2-pyridyl Ketone Research Articles

Reduction of Ketones and Coupling of Ketyls by a Zn-Zn-Bonded Compound.

The α-diimine-ligated Zn-Zn-bonded compound [K(THF)2]2[LZn-ZnL] (1, L = [(2,6-iPr2C6H3)NC(Me)]22-) displays diverse reactivities toward a variety of ketones. In the reaction of 1 with benzophenone or 4,4'-di-tert-butylbenzophenone, a multielectron transfer process was observed to give bimetallic (Zn/K) complexes with both ketyl radical fragments and C-C coupled pinacolate moieties (products 2 and 3). In contrast, treating 1 with 9-fluorenone only afforded pinacolate complex 5. Moreover, the reactions of 1 with N- or O-heterocycle-functionalized ketones, i.e., di(2-pyridyl)ketone, 2,2-pyrrolidinone, 9-xanthenone, or 10-methyl-9(10H)-acridone, were also carried out. Besides different transformations of the ketone moiety, the heteroatoms (nitrogen or oxygen) are also involved in coordination with zinc or potassium ions, yielding discrete aggregates or polymeric structures of products 6-9.

Synthesis of a Family of Pd(II) Complexes Using Pyridyl-Ketone Ligands: Crystal Structure, Thermal, Physicochemical, XRD/HSA, Docking, and Heck Reaction Application.

Four Pd(II) complexes, (dpk)PdCl2 (complex-1), and (dpk)Pd(OAc)2 (complex-2) have been prepared using di(2-pyridyl) ketone as the chelate ligand (dpk). The (dpk·EtOH)PdCl2 (complex-3) and (dpk·EtOH)Pd(OAc)2 (complex-4) were synthesized by selectively introducing complex-1 and complex-2 to an EtOH in situ nucleophilic addition reaction on the O=C of the dpk ligand, respectively. All complexes were characterized using CHN-EA, UV-vis, FT-IR, FAB-MS, EDX, TGA, and NMR physicochemical tools. The XRD-crystallography technique was employed to ascertain the structure of complex-3. The analysis revealed a monoclinic/P21/c crystal system characterized by a square planar structure oriented in the cis direction around the Pd center. Several C-H···Cl and O-H···O H-bonds constructing 2D-S12 and S7 synthons were confirmed via XRD/HSA interactions. The influence of EtOH addition to the O=C group of dpk in (dpk)PdCl2 was documented by using UV-vis/FT-IR spectra and TGA analysis. As catalysts, all complexes have demonstrated a notable catalytic function in the Heck reaction, resulting in a high yield under gentle conditions using iodobenzene and methyl acrylate as model reactions. Moreover, the complex-1 and complex-3 docking activity was evaluated against 1BNA-DNA.

Developing a Copper(II) Isopropyl 2-Pyridyl Ketone Thiosemicarbazone Compound Based on the IB Subdomain of Human Serum Albumin-Indomethacin Complex: Inhibiting Tumor Growth by Remodeling the Tumor Microenvironment.

To develop a next-generation metal agent and dual-agent multitargeted combination therapy, we developed a copper (Cu) compound based on the properties of the human serum albumin (HSA)-indomethacin (IND) complex to remodel the tumor microenvironment (TME). We optimized a series of Cu(II) isopropyl 2-pyridyl ketone thiosemicarbazone compounds to obtain a Cu(II) compound (C4) with significant cytotoxicity and then constructed an HSA-IND-C4 complex (HSA-IND-C4) delivery system. IND and C4 bind to the hydrophobic cavities of the IB and IIA domains of HSA, respectively. In vivo, the HSA-IND-C4 not only showed enhanced antitumor efficacy relative to C4 and C4 + IND but also improved their targeting ability and decreased their side effects. The antitumor mechanism of C4 + IND involved acting on the different components of the TME. IND inhibited tumor-related inflammation, while C4 not only induced apoptosis and autophagy of cancer cells but also inhibited tumor angiogenesis.

