Nanosized chiral octahedral M coordination cages were prepared self-assembly of sulfonylcalix[4]arene tetranuclear M(II) clusters (M = Co or Ni) with enantiomerically enriched linkers based on tris(dipyrrinato)cobalt(III) complexes, appended with peripheral carboxylic groups. Two pairs of enantiomers of cages were obtained and unambiguously characterized from a structural point of view, using single crystal X-ray diffraction. Chiral-HPLC was used to evidence the enantiomers.
View Article and Find Full Text PDFTo deeply investigate the interaction between a tetrathiafulvalene (TTF) unit and a Ti(IV) center, a monomeric heteroleptic octahedral Ti(IV) complex containing a diimine ligand composed of a 1,10-phenanthroline core fused with a TTF fragment (ligand ) was prepared. The stable complex formulated as Ti()(), where is a 2,2'-biphenolato derivative, was efficiently synthesized by following a one-step approach. This complex and its model species [Ti()()] were fully characterized in solution, and their solid-state structures were established by single-crystal X-ray diffraction analysis.
View Article and Find Full Text PDFGiant octahedral M coordination cages were prepared self-assembly of sulfonylcalix[4]arene-supported tetranuclear M(II) clusters (M = Co, Ni) with hybrid linker based on tris(dipyrrinato)cobalt(III) complexes appended with peripherical carboxylic groups. Due to intrinsic and extrinsic porosity, the obtained solid-state supramolecular architectures demonstrated good performance as adsorbents for the separation of industrially important gases mixtures.
View Article and Find Full Text PDFIntramolecular photocycloaddition reactions of 3,4-alkoxybenzonitriles derived from vanillin with alkenes have been investigated. In contrast to previous reports on photochemical reactions with these compounds, mainly [2 + 3] cycloaddition has been observed. A competing [2 + 2] photocycloaddition plays a minor role.
View Article and Find Full Text PDFThe fate of HKUST-1 (Cu(BTC), BTC = 1,3,5-benzenetricarboxylate) in the green Deep Eutectic Solvent (DES) reline (choline chloride/urea 1 : 2) was investigated, highlighting that not only reline can be used to make this MOF but also to transform it into another crystalline material. The synthesis of HKUST-1(reline) showing good textural properties and a particular rose morphology was indeed successfully achieved in this solvent. However, upon optimizing the reaction conditions such as concentration and metal/ligand ratio, it was found that another structure Cu(BTC)Cl also forms.
View Article and Find Full Text PDFSometimes named half-porphyrins, bis-pyrrolic dipyrrin ligands endow their metal complexes with unique properties such as the potential to functionalize the heterocyclic backbone or the meso position and the ability to catalyze interesting chemical transformations. Thus, strategies towards the derivatization of or at the meso group and the use of dipyrrin metal complexes for the formation of a broad range of polypyrrolic derivatives such as 2,2'-bis-dipyrrins, nor-/hetero-corroles and porphynoids have been elaborated. Furthermore, the chelating ability of dipyrrins and the possibility of modifying their steric and electronic characteristics by functionalization can be exploited for the development of numerous complexes featuring appealing properties.
View Article and Find Full Text PDFAssembly of a novel ethylenedithio-tetrathiafulvalene (EDT-TTF) derivative bearing two adjacent 4-thiopyridyl groups with M(NCS)2 nodes (M = Fe, Co) leads to two isostructural 1D coordination polymers showing an enhancement of their electronic conductivity by six orders of magnitude (10-6vs. 10-12 S cm-1), upon surface oxidation by iodine and subsequent generation of EDT-TTF-based radicals.
View Article and Find Full Text PDFA novel linear binuclear Zn(ii)/2,2'-bis-dipyrrin double-stranded helicate bearing peripheral p-benzaldehyde moieties has been strapped by formation of imine bonds upon reaction with m-xylylenediamine and characterized by 1H- and 13C-NMR spectroscopy, UV-Visible spectroscopy and high-resolution mass spectrometry.
