Synthesis of Bis‐Heterocyclic 1H‐Imidazole 3‐Oxides from 3‐Oxido‐1H‐imidazole‐4‐carbohydrazides

The reaction of 1H‐imidazole‐4‐carbohydrazides 1 , which are conveniently accessible by treatment of the corresponding esters with NH₂NH₂?H₂O, with isothiocyanates in refluxing EtOH led to thiosemicarbazides (=hydrazinecarbothioamides) 4 in high yields (Scheme 2). Whereas 4 in boiling aqueous NaOH yielded 2,4‐dihydro‐3H‐1,2,4‐triazole‐3‐thiones 5 , the reaction in concentrated H₂SO₄ at room temperature gave 1,3,4‐thiadiazol‐2‐amines 6 . Similarly, the reaction of 1 with butyl isocyanate led to semicarbazides 7 , which, under basic conditions, undergo cyclization to give 2,4‐dihydro‐3H‐1,2,4‐triazol‐3‐ones 8 (Scheme 3). Treatment of 1 with Ac₂O yielded the diacylhydrazine derivatives 9 exclusively, and the alternative isomerization of 1 to imidazol‐2‐ones was not observed (Scheme 4). It is important to note that, in all these transformations, the imidazole N‐oxide residue is retained. Furthermore, it was shown that imidazole N‐oxides bearing a 1,2,4‐triazole‐3‐thione or 1,3,4‐thiadiazol‐2‐amine moiety undergo the S‐transfer reaction to give bis‐heterocyclic 1H‐imidazole‐2‐thiones 11 by treatment with 2,2,4,4‐tetramethylcyclobutane‐1,3‐dithione (Scheme 5).     

A two‐dimensional cadmium(II) coordination polymer constructed from 4‐carboxy‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐5‐carboxylate and 1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐4‐carboxylate ligands

Crystals of poly[[aqua[μ₃‐4‐carboxy‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐5‐carboxylato‐κ⁵O¹O^1′:N³,O⁴:O⁵][μ₄‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐4‐carboxylato‐κ⁷N³,O⁴:O⁴,O^4′:O¹,O^1′:O¹]cadmium(II)] monohydrate], {[Cd₂(C₁₅H₁₄N₂O₄)(C₁₆H₁₄N₂O₆)(H₂O)]·H₂O}_n or {[Cd₂(Hcpimda)(cpima)(H₂O)]·H₂O}_n, (I), were obtained from 1‐(4‐carboxybenzyl)‐2‐propyl‐1H‐imidazole‐4,5‐dicarboxylic acid (H₃cpimda) and cadmium(II) chloride under hydrothermal conditions. The structure indicates that in‐situ decarboxylation of H₃cpimda occurred during the synthesis process. The asymmetric unit consists of two Cd²⁺ centres, one 4‐carboxy‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐5‐carboxylate (Hcpimda²⁻) anion, one 1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐4‐carboxylate (cpima²⁻) anion, one coordinated water molecule and one lattice water molecule. One Cd²⁺ centre, i.e. Cd1, is hexacoordinated and displays a slightly distorted octahedral CdN₂O₄ geometry. The other Cd centre, i.e. Cd2, is coordinated by seven O atoms originating from one Hcpimda²⁻ ligand and three cpima²⁻ ligands. This Cd²⁺ centre can be described as having a distorted capped octahedral coordination geometry. Two carboxylate groups of the benzoate moieties of two cpima²⁻ ligands bridge between Cd2 centres to generate [Cd₂O₂] units, which are further linked by two cpima²⁻ ligands to produce one‐dimensional (1D) infinite chains based around large 26‐membered rings. Meanwhile, adjacent Cd1 centres are linked by Hcpimda²⁻ ligands to generate 1D zigzag chains. The two types of chains are linked through a μ₂‐η² bidentate bridging mode from an O atom of an imidazole carboxylate unit of cpima²⁻ to give a two‐dimensional (2D) coordination polymer. The simplified 2D net structure can be described as a 3,6‐coordinated net which has a (4³)₂(4⁶.6⁶.8³) topology. Furthermore, the FT–IR spectroscopic properties, photoluminescence properties, powder X‐ray diffraction (PXRD) pattern and thermogravimetric behaviour of the polymer have been investigated.     

