1‐{4‐[4‐(1H‐1,2,4‐triazol‐1‐yl)phenoxy]phenyl}‐1H‐1,2,4‐triazole (TPPT), has been designed and synthesized. By using TPPT as a building block for self‐assembly with Cd(NO₃)₂ ? 4 H₂O and CdCl₂ ? 10.5 H₂O, novel 1D double‐chain {[Cd(TPPT)(NO₃)₂] ? 3 H₂O}_n ( 1 ) and 2D (4,4) layer [Cd(TPPT)Cl₂(H₂O)]_n ( 2 ) have been constructed. When 1 was employed as a precursor and exposed to DMF or N,N′‐dimethylacetamide (DMAC), the crystals of 1 dissolved and reassembled into two types of brown block‐shaped crystals of 1D double chains: {[Cd(TPPT)₂(NO₃)₂] ? DMF}_n ( 1 a ) and {[Cd(TPPT)₂(NO₃)₂] ? DMAC}_n ( 1 b ). The anion‐exchange reactions of complex 2 have also been investigated. After gently stirring crystals of 2 in CHCl₃/C₂H₅OH/H₂O containing NaBr, NaI ? 2 H₂O, or NaOAc ? 3 H₂O, the crystals retained their crystalline appearances. A remarkable single crystal to single crystal transformation was observed and 1D double chains of {[Cd(TPPT)Br₂] ? C₂H₅OH}_n ( 2 a ) and {[Cd(TPPT)₂I₂] ? CHCl₃}_n ( 2 b ), and 1D single chains of [Cd(TPPT)(H₂O)₂(CH₃COO)₂]_n ( 2 c ), can be obtained. Luminescent properties indicate that 1 shows excellent selectivity for Ca²⁺ and cyano complexes. To the best of our knowledge, this is the first example of a luminescent probe for Ca²⁺ based on triazole derivatives.     

Interfacial passivation mechanism of sulfide towards quantum dot-sensitized nanocrystalline thin films

Journal of Solid State Electrochemistry - We report on the interfacial passivation mechanism in CdSe quantum dot-sensitized ZnO nanocrystalline thin film, where different sulfide semiconductors...     

基于双三唑甲烷的两种新型Cu(Ⅱ)配合物的结构和性质

本文利用柔性配体双三唑甲烷(btm),在水热条件下合成了2个新的配合物[Cu0.5(btm)Cl]n(1)和[Cu(btm)Cl2]n(2)。实验表明,氯离子的配位模式会随着金属和配体的比例的不同而改变,从而得到了两种结构不同的配合物。化合物1为一维链状结构,链与链之间通过四重Cl…H-C氢键组合成了三维超分子结构。化合物2为二维(4.4)连接的网状结构,单重氢键Cl…H-C将二维层连接为三维结构。两种配合物用单晶X-衍射、元素分析、热重、顺磁共振等技术进行了表征。     

基于4-氨基-1,2,4-三唑和多金属氧酸盐为杂化配体的CuⅡ和CuⅠ配合物的水热合成及光催化性能

在水热条件下,制备了2个基于多金属氧酸盐（POM）的Cu^Ⅱ和Cu^Ⅰ新型杂化配合物材料,即[Cu₂（4-NH₂-trz）₄（Mo₈O₂₆）（H₂O）₄]·5H₂O（1）和[Cu₄（4-NH₂-trz）₄Mo₈O₂₆]（2）（4-NH₂-trz=4-氨基-1,2,4-三唑）。通过单晶X射线衍射、傅里叶变换红外光谱和粉末X射线衍射分析确定了它们的结构。在配合物1中,4-氨基-1,2,4-三唑双齿配体连接2个相邻的Cu^Ⅱ中心形成双核结构单元,这些双核结构单元进一步通过Mo₈O₂₆^4-连接形成一维（1D）的杂化配位结构。在配合物2中,4-氨基-1,2,4-三唑双齿配体连接相邻Cu^Ⅰ中心构筑了独特的[Cu₄（4-NH₂-trz）₄]_n一维螺旋链,这些左手和右手的一维螺旋链再通过（β-Mo₈O₂₆）^4-连接形成2D杂化骨架。光催化实验研究表明,样品1和样品2对于不同有机染料（亚甲基蓝（MB）、罗丹明B（RhB）和甲基橙（MO））具有很好的光催化降解能力。