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We describe the preparation, dynamic, assembly characteristics of vase-shaped basket 1 3- along with its ability to form an inclusion complex with anticancer drug mitoxantrone in abiotic and biotic systems. This novel cavitand has a deep nonpolar pocket consisting of three naphthalimide sides fused to a bicyclic platform at the bottom while carrying polar glycines at the top. The results of 1 H Nuclear Magnetic Resonance (NMR), 1 H NMR Chemical Exchange Saturation Transfer (CEST), Calorimetry, Hybrid Replica Exchange Molecular Dynamics (REMD), and Microcrystal Electron Diffraction (MicroED) measurements are in line with 1 forming dimer [1 2 ] 6- , to be in equilibrium with monomers 1 (R) 3- (relaxed) and 1 (S) 3- (squeezed). Through simultaneous line-shape analysis of 1 H NMR data, kinetic and thermodynamic parameters characterizing these equilibria were quantified. Basket 1 (R) 3- includes anticancer drug mitoxantrone (MTO 2+ ) in its pocket to give stable binary complex [MTO⊂1] - (K d =2.1 μM) that can be precipitated in vitro with UV light or pH as stimuli. Both in vitro and in vivo studies showed that the basket is nontoxic, while at a higher proportion with respect to MTO it reduced its cytotoxicity in vitro. With well-characterized internal dynamics and dimerization, the ability to include mitoxantrone, and biocompatibility, the stage is set to develop sequestering agents from deep-cavity baskets., (© 2023 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

Developing K-ion conducting solid-state electrolytes (SSEs) plays a critical role in the safe implementation of potassium batteries. In this work, a chalcogenide-based potassium ion SSE is reported, K 3 SbSe 4 , which adopts a trigonal structure at room temperature. Single-crystal structural analysis reveals a trigonal-to-cubic phase transition at the low temperature of 50 °C, which is the lowest among similar compounds and thus provides easy access to the cubic phase. The substitution of barium for potassium in K 3 SbSe 4 leads to the creation of potassium vacancies, expansion of lattice parameters, and a transformation from a trigonal phase to a cubic phase. As a result, the maximum conductivity of K 3-2 x Ba x SbSe 4 reaches around 0.1 mS cm -1 at 40 °C for K 2.2 Ba 0.4 SbSe 4 , which is over two orders of magnitude higher than that of undoped K 3 SbSe 4 . This novel SSE is successfully employed in a K-O 2 battery operating at room temperature where a polymer-laminated K 2.2 Ba 0.4 SbSe 4 pellet serves as a separator between the oxygen cathode and the potassium metal anode. Effective protection of the K metal anode against corrosion caused by O 2 is demonstrated., (© 2023 The Authors. Advanced Materials published by Wiley-VCH GmbH.)