Metal Derivatives of Heterocyclic Thioamides: Synthesis and Crystal Structures of Copper Complexes with 1‐Methyl‐1,3‐imidazoline‐2‐thione and 1,3‐Imidazoline‐2‐thione

Reactions of copper(I) halides (Cl, Br, I) with 1‐methyl‐1, 3‐imidazoline‐2‐thione (mimzSH) in 1 : 2 molar ratio yielded sulfur‐bridged dinuclear [Cu₂X₂(μ‐S‐mimzSH)₂(η¹‐S‐mimzSH)₂] (X = I, 1 , Br, 2 ; Cl, 3 ) complexes. Copper(I) iodide with 1,3‐imidazoline‐2‐thione (imzSH₂) and Ph₃P in 1 : 1 : 1 molar ratio has also formed a sulfur‐bridged dinuclear [Cu₂I₂(μ‐S‐imzSH₂)₂(PPh₃)₂] ( 4 ) complex. The central Cu(μ‐S)₂Cu cores form parallelograms with unequal Cu–S bond distances {2.324(2), 2.454(3) Å} ( 1 ); {2.3118(6), 2.5098(6) Å} ( 2 ); {2.3075(4), 2.5218(4) Å} ( 3 ); {2.3711(8), 2.4473(8) Å} ( 4 ). The Cu···Cu separations, 2.759–2.877Å in complexes 1 – 3 are much shorter than 3.3446Å in complex 4 . The weak intermolecular interactions {H₂CH···S^# ( 2 ); CH···Cl^# ( 3 ); NH···I^# ( 4 )} between dimeric units in complexes 2 – 4 lead to the formation of linear 1D polymers.     

Syntheses of 4‐(5‐oxo‐1,2,4‐triazol‐3‐yl)‐sydnones and 4‐(4‐arylamino‐5‐oxo‐1,2,4‐triazol‐3‐yl)‐sydnones from Sydnone Derivatives and Their Fragments

4‐(5‐oxo‐1,2,4‐triazol‐3‐yl)‐sydnones 11 and 4‐(4‐arylamino‐5‐oxo‐1,2,4‐triazol‐3‐yl)‐sydnones 13 have been obtained from a‐chloroformylarylhydrazine hydrochloride 2 . Moreover, the intermediates, including 3, 4 , 9 and 10 , in this study are synthetically informative and valuable. It is also noteworthy that three reactants, 1, 2 and sydnonecarbaldehydes, were prepared from sydnone derivatives and their fragments. The oxidative cyclizations of sydnonecarbaldehyde semicarbazones 9 and carbazones 10 with two different oxidizing agents (Cu(ClO₄)₂ and Fe(ClO₄)₃) have been extensively examined. The reaction time and the yields of cyclizations were affected by the substituents of semicarbazones 9 and carbazones 10.     

1,1‐Diethyl‐1‐germa‐2,3,4,5‐tetra‐tert‐butyl‐2,3,4,5‐tetraphospholan (C2H5)2Ge(tBuP)4, Molekül‐ und Kristallstruktur

1,1‐Diethyl‐1‐germa‐2,3,4,5‐tetra‐ tert ‐butyl‐2,3,4,5‐tetraphospholane (C₂H₅)₂Ge( t BuP)₄, Molecular and Crystal Structure The reaction of the diphosphide K₂[(tBuP)₄] · THF ( 1 ) with the germanium(IV) compound (C₂H₅)₂GeCl₂ leads via a [4 + 1]‐cyclo‐condensation reaction to 1,1‐diethyl‐1‐germa‐2,3,4,5‐tetra‐tert‐butyl‐2,3,4,5‐tetraphospholane (C₂H₅)₂Ge(tBuP)₄ ( 2 ) with the 5‐membered GeP₄ ring system. 2 could be characterized ³¹P NMR spectroscopically, mass spectrometrically and by a single crystal structure analysis.     

