Hydrogels Composed of Organic Amphiphiles and α‐Cyclodextrin: Supramolecular Networks of Their Pseudorotaxanes in Aqueous Media

Mixtures of N‐alkyl pyridinium compounds [py‐N‐(CH₂)_nOC₆H₃‐3,5‐(OMe)₂]⁺(X^?) ( 1b Cl: n=10, X=Cl; 1c Br: n=12, X=Br) and α‐cyclodextrin (α‐CD) form supramolecular hydrogels in aqueous media. The concentrations of the two components influences the sol–gel transition temperature, which ranges from 7 to 67 °C. Washing the hydrogel with acetone or evaporation of water left the xerogel, and ¹³C CP/MAS NMR measurements, powder X‐ray diffraction (XRD), and scanning electron microscopy (SEM) revealed that the xerogel of 1b Cl (or 1c Br) and α‐CD was composed of pseudorotaxanes with high crystallinity. ¹³C{¹H} and ¹H NMR spectra of the gel revealed the detailed composition of the components. The gel from 1b Cl and α‐CD contains the corresponding [2]‐ and [3]pseudorotaxanes, [ 1b? (α‐CD)]Br and [ 1b? (α‐CD)₂]Br, while that from 1c Br and α‐CD consists mainly of [3]pseudorotaxane [ 1c? (α‐CD)₂]Br. 2D ROESY ¹H NMR measurements suggested intermolecular contact of 3,5‐dimethoxyphenyl and pyridyl end groups of the axle component. The presence of the [3]pseudorotaxane is indispensable for gel formation. Thus, intermolecular interaction between the end groups of the axle component and that between α‐CDs of the [3]pseudorotaxane contribute to formation of the network. The supramolecular gels were transformed into sols by adding denaturing agents such as urea, C₆H₃‐1,3,5‐(OH)₃, and [py‐N‐nBu]⁺(Cl^?).     

Controlled Self‐Assembly by Mono‐p‐sulfonatocalix[n]arenes and Bis‐p‐sulfonatocalix[n]arenes

The complexation‐induced critical aggregation concentrations of 1‐pyrenemethylaminium by mono‐p‐sulfonatocalix[n]arenes and bis‐p‐sulfonatocalix[n]arenes (n=4, 5) were systemically measured by fluorescence spectroscopy. In all cases, the complexation‐induced critical aggregation concentration decreases by about 3 times upon addition of p‐sulfonatocalix[n]arenes. However, the optimal molar ratios for the aggregation of 1‐pyrenemethylaminium by mono‐p‐sulfonatocalix[n]arenes and bis‐p‐sulfonatocalix[n]arenes are distinctly different: For mono‐p‐sulfonatocalix[n]arenes, the optimum mixing ratio for the aggregation of 1‐pyrenemethylaminium is 1:4 mono‐p‐sulfonatocalix[n]arenes/1‐pyrenemethylaminium, whereas only 2.5 molecules of 1‐pyrenemethylaminium can be bound by one cavity of bis‐p‐sulfonatocalix[n]arenes. The intermolecular complexation of mono‐p‐sulfonatocalix[n]arenes and bis‐p‐sulfonatocalix[n]arenes with 1‐pyrenemethylaminium led to the formation of two distinctly different nanoarchitectures, which were shown to be nanoscale vesicle and rod aggregates, respectively, by using dynamic laser scattering, TEM, and SEM. This behavior is also different from the fiber‐like aggregates with lengths of several micrometers that were formed by 1‐pyrenemethylaminium itself above its critical aggregation concentration. Furthermore, the obtained nanoaggregates exhibit benign water solubility, self‐labeled fluorescence, and, more importantly, temperature responsiveness.     