Copper perchlorate catalyzed oxidative cyclisation of a novel bishydrazone ligand, formation of an unusual copper complex and in vitro biological implications

A novel hexadentate bishydrazone ligand, 1,10-bis(di(2-pyridyl)ketone) adipic acid dihydrazone (H2L1) is synthesized and characterized. With copper perchlorate as a catalytic oxidant, the ligand undergoes oxidative cyclisation and resulted in the formation of an unusual copper complex [Cu(L1a)2Cl]ClO4 (1), where L1a is 3-(2-pyridyl)triazolo[1,5-a]-pyridine. The Cu(II) complex was characterized physicochemically, while the molecular structure was confirmed by single crystal X- ray diffraction. In the complex cation, copper(II) is in a distorted trigonal bipyramidal coordination environment, surrounded by two triazolo nitrogen atoms and two pyridyl nitrogen atoms of L1a and a chloride atom. The relevant non covalent intermolecular interactions of the complex quantified using Hirshfeld surface analysis reveals that the O···H/ H···O (27.2%) contacts has the highest contribution. The solution phase bandgaps of the compounds were calculated using Tauc plot, whereas the solid-state band gaps were calculated by Kubelka-Munk model. DFT studies of the compounds indicate that the theoretical calculations corroborate with the experimental data. DPPH antioxidant activity assay of the synthesized compounds showed that the proligand H2L1 has a lower IC50 value (24.1 μM) than that of complex 1 (29.7 μM). The in vitro antibacterial activity was evaluated against Escherichia coli and Staphylococcus aureus, which revealed that complex 1 have excellent activity against E. coli, much as the standard ciprofloxacin. The cytotoxic efficacy investigation of the compounds against A549 (lung) adenocarcinoma cells suggested that H2L1 has more anticancer activity (IC50 value of 149.08 μM) than that of complex 1(IC50 value of 176.70 μM).

Methyl 4-pyridyl ketone thiosemicarbazone (4-PT) as an effective and safe inhibitor of mushroom tyrosinase and antibrowning agent

Enzymatic browning is of concern as it can affect food safety and quality. In this study, an effective and safe tyrosinase inhibitor and anti-browning agent, methyl 4-pyridyl ketone thiosemicarbazone (4-PT), was synthesised and characterised using Fourier-transform infrared (FTIR) spectroscopy, CHNS elemental analysis, and proton (1H) and carbon-13 (13C) nuclear magnetic resonance (NMR) spectroscopy. The vibrational frequencies of 4-PT were studied theoretically using vibrational energy distribution analysis (VEDA). Density functional theory (DFT) was applied to elucidate its chemical properties, including the Mulliken atomic charges, molecular electrostatic potential (MEP), quantum theory of atoms in molecules (QTAIM) and reduced density gradient non-covalent interactions (RDG-NCIs). Moreover, 4-PT was compared with kojic acid in terms of its effectiveness as a tyrosinase inhibitor and anti-browning agent. The toxicity and physicochemical properties of 4-PT were predicted via ADME evaluation, which proved that 4-PT is safer than kojic acid. Experimentally, 4-PT (IC50 = 5.82 μM, browning index (10 days) = 0.292 ± 0.002) was proven to be an effective tyrosinase inhibitor and anti-browning agent compared to kojic acid (IC50 = 128.17 μM, browning index (10 days) = 0.332 ± 0.002). Furthermore, kinetic analyses indicated that the type of tyrosinase inhibition is a mixed inhibition, with Km and Vmax values of 0.85 mM and 2.78 E-09 μM/s, respectively. Finally, the mechanism of 4-PT for tyrosinase inhibition was proven by 1D, second derivative and 2D IR spectroscopy, molecular docking and molecular dynamic simulation approaches.

DNA and BSA Binding Studies of New Pd(II) Bisthiocarbohydrazone Complexes: From Anticancer Drug Analogue to Anticovid Candidates

Two new Pd(II) complexes derived from bioactive 1,5-bis(2-benzoylpyridine)thiocarbohydrazone (1) and 1,5-bis(di(2-pyridyl)ketone)thiocarbohydrazone (2) are found to have high putative propensity to the active sites of the SARS-CoV-2 viral protease Mpro compared to active repurposed drugs. The complexes were physicochemically characterized and their solid state band gaps (Eg) were determined. The DFT calculations corroborate with the experimental data and provide insight about their possible chemical and biological reactivity. Both the complexes showed enhanced in vitro cytotoxicity against DLA tumor cells with their increasing concentration. The in silico molecular docking studies of the palladium(II) complexes with the biomolecules duplex DNA and BSA protein exhibit good binding affinity. The interaction ability of these complexes with calf thymus DNA and BSA protein are explored. The absorption spectral study of the interaction with CT-DNA reveals that both the complexes effectively bind with DNA and the fluorescence spectral study confirms the groove mode of binding. The complex 2 having pyridyl groups in place of phenyl groups as compared to the complex 1, binds DNA more effectively. Both the complexes were found to have strong interactions with BSA protein also. The complex 2 again has more affinity for BSA protein based on experimental binding and quenching constant values and the putative molecular docking studies. The binding potential of both the complexes with the Omicron spike protein was also investigated and found to have a comparable efficiency with its controls ivermectin and levosalbutamol.