Competitive Molecular‐/Ion‐Recognition Responsive Characteristics of Poly(N‐isopropylacrylamide‐co‐benzo‐12‐crown‐4‐acrylamide) Copolymers with Benzo‐12‐crown‐4 as Both Guest and Host Units

Novel dual molecular‐ and ion‐recognition responsive poly(N‐isopropylacrylamide‐co‐benzo‐12‐crown‐4‐acrylamide) (PNB₁₂C₄) linear copolymers with benzo‐12‐crown‐4 (B12C4) as both guest and host units are prepared. The copolymers exhibit highly selective sensitivities toward γ‐cyclodextrin (γ‐CD) and Na⁺. The presence of γ‐CD induces the lower critical solution temperature (LCST) of PNB₁₂C₄ copolymer to shift to a higher value due to the formation of 1:1 γ‐CD/B12C4 host‐guest inclusion complexes, while Na⁺ causes a negative shift in LCST due to the formation of 2:1 “sandwich” B12C4/Na⁺ host‐guest complexes. Regardless of the complexation order, when γ‐CD and Na⁺ coexist with PNB₁₂C₄, competitive complexation actions of B12C4 as both guest and host units toward γ‐CD and Na⁺ finally form equilibrium 2:2:1 γ‐CD/B12C4/Na⁺ composite complexes, and the final LCST values of PNB₁₂C₄ copolymer reach almost the same level. The results provide valuable guidance for designing and applying PNB₁₂C₄‐based smart materials in various applications.

     

Isolation and Structural Characterization of Di‐ and Tetra‐protonated Forms of the Macrocyclic Hexaamine trans‐6,13‐Dimethyl‐1,4,8‐11‐tetraazacyclodecane‐6,13‐diamine

Cations derived by protonation of the ligand title compound (L¹) have been structurally characterized in their di‐ and tetra‐ protonated forms in the salts [H₂L¹][ClO₄]₂·2H₂O and [H₄L¹][ZnCl₄]₂·4H₂O. In both structures, one half of the formula unit comprises the asymmetric unit of the structure, the macrocycle being centrosymmetric, with the two macrocycles adopting similar conformations. In both salts, a pair of diagonally opposed macrocyclic secondary amine groups are protonated; in the [H₄L¹]⁴⁺ salt, the additional pair of protons are accommodated on the exocyclic pendant amine groups. The dispositions of the pendent amines differ between the two structures, being ‘equatorial’ with respect to the macrocyclic ring in the [H₂L¹]²⁺ salt, and ‘axial’ in the [H₄L¹]⁴⁺ salt. In other structurally characterized compounds containing [H₄L¹]⁴⁺ the equatorial disposition was found in the ferricyanide adduct, while in the tetraperchlorate salt the axial disposition was identified. The differences in disposition of the exocyclic groups are ascribed to the extensive H‐bonding in the lattices.     

3‐Cyano‐6‐hydroxy‐4‐methyl‐2‐pyridone: two new pseudopolymorphs and two cocrystals with products of an in situ nucleophilic aromatic substitution