(4,4′‐Bipyridine)mercury(II) Coordination Polymers,Syntheses, and Structures

Mercury(II) complexes with 4,4′‐bipyridine (4,4′‐bipy) ligand were synthesized and characterized by elemental analysis, and IR, ¹H‐ and ¹³C‐NMR spectroscopy. The structures of the complexes [Hg₃(4,4′‐bipy)₂(CH₃COO)₂(SCN)₄]_n ( 1 ), [Hg₅(4,4′‐bipy)₅(SCN)₁₀]_n ( 2 ), [Hg₂(4,4′‐bipy)₂(CH₃COO)₂]_n(ClO₄)_2n ( 3 ), and [Hg(4,4′‐bipy)I₂]_n ( 4 ) were determined by X‐ray crystallography. The single‐crystal X‐ray data show that 2 and 4 are one‐dimensional zigzag polymers with four‐coordinate Hg‐atoms, whereas 1 is a one‐dimensional helical chain with two four‐coordinate and one six‐coordinate Hg‐atom. Complex 3 is a two‐dimensional polymer with a five‐coordinate Hg‐atom. These results show the capacity of the Hg‐ion to act as a soft acid that is capable to form compounds with coordination numbers four, five, and six and consequently to produce different forms of coordination polymers, containing one‐ and two‐dimensional networks.     

Syntheses and Structures of Three Copper Coordination Polymers Based on Bis(triazol‐1‐ylmethyl)benzene

Three copper(II) coordination polymers [Cu(mbtz)₂(NCS)₂]_n ( 1 ), [Cu(mbtz)₂Cl₂]_n ( 2 ) and [Cu(mbtz)(btec)_0.5]_n ( 3 ) (mbtz=1,3‐bis(1,2,4‐triazol‐1‐ylmethyl)benzene, btec=1,2,4,5‐benzenetetracarboxylate) were synthesized. In 1 and 2 , two mbtz ligands are wrapped around each other and are held together by Cu(II) atoms to form one‐dimensional double chain. In 3 , each btec ligand connects four Cu(II) atoms through its four carboxylate groups, resulting in a planar two‐dimensional [Cu(btec)_0.5]_n network. The Cu(II) atoms are further coordinated mbtz ligands to fulfil their coordination geometry and construct new [Cu(btec)_0.5(mbtz)]_n network. 2 and 3 further form the three‐dimensional network through the π···π stacking interactions between the mbtz ligands. The thermal stabilities of 1 , 2 and 3 were measured.     

Hybrid Molecular Systems Containing Tetrathiafulvalene and Iron‐Alkynyl Electrophores: Five‐Component Functional Molecules Obtained from C?H Bond Activation

Treatment of [Cp*(dppe)Fe? C?C‐TTFMe₃] ( 1 ) with Ag[PF₆] (3 equiv) in DMF provides the binuclear complex [Cp*(dppe)Fe?C?C?TTFMe₂?CH? CH?TTFMe₂?C?C=Fe(dppe)Cp*][PF₆]₂ ( 2 [PF₆]₂) isolated as a deep‐blue powder in 69 % yield. EPR monitoring of the reaction and comparison of the experimental and calculated EPR spectra allowed the identification of the radical salt [Cp*(dppe)Fe?C?C?TTFMe₂?CH][PF₆]₂ ([ 1‐CH ][PF₆]) an intermediate of the reaction, which results from the activation of the methyl group attached in vicinal position with respect to the alkynyl–iron on the TTF ligand by the triple oxidation of 1 leading to its deprotonation by the solvent. The dimerization of [ 1‐CH ][PF₆] through carbon–carbon bond formation provides 2 [PF₆]₂. The cyclic voltammetry (CV) experiments show that 2 [PF₆]₂ is subject to two sequential well‐reversible one‐electron reductions yielding the complexes 2 [PF₆] and 2 . The CV also shows that further oxidation of 2 [PF₆]₂ generates 2 [PF₆]_n (n=3–6) at the electrode. Treatment of 2 [PF₆]₂ with KOtBu provides 2 [PF₆] and 2 as stable powders. The salts 2 [PF₆] and 2 [PF₆]₂ were characterized by XRD. The electronic structures of 2 ⁿ⁺ (n=0–2) were computed. The new complexes were also characterized by NMR, IR, Mössbauer, EPR, UV/Vis and NIR spectroscopies. The data show that the three complexes 2 [PF₆]_n are iron(II) derivatives in the ground state. In the solid state, the dication 2 ²⁺ is diamagnetic and has a bis(allenylidene‐iron) structure with one positive charge on each iron building block. In solution, as a result of the thermal motion of the metal–carbon backbone, the triplet excited state becomes thermally accessible and equilibrium takes place between singlet and triplet states. In 2 [PF₆], the charge and the spin are both symmetrically distributed on the carbon bridge and only moderately on the iron and TTFMe₂ electroactive centers.     

