Perylene diimide-appended mixed (phthalocyaninato)(porphyrinato) europium(III) double-decker complex: Synthesis, spectroscopy and electrochemical properties

Treatment of sandwich-type mixed (phthalocyaninato)(porphyrinato) metal complex [HEu^III{Pc(α-3-OC₅H₁₁)₄}{TriBPP(NH₂)}] (3) [Pc(α-3-OC₅H₁₁)₄ = 1,8,15,22-tetrakis(3-pentyloxy)-phthalocyaninate, TriBPP(NH₂) = 5,10,15-tris(4-tert-butylphenyl)-20-(4-aminophenyl)porphyrinate] with N-n-butyl-1,6,7,12-tetra(4-tert-butylphenoxyl)perylene-3,4-dicarboxylate anhydride-9,10-dicarboxylate imide (2) in the presence of imidazole in toluene afforded the novel perylene diimide-appended mixed (phthalocyaninato)(porphyrinato) europium(III) double-decker complex (5). Porphyrin-PDI dyad 4 was also obtained by similar method. The electronic absorption spectroscopic and electrochemical properties of PDI-appended double-decker 5 and the model compounds 2, 3, and 4 were studied, the results indicated that there was no considerable ground-state interaction between the double-decker unit and the PDI unit in 5. The fluorescence measurements revealed that the emission of PDI unit was effectively quenched by the double-decker unit, suggesting remarkable intramolecular interaction in 5 under excited state.     

A tetranuclear manganese oxo complex with terminal and bridging trifluoroacetate ligands: synthesis and structure of [Mn4O2(O2CCF3)8(bpy)2]

Efforts to prepare tetranuclear manganese oxo complexes that model the water oxidizing center in Photosystem II have focused largely on using unsubstituted acetate and benzoate ligands. We report the reaction of Mn(O₂CCF₃)₂, (n-Bu₄N)[MnO₄], and bipyridine in trifluoroacetic acid yields the compound [Mn₄O₂(O₂CCF₃)₈(bpy)₂]. X-ray crystallographic studies of this complex show a non-planar {Mn₄O₂}⁸⁺ center with an arrangement of bipyridine and bridging trifluoroacetate ligands that is very similar to the acetate complex [Mn₄O₂(O₂CCH₃)₇(bpy)₂]⁺ [Christou, et al. J. Am Chem. Soc. 11 (1989) 2086]. The structure differs, however, in that the coordination sites occupied previously by a bridging bidentate acetate ligand are occupied by two terminal monodentate trifluoroacetate ligands in a cis arrangement. One of the terminal trifluoroacetate ligands is hydrogen-bonded to a co-crystallized trifluoroacetic acid molecule.     

Graphit einlagerungsverbindungen mit thallium(III) bromid

Intercalation compounds of graphite with TlBr₃ were prepared by the following procedures. Method I: graphite and TlBr were reacted with liquid bromine (which oxidizes TlBr to TlBr₃). After refluxing this mixture for 2–4 days, the bromine was filtrated off, and then the samples were washed with a solution of methanol containing bromine in order to remove any thallium bromide excess. Method II: mixtures of graphite, TlBr and bromine were heated in sealed tubes for definite times at pre-selected temperatures. After heating, the samples were separated as described before. The conditions of these intercalating experiments and results of analyses are given in Table 1.The results shown in this table confirm that TlBr₃ can be intercalated in graphite in substantial quantities, in spite of the fact that genuine TlBr₃ is a nonexisting compound. TlBr₃-graphite is a ternary compound analogous to AlBr₃-graphite [2] or GaBr₃-graphite[3]. Some of the co-intercalated bromine could be removed by evacuation, but the ratio $\text{Br}\text{Tl}$ obtained was never less than 3.3. Like other metal halide graphite compounds [1,8] TlBr₃-graphite may be given the formula: C_n⁺[TlBr₄^?]·2TlBr₃.All compounds shown in Table 1 are of the 2nd stage type. The I_c-values vary somewhat with the amount of bromine. The distance of two carbon layers separated by intercalated TlBr₃ was found to be 1005 pm (compound 6), as compared to be 1000 pm for C₂₄AlBr_3.3[2]. It is, therefore, assumed that TlBr₃, like AlBr₃, is intercalated in form of sheets made up of Tl₂Br₆ molecules.In contrast to TlBr₃ which exists only in liquid bromine and decomposes immediately as soon as the bromine is removed, the intercalated TlBr₃ is still stable at 150°C. Obviously TlBr₃ is stabilized by intercalation.By treating a 2nd stage TlBr₃-graphite with TlCl₃ in refluxing SOCl₂ a compound with the composition C_12.5TlCl_1.8Br_1.6 (Table 3) was obtained. As X-ray studies confirmed this compound has a structure of stage 1 made up of alternating TlBr₃ and TlCl₃ layers separated by a carbon sheet.The resemblances as well as the differences between TlBr₃-graphite and AlBr₃-graphite or GaBr₃-graphite are discussed.     

