Composition, Structure, and Thermal Properties of Potassium Acetate Hydrates.

The crystal structure determines the properties of compounds and materials, although one can find simple yet industrially relevant compounds such as potassium acetate (KOAc) and its hydrates for which the properties and even the composition still remain misunderstood, owing to the lack of structural data. In this study, the crystal structures of KOAc polymorphs and hydrates were determined for the first time. The water content in the crystal hydrates was reliably determined revealing two new phases 3KOAc·2HO and KOAc·HO ( = 0.

Access to Bicyclo[3.1.0]hexane and Cyclopenta[]pyrazole Scaffolds via Solvent-Directed Divergent Reactivity of 5-Iodotriazoles.

Divergent access to bicyclo[3.1.0]hexane and cyclopenta[]pyrazole scaffolds bearing azole and azine units has been developed.

Synthesis, Structure, and Properties of Nontrivial Iridium(III) Complexes Based on Anthracene-Decorated Benzimidazole Ligand.

Reactions of iridium trichloride hydrate with bulky 2-(9-anthracenyl)-1-phenyl-benzimidazole (anbi) in the presence of N-donor ligands afforded a number of unique noncyclometalated complexes, while attempts to prepare a common μ-chloro-bridged bis-cyclometalated dimer systematically gave a monocyclometalated complex -[Ir(,-anbi)(-anbi)Cl] instead. The obtained complexes were characterized by H NMR, high-resolution mass spectrometry, single-crystal and powder X-ray diffraction, UV-vis spectroscopy, and cyclic voltammetry. The noncyclometalated complexes -[Ir(-anbi)(N^N)Cl)], where N^N are 4,4'-disubstituted 2,2'-bipyridines, are octahedral and contain the anthracene and 2,2'-bipyridine units in a close cofacial arrangement.

IrCytoToxDB: a dataset of iridium(III) complexes cytotoxicities against various cell lines.

Iridium(III) complexes nowadays became rising stars in various health-related applications. Thus, there is a necessity to assess cytotoxicity of the synthesized molecules against cancer/normal cell lines. In this report, we present a dataset of 2694 experimental cytotoxicity values of 803 iridium complexes against 127 different cell lines.

Synthesis and crystal structures of 5,17-di-bromo-26,28-dihy-droxy-25,27-dipropynyloxycalix[4]arene, 5,17-di-bromo-26,28-dipropoxy-25,27-dipropynyloxycalix[4]arene and 25,27-bis-(2-azido-eth-oxy)-5,17-di-bromo-26,28-di-hydroxy-calix[4]arene.

The calixarenes, 5,17-di-bromo-26,28-dihy-droxy-25,27-dipropynyloxycalix[4]arene (CHBrO, ), 5,17-di-bromo-26,28-dipropoxy-25,27-dipropynyloxycalix[4]arene (CHBrO, ) and 25,27-bis-(2-azido-eth-oxy)-5,17-di-bromo-26,28-di-hydroxy-calix[4]arene (CHBrNO, ) possess a pinched cone mol-ecular shape for and , and a 1,3-alternate shape for compound . In calixarenes and , the cone conformations are additionally stabilized by intra-molecular O-H⋯O hydrogen bonds, while in calixarene intra-molecular Br⋯Br inter-actions consolidate the 1,3-alternate mol-ecular conformation. The dense crystal packing of the cone dialkyne is a consequence of π-π, C-H⋯π and C-H⋯O inter-actions.

Phosphorescent Cyclometalated Palladium(II) and Platinum(II) Complexes Derived from Diaminocarbene Precursors.

Metal-mediated self-assembly of isocyanides and methyl 4-aminopyrimidine-5-carboxylate leads to luminescent Pd and Pt complexes featuring C,N-cyclometalated acyclic diaminocarbene (ADC) ligands. The solid-state luminescent properties of these diaminocarbene derivatives are attributed to their triplet-state metal/metal-to-ligand charge-transfer (MMLCT) nature, which is driven by attractive intermolecular M···M interactions further reinforced by the intramolecular π-π interactions even in the structure of the Pd compound, which is the first Pd-ADC phosphor reported.

Aggregation-induced emission of cyclometalated rhodium(III) and iridium(III) phenylpyridine complexes with ancillary 1,3-diketones.

A joint structural and spectroscopic study of simple bis-cyclometataled rhodium(III) and iridium(III) complexes with 2-phenylpyridine and aromatic β-diketones (dibenzoylmethane, benzoylacetone, benzoyltrifluoroacetone, and 2-thenoyltrifluoroacetone) reveals an interplay between the solid-state emission efficiency and crystal packing peculiarities of the complexes. Although the prepared rhodium(III) cyclometalates are isostructural with iridium(III) analogues, different types of π-π interactions are responsible for the aggregation-induced emission (AIE) of the complexes depending on the metal ion. For iridium(III) complexes, pyridyl-pyridyl contacts are essential for AIE because they lower the energy of the emissive metal-to-ligand charge transfer state below that of the non-emissive state located at the ancillary ligand.

Rational design of efficient photosensitizers based on cyclometalated iridium(III) complexes with 2-arylbenzimidazole and aromatic 1,3-diketone ligands.

