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Morpholine motifs have been used extensively as targeting moieties for lysosomes, primarily in fluorescence imaging agents. Traditionally these imaging agents are based on organic molecules which have several shortcomings including small Stokes shifts, short emission lifetimes, and susceptibility to photobleaching. To explore alternative lysosome targeting imaging agents we have used a rhenium based phosphorescent platform which has been previously demonstrated to have an improved Stokes shift, a long lifetime emission, and is highly photostable. Rhenium complexes containing morpholine substituted ligands were designed to accumulate in acidic compartments. Two of the three complexes prepared exhibited bright emission in cells, when incubated at low concentrations (20 μM) and were non-toxic at concentrations as high as 100 μM, making them suitable for live cell imaging. We show that the rhenium complexes are amenable to chemical modification and that the morpholine targeted derivatives can be used for live cell confocal fluorescence imaging of endosomes–lysosomes. [ABSTRACT FROM AUTHOR]

Functionalising organic molecular photoswitches with metal complexes has been shown to alter and enhance their switching states. These organometallic photoswitches provide a promising basis for novel smart molecular materials and molecular electronic devices. We have detailed the synthesis and characterisation of mono- and bimetallic half-sandwich ruthenium and iron complexes functionalised with alkynyl dihydropyrenes (DHP). Their electronic and photophysical properties were determined by the use of chemical, electrochemical and spectroelectrochemical techniques. The introduction of the metal alkynyl moiety allows access to additional redox and protonation states not accessible by the DHP alone. An additional metal alkynyl moiety inhibits observable photochromic switching. Analysis of the NIR and IR bands in the mixed valence complexes suggests there is a high degree of charge delocalisation across the DHP. [ABSTRACT FROM AUTHOR]

Single‐crystal X‐ray diffraction studies for a variety of metal ion complexes of functionalised sarcophagines (sarcophagine=sar=3,6,10,13,16,19‐hexa‐azabicyclo[6.6.6]icosane) have further confirmed not only that the form of the metal ion/sar unit is unique for each metal, albeit with a sensitivity of the conformation to the associated counter anions, but also that for any given metal and ligand substituent, the dimensions (bond lengths and angles) of the complex and the substituent at the secondary nitrogen centres do not differ significantly from those of the isolated components. Despite this, where the substituent contains reactive sites, the reactivity differs markedly from that of their form in an uncoordinated substrate. Rationalisations are offered for these differences, in part through the use of Hirshfeld surface analysis of the intermolecular interactions. The kinetic inertness of the complexes means that the metal ions can be considered to act as regioselective protecting groups. [ABSTRACT FROM AUTHOR]

The crystal structure of tetra-n-butylammonium perchlorate has been successfully elucidated using single-crystal X-ray diffraction. The compound crystallizes in the triclinic space group P 1 ¯ with unit cell of dimensions a = 14.2706(7) Å, b = 20.6904(9) Å, c = 39.970(2) Å, α = 89.316(4)°, β = 88.638(4)°, and γ = 87.801(4)°. Although complicated by partial disorder, the structure has remarkable features where columns of some of the perchlorate anions running down [100] lie within what can be regarded as nanotubular entities formed by some of the tetrabutylammonium cations, while the remaining tetrabutylammonium cations lie in parallel columns surrounded by the remaining perchlorate anions, one entity being essentially the inverse of the other. Interactions within the structure have been characterized using Hirshfeld surface analysis and comparisons drawn with other unsolvated salts of the cation. [ABSTRACT FROM AUTHOR]

The modification of conjugated organic compounds with organometallic moieties allows the modulation of the electronic and optoelectronic properties of such compounds and lends them to a variety of material applications. The organometallic complexes [M(Cp′)(L) n ] (M = Ru or Fe; Cp′ = cyclopentadiene (Cp) or pentamethylcyclopentadiene (Cp*); (L) n = (PPh3)2 or 1,2-bi(diphenylphosphino)ethane (dppe)) and [M(L) n ] (M = Ru; (L) n = (dppe)2 or (P(OEt)3)4; or M = Pt; (L) n = (PEt3)2, (PPh3)2 or tricyclohexylphosphine, (PCy3)2) modified with a 5-ethynyl-1,3,3-trimethyl-3 H -indole ligand were prepared and characterised by NMR spectroscopy, IR and single-crystal X-ray diffraction. Cyclic voltammetry and IR spectroelectrochemistry of the ruthenium systems showed a single-electron oxidation localised over the M–C≡C–aryl moiety. The N-heteroatom of the indole ligand showed Lewis base properties and was able to extract a proton from a vinylidene intermediate as well as coordinate to CuI. Examples from the wire-like compounds were also studied by single-molecule break junction experiments but molecular junction formation was not observed. This is most likely attributable to the binding characteristics of the substituted terminal indole groups used here to the gold contacts. A series of organometallic σ-alkynyl complexes incorporating the 3 H -indole moiety were designed and synthesised. The complexes were studied using electrochemical and spectroelectrochemical techniques. The N-heteroatom of the indole ligand showed Lewis base properties and could extract a proton from a vinylidene intermediate and coordinate to CuI. [ABSTRACT FROM AUTHOR]

