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In this paper, we present the synthesis of four new complexes: the dimeric precursor [Ir(dmppz)2(μ-Cl)]2 (1) (Hdmppz -- 3,5-dimethyl-1-phenyl-1H-pyrazole) and heteroleptic bis-cyclometalated complexes: [Ir(dmppz)2(Py2CO)]PF6•½CH2Cl2 (2), [Ir(dmppz)2(H2biim)]PF6•H2O (3), and [Ir(dmppz)2(PyBIm)]PF6 (4), with auxiliary N,N-donor ligands: 2-di(pyridyl)ketone (Py2CO), 2,2'-biimidazole (H2biim) and 2-(2'-pyridyl)benzimidazole (PyBIm). In the obtained complexes, SC-X-ray analysis revealed that Ir(III) has an octahedral coordination sphere with chromophores of the type {IrN2C2Cl2} (1) or {IrN4C2} (2-4). The complexes obtained, which have been fully characterised by physicochemical methods (CHN, TG, FTIR, UV-Vis, PL and ¹H, 13C, 15N NMR), were used to continue our studies on the factors influencing the cytotoxic properties of potential chemotherapeutic agents (in vitro). To this end, the following studies are presented: (i) comparative analysis of the effects on the biological properties of N,N-donor ligands and C,N-donor ligands in the studied complexes, (ii) studies of the interactions of the compounds with the selected molecular target: DNA and BSA (UV-Vis, CD and PL methods), (iii) and the reactivity towards redox molecules: GSH, NADH (UV-Vis and/or ESI-MS methods), (iv) cytotoxic activity (IC50) of potential chemotherapeutics against MCF-7, K-562 and CCRF-CEM cell lines. [ABSTRACT FROM AUTHOR]

A case of organic–inorganic hybridized phosphotungstate modified using aromatic organophosphonic acid, K4Na4H11[KCo2(H2O)10P4W24O92{(PhPO)2}]·48H2O (1), was successfully synthesized in conventional aqueous solution. The prominent structural feature is that the total structure of [KP4W24O92{(PhPO)2}]23− resembles a V-shaped structure, which was stabilized by two [Co(H2O)5]2+ ions. Furthermore, it can be connected into a three-dimensional mesh structure using K+ ions. Surprisingly, 1 possesses a remarkably high proton conductivity of 1.59 × 10−2 S cm−1 at 95% RH and 318 K probably due to the fact that its structure contains large amounts of lattice water molecules, coordination water molecules and counter cations. [ABSTRACT FROM AUTHOR]

In this study, we present a series of theoretically designed B2G14G14' molecules, featuring four-membered-ring heterocycles containing boron and heavy group 14 elements (G14 and G14' = Si, Ge, Sn, and Pb). Through the use of density functional theory (DFT), natural bond orbital (NBO) analysis, quantum theory of atoms in molecules (QTAIM), and electron localization function (ELF), our studies demonstrate a strong π single bond between the bridgehead G14 and G14' atoms, with minimal participation from a very weak G14-G14' σ bond. Additionally, the nucleus independent chemical shift (NICS), anisotropy of current-induced density (ACID), and adaptive natural density partitioning (AdNDP) analyses definitively establish the presence of both σ-aromaticity and π-aromaticity in these inorganic four-membered heterocyclic neutral molecules. [ABSTRACT FROM AUTHOR]

The synthesis of three novel [C,N,N′] Pt(IV) cyclometallated compounds containing hydroxo, dichloroacetato or trifluoroacetato axial ligands is reported. Compound [PtCl(OH)2{(CH3)2N(CH2)2N＝CH(4-FC6H3)}] (3) was prepared by the oxidative addition of hydrogen peroxide to [C,N,N′] Pt(II) cyclometallated compound [PtCl{(CH3)2N(CH2)2N＝CH(4-FC6H3)}] (1) and further the reaction of compound 3 with dichloroacetate or trifluoroacetate anhydrides led to the formation of the corresponding compounds [PtCl(CHCl2COO)2{(CH3)2N(CH2)2N＝CH(4-FC6H3)}] (4) and [PtCl(CF3COO)2{(CH3)2N(CH2)2N＝CH(4-FC6H3)}] (5). The properties of the new compounds along with those of the compound [PtCl3{(CH3)2N(CH2)2N＝CH(4-FC6H3)}] (2), including stability in aqueous media, reduction potential using cyclic voltammetry, cytotoxic activity against the HCT116 CRC cell line, DNA interaction, topoisomerase I and cathepsin inhibition, and computational studies involving reduction of the Pt(IV) compounds and molecular docking studies, are presented. Interestingly, the antiproliferative activity of these compounds against the HCT116 CRC cell line, which is in all cases higher than that of cisplatin, follows the same trend as the reduction potentials so that the most easily reduced compound 2 is the most potent. In contrast, according to the electrophoretic mobility and molecular docking studies, the efficacy of these compounds in binding to DNA is not related to their cytotoxicity. The most active compound 2 does not modify the DNA electrophoretic mobility while the less potent compound 3 is the most efficient in binding to DNA. Although compounds 2 and 3 have only a slight effect on cell cycle distribution and apoptosis induction, generation of ROS to a higher extent for the most easily reduced compound 2 was observed. [ABSTRACT FROM AUTHOR]

Transforming current complementary metal–oxide–semiconductor (CMOS) technology to fabricate memory chips and microprocessors into environmentally friendlier electronics requires the development of new approaches to resource- and energy-efficient electron transport and switching materials. Metal and multi-metal oxide layers play a key role in high-end technical applications. However, these layers are commonly produced through high-energy and high-temperature procedures. Herein, we demonstrate our first attempts to obtain stimuli-responsive mixed-metal oxide thin films from solution-processed molecular precursors under milder conditions. The molecular compounds of interest were prepared by one-pot reactions of a CoII carboxylate complex, triethylamine (Et3N), N-butyldiethanolamine (H2bda), and a hexanuclear complex [Ce6O4(OH)4(piv)12] (Hpiv = pivalic acid) or [Zr6O4(OH)4(ib)12(H2O)]·3Hib (Hib = isobutyric acid) in acetonitrile solution. The resulting charge-neutral, heterometallic coordination compounds display a ligand-supported pentanuclear {Ce IV3 Co III2 } core (in 1) and a dodecanuclear {Zr IV6 Co II6 } core (in 2), exhibiting thermal stability up to ca. 100 °C in air. Compound 2 was deposited and analyzed on Au(111) and SiO2/Si(100) surfaces to explore its potential as a single-molecule precursor for the preparation of atomically precise, complex mixed-metal oxide thin films. The adsorption characteristics of it demonstrate the ability to form stable agglomerates on the investigated surfaces. [ABSTRACT FROM AUTHOR]

The current work demonstrates the reversible control of substantial molecular motion in 'nano-sized' molecules, where two structural isomers can 'open' and 'close' their cavities in response to light or heat. The isomers differ widely in their photophysical properties, including colour, polarity, two-photon absorption and π-conjugation, and can easily be separated through column chromatography and thus have wide applicability. [ABSTRACT FROM AUTHOR]