Coordination of Alkaline Earth Metal Ions in the Inverted Cucurbit[7]uril Supramolecular Assemblies Formed in the Presence of [ZnCl4]2− and [CdCl4]2−

A convenient method to isolate inverted cucurbit[7]uril (iQ[7]) from a mixture of water‐soluble Q[n]s was established by eluting the soluble mixture of Q[n]s on a Dowex (H⁺ form) column so that iQ[7] could be selected as a ligand for coordination and supramolecular assembly with alkaline earth cations (AE²⁺) in aqueous HCl solutions in the presence of [ZnCl₄]^2? and [CdCl₄]^2? anions as structure‐directing agents. Single‐crystal X‐ray diffraction analysis revealed that both iQ[7]–AE²⁺–[ZnCl₄]^2?–HCl and iQ[7]–AE²⁺–[CdCl₄]^2?–HCl interaction systems yielded supramolecular assemblies, in which the [ZnCl₄]^2? and [CdCl₄]^2? anions presented a honeycomb effect, and this resulted in the formation of linear iQ[7]/AE²⁺ coordination polymers through outer‐surface interactions of Q[n]s.     

Synthesis of cyclic polysulfides: Controlled ring‐expansion polymerization of cyclic tetrathioester with thiirane

We synthesized cyclic tetrathioesters containing thioester moieties at the o‐position (o‐CTE) and m‐position (m‐CTE) of an aromatic skeleton. The reaction of phenoxy propylenesulfide (PPS) with o‐CTE and m‐CTE was examined using tetrabutylammonium chloride as a catalyst in 1‐methyl‐2‐pyrrolidinone, yielding the corresponding cyclic polysulfides poly[o‐CTE(PPS)_n] with M_n's = 37,000–54,000 at 34–61% yields and poly[m‐CTE(PPS)_n] with M_n's = 46,600–107,200 at 63–>99% yields. Although the molecular weights of poly[o‐CTE(PPS)_n] could not be controlled, those of poly[m‐CTE(PPS)_n] could be controlled by the feed ratios of PPS and reaction temperature. Furthermore, the glass transition temperature (T_g) and thermal decomposition temperature (T_dⁱ) of poly[m‐CTE(PPS)_n] increased with decreasing molecular weights. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 857–866     

Electronic,bonding, and optical properties of 1d [CuCN]n (n = 1–10) chains, 2d [CuCN]n (n = 2–10) nanorings,and 3d [Cun(CN)n]m (n = 4, m = 2, 3; n = 10, m = 2) tubes studied by DFT/TD‐DFT methods

The electronic, bonding, and photophysical properties of one‐dimensional [CuCN]_n (n = 1–10) chains, 2‐D [CuCN]_n (n = 2–10) nanorings, and 3‐D [Cu_n(CN)_n]_m (n = 4, m = 2, 3; n = 10, m = 2) tubes are investigated by means of a multitude of computational methodologies using density functional theory (DFT) and time‐dependent‐density‐functional theory (TD‐DFT) methods. The calculations revealed that the 2‐D [CuCN]_n (n = 2–10) nanorings are more stable than the respective 1‐D [CuCN]_n (n = 2–10) linear chains. The 2‐D [CuCN]_n (n = 2–10) nanorings are predicted to form 3‐D [Cu_n(CN)_n]_m (n = 4, m = 2, 3; n = 10, m = 2) tubes supported by weak stacking interactions, which are clearly visualized as broad regions in real space by the 3D plots of the reduced density gradient. The bonding mechanism in the 1‐D [CuCN]_n (n = 1–10) chains, 2‐D [CuCN]_n (n = 2–10) nanorings, and 3‐D [Cu_n(CN)_n]_m (n = 4, m = 2, 3; n = 10, m = 2) tubes are easily recognized by a multitude of electronic structure calculation approaches. Particular emphasis was given on the photophysical properties (absorption and emission spectra) of the [CuCN]_n chains, nanorings, and tubes which were simulated by TD‐DFT calculations. The absorption and emission bands in the simulated TD‐DFT absorption and emission spectra have thoroughly been analyzed and assignments of the contributing principal electronic transitions associated to individual excitations have been made. © 2015 Wiley Periodicals, Inc.     