Single-crystal X-ray structure determinations are reported for four lanthanide complexes, [Dy(bipy)2Cl2(OH2)2]Cl.H2O (bipy = 2,2′-bipyridine), 1; [La2(phen)2(O2CCH3)4(NO3)2] (phen = 1,10-phenanthroline), 2; [Lu(terpy)(O2CCH3)3].NaNO3 (terpy = 2,2′;6′,2″-terpyridine) 3; and [Lu(phen)(O2CH)3(OH2)].H2O, 4. Dispersion interactions within the stacked arrays of coordinated aza-aromatic units found in all four complexes appear to be a significant structural influence in the solid state. For complex 1, there are additional interactions beyond dispersion, which suggests that it may be the means whereby the Δ and Λ forms contribute to the overall chiral nature of the crystal. These weak intermolecular interactions were investigated in detail using the Hirshfeld surface analysis. [ABSTRACT FROM AUTHOR]

The organic–inorganic lead halide hybrids comprising semiconducting perovskite components and organic modules have proven to be promising candidates for optoelectronic applications. The modulation of the inorganic components as optical centres by diverse organic cationic templates is under intense investigation. Herein, we successfully prepared new one-dimensional lead halide hybrid perovskites [L1]2n[Pb2Cl6]n∞·nH2O (1) and [PbBr2(L2)]n∞·0.5nH2O (2), and the dimeric complex [PbBr2(L3)]2 (3) in water media. In 1, 2-(2-hydroxyethyl)-2H-imidazo[1,5-a]pyridinium cation [L1]+ resulted from the oxidative condensation–cyclization between formaldehyde, ethanolamine and 2-pyridinecarbaldehyde (2-PCA); the polydentate Schiff base ligands L2 and L3 formed in the in situ condensation of 2-PCA and ethanolamine or ethylenediamine, respectively. The lead chloride hybrid 1 contains the previously unreported type of a [Pb2Cl6]∞ double chain constructed from three-edge- and five-edge-sharing PbCl6 octahedra, and cations forming π-bonded stacks aligned along the inorganic wires. In the crystal of 2, pairs of the double-side organically decorated [PbBr2(L2)]∞ chains built of corner-sharing PbBr3N2O octahedra arrange hydrophilic channels to host water molecules. In the solid state, the identically stacked dimers of 3 form columns parallel to the ab plane with the Pb2Br4 moieties in the column being strictly coplanar. Hirshfeld surface analysis was used to rationalize the packing patterns through hydrogen bonds of O−H···O/Cl and C−H···O/Cl types with the involvement of OH groups of [L1]+, L2 and water molecules in 1 and 2, as well as C–H∙∙∙Br hydrogen bonding in 2 and 3. The QTAIM analysis of non-covalent interactions in 1–3 was performed. According to the analysis of the solid-state UV–visible reflectance spectra by a Tauc plot, the optical band gap values of 1, 2 and 3 as direct gap semiconductors were estimated to be 3.36, 3.13 and 2.96 eV, respectively. [ABSTRACT FROM AUTHOR]

The hybrid salt bis(2-methylimidazo[1,5-a]pyridin-2-ium) hexachloridostannate( IV), (C8H9N2)2[SnCl6], crystallizes in the monoclinic space group P21/n with the asymmetric unit containing an Sn0.5Cl3 fragment (Sn site symmetry 1) and one organic cation. The five- and six-membered rings in the cation are nearly coplanar; bond lengths in the pyridinium ring of the fused core are as expected; the C--N/C bond distances in the imidazolium entity fall in the range 1.337 (5)-1.401 (5) Å. The octahedral SnCl62- dianion is almost undistorted with the Sn--Cl distances varying from 2.4255 (9) to 2.4881 (8) Å and the cis Cl--Sn--Cl angles approaching 90°. In the crystal, π-stacked chains of cations and loosely packed SnCl62- dianions form separate sheets alternating parallel to (101). Most of the numerous C--H• • •Cl--Sn contacts between the organic and inorganic counterparts with the H• • •Cl distances above the van der Waals contact limit of 2.85 Å are considered a result of crystal packing. [ABSTRACT FROM AUTHOR]