Crystallographic investigations of eight homoleptic N,N′-dimethylpropyleneurea (dmpu) coordinated metal ions in the solid state, [Mg(dmpu)5]I2 (1), [Ca(dmpu)6]I2 (2), [Ca(dmpu)6](ClO4)2 (3), [Ca(dmpu)6](CF3SO3)2 (4), [Sr(dmpu)6](CF3SO3)2 (5), [Ba(dmpu)6](CF3SO3)2 (6), [Sc(dmpu)6]I3 (7), and [Pr(dmpu)6]I(I3)2 (8), and the complex [CoBr2(dmpu)2] (9) as well as the structures of the dmpu coordinated calcium, strontium, barium, scandium(III) and cobalt(II) ions and the cobalt(II) bromide complex in dmpu solution as determined by EXAFS are reported. The methyl groups in the dmpu molecule are close to the oxygen donor atom, causing steric restrictions, and making dmpu space-demanding at coordination to metal ions. The large volume required by the dmpu ligand at coordination contributes to crowdedness around the metal ion with often lower coordination numbers than for oxygen donor ligands without such steric restrictions. The crowdedness is seen in M⋯H distances equal to or close to the sum of the van der Waals radii. To counteract the space-demand at coordination, the dmpu molecule has an unusual ability to increase the M–O–C bond angle to facilitate as large coordination numbers as possible. M–O–C bond angles in the range of 125–170° are reported depending on the crowdedness caused by the coordination figure and the M–O bond distance. All reported structures of dmpu coordinated metal ions in both the solid state and dmpu solution are summarized to study the relationship between the M–O–C bond angle and the crowdedness around the metal ion. However, highly symmetric complexes seem to be favoured in the solid state due to favourable lattice energies. As a result, the dmpu coordinated lanthanoid(III) ions are octahedral in the solid state, while they, except lutetium, are seven-coordinate in the dmpu solution. [ABSTRACT FROM AUTHOR]

Exploring feasible tactics to induce the formation of non-centrosymmetric (NCS) structures, especially from centrosymmetric (CS) structures, is essential for the development of nonlinear optical crystals with more potential. An NCS alkali metal-containing molybdenum iodate hydrate, namely, NaMoO3(IO3)(H2O), was designed based on the CS matrix NaMoO3(IO3) via introducing a water molecule into the structure. The introduction of one crystalline water molecule results in the rearrangement of Λ-shaped cis-[MoO4(IO3)2] units, and the proper array of the cis-[MoO4(IO3)2] units in NaMoO3(IO3)(H2O) results in its strong SHG response of 4.6 × KH2PO4. In addition, NaMoO3(IO3)(H2O) exhibits a wider optical bandgap of 3.44 eV and a larger birefringence of 0.231 than its matrix. Furthermore, the framework of NaMoO3(IO3)(H2O) is highly similar to that of α-KMoO3(IO3), with water molecules assisting Na+ cations in occupying the position of K+. However, due to the extra hydrogen bond of water molecules, the [MoO3(IO3)]∞ layers in NaMoO3(IO3)(H2O) retain a parallel-stacking arrangement, different from the antiparallel arrangement of layers in α-KMoO3(IO3) with a centric structure. This study confirms the feasibility of applying a water molecule to adjust the orientation of basic building block units to assemble an NCS structure based on CS crystals. [ABSTRACT FROM AUTHOR]

Non-heme mononuclear iron complexes, especially when supported by tripodal tetradentate ligands, show promising C–H bond activation efficiency in catalytic reactions. Nevertheless, they intrinsically decay readily to their dinuclear form, and the dimerization process is inevitable in homogenous solution, which dramatically hinders their further application. Hence, we demonstrate that the mononuclear iron complex [(TPA)FeII-2L]2+ (L = labile ligands, mainly solvent molecules) was successfully encapsulated in a highly robust metal–organic framework UiO-66 via a two-step "ship-in-a-bottle" strategy. The nearly perfect size matching of the octahedral cages of the host UiO-66 provides ideal space confinement for the guest complex to protect from dimerization and dramatically increases the mono-nuclear complex stability compared to its un-confined state. The successful encapsulation of [(TPA)FeII-2L]2+ in UiO-66 was verified thoroughly by spectroscopy, microscopy, N2 adsorption, and electrochemistry characterization techniques. This work shows that encapsulating an unstable molecular complex in MOFs via a two-step "ship-in-a-bottle" strategy highlights opportunities for extending the heterogenization of homogeneous complexes. [ABSTRACT FROM AUTHOR]

Ditopic di-o-quinone with a resorcinol bridge exhibits the ability to self-assemble in a reaction with copper, giving a cage-like binuclear complex that, due to the cofacially placed metal ions, is capable of encapsulation of different solvent molecules as guest ligands. Notably, the geometry of the internal cavity of this complex adjusts depending on the coordinating properties of the encapsulated molecule (mono- or bidentate). A feature of this species is that the cage-forming units are copper(II) bis-semiquinonate moieties, capable of undergoing ligand-centered redox transformations. Electrochemical and EPR spectroscopy studies showed that there is a channel for intramolecular electronic exchange interactions between the redox centres of the molecule. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) as types of proton conductive materials have attracted much attention. Here, an acylamide-functionalized 3D MOF, [Ni3(TPBTC)2(stp)2(H2O)4]·2DMA·32H2O, has been successfully constructed via combining Ni(NO3)2, TPBTC (TPBTC = benzene-1,3,5-tricarboxylic acid tris-pyridin-4-ylamide) and 2-H2stp (2-H2stp = 2-sulfoterephthalic acid monosodium salt) under solvothermal conditions. Single-crystal X-ray diffraction revealed that there are uncoordinated guest DMA molecules in the pores of the compound. On removal of guest DMA molecules, the proton conductivity of the compound increased to 2.25 × 10−3 S cm−1 at 80 °C and 98% RH which is about 110 times that of the original material. It is hoped that this work can provide essential insight for designing and obtaining improved crystalline-state proton conducting materials by considering the influences of guest molecules on proton conduction properties of porous materials. [ABSTRACT FROM AUTHOR]

The electronic structure of hexasilaprismane (HSP) was examined with different computational techniques to elucidate the bonding features and the electrostatic surface potential of HSP. The carbon dioxide adsorption and separation capacities of metal-ion-decorated hexasilaprismane (HSP) were examined with DFT and CBS-QB3. Furthermore, the 1,2,3,4,5,6-hexaphenylprismasilane (HPPS) molecule was examined for its binding with metal ions and gas adsorption capacity. The Mg2+ ion complexed HPPS molecule adsorbs 15CO2 molecules with an average binding free energy of −0.98 eV per molecule. The calculated gravimetric densities of 45.1 and 48.4 wt% show that these systems can be employed for CO2 capture. The substantial difference in the affinity of the designed systems for CO2 gas molecules compared to N2 and CH4 molecules show the potential of the systems for CO2 separation from N2 and CH4 gas molecules. [ABSTRACT FROM AUTHOR]

We synthesised and characterised the racemic and chiral versions of two Zn salan fluorine-based complexes from commercially available materials. The complexes are susceptible to absorbing H2O from the atmosphere. In solution (DMSO–H2O) and at the millimolar level, experimental and theoretical studies identify that these complexes exist in a dimeric-monomeric equilibrium. We also investigated their ability to sense amines via19F NMR. In CDCl3 or d6-DMSO, strongly coordinating molecules (H2O or DMSO) are the limiting factor in using these easy-to-make complexes as chemosensory platforms since their exchange with analytes requires an extreme excess of the latter. [ABSTRACT FROM AUTHOR]