A judicious selection of substituents in cyclometalating 2-arylbenzimidazoles and an ancillary aromatic 1,3-diketone enabled the creation of heteroleptic iridium(III) complexes demonstrating strong light absorption up to 500 nm ( ≈ 10 000-12 000 M cm). The complexes, which were studied by various spectroscopic techniques, single-crystal X-ray diffraction and cyclic voltammetry, displayed tunable absorption maxima depending on the nature of substituents and their positions. The experimental study was corroborated by quantum chemical calculations, which showed an increased contribution of intraligand charge transfer transitions to the visible light absorption in the case of complexes containing electron-withdrawing substituents in the ligands.

Tailoring the π-system of benzimidazole ligands towards stable light-harvesting cyclometalated iridium(III) complexes.

The synthesis, structure, optical and redox properties as well as photovoltaic studies of iridium(III) complexes with cyclometalated 2-arylbenzimidazoles decorated with various polyaromatic fragments and an ancillary aromatic β-diketone are reported. Despite the strong preference of the iridium(III) ion to form bis- or tris-cyclometalated complexes in which the metal participates in five-membered metallacycles, the cyclometalation of the benzimidazole ligands containing rigid π-extended systems yields dimeric complexes containing strained five- or six-membered metallacycles and allows for generating an extremely rare monocyclometalated complex. X-ray crystallography shows that the steric strain observed in the dimers is retained in heteroleptic diketonate complexes which is also corroborated by gas-phase DFT calculations.

A Panchromatic Cyclometalated Iridium Dye Based on 2-Thienyl-Perimidine.

Though 2-arylperimidines have never been used in iridium(III) chemistry, the present study on structural, electronic and optical properties of -unsubstituted and -methylated 2-(2-thienyl)perimidines, supported by DFT/TDDFT calculations, has shown that these ligands are promising candidates for construction of light-harvesting iridium(III) complexes. In contrast to -H perimidine, the -methylated ligand gave the expected cyclometalated μ-chloro-bridged iridium(III) dimer which was readily converted to a cationic heteroleptic complex with 4,4'-dicarboxy-2,2'-bipyridine. The resulting iridium(III) dye exhibited panchromatic absorption up to 1000 nm and was tested in a dye-sensitized solar cell.

Syntheses and crystal structures of 2-(-tol-yl)-1-perimidine hemihydrate and 1-methyl-2-(-tol-yl)-1-perimidine.

The title compounds, 2-(4-methylphenyl)-1-perimidine hemihydrate (, CHN·0.5HO) and 1-methyl-2-(4-methylphenyl)-1-perimidine (, CHN), were prepared and characterized by H NMR and single-crystal X-ray diffraction. The organic mol-ecule of the hemihydrate lies on a twofold rotation axis while the water mol-ecule lies on the inter-section of three twofold rotation axes (point group symmetry 222).

Inherently dinuclear iridium(III) architectures accessed by cyclometalation of calix[4]arene-based bis(aryltriazoles).

Conventional cyclometalation of calix[4]arene bis(aryltriazoles) with iridium(III) chloride hydrate leads to unique architectures in which the IrCl core is cross-bound by two (C^N) ligands, which allows further replacement of the chloride bridges with ancillary ligands while maintaining the dinuclear structures of the complexes having independent or coupled iridium pairs.

Synthesis and crystal structures of -H, -phenyl and -benzyl-2-(4-hexyl-oxyphen-yl)benzimidazoles.

The title compounds, 2-(4-hexyl-oxyphen-yl)-1-benzimidazole (CHNO; ), 2-(4-hexyl-oxyphen-yl)-1-phenyl-1-benzimidazole (CHNO; ) and 1-benzyl-2-(4-hexyl-oxyphen-yl)-1-benzimidazole (CHNO; ) were synthesized and their structures were determined by single-crystal X-ray analysis. The N-substituent at the imidazole moiety slightly affects the inter-planar angle between the 4-hexyl-oxyphenyl ring and the benzimidazole system. The unsubstituted benzimidazole () forms inter-molecular N-H⋯N bonds while in the crystal structures of and , the mol-ecules are assembled only through π-π and C-H⋯π inter-actions.

Sterically hindered phenanthroimidazole ligands drive the structural flexibility and facile ligand exchange in cyclometalated iridium(III) complexes.

A series of bis-cyclometalated iridium(iii) complexes with 2-arylphenanthroimidazole "antenna" ligands containing electron-donor or withdrawing substituents and a more flexible ancillary aromatic β-diketone bearing the "anchoring" carboxymethyl function has been prepared. Thorough X-ray study of the complexes revealed significant structural strains caused by bulky cyclometalated 2-arylphenanthroimidazoles resulting in dramatic distortions of the iridium octahedron and even in twist of the phenanthrene fragment. The crystal data were corroborated by gas-phase DFT calculations whereby the geometry of the complexes was distorted in the same way.

Synthesis and comparative structural study of 2-(pyridin-2-yl)-1-perimidine and its mono- and di--methyl-ated analogues.