Quaternary phosphonium salts are popular candidates used in many chemical transformations and synthetic chemistry, notably in catalysis. We have examined the single crystals of two bulky phosphonium compounds, tetra([1,1′-biphenyl]-4-yl) phosphonium dicyanamide (C48H36P+·N(CN)2−, compound 1), and tetra([1,1′-biphenyl]-4-yl) phosphonium bromide hydrate (C48H36P+·Br−, CH3CN, H2O, compound 2), and herein report the structural properties for the compounds with an emphasis on the influence of the ion-ion interaction towards self-assembly; the overall self-assembly for both structures is very similar, with subtle differences in the cell parameters. The symmetrical tetra ([1,1′-biphenyl]-4-yl) phosphonium cations in both compounds self-assembled to form robust stacked columns in the solid-state, with voids occupied by anions or solvent molecules. Quantitative examination of intermolecular interactions using Hirshfeld surface analysis found that classical and non-classical hydrogen bonding appears to be the dominant contributor in stabilizing the self-assembly in both cases. The present work can not only benefit in understanding the mutual interaction between the sterically encumbered tetra ([1,1′-biphenyl]-4-yl) phosphonium cations and between counterions, but also provide insights for the self-assembled arrays in the solid-state. [ABSTRACT FROM AUTHOR]

Naphthalene derived compounds that belong to the polycyclic aromatic hydrocarbons have significant importance in medicinal chemistry owing to their interesting biological activities. The structural knowledge of new naphthalene derived compounds can help in the understanding of their mechanism of action. In this study, we have investigated the molecular and structural landscape of three naphthalene-derived dications, namely, 1,1′-(naphthalene-2,6-diylbis(methylene))bis(3-methyl-1H-imidazolium), 1,1′-(naphthalene-2,7-diylbis(methylene))bis(3-methyl-1H-imidazolium) and 1,1′-(naphthalene-2,6-diylbis(methylene))bis(1-butylpyrrolidinium) as bromide salts. The structural details and non-covalent interactions for these structures were carefully examined using X-ray crystallography. Contributions to crystal packing from various types of intermolecular contacts were investigated and quantified using the Hirshfeld surface analysis. The backgrounds of these differences were analysed in terms of the key factors such as hydrogen bonding, the position of substituents appended on the naphthyl ring, and the presence of aromatic and non-aromatic moieties as substituents. The present work not only demonstrates how the position of the substituent group on the bicyclic ring influences the geometric conformation and overall packing, but also contributes toward a better understanding of how molecules self-assemble with respect to different functional groups (aromatic vs. non-aromatic). [ABSTRACT FROM AUTHOR]

Four ternary multi-component crystal structures comprising water-soluble p-sulfonatocalix[4]arene anion as the cavitand in the presence of different types of positively charged guest molecules comprising 1-butylimidazolium, 3,3′-(1,4-phenylenebis(methylene))bis(1-methylimidazolium), 3,3′,3′′-(benzene-1,3,5-triyltris(methylene))tris(1-methylimidazolium), or 3,3′,3′′,3′′′-(benzene-1,2,4,5-tetrayltetrakis(methylene))tetrakis(1-methylimidazolium) and aquated lanthanide(III) ions (Gd(III) or Ce(III)) are reported. Careful crystallographic analysis shows that all positively charged imidazole rings are encapsulated by p-sulfonatocalix[4]arene for 1-butylimidazolium and 3,3′-(1,4-phenylenebis(methylene))bis(1-methylimidazolium), however, partial encapsulation was observed for 3,3′,3′′-(benzene-1,3,5-triyltris(methylene))tris(1-methylimidazolium) and 3,3′,3′′,3′′′-(benzene-1,2,4,5-tetrayltetrakis(methylene))tetrakis(1-methylimidazolium). The formation of a molecular capsule prevails in all structures regardless of the type of guest species. Supermolecules in three of the complexes self-assemble into a bilayer arrangement in the extended structure, whilst those involving p-sulfonatocalix[4]arene and 1-butylimidazolium form hydrated channels through alternative packing. [ABSTRACT FROM AUTHOR]

The title compound, [Fe(C3H7NO)6][Cd2Cl7], crystallizes in the trigonal space group R3̅ and is assembled from discrete [Fe(DMF)6] 3+ cations (DMF = N,Ndimethylformamide) and [Cd2Cl7] 3- anions. In the cation, the iron(III) atom, located on a special position of 3̅ site symmetry, is coordinated by six oxygen atoms from DMF ligands with all Fe—O distances being equal [2.0072 (16) A˚ ]. A slight distortion of the octahedral environment of the metal comes from the cis O—Fe—O angles deviating from the ideal value of 90 [86.85 (7) and 93.16 (7)] whilst all the trans angles are strictly 180. The central Cl atom of the [Cd2Cl7] 3- anion is also located on a special position of 3̅ site symmetry and bridges two corner sharing, tetrahedrally coordinated CdII atoms. The two Cd atoms and the central Cl atom are colinear. The two sets of terminal chloride ligands on either side of the dumbbell-like anion are rotated relative to each other by 30. In the crystal, the cations and anions, stacked one above the other along the c-axis direction, are held in place principally by electrostatic interactions. There are also C—H...Cl and C—H...O interactions, but these are rather weak. Of the six crystal structures reported to date for ionic salts of [Fe(DMF)6] n+ cations (n = 2, 3), five contain FeII ions. The title compound is the second example of a stable compound containing the [Fe(DMF)6] 3+ cation. The existence of both [Fe(DMF)6] 2+ and [Fe(DMF)6] 3+ cations shows that the DMF ligand coordination sphere can accommodate changes in the charge and spin states of the metal centre. [ABSTRACT FROM AUTHOR]