Four crystal structures of 3‐cyano‐6‐hydroxy‐4‐methyl‐2‐pyridone (CMP), viz. the dimethyl sulfoxide monosolvate, C₇H₆N₂O₂·C₂H₆OS, (1), the N,N‐dimethylacetamide monosolvate, C₇H₆N₂O₂·C₄H₉NO, (2), a cocrystal with 2‐amino‐4‐dimethylamino‐6‐methylpyrimidine (as the salt 2‐amino‐4‐dimethylamino‐6‐methylpyrimidin‐1‐ium 5‐cyano‐4‐methyl‐6‐oxo‐1,6‐dihydropyridin‐2‐olate), C₇H₁₃N₄⁺·C₇H₅N₂O₂⁻, (3), and a cocrystal with N,N‐dimethylacetamide and 4,6‐diamino‐2‐dimethylamino‐1,3,5‐triazine [as the solvated salt 2,6‐diamino‐4‐dimethylamino‐1,3,5‐triazin‐1‐ium 5‐cyano‐4‐methyl‐6‐oxo‐1,6‐dihydropyridin‐2‐olate–N,N‐dimethylacetamide (1/1)], C₅H₁₁N₆⁺·C₇H₅N₂O₂⁻·C₄H₉NO, (4), are reported. Solvates (1) and (2) both contain the hydroxy group in a para position with respect to the cyano group of CMP, acting as a hydrogen‐bond donor and leading to rather similar packing motifs. In cocrystals (3) and (4), hydrolysis of the solvent molecules occurs and an in situ nucleophilic aromatic substitution of a Cl atom with a dimethylamino group has taken place. Within all four structures, an R₂²(8) N—H...O hydrogen‐bonding pattern is observed, connecting the CMP molecules, but the pattern differs depending on which O atom participates in the motif, either the ortho or para O atom with respect to the cyano group. Solvents and coformers are attached to these arrangements via single‐point O—H...O interactions in (1) and (2) or by additional R₄⁴(16) hydrogen‐bonding patterns in (3) and (4). Since the in situ nucleophilic aromatic substitution of the coformers occurs, the possible Watson–Crick C–G base‐pair‐like arrangement is inhibited, yet the cyano group of the CMP molecules participates in hydrogen bonds with their coformers, influencing the crystal packing to form chains.     

A one‐dimensional lead(II) coordination polymer with terminal and bridging 5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylate ligands

In the coordination polymer catena‐poly[[[diaqua[5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylato‐κ²N³,O⁴]lead(II)]‐μ‐5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylato‐κ³N³,O⁴:N²] dihydrate], {[Pb(C₁₀H₆N₃O₄)(H₂O)₂]·2H₂O}_n, the two 5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylate ligands have different coordination modes, one being terminal and the other bridging. The bridging ligand links Pb^II cations into one‐dimensional coordination polymer chains. The structure is also stabilized by intra‐ and interchain π–π stacking interactions between the pyridine rings, resulting in the formation of a two‐dimensional network. Extensive hydrogen‐bonding interactions lead to the formation of a three‐dimensional supramolecular network.     

Luminescence Regulation of Silver‐Thiolate Clusters Protected by 1,2‐Dithiolate‐o‐carborane

Engineering the surface of the metal clusters with the core structure maintained and tuning their luminescence in a wide range is still a challenge in the nanomaterial research. We modified six mono‐pyridyl ligands with different electronic effects (conjugation effect or induction effect) on a superatomic silver cluster [Ag₁₄(C₂B₁₀H₁₀S₂)₆(CH₃CN)₈] (denoted as Ag₁₄) through in situ site‐specific surface engineering, and obtained the corresponding clusters [Ag₁₄(C₂B₁₀H₁₀S₂)₆(CH₃CN)₆(L₁/L₂)₂] (denoted as NC‐1, 2, L₁/L₂ = 4‐acetylpyridine/ 4‐carboxypyridine) and [Ag₁₄(C₂B₁₀H₁₀S₂)₆(L₃/L₄/L₅/L₆)₈] (denoted as NC‐3, 4, 5, 6, L₃/L₄/L₅/L₆ = 4‐phenylpyridine/4‐(1‐naphthyl)pyridine/9‐(4‐pyridine)anthracene/9‐(4‐pyridine)pyrene). Through the modification of the Ag₁₄ cluster, a wide‐range luminescence from blue to red was realized. This work might provide a practical guide for improving the emission performance of metal clusters via surface engineering.     