We report Pd-catalyzed cyclotrimerization of (+)-α-bromoenone, obtained from monoterpene β-pinene, into an enantiopure cyclotrimer. This C 3 symmetric compound has three bicyclo[3.1.1]heptane rings fused to its central benzene with each ring carrying a carbonyl group. The cyclotrimer undergoes diastereoselective threefold alkynylation with the lithium salts of five terminal alkynes (41-63 %, de=4-83 %). The addition enabled a rapid synthesis of a small library of novel chiral cavitands that, in shape, resemble a tripod stand. These molecular tripods include a tris-bicycloannelated benzene head attached to three alkyne legs twisted in one direction to form a nonpolar cavity with polar groups as feet. Tripods with methylpyridinium and methylisoquinolinium legs, respectively, form inclusion complexes with anti-inflammatory and chiral drugs (R)/(S)-ibuprofen and (R)/(S)-naproxen. The mode of binding shows drug molecules docked in the cavity of the host through ion-ion, cation-π, and C-H-π contacts that, in addition of desolvation, give rise to complexes having millimolar to micromolar stability in water. Our findings open the door to creating a myriad of enantiopure tripods with tunable functions that, in the future, might give novel chemosensors, catalysts or sequestering agents., (© 2022 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

In this study, we describe a synthetic method for incorporating arenes into closed tubes that we name capsularenes. First, we prepared vase-shaped molecular baskets 4-7. The baskets comprise a benzene base fused to three bicycle[2.2.1]heptane rings that extend into phthalimide (4), naphthalimide (6), and anthraceneimide sides (7), each carrying a dimethoxyethane acetal group. In the presence of catalytic trifluoroacetic acid (TFA), the acetals at top of 4, 6 and 7 change into aliphatic aldehydes followed by their intramolecular cyclization into 1,3,5-trioxane ( 1 H NMR spectroscopy). Such ring closure is nearly a quantitative process that furnishes differently sized capsularenes 1 (0.7×0.9 nm), 8 (0.7×1.1 nm;) and 9 (0.7×1.4 nm;) characterized by X-Ray crystallography, microcrystal electron diffraction, UV/Vis, fluorescence, cyclic voltammetry, and thermogravimetry. With exceptional rigidity, unique topology, great thermal stability, and perhaps tuneable optoelectronic characteristics, capsularenes hold promise for the construction of novel organic electronic devices., (© 2022 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Living systems use chemical fuels to transiently assemble functional structures. As a step toward constructing abiotic mimics of such structures, we herein describe dissipative formation of covalent basket cage CBC 5 by reversible imine condensation of cup-shaped aldehyde 2 (i.e., basket) with trivalent aromatic amine 4. This nanosized [4+4] cage (V=5 nm 3 , M w =6150 Da) has shape of a truncated tetrahedron with four baskets at its vertices and four aromatic amines forming the faces. Importantly, tris-aldehyde basket 2 and aliphatic tris-amine 7 undergo condensation to give small [1+1] cage 6. The imine metathesis of 6 and aromatic tris-amine 4 into CBC 5 was optimized to bias the equilibrium favouring 6. Addition of tribromoacetic acid (TBA) as a chemical fuel perturbs this equilibrium to result in the transient formation of CBC 5, with subsequent consumption of TBA via decarboxylation driving the system back to the starting state., (© 2022 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

A novel metal-organic framework (MOF) containing one-dimensional, Fe 2+ chains bridged by dipyrazolate linkers and N,N-dimethylformamide (DMF) ligands has been synthesized. The unusual chain-type metal nodes feature accessible coordination sites on adjacent metal centers, resulting in motifs that are reminiscent of the active sites in non-heme diiron enzymes. The MOF facilitates direct reduction of nitric oxide (NO), producing nearly quantitative yields of nitrous oxide (N 2 O) and emulating the reactivity of flavodiiron nitric oxide reductases (FNORs). The ferrous form of the MOF can be regenerated via a synthetic cycle involving reduction with cobaltocene (CoCp 2 ) followed by reaction with trimethylsilyl triflate (TMSOTf)., (© 2021 Wiley-VCH GmbH.)

A redox-neutral S-nitrosation of thiol has been achieved at a dicopper(I,I) center. Treatment of dicopper (I,I) complex with excess NO . and thiol generates a dicopper (I,I) di-S-nitrosothiol complex [Cu I Cu I (RSNO) 2 ] 2+ or dicopper (I,I) mono-S-nitrosothiol complex [Cu I Cu I (RSNO)] 2+ , which readily release RSNO in 88-94 % yield. The S-nitrosation proceeds by a mixed-valence [Cu II Cu III (μ-O)(μ-NO)] 2+ species, which deprotonates RS-H at the basic μ-O site and nitrosates RS - at the μ-NO site. The [Cu II Cu III (μ-O)(μ-NO)] 2+ complex is also competent for O-nitrosation of MeOH. A rare [Cu II Cu II (μ-NO)(OMe)] 2+ intermediate was isolated and fully characterized, suggesting the S-nitrosation may proceed through the intermediary of analogous [Cu II Cu II (μ-NO)(SR)] 2+ species. This redox- and proton-neutral S-nitrosation process is the first functional model of ceruloplasmin in mediating S-nitrosation of external thiols, with implications for biological copper sites in the interconversion of NO . /RSNO., (© 2021 Wiley-VCH GmbH.)