A convenient modification to the established synthetic routes for the preparation of complexes [M(CRCR)(dppe)Cp'] (M = Fe, Ru; Cp' = η5-C5H5 (Cp), η5-C5Me5 (Cp*); R = C6H5, C6H4-p-OMe, C6H4-p-NO2, tBu) and [Ru(CRCR)(PPh3)2Cp] from the corresponding [MCl(PP)Cp0] complex and the alkyne HCRCR via an intermediate vinylidene is described. The complexes are generally obtained as high quality crystalline samples directly from the reaction mixture. In agreement with previous studies, the iron complexes undergo a predominantly metal-centred oxidation, whilst there is greater involvement of the acetylide ligand in the oxidation processes associated with the ruthenium analogues. Analysis of the redox properties and spectroelectrochemical investigations reveal limited differences in the gross electronic structures of the Cp vs. Cp* derivatives in each of the Fe and Ru series. [ABSTRACT FROM AUTHOR]

Driven by an interest in the impact of the para-substituent of calix[4]arenes on metal complexation and structural chemistry, studies of p-cyclohexylcalix[4]arene (L) have been carried out. The 1:1 dichloromethane and dimethylformamide solvates were found to be isostructural, and different to the typical bilayer structure often observed for p-t-butylcalix[4]arene solvates. The methanol solvate, in contrast, does form a bilayered structure but is also a 1:1 solvate, unlike the p-t-butylcalix[4]arene·2MeOH system. Lanthanoid complexation was investigated, resulting in the structural characterisation of two different DMF solvates of a 2:2 dimeric europium complex, Eu2(L–3H)2(DMF)4. A tetrazole derivative, 5,11,17,23-tetracyclohexyl-25,27-dihydroxy-26,28-bis(tetrazole-5-ylmethoxy)calix[4]arene, has been synthesised via the intermediate 5,11,17,23-tetracyclohexyl-25,27-dihydroxy-26,28-dicyanomethoxycalix[4]arene, with the latter compound being structurally characterised. Attempts to isolate lanthanoid clusters supported by the tetrazole derivative under conditions known to form Ln19 clusters with the p-t-butyl analogue were unsuccessful, resulting only in isolation of the ligand from the reaction mixture. [ABSTRACT FROM AUTHOR]

Four multi-component complexes based on p-sulfonatocalix[4]arene anion, the methyltriphenylphosphonium cation, lanthanide ions (Gd(III)) and different ionic liquid-based cations (1-methyl-3-butylimidazolium, 1-methyl-3-octylimidazolium and 1,4-bis((3-methylimidazolidinyl)methyl)benzene) were synthesised and structurally characterised. Common bilayer arrangements are formed in the extended structures of all four complexes, though the bilayer thicknesses varies depending on the components involved. Molecular capsule formation is facilitated by the inclusion of methyltriphenylphosphonium, 1-methyl-3-butylimidazolium and 1,4-bis((3-methylimidazolidinyl)methyl)benzene cations, but not in the case of the 1-methyl-3-octylimidazolium cation. Molecular capsule size depends on the nature of the included guest cation, and methyltriphenylphosphonium cations fill compact spaces between calixarenes in these new bilayer arrays. [ABSTRACT FROM AUTHOR]

Three new NiII/ZnII heterometallics, [NiZnL′2(OMe)Cl]2 (1), [NiZnL′′(Dea)Cl]2·2DMF (2) and [Ni2(H3L′′′)2(o-Van)(MeOH)2]Cl·[ZnCl2(H4L′′′)(MeOH)]·2MeOH (3), containing three-dentate Schiff bases as well as methanol or diethanolamine (H2Dea) or o-vanillin (o-VanH), all deprotonated, as bridging ligands were synthesized and structurally characterized. The Schiff base ligands were produced in situ from o-VanH and CH3NH2 (HL′), or NH2OH (HL"), or 2-amino-2-hydroxymethyl-propane-1,3-diol (H4L′′′); a zerovalent metal (Ni and Zn in 1, Zn only in 2 and 3) was employed as a source of metal ions. The first two complexes are dimers with a Ni2Zn2O6 central core, while the third compound is a novel heterometallic cocrystal salt solvate built of a neutral zwitterionic ZnII Schiff base complex and of ionic salt containing dinuclear NiII complex cations. The crystal structures contain either centrosymmetric (1 and 2) or non-symmetric di-nickel fragment (3) with Ni⋯Ni distances in the range 3.146–3.33 Å. The exchange coupling is antiferromagnetic for 1, J = 7.7 cm−1, and ferromagnetic for 2, J = −6.5 cm−1 (using the exchange Hamiltonian in a form Ĥ = J12). The exchange interactions in 1 and 2 are comparable to the zero-field splitting (ZFS). High-field EPR revealed moderate magnetic anisotropy of opposite signs: D = 2.27 cm−1, E = 0.243 cm−1 (1) and D = −4.491 cm−1, E = −0.684 cm−1 (2). Compound 3 stands alone with very weak ferromagnetism (J = −0.6 cm−1) and much stronger magnetic anisotropy with D = −11.398 cm−1 and E = −1.151 cm−1. Attempts to calculate theoretically the exchange coupling (using the DFT "broken symmetry" method) and ZFS parameters (with the ab initio CASSCF method) were successful in predicting the trends of J and D among the three complexes, while the quantitative results were less good for 1 and 3. [ABSTRACT FROM AUTHOR]