Reversible photoswitching molecules have been developed as promising candidates for building effective molecular motors. In aqueous medium many of such photoswitching molecules become either insoluble or stable in a particular state to abolish their reversible nature. Hence, it is a challenging task to explore the chemistry of such photochromic molecules in aqueous medium. This Frontier article discusses the recent developments in understanding the behaviour of photoswitching molecules in the confined nanospace of aqueous molecular vessels. [ABSTRACT FROM AUTHOR]

We have prepared new argentivorous molecules (L2 and L3) having different linker lengths between cyclen and anthracene units. The structures of Ag+ complexes with the new ligands were investigated in solution and solid states. The silver(I) ion-induced 1H NMR and UV-vis spectral changes of L2 and L3 showed the presence of 1 : 1 complexes. The solid-state structures of the Ag+ complexes with L2 and L3 are stable 1 : 1 complexes because four aromatic side-arms wrap the Ag+ incorporated in the cyclen unit. A photo-induced electron transfer (PET) effect that depends on the length of the linker connecting the nitrogen atoms of cyclen to the chromophore is also investigated. The result indicates a linear (log) correlation between the donor–chromophore average distances of the optimized structures calculated by DFT calculations and fluorescence intensities (log I), and the PET effect becomes ineffective at about 12 Å in this system. [ABSTRACT FROM AUTHOR]

Reactions of the known amidinate stabilised 1,2-disilylene, [{ArC(NDip)2}Si]21 (Dip = 2,6-diisopropylphenyl, Ar = 4-C6H4But) with a series of inert, unsaturated small molecule substrates have been carried out. Compound 1 reduces ButNC: to give the singlet biradicaloid 1,3-disilacyclobutanediyl [{ArC(NDip)2}Si(μ-CNBut)]23, which can be oxidised by 1,2-dibromoethane to give [{ArC(NDip)2}(Br)Si(μ-CNBut)]24. Disilylene 1 reduces two molecules of ethylene to give an unprecedented disilabicyclo[2.2.0]hexane, [{ArC(NDip)2}Si(μ-C2H4)]25. In contrast, only one molecule of ethylene inserts in the Ge–Ge bond of the digermylene analogue of 1, viz. [{ArC(NDip)2}Ge]26, leading to the formation of the bis(germylene), [{ArC(NDip)2}Ge]2(μ-C2H4) 7. Compound 1 reduces CO2, generating CO, and the oxo/carbonate-bridged disilicon(IV) system, {ArC(NDip)2}Si(μ-CO3)2(μ-O)Si{(NDip)2CAr} 10, while its reaction with N2O proceeds via generation of N2, and a hydrogen abstraction process, to give the oxo/hydroxy disilicon(IV) species, [{ArC(NDip)2}(HO)Si(μ-O)]211. This study highlights new small molecule activation chemistry for 1,2-disilylenes, which could lead to further adoption of compound 1 as a potent reducing reagent for the transformation of inert unsaturated molecules into value added products. [ABSTRACT FROM AUTHOR]

In this work we show the use of high-resolution 1H MAS NMR to distinguish between two kinds of aggregation states of (1R,2S)-ephedrine, a chiral organic structure directing agent, occluded within AFI-type microporous aluminophosphates. We investigate in particular the supramolecular assembly of the molecules through π⋯π type interactions of their aromatic rings when confined within the one-dimensional AFI channels. A series of high-resolution two-dimensional spin diffusion spectra combined with molecular simulations and DFT calculations allowed us to distinguish different aggregation states of ephedrine molecules and precisely estimate the distances between the aromatic rings and their closest protons inside the zeolite channels as a consequence of distinct proton spin diffusion profiles. [ABSTRACT FROM AUTHOR]

Three novel fluorescent Zn(II) frameworks, namely [Zn(DPA)(NDA)]2·2DMF (1), [Zn2(DPA)(OBA)2]·2DMF·4H2O (2) and [Zn(DPA)(HNTB)]·H2O (3) (DPA = 2,5-di(pyridin-4-yl)aniline, H2NDA = 1,4-naphthalenedicarboxylic acid, H2OBA = 4,4′-oxydibenzoic acid, H3NTB = 4,4′,4′′-nitrilotribenzoic acid, DMF = N,N-dimethylformamide), were successfully fabricated and structurally characterized. Due to the variety of organic linkers, 1–3 exhibit varied topologies: 1 is a 4-c three-dimensional (3D) framework with {65·8} topology, 2 is a 6-c 3D net with point symbol of {44·610·8}, and 3 is a 4-c two-dimensional network that further stacks into a 3D structure by hydrogen bonding interactions with {44·62} topology. Experiments related to fluorescence show that 1–3 can be utilized to quickly identify specific anions of CrO42−/Cr2O72−, and organic molecules such as 2,4,6-trinitrophenol and benzaldehyde. [ABSTRACT FROM AUTHOR]

Bis-silylenes do not only act as strong chelating σ-donor ligands, but also exhibit cooperative behaviour in the activation of small molecules. Three different P–Si containing molecules were prepared from the reaction between tBuC≡P and different bis-silylenes, which are bridged by ferrocenediyl, diaminobenzene, or o-carborane. [ABSTRACT FROM AUTHOR]

Carbon monoxide, the "silent killer" gas, is increasingly recognised as an important signalling molecule in human physiology, which has beneficial biological properties. A particular way of achieving controlled CO administration is based on the use of biocompatible molecules that only release CO when triggered by internal or external factors. These approaches include the development of pharmacologically effective prodrugs known as CO releasing molecules (CORMs), which can supply biological systems with CO in well-regulated doses. An overview of transition metal-based CORMs with cytotoxic properties is here reported. The mechanisms at the basis of the biological activities of these molecules and their potential therapeutical applications with respect to their stability and CO releasing properties have been discussed. The activation of metal-based CORMs is determined by the type of metal and by the nature and features of the auxiliary ligands, which affect the metal core electronic density and therefore the prodrug resistance towards oxidation and CO release ability. A major role in regulating the cytotoxic properties of these CORMs is played by CO and/or CO-depleted species. However, several mysteries concerning the cytotoxicity of CORMs remain as intriguing questions for scientists. [ABSTRACT FROM AUTHOR]

A redox-active molecule is grafted on graphene oxide (GO) via successive reactions. In the first step, GO is modified with diamine, which acts as a linker for the redox-active molecule. In the second step, the redox-active molecule is attached to the amino group of the linker by amide bond formation. Through these processes GO is partially reduced, enhancing its electrochemical properties. The structure of the functionalized GO is characterized by XPS, TGA, FTIR, and CV, and applied for electrodes in supercapacitors (SCs). The distance and direction of the redox-active molecule on the electrode affect the SC performance; ethylene diamine is the most promising linker to efficiently transfer electrons from the redox-active molecule to the electrode surface. [ABSTRACT FROM AUTHOR]

A range of titanium compounds containing the naturally occurring dyes quinizarin (QH2) and alizarin (AH2) was synthesized and structurally characterized in the solid state. Among these is the first examples of a discrete metallocyclic arrangement formed exclusively using quinizarin ligands and the first examples of lanthanide containing titanium compounds of the alizarin family of ligands. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses various reports within the issue on topics including nitrogenase, Single-molecule magnet behavior, and mononuclear gold.