Polymerization of epoxides catalyzed by a mixed‐valent iron trifluoroacetate [Fe3O(O2CCF3)6(H2O)3]

The readily available mixed‐valent iron trifluoroacetate complex [Fe₂^IIIFe^II(µ₃‐O)(O₂CCF₃)₆(H₂O)₃] is an effective catalyst for the polymerization of epoxides. A very small amount of the catalyst (1.0–0.01 mol%) could initiate the polymerization of cyclohexene oxide, cyclopentene oxide and epichlorohydrin. Based on quantitative end‐group analysis by ¹⁹F NMR spectroscopy, a Lewis acid (LA^⊕) catalyzed anionic reaction mechanism is proposed. Copyright © 2012 Society of Chemical Industry     

{[Cu(phen)]3Cl4}2[GeMo12O40]: Synthesis,crystal structure and magnetic property of a new trinuclear copper complex based on germanomolybdate

A new trinuclear copper complex based on germanomolybdate, {[Cu(phen)]₃(μ₂-Cl)₄}₂[GeMo₁₂O₄₀] (1) (phen = 1,10-phenanthroline), has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectroscopy, TG analysis, X-ray powder diffraction (XRPD) and single-crystal X-ray diffraction. Single crystal X-ray analysis reveals that the structural unit of 1 consists of two coordination cations {[Cu(phen)]₃(μ₂-Cl)₄}²⁺ (1a) and a saturated Keggin-type germanomolybdate polyoxoanion [GeMo₁₂O₄₀]^4?. In 1, the most intriguing feature is that each trinuclear copper cation {[Cu(phen)]₃(μ₂-Cl)₄}²⁺ is constructed from three [Cu(phen)]²⁺ cations bridged by four μ₂-Cl atoms. Magnetic measurements indicate 1 shows the ferromagnetic exchange interactions within Cu^II centers.     

Binaphthol-strapped chiral bis(porphyrinato) cerium double-decker complexes

(R)-(+)- or (S)-(−)-1,1′-bi-2-naphthol (BINOL) was applied as a remote chiral auxiliary to connect the two facing porphyrin rings, resulting in the BINOL-strapped chiral bis(porphyrinato) cerium double-decker complexes (R)-/(S)-1 and (R)-/(S)-2, which were carefully characterized by a range of spectroscopic and electrochemical methods. Perfect mirror images were observed in their circular dichroism (CD) spectra with a negative sign in the Soret band for (R)-enantiomers and a positive sign for (S)-enantiomers, which suggests the C₂-chirality of a BINOL strap is transcribed to the double-decker core as a defined chiral twist in the inter-porphyrin arrangement. Furthermore, the CD intensities of (R)-/(S)-1 are always larger than those of (R)-/(S)-2, indicating that the intramolecular chirality transfer efficiency can be finely tuned by changing the length of interlocking moieties.     

[Tl2(μ-Htdp)2(μ-H2O)]n (H2tdp = 4,4′-thiodiphenol) – A one-dimensional thallium(I) coordination polymer with a large tetranuclear metallacycle: Thermal,emission and structural studies

[Tl₂(μ-Htdp)₂(μ-H₂O)]_n (H₂tdp = 4,4′-thiodiphenol) (1), a new rarely reported Tl^I one-dimensional coordination polymer with a large tetranuclear metallacycle, has been synthesized, characterized by elemental analysis and IR spectroscopy and its structure determined by single-crystal X-ray diffraction. The thermal stability of compound 1 was studied by thermal gravimetric (TG) and differential thermal analyses (DTA). The single crystal X-ray analysis of compound 1 shows that the complex consists of horseshoe-shaped (μ-Htdp)Tl(μ-H₂O)Tl(μ-Htdp) subunits. Solid-state luminescent spectra of the ligand H₂tdp and compound 1 indicate emission band with the maximum intensity at 475 and 465 nm upon excitation at 300 nm, respectively.     