Structural studies on p-sulfonatocalix[4]arene coordination compounds involving diverse metal ions with respect to their size and charge, caesium(I), copper(II) and neodymium(III) are reported. The metal coordination-driven self-assembly forms metallosupramolecules, either as a two-dimensional (2 D) or a three-dimensional (3D) network while retaining the commonly established bilayer array for p-sulfonatocalix[4]arene. The complex (Cs5-p-sulfonatocalix[4]arene-H+)·6H2O has five crystallographically independent caesium(I) ions with high coordination numbers. In the divalent complex {[Cu3(H2O)12-2(p-sulfonatocalix[4]arene)]2-}·2([Cu(H2O)5])2+·2NO3-·7H2O, two different copper(II) coordination environments are present, one with octahedral stereochemistry while bridging two opposing calixarenes with the other having a square pyramidal geometry involving one sulfonate group. Eight-coordinate neodymium(III) metal ions prevail in Nd0.25(H2O)1.25(p-sulfonatocalix[4]arene + H+)0.25, involving four sulfonate groups from four different calixarenes. [ABSTRACT FROM AUTHOR]

Two multi-component crystal structures comprising a carboxylic acid-functionalized imidazolium zwitterion, a p-sulfonatocalix[4]arene anion and aquated metal ion (Na+ or Y3+) with or without an auxiliary component (the 3-methoxyphenyl-triphenylphosphonium cation) are reported. The carboxylic acid-functionalized imidazolium ion binds either as a monodentate or a bidentate ligand depending on the nature of the metal ions, and a bi-layer arrangement prevails in the extended structure regardless of the type of metal ion employed or presence/lack of auxiliary component. [ABSTRACT FROM AUTHOR]

Trinuclear lanthanoid clusters have been synthesised and investigated as toroidal spin systems. A pyridyl functionalised β-diketonate, 1,3-bis(pyridin-2-yl)propane-1,3-dione (o-dppdH) has been used to synthesise a family of clusters of the form [Dy3(OH)2(o-dppd)3Cl2(H2O)4]Cl2·7H2O (1), [Tb3(o-dppd)3(μ3-OH)2(CH3CH2OH)3Cl3][Tb3(o-dppd)3(μ3-OH)2(H2O)(CH3CH2OH)2Cl3]Cl2·H2O (2), [Ho3(OH)2(o-dppd)3Cl(H2O)5]Cl3·3H2O (3) and [Er3(OH)2(o-dppd)3Cl2(H2O)3(CH3OH)]Cl2·3H2O·CH3OH (4). Despite the previous occurrence of this structural motif in the literature, these systems have not been widely investigated in terms of torodic behaviour. Magnetic studies were used to further characterise the complexes. DC susceptibility studies support weak antiferromagnetic exchange in the complexes. Slow magnetic relaxation behaviour is observed in the dynamic AC magnetic studies for complex 1. Theoretical studies predict that complex 1 and 3 have a non-magnetic ground state based on a toroidal arrangement of spins. Changes to the coordination environment in 2 do not support a toroic spin state. The prolate nature of the ErIII centres in complex 4 and large transverse anisotropy do not support the toroidal arrangement of lanthanoid spins in the complex. [ABSTRACT FROM AUTHOR]

The organisation of the p-xylylenebis(triphenylphosphonium) dication in the solid state, in crystals formed under a variety of conditions, at different pH values and in the presence of THF and other potential building moieties including p-sulfonatocalix[4]arene, 1-methyl-3-butylimidazolium and aquated gadolinium(III) has been investigated using single crystal X-ray diffraction studies. Striking changes in the dication conformations (cis- and trans-) that contribute to the different crystal packings of the dication (two-dimensional layerings and three-dimensional scaffoldings) have been established for five different compounds. The interplay and the self-assembled arrays of the dication with other incorporated components and the overall non-covalent interactions have been quantified using Hirshfeld surface analyses. [ABSTRACT FROM AUTHOR]