A rare octacoordinated mononuclear iron(III) spin‐crossover compound: synthesis,crystal structure and magnetic properties

The chemistry of transition‐metal complexes with unusually high coordination numbers has been of interest because of their application in catalytic and biological systems. Deprotonation of the ionogenic tetradentate ligand 6,6′‐bis(1H‐tetrazol‐5‐yl)‐2,2′‐bipyridine [H₂bipy(ttr)₂] in the presence of iron(III) and tetra‐n‐butylammonium bromide, [n‐Bu₄N]Br, in solution resulted in the synthesis of a rare octacoordinated anionic mononuclear complex, tetra‐n‐butylammonium bis[6,6′‐bis(tetrazol‐1‐id‐5‐yl)‐2,2′‐bipyridine]iron(III) methanol hemisolvate dihydrate, (C₁₆H₃₆N)[Fe(C₁₂H₆N₁₀)₂]·0.5CH₃OH·2H₂O or [n‐Bu₄N][Fe{bipy(ttr)₂}₂]·0.5CH₃OH·2H₂O ( 1 ), which has been structurally characterized by elemental analysis, powder X‐ray diffraction (PXRD) and single‐crystal X‐ray diffraction. In 1 , the coordination sphere of the iron(III) ion is a distorted bis‐disphenoid dodecahedron, in which the eight coordination positions are occupied by eight N atoms from two independent tetradentate [bipy(ttr)₂]^2? anionic ligands, therefore forming the anionic [Fe{bipy(ttr)₂}₂]^? unit, with the negative charge balanced by a free [n‐Bu₄N]⁺ cation. An investigation of the magnetic properties of 1 revealed a gradual incomplete spin‐crossover behaviour below 150 K.     

Evaluation of a novel metal–organic framework as an adsorbent for the extraction of multiclass pesticides from coconut palm (Cocos nucifera L.): An analytical approach using matrix solid‐phase dispersion and liquid chromatography

We report the synthesis, characterization, and application of [Zn(1,4‐benzenedicarboxylate)(H₂O)₂]_n , Zn(1,4‐benzenedicarboxylate)_0.99(NH₂‐1,4‐benzenedicarboxylate)_0.01(H₂O)₂]_n , [Zn(1,4‐benzenedicarboxylate)_0.95(NH₂‐1,4‐benzenedicarboxylate)_0.05(H₂O)₂]_n , and [Zn(1,4‐benzenedicarboxylate)_0.9(NH₂‐1,4‐benzenedicarboxylate)_0.1(H₂O)₂]_n as sorbents for the extraction of multiclass pesticides from coconut palm. Liquid chromatography with ultraviolet diode array detection was used as the analysis technique, and the experiments were performed at one fortification level (0.1 μg/g). The recoveries were 47–67, 51–70, 58–72, and 64–76% for [Zn(1,4‐benzenedicarboxylate)(H₂O)₂]_n , Zn(1,4‐benzenedicarboxylate)_0.99(NH₂‐1,4‐benzenedicarboxylate)_0.01(H₂O)₂]_n , [Zn(1,4‐benzenedicarboxylate)_0.95(NH₂‐1,4‐benzenedicarboxylate)_0.05(H₂O)₂]_n , and [Zn(1,4‐benzenelate)_0.95(NH₂‐1,4‐benzenedicarboxylate)_0.05(H₂O)₂]_n , and [Zn(1,4‐benzenedicarboxylate)_0.9(NH₂‐1,4‐benzenedicarboxylate)_0.1(H₂O)₂]_n , respectively, with relative standard deviation ranging from 1 to 7% (n = 3). Detection and quantification limits were 0.01–0.05 and 0.05–0.2 μg/g, respectively, for the different pesticides studied. The method developed was linear over the range tested (0.01–10.0 μg/g) with r ² > 0.9991. A direct comparison of [Zn(1,4‐benzenedicarboxylate)_0.9(NH₂‐1,4‐benzenedicarboxylate)_0.1(H₂O)₂]_n with the commercially available neutral alumina showed that [Zn(1,4‐benzenedicarboxylate)_0.9(NH₂‐1,4‐benzenedicarboxylate)_0.1(H₂O)₂]_n was a similar extracting phase for the pesticides investigated.     