Structural conversion of cubane-type thallium complex to hexagon silver complex by solid-state mechanochemical reaction

Solid-state structural transformation of Tl^I supramolecular polymer comprised from cubane-type thallium complex of [Tl₄(μ₃-4-BN)₄] (1) (4-HBN = 4-hydroxy benzonitrile) to Ag^I coordination polymer with three nuclear units of [Ag₃(μ₃-4-BN)₂(μ₄-4-BN)] (2) has been studied upon mechanochemical reaction of compound 1 with AgNO₃.     

Synthesis and characterization of decanuclear Ln(III) cluster of mixed calix[8]arene-phosphonate ligands (Ln = Pr,Nd)

Two novel decanuclear Ln(III) compounds (Ln = Pr for 1, Nd for 2) have been solvothermally obtained by using p-tert-butylcalix[8]arene (H₈TBC8A) and phenylphosphonate (PhPO₃H₂) as ligands. Single crystal X-ray diffraction studies reveal that both compounds are stacked by dumbbell-like Ln₁₀ clusters, which are capped by two TBC8A^8 − supports and linked by four complementary PhPO₃^2 − ligands as well as other bridging anions. In addition, the self-assembly behavior of both compounds is interesting: the cationic Ln₁₀ cluster layers are separated by the layers of H₆TBC8A^2 − ligands. Moreover, the luminescent and magnetic properties of both compounds were examined.     

Synthesis and characterization of dinuclear lanthanide(III) and yttrium(III) cryptates of a hexavalent anionic polydentate ligand

Reaction of tris(2-aminomethyl)amine with bis(hydroxybenzaldehyde) (1) in presence of M(CF₃SO₃)₃ (M=Y, Gd, Tb, Dy, Ho, Er, Tm) in methanol yielded the dinuclear lanthanide(III) and yttrium(III) cryptates [M₂L] (2). The structure of [Y₂L] was established by X-ray crystallography. Each yttrium ion is in a seven-coordinate environment composed of three imine nitrogen atoms, one apical nitrogen atom, and three oxygen atoms. The dinuclear complexes were found to be a host for Rb⁺ and Cs⁺.     

Two 1D [CuxIx]-based coordination polymers of tetraphosphine ligands

Diffusion reactions of CuI with N,N,N′,N′-tetra(diphenylphosphanylmethyl)ethylene diamine) (dppeda) and 1,4-N,N,N′,N′-tetra(diphenylphosphanylmethyl)benzene diamine (dpppda) in MeCN/toluene in a zigzag glass tube or solvothermal reactions of CuI and dppeda or dpppda in MeCN produced two [Cu_xI_x]-based coordination polymers, [Cu₂I₂(dppeda)]·2MeCN (1·2MeCN) and [Cu₄I₄(dpppda)]·MeCN (2·MeCN), respectively. Both compounds were characterized by elemental analysis, IR spectroscopy, ¹H and ³¹P{¹H} NMR, ESI-MS and thermogravimetric analysis, and their structures were determined by single crystal X-ray diffraction. In 1, [Cu₂I₂] cores are interconnected by dppeda ligands in a μ-η²:η² end-to-end mode to form a 1D chain, while in 2 stair-like [Cu₄I₄] cores are linked by dpppda ligands in a unique Z-shaped μ-η²:η² side-by-side mode to produce the other kind of 1D chain.     

Coexistence of two distinct axial ligands and their thermo-induced substitution in trans-[FeL2(NCS)2][FeL2(CH3OH)2](NCS)2 (L = 4-amino-3-(p-chlorophenyl)-5-(2-pyridyl)-1,2,4-triazole)

A novel iron(II) complex, trans-[FeL₂(NCS)₂][FeL₂(CH₃OH)₂](NCS)₂ (1) with 4-amino-3-(p-chlorophenyl)-5-(2-pyridyl)-1,2,4-triazole (L) has been successfully synthesized and characterized. X-ray crystallography analysis shows that 1 is the first example in the mononuclear triazole-based complexes consisting of two distinct molecules: trans-[FeL₂(NCS)₂] and trans-[FeL₂(CH₃OH)₂](NCS)₂ with each octahedral iron(II) center coordinated axial by two NCS⁻ ions in Fe1 but two MeOH molecules in Fe2. Moreover, 1 can lose two MeOH molecules at 220 °C to form trans-[FeL₂(NCS)₂] (2) which can be transformed to 1 when recrystallizing 2 in methanol. Both 1 and 2 are high-spin species in the range of 1.8–300 K.     