Covalent capsule 1 was designed to include two molecular baskets linked with three mobile pyridines tucked into its inner space. On the basis of both theory (DFT) and experiments (NMR and X-ray crystallography), we found that the pyridine "doors" split the chamber (380 Å 3 ) of 1 so that two equally sizeable compartments (190 Å 3 ) became joined through a conformationally flexible aromatic barrier. The compartments of such unique host could be populated with CCl 4 (88 Å 3 ; PC=46 %), CBr 4 (106 Å 3 ; 56 %) or their combination CCl 4 /CBr 4 (PC=51 %), with thermodynamic stabilities ΔG° tracking the values of packing coefficients (PC). Halogen (C-X⋅⋅⋅π) and hydrogen bonding (C-H⋅⋅⋅X) contacts held the haloalkane guests in the cavities of 1. The consecutive complexations were found to occur in a negative allosteric manner, which we propose to result from the induced-fit mode of complexation. Newly designed 1 opens a way for probing the effects of inner conformational dynamics on noncovalent interactions, reactivity and intramolecular translation in confined spaces of hollow molecules., (© 2020 Wiley-VCH GmbH.)

Relative to other cyclic poly-phosphorus species (that is, cyclo-P n ), the planar cyclo-P 4 group is unique in its requirement of two additional electrons to achieve aromaticity. These electrons are supplied from one or more metal centers. However, the degree of charge transfer is dependent on the nature of the metal fragment. Unique examples of dianionic mononuclear η 4 -P 4 complexes are presented that can be viewed as the simple coordination of the [cyclo-P 4 ] 2- dianion to a neutral metal fragment. Treatment of the neutral, molybdenum cyclo-P 4 complexes Mo(η 4 -P 4 )I 2 (CO)(CNAr Dipp2 ) 2 and Mo(η 4 -P 4 )(CO) 2 (CNAr Dipp2 ) 2 with KC 8 produces the dianionic, three-legged piano stool complexes, [Mo(η 4 -P 4 )(CO)(CNAr Dipp2 ) 2 ] 2- and [Mo(η 4 -P 4 )(CO) 2 (CNAr Dipp2 )] 2- , respectively. Structural, spectroscopic, and computational studies reveal a similarity to the classic η 6 -benzene complex (η 6 -C 6 H 6 )Mo(CO) 3 regarding the metal-center valence state and electronic population of the planar-cyclic ligand π system., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Elemental white phosphorus (P 4 ) is well recognized as a critical precursor to organophosphorus compounds. However, regulatory constraints stemming from the toxic and pyrophoric nature of white phosphorus have significantly limited its accessibility. Herein is described a new approach to white phosphorus storage and release based on a unique example of photolytic reductive elimination of the tetrahedral P 4 molecule from a mononuclear cyclo-P 4 molybdenum complex. The latter functions as an air-stable, chemically-deactivated source of white phosphorus. The system features efficient photo-release of white phosphorus using inexpensive violet LED sources. Additionally, high-yield recapture of unspent white phosphorus by the molybdenum center can be achieved by post-photolysis heating at convenient temperatures., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Multimetallic clusters have long been investigated as molecular surrogates for reactive sites on metal surfaces. In the case of the μ 4 -nitrido cluster [Fe 4 (μ 4 -N)(CO) 12 ] - , this analogy is limited owing to the electron-withdrawing effect of carbonyl ligands on the iron nitride core. Described here is the synthesis and reactivity of [Fe 4 (μ 4 -N)(CO) 8 (CNAr Mes2 ) 4 ] - , an electron-rich analogue of [Fe 4 (μ 4 -N)(CO) 12 ] - , where the interstitial nitride displays significant nucleophilicity. This characteristic enables rational expansion with main-group and transition-metal centers to yield unsaturated sites. The resulting clusters display surface-like reactivity through coordination-sphere-dependent atom rearrangement and metal-metal cooperativity., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The regioselective formation of (E)-β-vinylstannanes has been a long-standing challenge in transition-metal-catalyzed