Alternative Synthesis of 2‐Hydroxy‐3,5,5‐trimethylcyclopent‐2‐en‐1‐one

The 2‐hydroxy‐3,5,5‐trimethylcyclopent‐2‐en‐1‐one ( 1 ) was synthesized in 42% yield by rearrangement of epoxy ketone 10 on treatment with BF₃⋅Et₂O under anhydrous conditions. Intermediate 10 was available from the known enone 8 , either via direct epoxidation (60% H₂O₂, NaOH, MeOH; yield 50%), or via reduction to the corresponding allylic alcohol 14 (LiAlH₄, THF), followed by epoxidation ([VO(acac)₂], ^tBuOOH) and reoxidation under Swern conditions, in 37% total yield.     

A three‐dimensional coordination polymer based on the Zn4(μ3‐OH)2 unit: poly[[(μ4‐benzene‐1,4‐dicarboxylato)bis(μ3‐benzene‐1,4‐dicarboxylato)bis(μ3‐hydroxido)bis(1,10‐phenanthroline‐5,6‐dione)tetrazinc] dihydrate]

The title compound, {[Zn₄(C₈H₄O₄)₃(OH)₂(C₁₂H₆N₂O₂)₂]·2H₂O}_n, has been prepared hydrothermally by the reaction of Zn(NO₃)₂·6H₂O with benzene‐1,4‐dicarboxylic acid (H₂bdc) and 1,10‐phenanthroline‐5,6‐dione (pdon) in H₂O. In the crystal structure, a tetranuclear Zn₄(OH)₂ fragment is located on a crystallographic inversion centre which relates two subunits, each containing a [ZnN₂O₄] octahedron and a [ZnO₄] tetrahedron bridged by a μ₃‐OH group. The pdon ligand chelates to zinc through its two N atoms to form part of the [ZnN₂O₄] octahedron. The two crystallographically independent bdc²⁻ ligands are fully deprotonated and adopt μ₃‐κO:κO′:κO′′ and μ₄‐κO:κO′:κO′′:κO′′′ coordination modes, bridging three or four Zn^II cations, respectively, from two Zn₄(OH)₂ units. The Zn₄(OH)₂ fragment connects six neighbouring tetranuclear units through four μ₃‐bdc²⁻ and two μ₄‐bdc²⁻ ligands, forming a three‐dimensional framework with uninodal 6‐connected α‐Po topology, in which the tetranuclear Zn₄(OH)₂ units are considered as 6‐connected nodes and the bdc²⁻ ligands act as linkers. The uncoordinated water molecules are located on opposite sides of the Zn₄(OH)₂ unit and are connected to it through hydrogen‐bonding interactions involving hydroxide and carboxylate groups. The structure is further stabilized by extensive π–π interactions between the pdon and μ₄‐bdc²⁻ ligands.     

Structural Diversity in the Self‐assembly of Cd(II) Complexes Containing 2,6‐Dimethyl‐3,5‐dicyano‐4‐(4‐pyridyl)‐1,4‐dihydropyridine

The syntheses, structures and properties of the complexes [CdBr₂( L )₂·4H₂O]_n [ L = 2,6‐dimethyl‐3,5‐dicyano‐4‐(4‐pyridyl)‐1,4‐dihydropyridine], 1 and [Cd(SCN)₂( L )₂(H₂O)]_n, 2 , are reported. In polymeric complexes 1 — 2 , the L ligands bridge the metal centers through the pyrimidyl and cyano nitrogen atoms forming 1‐D double‐stranded chain and zigzag chain, respectively. The L ligands in complex 1 act as κ1, κ1‐bidentate bridging ligand, whereas the L ligands in complex 2 act as κ1‐monodentae and κ1, κ1‐bidentate bridging ligand. The molecules of these complexes are interlinked through various weak interactions that form the packed structure. All the complexes exhibit emissions which may be tentatively assigned as intraligand (IL) π→π* transitions.     