X- and Q-band EPR on 57Fe-enriched [(C6H5)4As]2[FeI(NO)(mnt)2]

Abstract: X- and Q-band EPR spectra of the anionic 3d⁷ `low spin' (S=1/2) complex tetraphenylarsonium-bis(1,2-dicyanoethene-1,2-dithiolato)nitrosyliron(I) enriched with ⁵⁷Fe show resolved ⁵⁷Fe and ¹⁴N hyperfine patterns characterised by rhombic g, A^Fe and A^N tensors. The hyperfine parameters are used to determine the spin-density distribution in the FeNS₄ unit.     

Synthesis and structural characterization of isomeric monocarbon (η-dicyclopentenyl)-closo-rhodacarboranes stabilized by the agostic bonding interaction

The [7-Me₃N-nido-7-CB₁₀H₁₂] (1), after being treated with two molar equiv. of Proton Sponge, reacts with [(η⁴-C₁₀H₁₂)₂Rh₂(μ-Cl)₂] (2) in benzene–ethanol solution affording two isomeric monocarbon (η-dicyclopentenyl)-closo-rhodacarborane complexes, differing in hapticity of the carbocyclic ligand, viz. [2,2-{(2′,3′-η²):(5′-η¹)-C₁₀H₁₃}-1-(Me₃N)-2,1-closo-RhCB₁₀H₁₀] (3) and [2-{(1′-3′-η³)-C₁₀H₁₃}-1-(Me₃N)-2,1-closo-RhCB₁₀H₁₀] (4). Isomeric compounds 3 and 4 were characterized by analytical, multinuclear NMR spectroscopic data as well as by single-crystal X-ray diffraction study, which revealed the existence of an agostic C–H⋯Rh interaction in both the species.     

Ambipolar chemical sensors based on the self-assembled film of an amphiphilic (phthalocyaninato) (porphyrinato) europium complex

An amphiphilic mixed (phthalocyaninato) (porphyrinato) europium triple-decker complex Eu₂(Pc)₂(TPyP) has been synthesized and characterized. Introducing electron-withdrawing pyridyl substituents onto the meso-position of porphyrin ring in the triple-decker to ensure the sufficient hydrophilicity and suitable HOMO and LUMO energy levels and thus successfully realize amphiphilic ambipolar organic semiconductor. Importantly, high sensitive, reproducible p-type and n-type responses towards NH₃ and NO₂ respectively, based on the self-assembled film of the Eu₂(Pc)₂(TPyP) fabricated by a simple solution-based Quasi–Langmuir–Shäfer (QLS) method, have been first revealed. The good conductivity and crystallinity for the QLS film of Eu₂(Pc)₂(TPyP) render it excellent sensing property for both electron-donating gas NH₃ in 5–30 ppm range and electron-accepting gas NO₂ in 400–900 ppb range due to the optimized molecular packing in the uniform-sized nanoparticles depending on the effective intermolecular interaction between the triple-decker molecules, among the best results of phthalocyanine-based chemical sensors for room-temperature detection of NH₃ and NO₂, respectively. Furthermore, the responses of the QLS film are all linearly correlated to both NH₃ and NO₂ with excellent sensitivity of 0.04% ppm^− 1 and 31.9% ppm^− 1, respectively, indicating the great potential of semiconducting tetrapyrrole rare earth triple-decker compounds in the field of chemical sensors.     

Hydrothermal synthesis and characterization of a 3D luminescent lead(II) framework containing 3D Pb–X–Pb linkage (X = O and Cl) tuned by cis- and trans-ligand conformations

Under hydrothermal conditions using cis-butenedioic acid (H₂L) and corresponding lead(II) salts, a three-dimensional (3D) lead(II) complex {[Pb₂(L)(μ₂-Cl)(μ₃-Cl)]}_n (1) containing 3D Pb–X–Pb (X = O and Cl) linkage has been isolated. 1 also represents a truly 3D hybrid luminescent lead(II) framework with I³O⁰ type connectivity. Further analysis reveals that cis- and trans-conformations of butenedioic acid ligand greatly affect the lead(II) framework structure. Solid-state fluorescence spectrum of 1 exhibits the maximum emission peak at 379 nm.     