Three Mn-MOFs {[Mn3(μ4-L)2(H2O)7]·4H2O}n (1), {[Mn3(μ5-L)2(H2O)6]·4H2O}n (2) and {[Mn3(μ7-L)2(H2O)2]}n (3) (H3L = 5-(6-carboxypyridin-3-yl)isophthalic acid) were obtained under different reaction times and temperatures. Interestingly, induced by reaction time, compound 1 can lose one water molecule and SC–SC transform into compound 2. Similarly, compound 2 can also SC–SC transform into 3. Studies on two SC–SC transformation processes were carried out and the transformation mechanisms were deduced, which were verified by TG analyses. Different numbers of water molecules in the three compounds resulted in different coordination environments of the metal cation, coordination modes of the L3− ligand, continuities of hydrogen bonds, dimensions of framework and porosities. The AC impendence spectra studies revealed that compounds 1–3 can enhance the proton conductivities of the Nafion composite membrane to about 47.77%, 36.88% and 21.28%, respectively. It is speculated that the highest proton conductivity of compound 1 may be due to its continuous hydrogen bond chain and highest water uptake, which were mainly decided by the number of water molecules. [ABSTRACT FROM AUTHOR]

The hydrogenative conversions of the biobased platform molecules 4-hydroxycyclopent-2-enone and cyclopentane-1,3-dione to their corresponding 1,3-diols are established using a pre-activated Knölker-type iron catalyst. The catalyst exhibits a high selectivity for ketone reduction, and does not induce dehydration. Moreover, by using different substituents of the ligand, the cis–trans ratio of the products can be affected substantially. A decent compatibility of this catalytic system with various structurally related substrates is demonstrated. [ABSTRACT FROM AUTHOR]

Controlled bottom-up synthesis of amorphous coordination polymers with tailored metal coordination is a research field in its infancy. In this study, synthesis control was achieved to selectively prepare one-dimensional (1D) crystalline and amorphous zinc(II)-based coordination polymers and a dimeric molecular compound, all with similar coordination geometry as evidenced by X-ray diffraction and total scattering studies. The compounds were obtained by bottom up self-assembly of Zn(II) with terephthalate (tph2−) as linker and the enantiopure chelating ligand S-(1,2)-bis(1H-benzimidazol-2-yl)ethanol (L). The solvent and the coordination ability of the precursor zinc salt anion control the crystalline products formed by slow diffusion at room temperature: perchlorate allows isolation of the phase pure crystalline 1D polymer {[Zn(tph)(L)]·H2O·3DMF}n (1·H2O·3DMF, DMF = N,N-dimethylformamide). In contrast, zinc chloride leads to the formation of either a mixture of polymeric 1·H2O·3DMF and a dimeric molecular species [Zn2Cl2(tph)(L)2]·4DMF (2·4DMF), or to the phase pure dimer 2·4DMF, depending on the Zn(II) : tphH2 stoichiometry. A modified synthesis using zinc nitrate and fast precipitation by base addition results in an amorphous analogue of the 1D polymer (3). Chains of 1·H2O·3DMF pack into a non-porous crystalline material with a surface area of just 6 m2 g−1, while the outer surface area of amorphous polymer 3 is a factor of eight larger. Hence, the amorphous compound provides larger metal site accessibility for potential surface chemical reactions, while maintaining the coordination geometry of the metal sites. The temperature response of crystalline polymer 1·H2O·3DMF was studied using multi-temperature single crystal X-ray diffraction (100–300 K). The a = b axes display normal positive thermal expansion, while the c axis remains constant with increasing temperature due to partial relaxation of the terephthalate linkers and slightly changed geometry within the individual polymer chains. [ABSTRACT FROM AUTHOR]

In this work, we introduce the first enantiopure bistriazolate-based metal–organic framework, CFA-18 (Coordination Framework Augsburg-18), built from the R-enantiomer of 7,7,7′,7′-tetramethyl-6,6′,7,7′-tetrahydro-3H,3′H-5,5′-spirobi[indeno[5,6-d]-[1,2,3]triazole] (H2-spirta). The enantiopurity and absolute configuration of the new linker were confirmed by several chiroselective methods. Reacting H2-spirta in hot N,N-dimethylformamide (DMF) with manganese(II) chloride gave CFA-18 as colorless crystals. The crystal structure with the composition [Mn2Cl2(spirta)(DMF)2] was solved using synchrotron single-crystal X-ray diffraction. CFA-18 shows a framework topology that is closely related to previously reported metal–azolate framework (MAF) structures in which the octahedrally coordinated manganese(II) ions are triazolate moieties, and the chloride anions form crosslinked one-dimensional helical chains, giving rise to hexagonal channels. In contrast to MAFs crystallizing in the centrosymmetric space group R3¯, the handedness of the helices found in CFA-18 is strictly uniform, leading to a homochiral framework that crystallizes in the trigonal crystal system within the chiral space group P3121 (no. 152). [ABSTRACT FROM AUTHOR]

Triferrocenyl-substituted 1,3,5-triphenylbenzene was successfully synthesized in high yield. Single-crystal X-ray diffraction experiments revealed that the internal rotations of the ferrocenyl moieties are significantly restricted in the solid phase and that there are no significant π stacking interactions therein. The photoluminescence of the crystals is essentially the same as that of dilute chloroform solutions. However, studies of this cyan-light emitting substance in mixtures of chloroform and methanol revealed the aggregation-induced enhanced emission (AIEE) feature that boosts its fluorescence quantum yield from 13% up to 74%. We demonstrate the AIEE effect for a new class of easy-to-prepare aromatic molecules containing several metallocene units for the first time. [ABSTRACT FROM AUTHOR]

Recent advances in the practical applications of metallophthalocyanines (MPcs) in different technological fields have stimulated us to design and synthesize a new asymmetric AB3-type trimeric zinc(II)-phthalocyanine (1). This bulky and high molecular weight compound was characterized by elemental analysis, 1H, 13C DEPT, and 1H-1H NOESY NMR, HR MALDI-TOF mass spectrometry, UV-vis, and FT-IR (ATR) techniques. In-depth electrochemical studies show that 1 displays quasi-reversible three one-electron reductions and two one- or two-electron oxidation processes, rather than any redox processes including the transfer of three-electrons in one-step. Besides this, in situ spectroelectrochemical measurements suggest the good application potential of 1 as an electrochromic material in display technologies. A study of the nonlinear optical properties (NLOs) of 1 reveals that the poly(methylmethacrylate) (PMMA) composite film displays a much larger nonlinear absorption coefficient and a lower saturable absorption threshold for optical limiting when compared to the same Pc molecules in solution. Ultrafast transient absorption measurements reveal the intersystem crossing mechanism. Density functional theory (DFT) was used for the geometry optimizations and time dependent-DFT (TD-DFT) for HOMO/LUMO energies and electronic transitions for 1. [ABSTRACT FROM AUTHOR]