Lewis Acid Catalyzed Synthesis of Cyanidophosphates

Salts containing new cyanido(fluorido)phosphate anions of the general formula [PF_6?n(CN)_n]^? (n=1–4) were synthesized by a very mild Lewis‐acid‐catalyzed synthetic protocol and fully characterized. All [PF_6?n(CN)_n]^? (n=1–4) salts could be isolated on a preparative scale. It was also possible to detect the [PF(CN)₅]^? but not the [P(CN)₆]^? anion. The best results with respect to purity, yield, and low cost were obtained when the F^?/CN^? substitution reactions were carried out in ionic liquids.     

Synthesizing 2D and 3D Selenidostannates in Ionic Liquids: The Synergistic Structure‐Directing Effects of Ionic Liquids and Metal–Amine Complexes

Presented are the ionothermal syntheses, characterizations, and properties of a series of two‐ and three‐dimensional selenidostannate compounds synergistically directed by metal–amine complex (MAC) cations and ionic liquids (ILs) of [Bmmim]Cl (Bmmim=1‐butyl‐2,3‐dimethylimidazolium). Four selenidostannates, namely, 2D‐(Bmmim)₃[Ni(en)₃]₂[Sn₉Se₂₁]Cl ( 1 , en=ethylenediamine), 2D‐(Bmmim)₈[Ni₂(teta)₂(μ‐teta)]Sn₁₈Se₄₂ ( 2 , teta=triethylenetetramine), 2D‐(Bmmim)₄[Ni(tepa)Cl]₂[Ni(tepa)Sn₁₂Se₂₈] ( 3 , tepa=tetraethylenepentamine), and 3D‐(Bmmim)₂[Ni(1,2‐pda)₃]Sn₈Se₁₈ ( 4 , 1,2‐pda=1,2‐diaminopropane), were obtained. Single‐crystal X‐ray diffraction analyses revealed that compounds 1 and 2 possess a lamellar anionic [Sn₃Se₇]_n^2n? structure comprising distinct eight‐membered ring units, whereas 3 features a MAC‐decorated anionic [Ni(tepa)Sn₁₂Se₂₈]_n^6n? layered structure. In contrast to 1 – 3 , compound 4 exhibits a 3D open framework of anionic [Sn₄Se₉]_n^2n?. The structural variation from 1 to 4 clearly indicates that on the basis of the synergistic structure‐directing ability of the MACs and ILs, variation of the organic polyamine ligand has a significant impact on the formation of selenidostannates.     

Heterometallic SrII‐MII (M=Co,Ni, Zn and Cu) Coordination Polymers: Synthesis,Temperature‐Dependent Structural Transformation,and Luminescent and Magnetic Properties