Nine multipodal cationic molecules with adaptable cyclic and acyclic amine functional groups along with bromide as the counterion have been synthesised and structurally characterised by single crystal X-ray diffraction. In the solid-state, the dicationic bipodal molecule has a pincer-like geometry while the tricationic tripodal molecule has a cavity-like geometry. The tetracationic tetrapodal molecule crystallised as the chair conformer as a result of steric crowding by the heterocyclic amine functional groups (imidazolium and pyrrolidinium), which prohibits arrangement of the heterocyclic amine substituents in the same direction. This study also illustrates that the different packing motifs (including linear and corrugated layers, and channels) are affected by the substituents at the central core for each type of multipodal molecule. CrystalExplorer was used to visualise these weak intermolecular interactions and to quantitatively summarise the interactions that contribute to the overall stability to the crystal structure. [ABSTRACT FROM AUTHOR]

Eight organic salts made up of two different organic phosphonium monocations, tetraphenylphosphonium or benzyltriphenylphosphonium, and common anions of different shape, size and charge distribution have been structurally authenticated. The crystal packing for the tetraphenylphosphonium cations involves one-dimensional infinite stacked columns incorporating translational quadruple embraces (TQPE) regardless of the type of counter ion. As for benzyltriphenylphosphonium salts, different packing arrays were obtained with different anions. Interestingly, the anions control the intermolecular packing of the same phosphonium cation, while hydrogen bonding is found to be the dominant contributor in the overall self-assembly. Hydrophobic interactions between the phosphonium cations driven by the phenyl–phenyl embrace involving π⋯π and/or C–H⋯π interactions also contribute to the cohesion of the structures. Charge-assisted hydrogen bonding and halogen bonding were also evident, which are relatively strong compared to classical hydrogen bonds, as judged from the short intermolecular distances. The interactions have also been quantified using Hirshfeld surfaces analyses. [ABSTRACT FROM AUTHOR]

Reactions of [Ru{C=C(H)‐1,4‐C6H4C≡CH}(PPh3)2Cp]BF4 ([1 a]BF4) with hydrohalic acids, HX, results in the formation of [Ru{C≡C‐1,4‐C6H4‐C(X)=CH2}(PPh3)2Cp] [X=Cl (2 a‐Cl), Br (2 a‐Br)], arising from facile Markovnikov addition of halide anions to the putative quinoidal cumulene cation [Ru(=C=C=C6H4=C=CH2)(PPh3)2Cp]+. Similarly, [M{C=C(H)‐1,4‐C6H4‐C≡CH}(LL)Cp ]BF4 [M(LL)Cp'=Ru(PPh3)2Cp ([1 a]BF4); Ru(dppe)Cp* ([1 b]BF4); Fe(dppe)Cp ([1 c]BF4); Fe(dppe)Cp* ([1 d]BF4)] react with H+/H2O to give the acyl‐functionalised phenylacetylide complexes [M{C≡C‐1,4‐C6H4‐C(=O)CH3}(LL)Cp'] (3 a–d) after workup. The Markovnikov addition of the nucleophile to the remote alkyne in the cations [1 a–d]+ is difficult to rationalise from the vinylidene form of the precursor and is much more satisfactorily explained from initial isomerisation to the quinoidal cumulene complexes [M(=C=C=C6H4=C=CH2)(LL)Cp']+ prior to attack at the more exposed, remote quaternary carbon. Thus, whilst representative acetylide complexes [Ru(C≡C‐1,4‐C6H4‐C≡CH)(PPh3)2Cp] (4 a) and [Ru(C≡C‐1,4‐C6H4‐C≡CH)(dppe)Cp*] (4 b) reacted with the relatively small electrophiles [CN]+ and [C7H7]+ at the β‐carbon to give the expected vinylidene complexes, the bulky trityl ([CPh3]+) electrophile reacted with [M(C≡C‐1,4‐C6H4‐C≡CH)(LL)Cp'] [M(LL)Cp'=Ru(PPh3)2Cp (4 a); Ru(dppe)Cp* (4 b); Fe(dppe)Cp (4 c); Fe(dppe)Cp* (4 d)] at the more exposed remote end of the carbon‐rich ligand to give the putative quinoidal cumulene complexes [M{C=C=C6H4=C=C(H)CPh3}(LL)Cp']+, which were isolated as the water adducts [M{C≡C‐1,4‐C6H4‐C(=O)CH2CPh3}(LL)Cp'] (6 a–d). Evincing the scope of the formation of such extended cumulenes from ethynyl‐substituted arylvinylene precursors, the rather reactive half‐sandwich (5‐ethynyl‐2‐thienyl)vinylidene complexes [M{C=C(H)‐2,5‐cC4H2S‐C≡CH}(LL)Cp']BF4 ([7 a–d]BF4 add water readily to give [M{C≡C‐2,5‐cC4H2S‐C(=O)CH3}(LL)Cp'] (8 a–d)]. [ABSTRACT FROM AUTHOR]