alkyne hydrostannation. Herein, we report a well-defined molybdenum-based system featuring two encumbering m-terphenyl isocyanides that reliably and efficiently delivers (E)-β-vinylstannanes from a range of terminal and internal alkynes with high regioselectivity. The system is particularly effective for aryl alkynes and can discriminate between alkyl chains of low steric hindrance in unsymmetrically substituted dialkyl alkynes. Catalytic hydrostannation with this system is also characterized by an electronic effect that leads to a decrease in regioselectivity when electron-withdrawing groups are present on the alkyne substrate., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Nucleophilic substitution results in inversion of configuration at the electrophilic carbon center (S N 2) or racemization (S N 1). The stereochemistry of the nucleophile is rarely considered, but phosphines, which have a high barrier to pyramidal inversion, attack electrophiles with retention of configuration at P. Surprisingly, cyclization of bifunctional secondary phosphine alkyl tosylates proceeded under mild conditions with inversion of configuration at the nucleophile to yield P-stereogenic syn-phosphiranes. DFT studies suggested that the novel stereochemistry results from acid-promoted tosylate dissociation to yield an intermediate phosphenium-bridged cation, which undergoes syn-selective cyclization., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Bimetallic Sn-Pb catalysts with five different Sn/Pb atomic ratios were electrodeposited on Teflonated carbon paper and non-Teflonated carbon cloth using both fluoroborate- and oxide-containing deposition media to produce catalysts for the electrochemical reduction of CO 2 (ERC) to formate (HCOO - ). The interaction between catalyst composition, morphology, substrate, and deposition media was investigated by using cyclic voltammetry and constant potential electrolysis at -2.0 V versus Ag/AgCl for 2 h in 0.5 m KHCO 3 . The catalysts were analyzed before and after electrolysis by using SEM and XRD to determine the mechanisms of Faradaic efficiency loss and degradation. Catalysts that are mainly Sn with 15-35 at % Pb generated Faradaic efficiencies up to 95 % with a stable performance. However, pure Sn catalysts showed high initial stage formate production rates but experienced an extensive (up to 30 %) decrease of the Faradaic efficiency. The XRD results demonstrated the presence of polycrystalline SnO 2 after electrolysis using Sn-Pb catalysts with 35 at % Pb and its absence in the case of pure Sn. It is proposed that the presence of Pb (15-35 at %) in mainly Sn catalysts stabilized SnO 2 , which is responsible for the enhanced Faradaic efficiency and catalytic durability in the ERC., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The encumbered tetraisocyanide dianion Na 2 [Fe(CNArMes2 ) 4 ] reacts with two molecules of CO 2 to effect reductive disproportionation to CO and carbonate ([CO 3 ] 2- ). When the reaction is performed in the presence of silyl triflates, reductive disproportionation is arrested by silylative esterification of a mono-CO 2 adduct. This results in the formation of four-coordinate terminal iron carbynes possessing an aryl carbamate substituent owing to the direct attachment of an C(O)OSiR 3 group to an isocyanide nitrogen atom. Crystallographic, spectroscopic, and computational analyses of these iron-carbon multiply bonded species reveal electronic structure properties indicative of a conformationally locked iron carbyne unit., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