The achiral tetrapeptide Z‐Aib‐Aib‐Aib‐Gly‐OtBu

The title achiral peptide N‐benzyloxycarbonyl‐α‐aminoisobutyryl‐α‐aminoisobutyryl‐α‐aminoisobutyrylglycine tert‐butyl ester or Z‐Aib‐Aib‐Aib‐Gly‐OtBu (Aib is α‐aminoisobutyric acid, Z is benzyloxycarbonyl, Gly is glycine and OtBu indicates the tert‐butyl ester), C₂₆H₄₀N₄O₇, is partly hydrated (0.075H₂O) and has two different conformations which together constitute the asymmetric unit. Both molecules form incipient 3₁₀‐helices. They differ in the relative orientation of the N‐terminal protection group and at the C‐terminus. There are two 4→1 intramolecular hydrogen bonds.     

Preparation of novel palladium nanoparticles supported on magnetic iron oxide and their catalytic application in the synthesis of 2‐imino‐3‐phenyl‐2,3‐dihydrobenzo[d]oxazol‐5‐ols

Novel Pd nanoparticles were prepared in five successive stages: 1) preparation of the Fe₃O₄ magnetic nanoparticles (Fe₃O₄ MNPs), 2) coating of Fe₃O₄ MNPs with SiO₂ (Fe₃O₄@SiO₂), 3) functionalization of Fe₃O₄@SiO₂ with 3‐chloropropyltrimethoxy‐ silane (CPTMS) ligand (Fe₃O₄@SiO₂@CPTMS), 4) further functionalization with 3,5‐diamino‐1,2,4‐triazole (DAT) ligand (Fe₃O₄@SiO₂@CPTMS @DAT), and 5) the complexation of Fe₃O₄@SiO₂@CPTMS@DAT with PdCl₂ (Fe₃O₄@SiO₂@CPTMS@ DAT@Pd). Then, the obtained Pd nano‐catalyst characterized by different methods such as the elemental analysis (CHN), FT‐IR, XRD, EDX, SEM, TEM, TG‐DTA and VSM. Finally, the Pd catalyst was applied for the synthesis of various 2‐imino‐3‐phenyl‐2,3‐dihydrobenzo[d]oxazol‐5‐ols.     

A Convenient Synthesis of 2,3‐Dihydro‐4H‐thiopyrano[2,3‐b]‐, ‐[2,3‐c]‐, or ‐[3,2‐c]pyridin‐4‐ones by the Reaction of the Corresponding 1‐(Chloropyridinyl)alk‐2‐en‐1‐ones with NaSH

2,3‐Dihydro‐4H‐thiopyrano[2,3‐b]pyridin‐4‐ones 4 were prepared by a three‐step sequence from commercially available 2‐chloropyridine ( 1 ). Thus, successive treatment of 1 with ⁱPr₂NLi (LDA) and α,β‐unsaturated aldehydes gave 1‐(2‐chloropyridin‐3‐yl)alk‐2‐en‐1‐ols 2 , which were oxidized with MnO₂ to 1‐(2‐chloropyridin‐3‐yl)alk‐2‐en‐1‐ones 3 . The reactions of 3 with NaSH?n H₂O proceeded smoothly at 0° in DMF to provide the desired thiopyranopyridinones. Similarly, 2,3‐dihydro‐4H‐thiopyrano[2,3‐c]pyridin‐4‐ones 8 and 2,3‐dihydro‐4H‐thiopyrano[3,2‐c]pyridin‐4‐ones 12 were obtained starting from 3‐chloropyridine ( 5 ) and 4‐chloropyridine ( 9 ), respectively.     