Single ion magnets have long been considered good prospective candidates to record a bit of information. One of the smallest known single ion magnets is CoBr2(pyridine)2. This molecular compound exhibits slow relaxation of magnetization mainly due to the thermally activated Orbach process, [A. M. Majcher et al., Chem. Sci., 2018, 9, 7277–7286]. However, the total relaxation time is dramatically shortened at low temperatures due to the direct, Raman, and quantum tunneling of magnetization processes. At low temperatures, the distribution of the probability of the possible relaxation pathways in this case favours QTM and the direct process over the Orbach process. To prolong the relaxation time, the compound was diluted with diamagnetic ZnII, producing 5 analogues of the general formula: CoxZn1−xBr2(pyridine)2 (x = 0.91, 0.67, 0.43, 0.24, and 0.06), confirmed to be a solid solution by independent experimental techniques (powder X-ray diffraction, infrared spectroscopy). The presence of diamagnetic ZnII ions changes the distribution of the dipolar interactions between the CoII centres in the material, which results in a monotonous change in the relaxation times, which in turn become longer with increasing dilutions, which is explained by the diminishing QTM contribution. The appearance of multiple relaxation processes is also observed for higher x, which is explained as the creation of multiple, separate frequency domains, as a result of the competition between QTM and the direct process contributions. We present a thorough, systematic study of magnetic dilution, which will hopefully be useful to estimate optimal dilutions in similar solid solutions. [ABSTRACT FROM AUTHOR]

Single-molecule magnets (SMMs) with higher nuclearity provide opportunity for understanding the inherent nature of magnetic dynamics that are not limited to mononuclear SMMs. Herein, centrosymmetric [Dy2(L)2(9-AC)4(MeOH)2]·2CH2Cl2·2H2O (1, where 9-AC = anthracene-9-carboxylate) and equilateral triangular [Dy3(OH)(OMe)(L)3(dbm)3](OH)·3CH2Cl2·7H2O (2, where dbm = dibenzoylmethane anion) were isolated using the Schiff-base ligand 4-(anthracen-9-yl)-2-((quinolin-8-ylimino)methyl)phenol (HL). Static and dynamic magnetic measurements reveal that 1 and 2 display slow magnetic relaxation under zero and applied dc field, respectively. The magnetization relaxation for 1 is dominated by a Raman process due to its non-negligible transverse anisotropy. Complex 2 exhibits field-induced SMM behavior with a reversal barrier of 56 cm−1. By means of ab initio calculations and magnetic measurements, the multiple relaxation regime in 2 was investigated. We suggest that Orbach and Raman mechanisms dominate in the high/low temperature domains, respectively. [ABSTRACT FROM AUTHOR]

The combination of chemotherapeutic and photodynamic activities in an iridium-based molecular compound is less reported. Herein, two iridium complexes (IrC1 and IrC2) with β-carboline alkaloid ligands were designed and synthesized. Both complexes exhibited high anticancer activities with IC50 values of around 1 μM in the dark against several cell lines tested. Notably, the cytotoxicity of these two complexes against lung cancer (A549) cells increased significantly under light (425 nm) irradiation, with phototoxicity index (PI) values of 120 and 93, respectively. They were specifically enriched in the mitochondria. Cell-based assays demonstrated that IrC1 induced an increase in intracellular reactive oxygen species (ROS) levels, reduction in ATP production, mitochondrial DNA damage, an increase in lipid peroxidation levels, and proteasomal activity inhibition. Under light conditions (in some cases a two-photon laser was also applied), these effects were greatly enhanced. Overall, we have demonstrated that these iridium complexes have dual activities of chemotherapy and photodynamic therapy, which may help to design new metal-based anticancer agents for combined chemo-photodynamic therapy. [ABSTRACT FROM AUTHOR]

The "butterfly" molecule [Fe3Y(μ3-O)2(CCl3COO)8(H2O)(THF)3] (in brief {Fe3YO2}) includes three Fe3+ ions which build a robust Fe3 cluster with a strong intracluster antiferromagnetic exchange and a total spin S = 5/2. It represents the starting magnetic system to study further interactions with magnetic rare earths when Y is replaced with lanthanides. We present heat capacity and equilibrium susceptibility measurements below 2 K, which show that each cluster has a sizeable magnetic anisotropy pointing to the existence of intercluster interactions. However, no phase transition to a long-range magnetically ordered phase is observed down to 20 mK. The intercluster interaction is analysed in the framework of the one-dimensional Blume–Capel model with an antiferromagnetic chain interaction constant J/kB = −40(2) mK between Fe3 cluster spins, and a uniaxial anisotropy with parameter D/kB = −0.56(3) K. This is associated to single chains of Fe3 clusters oriented along the shortest intercluster distances displayed by the crystal structure of {Fe3YO2}. Ac susceptibility measurements reveal that the magnetic relaxation is dominated by a quantum tunnelling process below 0.2 K, and by thermally activated processes above this temperature. The experimental activation energy of this single chain magnet, Ea/kB = 3.4(6) K, can be accounted for by the combination of contributions arising from single-molecule magnetic anisotropy and spin–spin correlations along the chains. [ABSTRACT FROM AUTHOR]

The confinement of small amounts of benzene in InOF-1 (Bz@InOF-1) shows a contradictory behavior in the capture of CO2 and SO2. While the capture of CO2 is increased 1.6 times, compared to the pristine material, the capture of SO2 shows a considerable decrease. To elucidate these behaviors, the interactions of CO2 and SO2 with Bz@InOF-1 were studied by DFT periodical calculations postulating a plausible explanation: (a) in the case of benzene and CO2, these molecules do not compete for the preferential adsorption sites within InOF-1, providing a cooperative CO2 capture enhancement and (b) benzene and SO2 strongly compete for these preferential adsorption sites inside the MOF material, reducing the total SO2 capture. [ABSTRACT FROM AUTHOR]

Hydroxyapatite [Ca10(PO4)6(OH)2, HAP] has P–OH Brønsted acidic sites, Ca2+ Lewis acidic sites, and OH− and O2− basic sites on which acidic and basic gas molecules can be selectively adsorbed, and has no micropore onto which various molecules adsorb regardless of the chemical properties of gas molecules. The interaction between the surface sites and acidic and basic gas and water molecules has been investigated by evaluating the adsorption properties of various molecules on the surfaces of calcium-deficient HAP. The specific adsorption sites were assessed by examining the reversible and irreversible adsorption of NH3, CO2, aldehydes, and water vapor on HAP at the temperature of 298 K, using two HAP samples with different Ca/P ratios, but similar structures and surface areas: Ca-deficient HAP with an extreme lower Ca/P ratio (named P-HAP) and one with a higher Ca/P ratio (named C-HAP). Irreversible adsorption of NH3 on C-HAP is attributed to the adsorption on both Ca2+ Lewis acidic and P–OH Brønsted acidic sites. Irreversible adsorption on P-HAP is attributed to the adsorption on P–OH Brønsted acidic sites only. Irreversible adsorption of CO2 occurred on C-HAP only, and preferentially on OH− basic sites. Acetaldehyde undergoes a catalytic reaction over both OH− basic sites and surface P–OH Brønsted acidic sites at 298 K. Water irreversible adsorption was extensively observed for P-HAP, and water was barely desorbed at low pressures. In situ powder X-ray diffraction showed an asymmetric expansion of the lattice in the [100] direction, indicating that water was incorporated into P-HAP crystals, especially on structural OH− sites. Irreversible adsorption of acidic and basic molecules was therefore less observed on P-HAP than on C-HAP, but P-HAP had considerable irreversible adsorption of water vapor with associated asymmetric lattice expansion. The incorporation of water vapor was first observed and could be useful to improve adsorption or catalytic performance with the mediation of water vapor and/or hydration. [ABSTRACT FROM AUTHOR]