Discovering the Site-Selective Umpolung of Ketones Triggered by Hypervalent Fluoro-Iodanes – Why Investigating Side Reactions Matters!

AbstractIn this account, we describe our journey leading to the discovery of a generally applicable umpolung method for the α-functionalization of ketones. Central to this reaction is the cyclic hypervalent fluoro-iodane, which is mostly known for various alkene functionalizations enabling, for example, the synthesis of fluoro-benzoxazepines, indoles, and ketones. During this work, we encountered α-functionalized ketones as minor side products. This observation prompted us to further investigate this reactivity, thus revealing a directed umpolung of pyridyl ketones by the fluoro-iodane. The key to the success was the unexpected non-covalent interaction between the nucleophile, substrate, and iodane.1 Introduction2 Cyclizations Triggered by the Fluorination of Styrenes3 Umpolung Reactions Facilitated by Hypervalent Iodanes4 Discovering and Evolving a Fluoro-Iodane-Triggered Regioselective α-Functionalization of Carbonyl Compounds5 First Investigations on the Nitrogen-Directed Umpolung6 Conclusion

Dye-surfactant co-assembly as the chromogenic indicator for nanomolar level detection of Cu(I) ions via a color-changing response.

Polyaromatic amphiphilic probes have been developed, that can be involved in chromogenic detection of Cu+ ions in anionic micelles. A rapid change in solution color from yellow to orange was observed in the presence of Cu+ ions. The detection limit was found at the nanomolar range. To the best of our knowledge, this is the first report of the visible detection of Cu+ ions in aqueous medium using anionic micelles as a stabilizing agent. Interestingly, the compound can also detect Cu+ ions, generated in situ from physiological redox processes. The mechanistic investigation suggests that the probe molecule forms a diamagnetic tetrahedral complex with the Cu+ ion, coordinating through a pyridyl ketone unit. In addition, we have also followed the interaction with Cu+ on a bilayer surface made of anionic phospholipids. Further, a Cu2+-probe ensemble is used to assay the reducing ability of different biogenic thiols depending upon the pKa of their sulfhydryl (-SH) group. This allows us to determine the amount of reducing thiols present in human urine samples. Considering the high sensitivity of the present system, we screened water samples collected from different natural sources for Cu+ ions. Nearly 100% recovery values with considerably small relative standard deviations (<5%) indicate that the present system is indeed suitable for real-life sample analysis. Finally, low-cost, reusable, chemically-modified paper strips have been developed for rapid, on-location detection of Cu+ ions.

Design and Anticancer Properties of New Water-Soluble Ruthenium-Cyclopentadienyl Complexes.

Ruthenium complexes are emerging as one of the most promising classes of complexes for cancer therapy. However, their limited aqueous solubility may be the major limitation to their potential clinical application. In view and to contribute to the progress of this field, eight new water-soluble Ru(II) organometallic complexes of general formula [RuCp(mTPPMS)n(L)] [CF3SO3], where mTPPMS = diphenylphosphane-benzene-3-sulfonate, for n = 2, L is an imidazole-based ligand (imidazole, 1-benzylimidazole, 1-butylimidazole, (1-(3-aminopropyl)imidazole), and (1-(4-methoxyphenyl)imidazole)), and for n = 1, L is a bidentate heteroaromatic ligand (2-benzoylpyridine, (di(2-pyridyl)ketone), and (1,2-(2-pyridyl)benzo-[b]thiophene)) were synthesized and characterized. The new complexes were fully characterized by NMR, FT-IR, UV–vis., ESI-HRMS, and cyclic voltammetry, which confirmed all the proposed molecular structures. The antiproliferative potential of the new Ru(II) complexes was evaluated on MDAMB231 breast adenocarcinoma, A2780 ovarian carcinoma, and HT29 colorectal adenocarcinoma cell lines, showing micromolar (MDAMB231 and HT29) and submicromolar (A2780) IC50 values. The interaction of complex 6 with human serum albumin (HSA) and fatty-acid-free human serum albumin (HSAfaf) was evaluated by fluorescence spectroscopy techniques, and the results revealed that the ruthenium complex strongly quenches the intrinsic fluorescence of albumin in both cases.