While interest in cooperative reactivity of transition metals and Lewis acids is receiving significant attention, the scope of known reactions that directly exploit the polarized reverse-dative σ-bond of metal-borane complexes (i.e., M→BR 3 ) remains limited. Described herein is that the platinum (boryl)iminomethane (BIM) complex [Pt(κ 2 -N,B- Cy2 BIM)(CNAr Dipp2 )] can effect the oxidative insertion of a range of unsaturated organic substrates, including azides, isocyantes, and nitriles, as well as CO 2 and elemental sulfur (S 8 ). In addition, alkyl migration processes available to the BIM framework allow for post-insertion reaction sequences resulting in product release from the metal center., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Complexes of the ubiquitous β-diketiminates (NacNac) ligands have been reported with most elements of the periodic table, including Group 14 Si, Ge, Sn, and Pb. The striking absence of carbon representatives has been attributed to the extreme electrophilicity of the putative C-NacNac adducts. An electron enriched 2,4-(dimethylamino)diketiminato backbone is described, which allowed for the synthesis and isolation of such stable pyrimidin-1,3-diium and pyrimidinium-2-ylidene salts. Structural and preliminary reactivity studies are reported, including an air-stable gold complex. An unforeseen original class of stable N-heterocyclic carbenes and, more generally, the potential of electron-rich NacNac patterns for taming highly electrophilic centers are showcased., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The 17e(-) monoradical [Mn(CO)5 ] is widely recognized as an unstable organometallic transient and is known to dimerize rapidly with the formation of a MnMn single bond. As a result of this instability, isolable analogues of [Mn(CO)5 ] have remained elusive. Herein, we show that two sterically encumbering isocyanide ligands can destabilize the MnMn bond leading to the formation of the isolable, manganese(0) monoradical [Mn(CO)3 (CNAr(Dipp2) )2 ] (Ar(Dipp2) =2,6-(2,6-(iPr)2 C6 H3 )2 C6 H3 ). The persistence of [Mn(CO)3 (CNAr(Dipp2) )2 ] has allowed for new insights into nitrosoarene spin-trapping studies of [Mn(CO)5 ]., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Pincer protic N-heterocyclic carbene (PNHC) complexes were synthesized by direct metalation, the formation of a metal carbon bond from an unfunctionalized CH bond in a single synthetic step. Significantly, direct metalation succeeded even for a first-row metal, nickel. The chloride complexes were isolated and then converted to the acetate, triflate, or in the platinum case, a hydride analogue. Crystal structures and (1) H, (13) C, and (15) N NMR data, as well as IR spectra, document the effects of intramolecular hydrogen bonding and the planar but flexible pincer framework. Anti-Markovnikov addition of OH bonds to alkynes, including catalyzed alkyne hydration, were demonstrated on the Pt triflate analog., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A stable cyclic (alkyl)(amino)carbene (CAAC) 1 inserts into the para-CF bond of pentafluoropyridine, and after fluoride abstraction, the iminium-pyridyl adduct [3](+) was isolated. A cyclic voltammetry study shows a reversible three-state redox system involving [3](+) , [3](⋅) , and [3](-) . The CAAC-pyridyl radical [3](⋅) , obtained by reduction of [3](+) with magnesium, has been spectroscopically and crystallographically characterized. In contrast to the lack of π communication between the CAAC and the pyridine units in cation [3](+) , the unpaired electron of [3](⋅) is delocalized over an extended π system involving both heterocycles., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The synthesis of air- and moisture-stable trinuclear mixed-valence gold(I)/gold(0) clusters is described. They promote the catalytic carbonylation of amines under relatively mild conditions. The synthetic route leading to the trinuclear clusters involves a simple ligand exchange from the readily available μ(3)-oxo-[(Ph3 PAu)3O](+) complex. This synthetic method paves the way for the preparation of a variety of mixed-valence gold(I)/gold(0) polynuclear clusters. Moreover, the well-defined nature of the complexes demonstrates that the catalytic process involves a rare example of a definite change of oxidation state of gold from Au(0)2Au(I) to Au(I)3., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A cyclic alkyl(amino)carbene readily