Biotinylated pharmaceuticals are of great interest due to the strong interactions between biotinyl-functionality and streptavidin/avidin, which opens up avenues for efficient targeting and localisation. Three new carbon monoxide-releasing molecules (CO-RMs) have been synthesised and characterised using chemical and biological analysis. An alkyne-containing CO-RM 2 was found to be toxic to RAW 264.7 murine macrophages; and thus therapeutically viable CO-RM 1 was employed as the alkyne precursor for [3 + 2] cycloaddition chemistry enabling a new acid-containing CO-RM 4 and biotin-bioconugate-CO-RM (BiotinCORM 5) to be prepared. CO-RM 4 showed significantly improved solubility and BiotinCORM 5 acts as a photo-CO-RM. We have found that an avidin–CORM adduct of 5 is a CO-releasing protein, releasing CO on irradiation with light (400 nm). The avidin–biotinCORM adduct of 5 was found to have a binding energy of 10 kcal mol−1. [ABSTRACT FROM AUTHOR]

Four metal–organic frameworks employing the m-terphenyl diisophthalate linker molecule with 2′ substitution by P(V)-based functional groups of the central aryl have been synthesised. The dense packing of POMe2/PSMe2 functional groups within UHM-60/UHM-61 (UHM: University of Hamburg Materials) with an underlying net of ucp topology was overcome by increasing the sterical demand of phosphorus substituents. Replacement of the PEMe2 (E = O, S) functional groups by POEt2 or POPh2 gave UHM-62 and UHM-63, respectively, where valid deconstructions of the underlying topology to types 3,3,4,4T199, tim, and tst were found. The potential influence of the now-accessible phosphoryl functional group towards CO2 and CH4 adsorption as well as the selectivity towards CO2/CH4 separation was studied. Based on a comprehensive survey of literature-known Cu(II)-based MOFs with m-terphenyl-based linker molecules, we propose the deconstruction of inter-isophthalate plane angles to angular components of twist and fold allowing for the sophisticated classification of topologies that can be realised in Cu(II)-based MOFs using the m-terphenyl tetracarboxylate linker molecule. [ABSTRACT FROM AUTHOR]

Silicon-based moieties were anchored in heterometallic alkoxide platforms to obtain molecular clusters based on the M–O–M′–O–Si motif for the generation of mixed-metal silicate materials. Single-source molecular precursors with structures [M{(μ-ddbfo)2Al(OSiPh3)2}2], where dbbfoH = 2,3-dihydro-2,2-dimethylbenzofuran-7-ol and M = Ba (1), Sr (2), [Sr4Ti2(μ6-O)(μ3,η2-OCH2CH2OMe)8(η-OCH2CH2OMe)2(OSiPh3)4] (3), [Sr4M′2(μ4-OH)(μ3,η2-OCH2CH2OMe)4(μ,η2-OCH2CH2OMe)6(μ-X)(OSiPh3)4] (4, with M′ = Zr and X = Cl; 5 with M′ = Hf and X = OH), [Sr3Hf2(μ5-O)(μ3,η2-OCH2CH2OMe)4(OCH2CH2OMe)4(OSiPh3)4] (6), and [Ca2M′2(μ3-OH)2(μ,η2-OCH2CH2OMe)4(η2-HOCH2CH2OMe)2(η-OCH2CH2OMe)2(OSiPh3)4] for M′ = Zr (7), Hf (8), were prepared by substitution of methyl groups, using Ph3SiOH or chloride atoms with KOSiPh3, in [M{(μ-ddbfo)2AlMe2}2] (M = Sr, Ba) or [M4M′2(μ6-O)(μ3,η2-OCH2CH2OMe)8(OCH2CH2OMe)2(HOCH2CH2OMe)xCl4] (M = Ca, Sr, Ba, M′ = Ti, Zr, Hf and x = 0, 4). The precursors were characterized by elemental analysis, NMR spectroscopy, and single-crystal X-ray structural analysis. Thermal decomposition of compounds 1–8 at 1000 °C led to formation of ceramic materials that consisted of mixed-metal oxide nanocrystallites embedded in an amorphous SiO2 matrix. Compounds 1 and 2 decomposed to BaAl2Si2O8 and SrAl2Si2O8 aluminosilicates, 4 gave a mixture of SrSiO3, ZrO2, SrZrO3 and Sr7ZrSi6O21, 5 and 6 gave mixtures of various compounds, including SrHfO3, Hf0.96Si0.04O2, and SiO2, 7 lead to CaZrO3, ZrO2 and Ca3ZrSi2O9 and 8 gave a HfO2, Ca2HfSi4O12 and SiO2 phase. The thermolysis of compound 3 gave SiO2 particles of average size 40–90 nm, which contained spherical SrTiO3, SrSiO3 and Sr2TiSi2O8 nanocrystallites of diameter 5–16 nm. [ABSTRACT FROM AUTHOR]

Four diiron(ii) carbonyl complexes, [Fe2(μ-SR)3(CO)5X] (X− = Br−, I−; R = CH2CH3, CH2CH2CH3) were facilely synthesized by reacting [Fe(CO)4X2] with monothiolates. Their potential as carbon monoxide-releasing molecules (CORMs) was systematically investigated, revealing that their CO-releasing behaviour is highly solvent-dependent. Specifically, in dimethyl sulfoxide (DMSO), the CO-releasing kinetics were fast. Intermediates with a lower oxidation state might be involved in the reaction. By contrast, in less polar solvents such as methanol, acetonitrile and dichloromethane, intermediates featuring the triiron carbonyl cation, [Fe3(μ-SCH2CH3)6(CO)6]+, were isolated. The triiron intermediate underwent further decomposition to liberate CO. One of the iodo complexes was also examined for its CO-release in PBS solution when solubilised with DMSO in the presence of deoxy-Mb and the CO-release was found to be quantitative. Furthermore, kinetic analyses were performed and the CO-release in general obeyed a first-order kinetic model. Plausible CO-releasing pathways are proposed for the parent complexes and the triiron intermediate. Assessments in cytotoxicity indicated that the cytoxicity of the diiron(ii) complexes varied with both the halide and thiolate and those bearing bromide and the thiolate with longer chains were more biocompatible. [ABSTRACT FROM AUTHOR]