Self-assembled chloro-bridged metallo-prismatic cations of the general formula [M6(η-C5Me5)6(μ3-tpt)2(μ-Cl)6] (M = Rh, Ir; tpt = 2,4,6-tri(pyridin-4-yl)-1,3,5-triazine)

Two cationic pentamethylcyclopentadienyl metal-based hexanuclear complexes with trigonal prismatic architecture have been synthesised through a two-step strategy. The dinuclear complexes [M(η⁵- C₅Me₅)(μ-Cl)Cl]₂ (M = rhodium and iridium) react with 2,4,6-tri(pyridin-4-yl)-1,3,5-triazine (tpt) in dichloromethane to give the trinuclear complexes [Rh₃(η⁵-C₅Me₅)₃(μ₃-tpt)Cl₆] (1) and [Ir₃(η⁵-C₅Me₅)₃(μ₃-tpt)Cl₆] (2), respectively. Addition of silver triflate to 1 and 2 in dichloromethane connects two identical triangular panels to form the hexanuclear metallo-prismatic cations [Rh₆(η⁵-C₅Me₅)₆(μ₃-tpt)₂(μ-Cl)₆]⁶⁺ (3) and [Ir₆(η⁵-C₅Me₅)₆(μ₃-tpt)₂(μ-Cl)₆]⁶⁺ (4), respectively. Cations 3 and 4 have been isolated as their triflate salts and characterised by ¹H NMR, IR and UV/visible spectroscopy.     

Graphit einlagerungsverbindungen mit thallium(III) chlorid

Whilst graphite lamellar compounds with AlCl₃, GaCl₃ and InCl₃[1,2] have been extensively studied, the analogous compounds with TlCl₃ have received scant attention although it has been known for many years that TlCl₃ forms intercalation compounds [4,5]. As a part of a systematic investigation of metal halide graphite compounds [8] we studied the system TlCl₃/graphite in detail.TlCl₃-graphite compounds were prepared by heating mixtures of anhydrous TlCl₃ and graphite in sealed tubes. The reaction conditions are summarized in Table 1. In method (I) the tubes had been evacuated, in (II) filled with nitrogen, and in (III) filled with chlorine. In (IV) the tubes contained 2 ml liquid chlorine before sealing. In (V) TlCl instead of TlCl₃ was heated with graphite in chlorine vapor. The samples were washed with methanol saturated with chlorine.Table 1 shows that the preparation of TlCl₃-graphite is best affected by heating up to 150°C in the presence of chlorine. Samples 10 and 11, obtained in inert atmosphere, were only of the 2nd stage type. They were contaminated with TlCl and mixed Tl(I)-Tl(III) chlorides. In this case the chlorine, the presence of which is a basic requirement for intercalation, had been generated by dissociation of TlCl₃. The metal: chlorine ratios in samples having been prepared in chlorine vapor resemble those in AlCl₃-graphite[2]. Accordingly the TlCl₃-graphite can be formulated as C_n⁺[TlCl₄^?]·XTlCl₃ (X = 2.5–3).Preparation of TICl₃-graphite (1st stage) was also accomplished by refluxing a solution of TlCl₃ in SOCl₂ or in SO₂Cl₂ with graphite with or without bubbling chlorine through the solution. The results are listed in Table 2.Reaction of graphite with TlCl₃ in nitromethane gave only a 2nd stage compound. The ease of intercalation of TlCl₃ in the three solvents follows the order: SO₂Cl₂ > SOCl₂ > NM. This is explained with the different Gutmann donor numbers [11] of the solvents.Compound formation was verified by means of X-ray diffraction. The reflexes of a 1st stage compound are listed in Table 5. The identity period along the c-axes is I_c = 977 ± 5 pm for the 1st stage, 1312 pm for the 2nd stage, and 1645 pm for the 3rd stage.The intercalated TlCl₃ is considerably more stable than the free TlCl₃ which decomposes above 100°C.No explanation can be given why AlCl₃, GaCl₃, and TlCl₃ form the 1st stage compound whereas with InCl₃ only the 2nd stage could be obtained.