Pentanuclear Thorium(IV) Coordination Cluster from the Use of Di(2-pyridyl) Ketone.

The Th(NO3)4·5H2O/di(2-pyridyl) ketone [(py)2CO] reaction system gives a pentanuclear cluster containing the doubly deprotonated form of the gem-diol derivative of the ligand. The cluster consists of a tetrahedral arrangement of four ThIV ions centered on the fifth ion, which is the first characterized ThIV5 complex. The analysis of its structure reveals that this is a Kuratowski-type coordination compound.

Synthesis and Structure of Novel Copper(II) Complexes with N,O- or N,N-Donors as Radical Scavengers and a Functional Model of the Active Sites in Metalloenzymes.

To evaluate the antioxidant activity of potential synthetic enzyme mimetics, we prepared new five copper(II) complexes via a self-assembly method and named them [Cu(2-(HOCH2)py)3](ClO4)2 (1), [Cu(2-(HOCH2)py)2(H2O)2]SiF6 (2), [Cu2(2-(HOCH2CH2)py)2(2-(OCH2CH2)py)2](ClO4)2 (3), [Cu(pyBIm)3](BF4)2·1.5H2O (4) and [Cu(py2C(OH)2)2](ClO4)2 (5). The synthetic protocol involved N,O- or N,N-donors: 2-(hydroxymethyl)pyridine (2-(HOCH2)py), 2-(hydroxyethyl)pyridine (2-(HOCH2CH2)py), 2-(2-pyridyl)benzimidazole (pyBIm), di(2-pyridyl)ketone (py2CO). The obtained Cu(II) complexes were fully characterised by elemental analysis, FTIR, EPR, UV-Vis, single-crystal X-ray diffraction and Hirshfeld surface analysis. Crystallographic and spectroscopic analyses confirmed chromophores of both monomeric ({CuN3O3} (1), {CuN2O4} (2), {CuN6} (4), {CuN4O2} (5)) and dimeric complex ({CuN2O3} (3)). Most of the obtained species possessed a distorted octahedral environment, except dimer 3, which consisted of two copper centres with square pyramidal geometries. The water-soluble compounds (1, 3 and 5) were selected for biological testing. The results of the study revealed that complex 1 in solutions displayed better radical scavenging activity than complexes 3, 5 and free ligands. Therefore, complex 1 has been selected for further studies to test its activity as an enzyme mimetic. The chosen compound was tested on the erythrocyte lysate of two groups of patients after undergoing chemotherapy and chemoradiotherapy. The effect of the tested compound (1) on enzyme activity levels (TAS, SOD and CAT) suggests that the selected complex can be treated as a functional mimetic of the enzymes.

Indium(III) in the "Periodic Table" of Di(2-pyridyl) Ketone: An Unprecedented Transformation of the Ligand and Solid-State 115In NMR Spectroscopy as a Valuable Structural Tool.

Reactions of di(2-pyridyl) ketone, (py)2CO, with indium(III) halides in CH3NO2 have been studied, and a new transformation of the ligand has been revealed. In the presence of InIII, the C═O bond of (py)2CO is subjected to nucleophilic attack by the carbanion -:CH2NO2, yielding the dinuclear complexes [In2X4{(py)2C(CH2NO2)(O)}2] (X = Cl, 1; X = Br, 2; X = I, 3) in moderate to good yields. The alkoxo oxygens of the two η1:η2:η1-(py)2C(CH2NO2)(O)- ligands doubly bridge the InIII centers and create a {In2(μ2-OR)2}4+ core. Two pyridyl nitrogens of different organic ligands and two terminal halogeno ions complete a distorted-octahedral stereochemistry around each In(III) ion. After maximum excitation at 360 or 380 nm, the solid chloro complex 1 emits blue light at 420 and 440 nm at room temperature, the emission being attributed to charge transfer within the coordinated organic ligand. Solid-state 115In NMR spectra, in combination with DFT calculations, of 1-3 have been studied in detail at both 9.4 and 14.1 T magnetic fields. The nuclear quadrupolar and chemical shift parameters provide valuable findings concerning the electric field gradients and magnetic shielding at the nuclei of indium, respectively. The experimentally derived CQ values are 40 ± 3 MHz for 1, 46 ± 5 MHz for 2, and 50 ± 10 and 64 ± 7 MHz for the two crystallographically independent InIII sites for 3, while the δiso values fall in the range 130 ± 30 to -290 ± 60 ppm. The calculated CQ and asymmetry parameter (ηQ) values are fully consistent with the experimental values for 1 and 2 and are in fairly good agreement for 3. The results have been analyzed and discussed in terms of the known (1, 3) and proposed (2) structural features of the complexes, demonstrating that 115In NMR is an effective solid-state technique for the study of indium(III) complexes.