Cube‐like 12‐MC‐4 and Offset Stacked 10‐MC‐3 Metallacrowns: Synthesis,Structure, and Magnetic Properties

Two complexes [Mn^III₄(naphthsao)₄(naphthsaoH)₄] ( 1 ) and [Fe^III₆O₂(naphthsao)₄(O₂CPh)₆] ( 2 ) [naphthsao = 1‐(1‐hydroxy‐naphthalen‐2‐yl)ethanone oxime] were obtained through the reactions of naphthsao ligand and MnCl₂ · 4H₂O or FeCl₃ · 6H₂O in the presence of triethylamine (Et₃N). Their structures were determined by X‐ray single crystal diffraction, elemental analysis, and IR spectra. Complex 1 displays 12‐MC‐4 metallacrown structural type with cube‐like configuration and 2 shows an offset stacked 10‐MC‐3 structural type with the ring connectivity containing Fe–O–C–O–Fe–O–N–Fe–O–N. Magnetic susceptibility measurement reveals the ferromagnetic interactions and field‐induced slow relaxation of the magnetization for 1 , whereas out‐of‐phase signal is not observed for 2 .     

Difunctionalized {closo‐1‐CB11} Clusters: 1‐ and 2‐Amino‐12‐ethynylcarba‐closo‐dodecaborates

Carba‐closo‐dodecaborate anions with two functional groups have been synthesized via a simple two‐step procedure starting from monoamino‐functionalized {closo‐1‐CB₁₁} clusters. Iodination at the antipodal boron atom provided access to [1‐H₂N‐12‐I‐closo‐1‐CB₁₁H₁₀]^? ( 1 a ) and [2‐H₂N‐12‐I‐closo‐1‐CB₁₁H₁₀]^? ( 2 a ), which have been transformed into the anions [1‐H₂N‐12‐RC?C‐closo‐1‐CB₁₁H₁₀]^? (R=H ( 1 b ), Ph ( 1 c ), Et₃Si ( 1 d )) and [2‐H₂N‐12‐RC?C‐closo‐1‐CB₁₁H₁₀]^? (R=H ( 2 b ), Ph ( 2 c ), Et₃Si ( 2 d )) by microwave‐assisted Kumada‐type cross‐coupling reactions. The syntheses of the inner salts 1‐Me₃N‐12‐RC?C‐closo‐1‐CB₁₁H₁₀ (R=H ( 1 e ), Et₃Si ( 1 f )) and 2‐Me₃N‐12‐RC?C‐closo‐1‐CB₁₁H₁₀ (R=H ( 2 e ), Et₃Si ( 2 f )) are the first examples for a further derivatization of the new anions. All {closo‐1‐CB₁₁} clusters have been characterized by multinuclear NMR and vibrational spectroscopy as well as by mass spectrometry. The crystal structures of Cs 1 a , [Et₄N] 2 a , K 1 b , [Et₄N] 1 c , [Et₄N] 2 c , 1 e , and [Et₄N][1‐H₂N‐2‐F‐12‐I‐closo‐1‐CB₁₁H₉]?0.5 H₂O ([Et₄N ]4 a ?0.5 H₂O) have been determined. Experimental spectroscopic data and especially spectroscopic data and bond properties derived from DFT calculations provide some information on the importance of inductive and resonance‐type effects for the transfer of electronic effects through the {closo‐1‐CB₁₁} cage.     