Structurally authenticated complexes of the cone-shaped p -sulfonatocalix[4]arene and conformationally flexible p -sulfonatocalix[6]arene devoid of co-ligands/ancillary molecules are limited. Early and late members of the lanthanide series as their trivalent ions, La3+, Er3+, and Yb3+, form complexes from aqueous media under these conditions. For La3+ and Er3+, distinct hydrophobic and hydrophilic bilayers are formed with p -sulfonatocalix[4]arene, whereas for Yb3+, two complexes form that deviate from the well-known bilayer arrangement of calixarenes. Replacing the calixarene with p -sulfonatocalix[6]arene results in a hydrogen-bonded network with alternating hydrophobic–hydrophilic layers associated with primary coordination of Yb3+, with the larger macrocyclic calixarene in a partial cone conformation. Bilayers are created when cone-shaped p -sulfonatocalix[4]arene forms complexes with La3+ and Er3+, whereas with Yb3+ overall assembly deviates from the bilayer arrangement. With conformational flexible p -sulfonatocalix[6]arene, this results in a hydrogen bonded network with alternating hydrophobic-hydrophilic layers associated with primary coordination of Yb3+, with the calixarene crystallised in a partial cone conformation. [ABSTRACT FROM AUTHOR]

Reactions of the lanthanide(iii) picrates (picrate = 2,4,6-trinitrophenoxide = pic) with 1,10-phenanthroline (phen) and 2,2′:6′,2′′-terpyridine (terpy) in a 1 : 2 molar ratio have provided crystals suitable for X-ray structure determinations in instances predominantly involving the lighter lanthanides. In all, the aza-aromatic ligands chelate the lanthanide ion, none being found as 'free' ligands within the lattice. The complexes of 1,10-phenanthroline have been characterised in two forms, one unsolvated (Ln = La, Sm, Eu; monoclinic, C 2/ c , Z 8), one an acetonitrile monosolvate (Ln = Gd; monoclinic, P 21/ a , Z 4), the latter being the only previously known form (with Ln = La). In both forms, the LnIII is nine-coordinate, in an approximately tricapped trigonal-prismatic environment, with two picrate ligands chelating through phenoxide and 2-nitro group oxygen atoms, the third being bound through phenoxide-O only. The 2,2′:6′,2′′-terpyridine complexes, all acetonitrile monosolvates defined for Ln = La, Gd, Er, and Y (monoclinic, C 2/ c , Z 4), are ionic, one picrate having been displaced from the primary coordination sphere. For Ln = La, the two bound picrates are again chelating, making the LaIII 10-coordinate in a distorted bicapped square-antiprismatic environment but in the other species they are bound through phenoxide-O only, making the LnIII ions eight-coordinate in a distorted square-antiprismatic environment. Stacked arrays of the ligands can be found in both series of complexes, with intramolecular picrate–picrate and picrate–aza-aromatic stacks being prominent features. Structure determinations on complexes of lanthanide(III) picrates with aza-aromatic ligands provide examples of various stacking arrays. The chain of [La(terpy)2(pic)2]+ cations (shown in space-filling mode) present in the lattice of [La(terpy)2(pic)2](pic)·CH3CN involves both intra- and intermolecular heterogeneous stacks. [ABSTRACT FROM AUTHOR]

Adducts of the form Ln(pic)3(tmp)3 (Ln = lanthanide(iii); pic = picrate = 2,4,6-trinitrophenoxide; tmp = trimethylphosphate, (MeO)3PO) have been prepared for extremal Ln = La, Lu and some intermediate members, also Y, and characterised by single crystal X-ray structure determinations as unsolvated, mononuclear, molecular species. The lanthanide atom has nine-coordinate, tri-capped trigonal prismatic stereochemistry in all cases, the picrate components behaving as O , O ′-bidentate ligands chelating through the phenoxy- and an adjacent O -nitro oxygen atom, thus: [Ln(tmp- O)3(pic- O , O ′)3]. Two isomeric forms are found, one mer in which the three unidentate tmp- O ligands coordinate in cis -sites spanning the upper and lower triangles and a capping site of the coordination sphere, and fac , in which all three unidentate ligands occupy the mutually cis -sites of one triangular face. The mer isomer has been described as an isomorphous series in a monoclinic P 21/ c , Z 4, form, for Ln = La, Ce, Pr, Nd, Sm, Gd, Lu, and Y, presumptively accessible for the full gamut of Ln. The fac -isomer also crystallises in a monoclinic P 21/ c form, Z 8, two independent molecules of similar stereochemistry here comprising the asymmetric unit and described for Ln = Eu, Lu(isomorphous); it has also been described in a triclinic P CH19176_IE1.gif , Z 2 form for Ln = La. Trimethylphosphate (tmp) is the first of a series of related O-donor solvates of lanthanide(III) picrates to give isomeric mer- and fac- [Ln(pic)3(tmp)3] complexes. [ABSTRACT FROM AUTHOR]