View Article and Find Full Text PDFCoordination of 2,2'-bisdipyrrin based ligands to Zn(ii) cations leads to the formation of binuclear helicates with pre-organized pyrrolic strands as well as peripheral aromatic moieties for Ag-π interactions, thus affording crystalline heterometallic networks upon further interactions with Ag(i) salts without the assistance of additional heteroatom-based coordinating units.
View Article and Find Full Text PDFCoordination of two 2,2'-bisdipyrrin ligands, bearing methyl ester or methylthioether peripheral groups, with Zn(II) cations leads not only to the formation of the expected linear helicates but also concomitantly to novel tri- and tetra-nuclear circular species that have been isolated and fully characterized in solution and by X-ray diffraction.
View Article and Find Full Text PDFA strategy for the conversion of homometallic coordination networks into mixed metal-organic frameworks (MM'MOFs) is proposed. Ni(II) complexes of dipyrrin (dpm) ligands bearing peripheral pyridyl or imidazolyl units have been shown to self-assemble into coordination polymers with the metal cation in an octahedral environment coordinated to two bis-pyrrolic chelates and two neutral monodentate coordinating units such as pyridyl or imidazolyl moieties. Taking advantage of the chelate effect, the two monodentate units may be replaced by a diimine ligand leading to the disassembly of the networks by the formation of discrete soluble complexes.
View Article and Find Full Text PDFAn unprecedented mode of assembly of helical motives and Ag(I) ions in the crystalline state is described. The combination of a Zn(II) helicate based on a 2,2'-bisdpm bearing peripheral benzonitrile moieties with AgX salts, leads to the formation of a tetranuclear core containing Ag-π interactions. Depending on the coordinating ability of the X(-) anion and the solvents used, the tetranuclear complex self-assembles into coordination polymers of varying dimensionality.
View Article and Find Full Text PDFBoth sequential and one-pot strategies for the preparation of a series of grid-type mixed metal-organic frameworks (MM'MOFs) based on dipyrrin ligands appended with either a pyridyl or a phenyl-imidazolyl moiety have been investigated. For the stepwise approach, the differentiation between the two coordination sites (nature, charge, and denticity) was exploited for the synthesis of a family of five discrete Zn(II), Cu(II), and Pd(II) complexes. Acting as metallatectons, these construction building blocks lead to the formation of a series of MM'MOFs upon self-assembly with CdCl2.
View Article and Find Full Text PDFWhile they may have been overshadowed by the brightness of their BODIPY analogues, dipyrrin based metal complexes have recently appeared as novel interesting luminescent species owing to the development of various synthetic strategies for the preparation of such coordination compounds with appreciable quantum yields and tuneable emission wavelength. Not only the rigidification brought by functionalization of the dipyrrin backbone either at position 5 or positions 1 and 9, but also a careful choice of the ligands present in the complex coordination sphere have been key in these developments leading to bright and stable emitters. At position 5, equivalent to the meso position of a porphyrin, introduction of peripheral groups, such as the mesityl moiety hindering the rotational freedom of this unit, has been particularly targeted, hence limiting a favourable non-radiative deactivation pathway.
View Article and Find Full Text PDFA series of novel Cd(II) complexes based on α,β-unsubstituted dipyrrin ligands (dpm) has been prepared and characterised both in solution and in the solid state. These compounds are of the [Cd(dpm)(2)] type, with the coordination sphere of the metal centre occupied by two dpm chelates. Interestingly, in contrast to what has been reported for the Zn(II) analogues, in the presence of a pyridyl- or imidazolyl-appended dpm ligand, the coordination number of the Cd(II) cation can be increased to six, leading to an octahedral coordination sphere.
View Article and Find Full Text PDFAn imidazole-appended dipyrrin ligand yields, upon coordination to Cu(II) cations, a linear metallatecton that self-assembles with Cd(II) salts to afford 2D grid-type MOFs which, upon parallel stacking, lead to porous crystals offering 1D channels.