Ni-catalyzed enantioselective [2 + 2 + 2] cycloaddition of malononitriles with alkynes

Summary Efficient strategies to assemble enantioenriched pyridine derivatives are highly important, given their significance in both synthetic and medicinal chemistry. Here, we report an enantioselective nickel-catalyzed intermolecular [2 + 2 + 2] cycloaddition of alkyne-tethered malononitriles with alkynes for the synthesis of densely substituted pyridines. The α-all-carbon quaternary center adjacent to pyridine is introduced by desymmetrizing the two cyano groups of disubstituted malononitriles. Notably, terminal alkynes are also tolerated with good regioselectivity to afford tetrasubstituted pyridines. Zinc halide is essential to enable the occurrence of the transformation by promoting the hetero-cyclometallation step. The reaction uses bio-renewable 2-MeTHF as the solvent and features mild reaction conditions, good functional group compatibilities, and enantioselectivities. This study offers a straightforward approach to the valuable enantioenriched heteroarenes from feedstock chemicals by forming three bonds and one quaternary stereocenter simultaneously in a single reaction step.

Reversible PtII-CH3 deuteration without methane loss: metal-ligand cooperation vs. ligand-assisted PtII-protonation.

Di(2-pyridyl)ketone dimethylplatinum(ii), (dpk)PtII(CH3)2, reacts with CD3OD at 25 °C to undergo complete deuteration of Pt–CH3 fragments in ∼5 h without loss of methane to form (dpk)PtII(CD3)2 in virtually quantitative yield. The deuteration can be reversed by dissolution in CH3OH or CD3OH. Kinetic analysis and isotope effects, together with support from density functional theory calculations indicate a metal–ligand cooperative mechanism wherein DPK enables Pt–CH3 deuteration by allowing non-rate-limiting protonation of PtII by CD3OD. In contrast, other model di(2-pyridyl) ligands enable rate-limiting protonation of PtII, resulting in non-rate-limiting C–H(D) reductive coupling. Owing to its electron-poor nature, following complete deuteration, DPK can be dissociated from the PtII-centre, furnishing [(CD3)2PtII(μ-SMe2)]2 as the perdeutero analogue of [(CH3)2PtII(μ-SMe2)]2, a commonly used PtII-precursor.

Heterometallic Complexes Containing the NiII-LnIII-NiII Moiety—Structures and Magnetic Properties

This review summarizes the structural characteristics and magnetic properties of trinuclear complexes containing the NiII-LnIII-NiII moiety and also oligonuclear complexes and coordination polymers containing the same trinuclear moiety. The ligands used are mainly polydentate Schiff base ligands and reduced Schiff base ligands and, in some cases, oximato, β-diketonato, pyridyl ketone ligands and others. The compounds reported are restricted to those containing one, two and three oxygen atoms as bridges between the metal ions; examples of carboxylato and oximato bridging are also included due to structural similarity. The magnetic properties of the complexes range from ferro- to antiferromagnetic depending on the nature of the lanthanide ion.

α-Functionalization of Ketones via a Nitrogen Directed Oxidative Umpolung.

Reversing the polarity in molecules is a versatile tool for expanding the boundaries of structural space. Despite a manifold of different umpolung methods available today, overcoming the inherent reactivity still remains a constant challenge in organic chemistry. The oxidative α-functionalization of ketones by external nucleophiles constitute such an example. Herein, we present a hypervalent F-iodane mediated umpolung of pyridyl ketones triggered by Lewis base/Lewis acid noncovalent interactions. A wide variety of external nucleophiles are introduced with high regioselectivity applying this substrate-directing concept.