A three‐dimensional zinc‐based coordination polymer built from 5‐carboxylato‐1‐carboxylatomethyl‐2‐oxidopyridinium with a 4‐connected sra topology

A novel three‐dimensional Zn^II complex, poly[aqua(μ₄‐5‐carboxylato‐1‐carboxylatomethyl‐2‐oxidopyridinium)zinc(II)], [Zn(C₈H₅NO₄)(H₂O)]_n, has been prepared by hydrothermal assembly of Zn(CH₃COO)₂·2H₂O and 5‐carboxy‐1‐(carboxymethyl)pyridin‐1‐ium‐2‐olate (H₂ccop). The ccop²⁻ anions bridge the Zn^II cations in a head‐to‐tail fashion via monodentate aromatic carboxylate and phenolate O atoms to form an extended zigzag chain which runs parallel to the [011] direction. One O atom of the aliphatic carboxylate group of the ccop²⁻ ligand coordinates to the Zn^II atom of a neighbouring chain thereby producing undulating layers which lie parallel to the (01) plane. A similar parallel undulating planar structure can be obtained if a path involving the other O atom of the aliphatic carboxylate group is considered. Thus, the aliphatic carboxylate group acts in a bridging bidentate mode to give extended –Zn–O–C–O–Zn– sequences running parallel to [001] which link the layers into an overall three‐dimensional framework. The three‐dimensional framework can be simplified as a 4‐connected sra topology with a Schläfli symbol of 4².6³.8 if all the Zn^II centres and ccop²⁻ anions are regarded as tetrahedral 4‐connected nodes. The three‐dimensional luminescence spectrum was measured at room temperature with excitation and emission wavelengths of 344–354 and 360–630 nm, respectively, at intervals of 0.15 and 2 nm, respectively.     

Synthesis,crystal structures and anti‐inflammatory activity of four 3,5‐bis(arylidene)‐N‐benzenesulfonyl‐4‐piperidone derivatives

3,5‐Bis(arylidene)‐4‐piperidone (BAP) derivatives display good antitumour and anti‐inflammatory activities because of their double α,β‐unsaturated ketone structural characteristics. If N‐benzenesulfonyl substituents are introduced into BAPs, the configuration of the BAPs would change significantly and their anti‐inflammatory activities should improve. Four N‐benzenesulfonyl BAPs, namely (3E,5E)‐1‐(4‐methylbenzenesulfonyl)‐3,5‐bis[4‐(trifluoromethyl)benzylidene]piperidin‐4‐one dichloromethane monosolvate, C₂₈H₂₁F₆NO₃S·CH₂Cl₂, ( 4 ), (3E,5E)‐1‐(4‐fluorobenzenesulfonyl)‐3,5‐bis[4‐(trifluoromethyl)benzylidene]piperidin‐4‐one, C₂₇H₁₈F₇NO₃S, ( 5 ), (3E,5E)‐1‐(4‐nitrobenzenesulfonyl)‐3,5‐bis[4‐(trifluoromethyl)benzylidene]piperidin‐4‐one, C₂₇H₁₈F₆N₂O₅S, ( 6 ), and (3E,5E)‐1‐(4‐cyanobenzenesulfonyl)‐3,5‐bis[4‐(trifluoromethyl)benzylidene]piperidin‐4‐one dichloromethane monosolvate, C₂₈H₁₈F₆N₂O₃S·CH₂Cl₂, ( 7 ), were prepared by Claisen–Schmidt condensation and N‐sulfonylation. They were characterized by NMR, FT–IR and HRMS (high resolution mass spectrometry). Single‐crystal structure analysis reveals that the two 4‐(trifluoromethyl)phenyl rings on both sides of the piperidone ring in ( 4 )–( 7 ) adopt an E stereochemistry of the olefinic double bonds. Molecules of both ( 4 ) and ( 6 ) are connected by hydrogen bonds into one‐dimensional chains. In ( 5 ) and ( 7 ), pairs of adjacent molecules embrace through intermolecular hydrogen bonds to form a bimolecular combination, which are further extended into a two‐dimensional sheet. The anti‐inflammatory activity data reveal that ( 4 )–( 7 ) significantly inhibit LPS‐induced interleukin (IL‐6) and tumour necrosis factor (TNF‐α) secretion. Most importantly, ( 6 ) and ( 7 ), with strong electron‐withdrawing substituents, display more potential inhibitory effects than ( 4 ) and ( 5 ).