View Article and Find Full Text PDFUsing ligands based on either an acetylacetonate or a dipyrrin moiety appended with pyridyl groups, a series of novel heteroleptic copper(II) and cobalt(III) complexes combining both chelate units such as (acacpy(2))Cu(dpm-py) and (acacpy(2))Co(dpm-py)(2) (acacpy(2) = 1,3-bis(4-pyridyl)-1,3-propanedionate; dpm-py = 5-(4-pyridyl)dipyrrin) have been prepared and fully characterized. These two complexes were obtained upon reaction of dpm-py with the (acacpy(2))M homoleptic species (M = Cu(II), Co(II)). In the solid state, the (acacpy(2))Cu(dpm-py) complex behaves as a self-complementary metallatecton and leads to the formation of a 1D coordination polymer (CP) through the coordination of a peripheral pyridyl group to the copper centre.
View Article and Find Full Text PDFLuminescent cyclometalated iridium complexes based on pyridyl appended dipyrrin ligands were prepared and characterized both in the solid state and in solution. The functionalization of the peripheral pyridyl moiety causes dramatic changes on the emission properties of both mono- and hetero- binuclear complexes. A detailed photophysical investigation of the two mononuclear derivatives of the [(Ppy)(2)Ir(dpm-py)] family (Ppy=2-phenylpyridine, dpm-py=5-(4-pyridyl)dipyrrin) was carried out.
View Article and Find Full Text PDFIn order to take advantage of the peculiar mode of interaction consisting in the combination of hydrogen and coordination bonding displayed by the 7-azaindole core towards tetraacetate paddlewheel type complexes, a series of new derivatives, bearing peripheral interacting sites at the position 3, have been prepared and their self-assembly into dimeric H-bonded species was established in the solid state. Furthermore, the heterochelate mode of binding was exploited both in the solid state and in solution using [Rh(2)(OAc)(4)] paddlewheel to generate discrete capped complexes resulting from the coordination of the pyridyl nitrogen atom to the axial position of the Rh(ii) cations and hydrogen bonding between the pyrrolic NH and an oxygen atom of one of the equatorial acetate groups. The extension to infinite hybrid networks was achieved using derivatives bearing self complementary H-bond donor and acceptor groups such as a carboxylic moiety.
View Article and Find Full Text PDFThe unprecedented combined reduction of chloroauric acid and capping of the resulting gold nanoparticles in the absence of an external reducing agent are demonstrated using a novel heteroleptic Ir(III) complex incorporating a 4,5-diazafluorenedithiolate ligand. The reduction process in basic medium results from a cascade mechanism involving oxidation of the ligand, reduction of the gold salt, and stabilization and functionalization of the gold nanoparticles.
View Article and Find Full Text PDFThe synthesis and characterization of a series of [2 + 2] metallamacrocycles based on combinations of silver salts AgX (X = BF(4)(-), PF(6)(-), SbF(6)(-), TfO(-)) with pyridyl, p-phenyl-pyridyl and p-phenyl-imidazolyl appended dipyrrin (dpm) derivatives is reported. In these species, the silver ion is linearly coordinated to one of the two pyrrolic groups of the dpm moiety through the nitrogen atom and to a N atom belonging to the peripheral coordinating group. The organisation of the cyclic complexes in the solid state is dependent on the nature of the anion X(-) and on the hydrogen bonding patterns formed with the pyrrolic NH group, acting as a donor.
View Article and Find Full Text PDFA strategy for the formation of heterometallic coordination polymers based on novel copper(II) and cobalt(III) heteroleptic complexes (acacCN)Cu(dpm) and (acacCN)Co(dpm)(2) (acacCN = 3-cyanoacetylacetonate; dpm = dipyrrin) is presented. Using dipyrrins appended with a p- or m-pyridyl group, dpm-4py and dpm-3py, four novel copper and cobalt complexes were prepared and characterized both in solution and in the solid state. These two classes of complexes show different electrochemical properties upon investigation by cyclic voltammetry in CH(2)Cl(2).
View Article and Find Full Text PDFReaction of a heteroleptic cyclometalated iridium complex incorporating a carboxylic acid appended dipyrrin with copper acetate leads to the formation of a hexanuclear species with the paddlewheel structure.
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