Practical and rapid construction of 2-pyridyl ketone library in continuous flow

2-Pyridyl ketones widely appear in bioactive molecules, natural products, and are employed as precursors of chiral 2-pyridine alky/aryl alcohols or 2-aminoalkyl pyridine ligands for asymmetric catalysis. Herein, a practical method for the rapid synthesis of 2-pyridyl ketone library in continuous flow is reported, in which the 2-lithiopyridine formed by Br/Li exchange reacts with commercially available esters to obtain 2-pyridyl ketones in a good yield at short reaction time. This protocol functions broadly on a variety of esters and has been applied to the synthesis of TGF-β type 1 receptor inhibitor LY580276 intermediate in an environmentally friendly method. It is rapid, reliable, and cost-efficient to afford diverse kinds of 2-pyridyl ketones in the compound library.

Synthesis, characterization, thermal properties and biological activity of diazine-ring containing hydrazones and their metal complexes

New coordination compounds have been synthesized by reacting Zn(II) and Co(II) nitrate or acetate in the presence of triethylamine with Schiff-base ligands containing diazine-ring, pyridine-2-carbaldehyde phthalazine-1-hydrazone, HzPYH, and di(2-pyridyl)ketone 3-chloro-pyridazine-6-hydrazone, HpDPKH. Complexes of [Co(HzPY)2]·3.4H2O, [Zn(HzPY)2] and [Co(HpDPK)2]NO3·H2O were obtained. The crystal and the molecular structure of [Co(HzPY)2]·3.4H2O were determined using X-ray diffraction structure analysis. The compounds were characterized by elemental analysis, FT-IR and UV–Vis spectral data, conductivity and magnetic measurements, too. Except for the diamagnetic Co(III) compound with a nitrate counter-ion, [Co(HpDPK)2]NO3·H2O, all the complexes are neutral-type. The magnetic moment of [Co(HzPY)2]·3.4H2O indicated a low-spin octahedral complex which is relatively rear amongst octahedral Co(II) complexes. Hence, its magnetic moment was measured in the temperature range of 3–300 K. To obtain products in the form of single crystals and/or to increase the yield, the reactions were carried out in solutions with different solvents or recrystallized from solvent mixtures. To determine the nature of the solvent (if any) in the crystalline products and to gain better insight into the decomposition mechanism, coupled TG–MS measurements were carried out. The desolvated compounds were stable at relatively high temperatures (> 200 °C). The cytotoxic, antiproliferative and efflux pump inhibitory effects of the compounds were tested in multidrug-resistant mouse T-lymphoma cells to study their effect on the suppression of MDR. The antibacterial activity of the compounds was also tested. The results of the antibacterial tests were analysed to understand better the effect of the central atoms and the structure on a specific activity.

Coordination complexes of di(2-pyridyl)ketone with copper(I) and their formation in solution and under solvent-free conditions

Four copper(I) complexes of the ligand di(2-pyridyl)ketone (dpk) were synthesized using Cu(I)Cl, Cu(I)Br, Cu(I)CN and Cu(I)I in MeCN solution and under solvent-free conditions. The solid compounds show a reaction when mixed without solvent, which is indicated by a rapidly occurring color change. The resulting products were characterized by IR spectroscopy, MS and single crystal X-ray diffraction. In case of the Cu(I)Cl, a 1:2-complex is formed, showing a six-membered, cyclic Cu3X3-unit with quasi-boat confirmation. With Cu(I)Br, Cu(I)CN and Cu(I)I, 1:1-complexes are obtained. The Cu(I)Br and Cu(I)I complexes are binuclear and bridged by bromide and iodide anions respectively, resulting in Cu2Br2/ Cu2I2 halide-bridged square dimers. The copper(I) cation and the cyanide anion of the Cu(I)CN dpk complex are forming a one-dimensional chain bridged by the cyanide groups. The structures were further characterized by Hirshfeld analysis, showing the weak interactions in the crystal, which are consistent with the observed physical properties.

Transformation Network Culminating in a Heteroleptic Cd6L6L'2 Twisted Trigonal Prism.

Transformations between three-dimensional metallosupramolecular assemblies can enable switching between the different functions of these structures. Here we report a network of such transformations, based upon a subcomponent displacement strategy. The flow through this network is directed by the relative reactivities of different amines, aldehydes, and di(2-pyridyl)ketone. The network provides access to an unprecedented heteroleptic Cd6L6L′2 twisted trigonal prism. The principles underpinning this network thus allow for the design of diverse structural transformations, converting one helicate into another, a helicate into a tetrahedron, a tetrahedron into a different tetrahedron, and a tetrahedron into the new trigonal prismatic structure type. The selective conversion from one host to another also enabled the uptake of a desired guest from a mixture of guests.