Pursuing the structural planarization of energetic materials is an efficient method for achieving improved performance. Although many planar energetic molecules have been prepared so far, the innovation of advanced planar explosives still relies on the scientific intuition, experience and trial-and-error of researchers. Now, a triazole-induced planarization strategy is proposed based on the regulation of aromaticity, charge distribution, and hydrogen bonds. The incorporation of a triazole ring into the non-planar molecule 5-amino-1-nitriminotetrazole (VII) results in a planar energetic material named N-[5-amino-1-(1H-tetrazol-5-yl)-1H-1,2,4-triazol-3-yl]nitramide (3). Compared with VII (Td = 85 °C; IS < 0.25 J; FS < 5 N), 3 shows remarkably improved thermal stability (Td = 145 °C) and reduced sensitivities (IS = 20 J; FS > 360 N). The variation of thermal stability and mechanical sensitivity from VII to 3 reflects the effectiveness and superiority of the planarization strategy. Benefiting from the properties of 3, its energetic salt 5 exhibits excellent overall performance (Dv = 9342 m s−1; P = 31.6 GPa; Td = 201 °C; IS = 20 J; FS = 360 N), which is comparable to that of HMX. Moreover, the triazole-induced planarization strategy may serve as a guide for exploring advanced energetic materials. [ABSTRACT FROM AUTHOR]

The N-Heterocyclic Carbene (NHC) alane and gallane adducts (NHC)·Cp*AlH2 (NHC = Me2ImMe5, iPr2ImMe6, Dipp2Im 7) and (NHC)·Cp*GaH2 (NHC = Me2ImMe8, iPr2ImMe9, Dipp2Im 10; R2Im = 1,3-di-organyl-imidazolin-2-ylidene; Dipp = 2,6 diisopropylphenyl; Me2ImMe = 1,3,4,5-tetra-methyl-imidazolin-2-ylidene; Cp* = C5Me5) were prepared either via the reaction of (AlH2Cp*)31 with the NHC or by the treatment of (NHC)·GaH2I (NHC = Me2ImMe2, iPr2ImMe3, Dipp2Im 4) with KCp*. The reaction of (AlH2Cp*)31 with the backbone saturated NHC Dipp2ImH led to NHC ring expansion instead with the formation of (RER-Dipp2ImHH2)AlCp* 12. Heating solutions of the gallium compounds 8–10 triggered reductive elimination of Cp*H and afforded Cp*GaI16. The reaction of the alane adduct (Me2ImMe)·Cp*AlH25 with cAACMe led to the insertion of cAACMe into the Al–H bond with the formation of the compound rac-(Me2ImMe)·AlHCp*(cAACMeH) rac -14. Heating a solution of rac -14 led to irreversible isomerisation with the formation of (Me2ImMe)·AlHCp*(cAACMeH) meso- 14. The alane adducts (iPr2ImMe)·Cp*AlH26 and (Dipp2Im)·Cp*AlH27 react with cAACMe with the release of the NHC and formation of the exceptionally stable oxidative addition product (cAACMeH)AlHCp* 15. Reactions of the gallane adducts 8–10 with cAACMe led to reductive elimination of cAACMe–H2 and the formation of Cp*GaI16. [ABSTRACT FROM AUTHOR]

An olefin-containing pyridinium derivative, 1-(4-carboxybenzyl)-4-[2-(4-pyridyl)-vinyl]-pyridinium chloride (HBCbpeCl) has been introduced into a novel 2D metal–organic framework with rare right- and left-handed spiral nanotubular channels arranged alternately in the structure. The 1D channel is modified by positively-charged pyridinium segments, which shows high affinities to Lewis basic molecules such as methanol, ethanol, and water vapor. Additionally, the BCbpe molecules in the structure have been directed through cation–π interactions to be aligned antiparallel to each other with the C=C double bond arranged properly for [2 + 2] photocycloaddition, which can be triggered to undergo structural transformation from 2D to 3D. This post-cycloaddition modification strategy has been used to separate alcohols and water, which includes a successful adjustment of large tailor-made channels by the [2 + 2] cycloaddition reaction. The gas-chromatographic separation experiments show that ethanol can be better separated from water through a column filled with a post-cycloaddition modified sample than the as-synthesized one. [ABSTRACT FROM AUTHOR]

Five examples of α,α′-bis(arylimino)-2,3:5,6-bis(pentamethylene)pyridyl-chromium(iii) chlorides (aryl = 2,6-Me2Ph Cr1, 2,6-Et2Ph Cr2, 2,6-i-Pr2Ph Cr3, 2,4,6-Me3Ph Cr4, 2,6-Et2-4-MePh Cr5) have been synthesized by the one-pot template reaction of α,α′-dioxo-2,3:5,6-bis(pentamethylene)pyridine, CrCl3·6H2O and the corresponding aniline. The molecular structures of Cr1 and Cr4 reveal distorted octahedral geometries with the N,N,N-ligand adopting a mer-configuration. On activation with an aluminium alkyl co-catalyst, Cr1–Cr5 exhibited high catalytic activities in ethylene polymerization and showed outstanding thermal stability operating effectively at 80 °C with activities up to 1.49 × 107 g of PE (mol of Cr)−1 h−1. Significantly, the nature of the co-catalyst employed had a dramatic effect on the molecular weight of the polymeric material obtained. For example, using diethylaluminium chloride (Et2AlCl) in combination with Cr4 gave high density/high molecular weight polyethylene with broad molecular weight distributions (30.9–39.3). By contrast, using modified methylaluminoxane (MMAO), strictly linear polyethylene waxes of lower molecular weight and narrow molecular weight distribution (1.6–2.0) were obtained with vinyl end-groups. [ABSTRACT FROM AUTHOR]

The new aminoalcohol phenol 2,4-di-tert-butyl-6-(((2-hydroxy-2-phenylethyl)amino)methyl)phenol (H2L) was prepared by a facile solvent-free synthesis and used as a tridentate ligand for new cis-dioxomolybdenum(vi)(L) complexes. In the presence of a coordinating solvent (DMSO, MeOH, pyridine), the complexes crystallise as monomeric solvent adducts while in the absence of such molecules, a trimer with asymmetric Mo=O→Mo bridges crystallises. The complexes can catalyse epoxidation of cis-cyclooctene and sulfoxidation of methyl-p-tolylsulfide, using tert-butyl hydroperoxide as oxidant. [ABSTRACT FROM AUTHOR]

In this article, we investigate a single molecule magnet bis(phthalocyaninato)terbium(iii) (TbPc2) molecule film by using low temperature STM. In order to investigate the effect of molecule–substrate interaction on the electronic and spin properties of the adsorbed molecule, we tune the molecule–substrate coupling by switching the substrate between Au(111) and Ag(111), the latter of which provides stronger interaction with the molecule than the former. Despite the enhanced chemical reactivity of the Ag(111) surface compared with Au(111), a well-organized pseudo-square film is formed. In addition, a checker-board type contrast variation is identified, which is well explained by the existence of two types of molecules whose rotational angle between the top and bottom Pc is ϑ = 45° (bright molecule) and ϑ = 30° (dark molecule). The expected stronger molecule–substrate interaction, however, appears as an intriguing dI/dV mapping image which reveals the spatial distribution of the density of states (DOS). We identify the contrast reversal in the dI/dV mapping for the molecules of ϑ = 45° and ϑ = 30° at the sample voltages of V = 0.7 eV and 1.1 eV. Combined with the density functional theory (DFT) calculation, we attribute this change to the shift of an electronic state due to the rotation of the mutual angle between the top and bottom Pc. For the spin behavior, we previously observed a Kondo resonance for the TbPc2 molecule adsorbed on the Au(111) surface. On the Ag(111) surface, the Kondo resonance is hardly observed, which is due to the annihilation of the π radical spin by the charge transfer from the substrate to the molecule. Instead we observe a Kondo peak for the molecule on the second layer, for which the spin recovers due to the reduction of the coupling with the substrate. In addition, when a magnetic field of 2 T normal to the surface is applied, the second layer molecule shows a sharp dip at the Fermi level. We attribute this to the inelastic tunneling feature caused by the spin flipping. This feature is not observed for the TbPc2/Au(111) system, suggesting that the decoupling between the TbPc2 molecule and Ag(111) by the presence of the first layer produces an inelastic feature in the tunneling spectra. [ABSTRACT FROM AUTHOR]