The title compounds, 2-(pyridin-2-yl)-1-perimidine (CHN; ), 1-methyl-2-(pyridin-2-yl)-1-perimidine (CHN; ), and 1,3-dimethyl-2-(pyridin-2-yl)-1-perimidinium iodide (CHN ·I; ) were synthesized under mild conditions and their structures were determined by H NMR spectroscopy and single-crystal X-ray analysis. The -methyl-ation of the nitro-gen atom() at the perimidine moiety results in a significant increase of the inter-plane angle between the pyridin-2-yl ring and the perimidine system. The unsubstituted perimidine () forms a weak intra-molecular N-H⋯N bond that consolidates the mol-ecular conformation.

Cyclometalated Ru(II) complexes with tunable redox and optical properties for dye-sensitized solar cells.

Cyclometalated Ru(ii) complexes with 2-arylbenzimidazole antenna ligands bearing electron-donor/withdrawing substituents and anchoring 4,4'-dimethoxycarbonyl-2,2'-bipyridine have been prepared and their structure, optical and electrochemical properties have been studied. The complexes possess enhanced light-harvesting characteristics compared to those of the standard N719 dye and absorb light up to 750 nm. In addition, they demonstrate reversible redox behavior with Ru3+/Ru2+ potentials being finely tuned by the change of the electron-donating ability of cyclometalated ligands.

Heteroleptic Ruthenium(II) Complexes with Bathophenanthroline and Bathophenanthroline Disulfonate Disodium Salt as Fluorescent Dyes for In-Gel Protein Staining.

The in-gel detection of proteins for various proteomic experiments is commonly done with the fluorescent Ru tris(bathophenanthroline disulfonate) complex (Ru(BPS)), which is more cost-effective compared to commercial Ru-based formulations but requires tedious procedures for its preparation and strongly acidic staining conditions. Herein, we report the synthesis and characterization of heteroleptic Ru complexes Ru(BPS)(BP) and Ru(BPS)(BP) containing bathophenanthroline (BP) and bathophenanthroline disulfonate disodium salt (BPS) in comparison with Ru(BPS). It was shown by fluorescent and UV-vis measurements that novel Ru complexes were excitable in both UV and visible light, close to emission bands of classical lasers, which is important for successful in-gel protein detection.

Stereocontrolled [3+2] Cycloaddition of Donor-Acceptor Cyclopropanes to Iminooxindoles: Access to Spiro[oxindole-3,2'-pyrrolidines].

A novel stereocontrolled assembly of spiro[oxindole-3,2'-pyrrolidines] via [3+2]-cycloaddition of donor-acceptor cyclopropanes to electron-poor ketimines, iminooxindoles, was developed. The method allows for efficient employment of common readily available donor-acceptor cyclopropanes, functionalized with ester, keto, nitro, cyano etc. groups, and N-unprotected iminooxindoles.

Synthesis and crystal structure of methyl 3-(3-hy-droxy-3-phenyl-prop-2-eno-yl)benzoate.

The title compound, CHO, was synthesized under mild conditions and characterized by various analytical techniques. Combined NMR and X-ray diffraction data show that the substance exists exclusively in the enol tautomeric form. An intra-molecular ⋯O=C-C=C-OH⋯ hydrogen bond is present in the mol-ecular structure.

Overcoming the Inertness of Iridium(III) in a Facile Single-Crystal to Single-Crystal Reaction of Iodine Vapor with a Cyclometalated Chloride Monomer.

Iridium(III) is often considered to be one of the most inert octahedral metal ions. Herein we present a phenanthroimidazole-based bis-cyclometalated iridium(III) chloride undergoing a facile chloro ligand exchange with iodine, in a gas-solid reaction under ambient conditions. Monitoring the progress of the reaction by X-ray diffraction analysis reveals the crystal-packing-induced exceptional stereoselectivity of this topochemical transformation.

Donor-acceptor cyclopropanes as ortho-quinone methide equivalents in formal (4 + 2)-cycloaddition to alkenes.

A new type of donor-acceptor cyclopropane reactivity towards alkenes was revealed for 2-arylcyclopropane-1,1-diesters that contain an OH-group in the ortho-position of the aryl substituent. In this case, the initial cyclopropanes participate in formal (4 + 2)-cycloaddition as synthetic equivalents of ortho-quinone methides which are potential intermediates generated under mild conditions in the presence of a Lewis acid.

BODIPY dyes with thienyl- and dithienylthio-substituents - synthesis, redox and fluorescent properties.

8-Phenyl- and 8-(4-nitrophenyl)-BODIPYs with thien-2-ylthio- and (2,2'-dithien-5-yl)-thio-substitution at the 3,5-positions were synthesized. 2-Thienylthio derivatives were obtained using two different sequences, i.e.

Crystal structure of 2,3,5,6-tetra-kis-(pyridin-2-yl)pyrazine hydrogen peroxide 4.75-solvate.

The structure of the title co-crystal, CHN·4.75HO, consists of a 2,3,5,6-tetra-kis-(pyridin-2-yl)pyrazine coformer and hydrogen peroxide solvent mol-ecules in an overall ratio of 1:4.75.