The use of pyridine‐2,4‐dicarboxylic acid (H₂pydc) in the construction of Sr^II and Sr^II‐M^II (M=Co, Ni, Zn and Cu) coordination polymers is reported. Eight complexes, that is, [Sr(pydc)H₂O]_n ( 1 ), [MSr(pydc)₂(H₂O)₂]_n (M=Co ( 2 ), Ni ( 3 ), Zn ( 4 )), [ZnSr(pydc)₂(H₂O)₇]_n?4 nH₂O ( 5 ), [SrCu(pydc)₂]_n ( 6 ), [SrCu(pydc)₂(H₂O)₃]_n?2 nH₂O ( 7 ), and [Cu₃Sr₂(pydc)₄(Hpydc)₂(H₂O)₂]_n ( 8 ), have been synthesized via dexterously choosing the appropriate strontium sources and transition metal salts, and rationally controlling the temperature of the reaction systems. Complexes 1 , 2 ( 3 , 4 ), 6 , and 8 display four types of 3‐D framework structures. Complexes 5 and 7 exhibit a 2‐D network and a 1‐D chain structure, respectively. The 2‐D complex 7 can be reversibly transformed into 3‐D compound 6 through temperature‐induced solvent‐mediated structural transformation. The luminescent property studies indicated that complex 1 shows a strong purple luminescent emission and 4 exhibits a strong violet luminescence emission. The magnetic properties of 2 , 3 , and 8 were also studied. Antiferromagnetic M^II???M^II interactions were determined for these complexes.     

[Te8]2[Ta4O4Cl16]: A Two‐dimensional Tellurium Polycation obtained via Ionic Liquid‐Based Synthesis

By reaction of elemental tellurium, tellurium(IV) chloride, tantalum(V) chloride and tantalum(V) oxychloride in the ionic liquid [BMIM]Cl ([BMIM]Cl:1‐Butyl‐3‐methylimidazolium chloride),[Te₈]₂[Ta₄O₄Cl₁₆] is obtained in the form of lucent black crystals. The title compound consists of infinite [Te–Te–(Te₆)]_n²⁺ chains (Te–Te: 264.9(1)–284.3(1) pm) and isolated [Ta₄O₄Cl₁₆]^4– anions. The [Te–Te–(Te₆)]_n²⁺ chains are interconnected to form a two‐dimensional tellurium network (Te–Te: 335.9 pm). Due to this interaction the [Te–Te–(Te₆)]_n²⁺ chains in [Te₈]₂[Ta₄O₄Cl₁₆] show an arrangement that differs significantly from known polycationic [Te₈]_n²⁺ chains. The two‐dimensional tellurium network is finally separated by tetrameric, corner‐sharing oxidochloridotantalate anions [(TaO_2/2Cl_4/1)₄]^4– that are firstly observed. The composition of [Te₈]₂[Ta₄O₄Cl₁₆] is confirmed by EDX analysis; its optical band gap is estimated to 1.1–1.2 eV via UV/Vis spectroscopy.     

A Comparative Study of (Poly)ether Adducts of Alkaline Earth Iodides – An Overview Including New Compounds

New homoligand and mixed‐ligand adducts of the heavier alkaline earth metal (Ca, Sr, Ba) halides with oxygen‐donor polyether ligands have been isolated and characterized and are compared with previously obtained compounds of the same class in order to give an overview on structures and properties. Homoligand halide adducts, discussed herein, are [CaI(DME)₃]I ( 1 ), trans‐[SrI₂(DME)₃] ( 2 ), trans‐[BaI₂(DME)₃] ( 3 ), (DME = ethylene glycol dimethyl ether), [CaI(diglyme)₂]I ( 4 ), cis‐[SrI₂(diglyme)₂] ( 5 ), trans‐[BaI₂(diglyme)₂] ( 6 ),(diglyme = diethylene glycol dimethyl ether, [SrI(triglyme)₂]I ( 7 ), and [BaI(triglyme)₂]I ( 8 ), (triglyme = triethylene glycol dimethyl ether). Introduction of the mono‐coordinating THF ligand (THF = tetrahydrofuran) in the coordination sphere of 1 , 2 , 3 , 4 allows the formation of the new mixed‐ligand compounds trans‐[CaI₂(DME)₂(THF)] ( 9 ), trans‐[SrI₂(DME)₂(THF)] ( 10 ), trans‐[BaI₂(DME)₂(THF)₂] ( 11 ), and trans‐[CaI₂(diglyme)₂(THF)₂] ( 12 ). These compounds were obtained from the metal halide salts in solution with pure or mixtures of ether solvents. While compounds 1 – 8 appear to be very stable and non‐reactive, adducts 9 – 12 present a comparable reactivity to the well known THF adducts [MI₂(thf)_n] (M = Ca, n = 4; Sr, Ba, n = 5).     