The uranium metallacyclopropene (η5-C5Me5)2U[η2-C2(SiMe3)2] (1) reacts with various small unsaturated organic molecules. For example, replacement of bis(trimethylsilyl)acetylene occurs when complex 1 is exposed to alkynes, conjugated alkenes, nitriles and quinones. Reaction of 1 with internal phenyl(alkyl)acetylene PhC≡CMe selectively yields the Cs symmetric uranium metallacyclopentadiene (η5-C5Me5)2U[η2-C(Ph)=C(Me)–C(Ph)=C(Me)] (6) after the loss of bis(trimethylsilyl)acetylene, while treatment of 1 with phenyl(silyl)acetylenes (PhC≡CR, R = SiHMe2, SiMe3) gives the corresponding C2v symmetric isomers (η5-C5Me5)2U[η2-C(R)=C(Ph)–C(Ph)=C(R)] (R = SiHMe2 (7), SiMe3 (8)). Furthermore, while no deprotonation occurs between complex 1 and pyridine derivatives, cyclohexanone can be inserted into the uranium metallacyclopropene moiety of 1 to yield the five-membered, heterocyclic complex (η5-C5Me5)2U[OC(CH2)5(C2(SiMe3)2)] (14) in quantitative conversion. Density functional theory (DFT) studies have been performed to complement the experimental studies. [ABSTRACT FROM AUTHOR]

An anionic zeolite-like metal–organic framework (AZMOF) with a twisted partially augmented the net, known as the “Moravia” net, [(CH3)2NH2]6[Sr13(O)3(BTTC)8(OH)2(H2O)16]·xS (Sr-BTTC, where S represents non-coordinated solvent molecules, and BTTC is the abbreviation of benzo-(1,2;3,4;5,6)-tris-(thiophene-2′-carboxylic acid)), has been solvothermally synthesized and characterized, which possesses an anionic framework and nano-sized sodalite cage. Through cation-exchange, Sr-BTTC is capable of uptaking large organic cationic dyes including Rhodamine B (RB), Basic Red 2 (BR2), Crystal Violet (CV) and Methylene Blue (MB), amongst which the adsorption capability for RB (up to 545 mg g−1), and BR2 (up to 675 mg g−1) is the highest for reported absorbants to date. [ABSTRACT FROM AUTHOR]

Four novel mononuclear Schiff base copper(ii) complexes, namely, [Cu(L)(OAc)]·H2O (1), [Cu(HL)(C2O4)(EtOH)]·EtOH (2), [Cu(L)(Bza)] (3) and [Cu(L)(Sal)] (4) (HL = 1-(((2-((2-hydroxypropyl)amino)ethyl)imino)methyl)naphthalene-2-ol), Bza = benzoic acid, Sal = salicylic acid), were synthesized and characterized by X-ray crystallography, elemental analysis and infrared spectroscopy. Single-crystal diffraction analysis revealed that all the complexes were mononuclear molecules, in which the Schiff base ligand exhibited different coordination modes and conformations. The N–H…O and O–H…O inter- and intramolecular hydrogen bonding interactions linked these molecules into multidimensional networks. Their interactions with calf thymus DNA (CT-DNA) were investigated by UV-visible and fluorescence spectrometry, as well as by viscosity measurements. The magnitude of the Kapp values of the four complexes was 105, indicating a moderate intercalative binding mode between the complexes and DNA. Electrophoresis results showed that all these complexes induced double strand breaks of pUC19 plasmid DNA in the presence of H2O2 through an oxidative pathway. In addition, the fluorescence spectrum of human serum albumin (HSA) with the complexes suggested that the quenching mechanism of HSA by the complexes was a static process. Moreover, the antiproliferative activity of the four complexes against HeLa (human cervical carcinoma) and HepG-2 (human liver hepatocellular carcinoma) cells evaluated by colorimetric cell proliferation assay and clonogenic assay revealed that all four complexes had improved cytotoxicity against cancer cells. Inspiringly, complex 4, with salicylic acid as the auxiliary ligand, displayed a stronger anticancer activity, suggesting that a synergistic effect of the Schiff base complex and the nonsteroidal anti-inflammatory drug may be involved in the cell killing process. The biological features of mixed-ligand copper(ii) Schiff base complexes and how acetic auxiliary ligands manipulate these features are also discussed. [ABSTRACT FROM AUTHOR]

Two bis-μ-phenoxido–bis-μ-acetato heterobimetallic {CoIIIDyIII} complexes 1 and 2, formulated as [CoIIIDyIIIL(μ-OAc)2(NO3)2] derived from the comparable hexadentate Schiff bases N,N′-ethylenebis(3-ethoxysalicylaldimine) and N,N′-ethylenebis(3-methoxysalicylaldimine) were synthesized and X-ray structure analysis confirms their nearly identical structures. These are the first examples of bis(μ-phenoxido)–bis(μ-carboxylato) {CoIIIDyIII} systems. The AC susceptibility measurements show that both complexes exhibit a field-induced slow magnetic relaxation with two relaxation branches. While the high-frequency process spans the usual range of the relaxation time for analogous single molecule magnets (τ0∼ 10−7 s), the low-frequency branch is as slow as τ∼ 0.1 s at T = 1.9 K and B = 0.2 T. [ABSTRACT FROM AUTHOR]

By doping an Al12N12 nanocage with superalkali Li3O, a series of Li3O@Al12N12 compounds were theoretically designed and investigated for the first time. Computational results reveal that these species contain diffuse excess electrons, and thus can be regarded as inorganic electrides of a new type. As expected, these proposed electrides possess considerable first hyperpolarizabilities (β0) up to 1.86 × 107 au. In particular, the lowest-energy Li3O@Al12N12 exhibits high stability and excellent deep-ultraviolet transparency. Moreover, the effects of superalkali and nanocage subunits on the NLO responses of M3O@Al12N12 (M = Li, Na, K) and Li3O@X12Y12 (X = B, Al; Y = N, P) are systemically investigated. Results show that the respective substitution of Na3O and B12P12 for Li3O and Al12N12 can bring a larger β0 for such electrides. This study may be significant in terms of providing an effective strategy to design thermally stable inorganic electrides as potential high-performance NLO molecules. [ABSTRACT FROM AUTHOR]