reacts with SbCl3 to form the corresponding Sb(III) adduct. One-electron reduction gives rise to the first example of a neutral antimony-centered radical characterized in solution. Two-electron reduction affords a Lewis base stabilized chloro-stibinidene, whereas three-electron reduction gives an antimony diatomic species capped by two carbenes. The radical has been characterized by EPR spectroscopy, while the structure of the other three species has been ascertained by single-crystal X-ray diffraction. In these four species, the formal oxidation state of the metalloid diminishes from III, to II, to I, and finally 0., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Alkyl Grignard reagents that contain β-hydrogen atoms were used in a stereospecific nickel-catalyzed cross-coupling reaction to form C(sp(3))-C(sp(3)) bonds. Aryl Grignard reagents were also utilized to synthesize 1,1-diarylalkanes. Several compounds synthesized by this method exhibited selective inhibition of proliferation of MCF-7 breast cancer cells., (Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A lucky break: A combination of steric pressure and electron asymmetry has provided the first example of a diiron dithiolate that is both rotated and basic. The present work establishes the feasibility of a hydride free rotated structure for the Hred state of the enzyme., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Outside the cage: A change in the redox properties of a triazole fused to a carborane anion through methylation to form a zwitterion enabled facile chemical reduction of the compound to an isolable triazole radical anion (see structure: C gray, H white, N blue, B brown, Cl green). The radical anion is stabilized by kinetic protection by the chlorinated carborane and the delocalization of spin density throughout the exo-cluster π system., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The α, β, and δ polymorphs of [TTF][TCNE] (TTF=tetrathiafulvalene; TCNE=tetracyanoethylene) exhibit a new type of long, multicenter bonding between the [TTF](δ+) and [TCNE](δ-) moieties, demonstrating the existence of long, hetero-multicenter bonding with a cationic(δ+)···anionic(δ-) zwitterionic-like structure. These diamagnetic π-[TTF](δ+) [TCNE](δ-) heterodimers exhibit a transfer of about 0.5 e(-) from the TTF to the TCNE fragments, as observed from experimental studies, in accord with theoretical predictions, that is, [TTF(δ+)···TCNE(δ-)] (δ≅0.5). They have several interfragment distances <3.4 Å, and a computed interaction energy of -21.2 kcal mol(-1), which is typical of long, multicenter bonds. The lower stability of [TTF](δ+) [TCNE](δ-) with respect to typical ionic bonds is due, in part, to the partial electron transfer that reduces the electrostatic bonding component. This reduced electrostatic interaction, and the large interfragment dispersion stabilize the long, heterocationic/anionic multicenter interaction, which in [TTF(δ+)···TCNE(δ-)] always involves two electrons, but have ten, eight, and eight bond critical points (bcps) involving C-C, N-S, and sometimes C-S and C-N components for the α, β, and δ polymorphs, respectively. In contrast, γ-[TTF][TCNE] possesses [TTF](2)(2+) and [TCNE](2)(2-) dimers, each with long, homo-multicenter 2e(-)/12c (c=center, 2 C+4 S) [TTF](2)(2+) cationic(+)···cationic(+) bonds, as well as long, homo-multicenter 2e(-)/4c [TCNE](2)(2-) anionic(-)···anionic(-) bonding. The MO diagrams for the α, β, and δ polymorphs have all of the features found for conventional covalent C-C bonds, and for all of the previously studied multicenter long bonds, for example, π-[TTF](2)(2+) and π-[TCNE](2)(2-). The HOMOs for α-, β-, and δ-[TTF][TCNE] have 2c C-S and 3c C-C-C orbital-overlap contributions between the [TTF](δ+-) and [TCNE](δ-) moieties; these are the shortest intra [TTF···TCNE] separations. Thus, from an orbital-overlap perspective, the bonding has 2c and 3c components residing over one S and four C atoms., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)