Six Coordination Polymers based on 4‐(1H‐Imidazol‐1‐yl)phthalic Acid: Structural Diversities,Magnetism and Luminescence Properties

The coordination polymers (CPs), [Ni(L)(H₂O)₄]_n ( 1 ), [Co(HL)₂(H₂O)₂]_n ( 2 ), {[Cu(L)(H₂O)₃] · H₂O}_n ( 3 ), [Mn(L)(H₂O)₂]_n ( 4 ), [Cd(L)(H₂O)₂]_n ( 5 ), and {[Zn₂(L)₂] · H₂O}_n ( 6 ), were solvothermally synthesized by employing the imidazol‐carboxyl bifunctional ligand 4‐(1H‐imidazol‐1‐yl) phthalic acid (H₂L). Single‐crystal X‐ray diffraction indicated that the L^2–/HL^– ligands display various coordination modes with different metal ions in 1 – 6 . Complexes 1 and 2 show one‐dimensional (1D) chain structures, whereas complexes 3 – 6 show 2D layered structures. The magnetic properties of these complexes were investigated. Complexes 1 and 3 indicate weak ferromagnetic interactions, whereas complexes 2 and 4 demonstrate antiferromagnetic interactions. In addition, luminescence properties of 5 and 6 were measured and studied in detail.     

catena‐Poly­[europium(III)‐tri‐μ‐2,3‐di­methoxy­benzoato]

The title compound, [Eu(C₉H₉O₄)₃]_n or [Eu(2,3‐DMOBA)₃]_n, where 2,3‐DMOBA is 2,3‐di­methoxy­benzoate, is an infinite one‐dimensional non‐centrosymmetric coordination polymer. The unique Eu^III atom is bridged by six carboxyl­ate ligands; it is ennea‐coordinated and has a distorted tricapped trigonal prism geometry. The Eu—O distances are in the range 2.315 (3)–2.959 (5) Å.     

Attenuated Organomagnesium Activation of White Phosphorus

Sequential reactions between a 2,6‐diisopropylphenyl‐substituted β‐diketiminato magnesium n‐butyl derivative and P₄ allow the highly discriminating synthesis of unusual [nBu₂P₄]^2? and [nBu₂P₈]^2? cluster dianions.     

A Nexus between Theory and Experiment: Non‐Empirical Quantum Mechanical Computational Methodology Applied to Cucurbit[n]uril⋅Guest Binding Interactions

A training set of eleven X‐ray structures determined for biomimetic complexes between cucurbit[n]uril (CB[7 or 8]) hosts and adamantane‐/diamantane ammonium/aminium guests were studied with DFT‐D3 quantum mechanical computational methods to afford ΔG_calcd binding energies. A novel feature of this work is that the fidelity of the BLYP‐D3/def2‐TZVPP choice of DFT functional was proven by comparison with more accurate methods. For the first time, the CB[n] ? guest complex binding energy subcomponents [for example, ΔE_dispersion, ΔE_{electrostatic}, ΔG_solvation, binding entropy (?TΔS), and induced fit E_{deformation(host)}, E_{deformation(guest)}] were calculated. Only a few weeks of computation time per complex were required by using this protocol. The deformation (stiffness) and solvation properties (with emphasis on cavity desolvation) of cucurbit[n]uril (n=5, 6, 7, 8) isolated host molecules were also explored by means of the DFT‐D3 method. A high ρ²=0.84 correlation coefficient between ΔG_exptl and ΔG_calcd was achieved without any scaling of the calculated terms (at 298 K). This linear dependence was utilized for ΔG_calcd predictions of new complexes. The nature of binding, including the role of high energy water molecules, was also studied. The utility of introduction of tethered [‐(CH₂)_nNH₃]⁺ amino loops attached to N,N‐dimethyl‐adamantane‐1‐amine and N,N,N′,N′‐tetramethyl diamantane‐4,9‐diamine skeletons (both from an experimental and a theoretical perspective) is presented here as a promising tool for the achievement of new ultra‐high binding guests to CB[7] hosts. Predictions of not yet measured equilibrium constants are presented herein.