The title compounds [(Ph3As)2AuI] and [(Ph3As)3AuI] have been crystallized from equimolar solutions of Bu4NAuI2 and AsPh3 in dimethylformamide and structurally characterized by single crystal X-ray diffraction studies. [(Ph3As)2AuI] crystallizes in space group C 2/ c , Z 4, and is isomorphous with other [(Ph3E)2MX] (MX = coinage metal(i) salt) arrays, with the Au–I bond being disposed on a crystallographic 2-axis: Au–I, As 2.7008(2), 2.4337(2) Å, As–Au–As, I 125.736(8)°, 117.132(4)° (153 K). [(Ph3As)3AuI] crystallizes as a triclinic phase in space group CH19340_IE1.gif , Z 4, and is isomorphous with [(Ph3Sb)3CuI] and [(Ph3P)3AgI]: Au–As 2.4847–2.5049(10), Au–I 2.8518(8), 2.8597(7) Å with As–Au–As, I 109.67(3)–115.97(3)°, 101.33(2)–106.85(3)°. A second '[(Ph3As)3AuI]' product was obtained as a co-crystalline phase in space group P 21/ n containing [(Ph3As)3AuI], and [(Ph3As)2AuI] accompanied by an additional unbound Ph3As molecule, i.e. [(Ph3As)3AuI]·[(Ph3As)2AuI·Ph3As], with structural parameters closely similar to those for the corresponding separate [(Ph3As)3AuI] and [(Ph3As)2AuI] complexes described above. Comparison of the bond lengths for these and related complexes show that they are generally consistent with the 'gold is smaller than silver' phenomenon caused by relativistic orbital contraction effects in gold, but the results also show that the magnitude of this effect is dependent on the nature of the metal–ligand bonds involved, and on changes in the metal coordination environment, which can in some circumstances yield trends in which the effect on particular bonds is partially masked or even reversed. Comparison of the bond lengths in [(Ph3As)2AuI] and [(Ph3As)3AuI] and related complexes show that they are generally consistent with the 'gold is smaller than silver' phenomenon caused by relativistic orbital contraction effects in gold, but the results also show that the magnitude of this effect is dependent on the nature of the metal–ligand bonds involved. [ABSTRACT FROM AUTHOR]

The carboxamide-O donor ligands dimethylacetamide (dma) and N -methylpyrrolidinone (nmp) form complexes of lanthanide picrates, Ln(pic)3, of stoichiometry Ln(pic)3(carboxamide)3 in a remarkable variety of phases. Complexes [Ln(pic)3(dma)3], Ln = La, Ce, Nd, Sm, Gd, Yb, Lu, and Y, adopt the 9-coordinate molecular form of tricapped trigonal-prismatic coordination geometry seen to predominate, as two stereoisomers, in related species involving dimethylsulfoxide (dmso), trimethylphosphate (tmp), and hexamethylphosphoramide (hmpa) but as four different phases (depending on Ln), none of which is the same as for the previously known La complex. For Ln = Pr, 9-coordinate species of composition [Pr(pic)3(dma)2(alcohol)] (alcohol = ethanol and propan-2-ol) have been characterised and a low quality determination indicates that a similar species (with propan-2-ol) is formed by Y. For nmp, the composition [Ln(pic)3(nmp)3] is maintained across the series for Ln = La, Ce, Pr, Nd, Gd, Er, Tm, Yb, and Lu but 9-coordination is not for Ln = Er, Tm, Yb, and Lu. A decreased coordination there is a result of one or two picrate ligands acting as phenoxide-O donors only, a marked contrast with the analogous Ln(pic)3 complexes with dmso, tmp, hmpa, and dma, where picrate chelation is universal, but with some parallel to related ScIII complexes. Several polymorph pairs can be identified among the nmp complexes. Structural studies of the adducts of lanthanide picrates with dimethylacetamide (dma) and N-methylpyrrolidinone (nmp) add further variety to the nature of simple O-donor ligand complexes of these picrates. Polymorphism is readily detected in the dma complexes, while, with the heavier lanthanides, nmp causes partial detachment of the picrate ligands. [ABSTRACT FROM AUTHOR]

Single crystal X-ray structure determinations have been executed for several title compounds of the mononuclear form [LMX2], namely [(bpy)ZnX2], X = Cl, Br; [(phen)ZnX2], X = Cl, Br, I (bpy = 2,2′-bipyridine; phen = 1,10-phenanthroline). Also reported are the crystal structures of ZnSO4/bpy/H2O (1 : 1 : 5) (≡ [(bpy)Zn(OH2)4](SO4)·H2O) and Zn(NO3)2/bpy/H2O (1 : 1 : 3) (≡ [(bpy)Zn(OH2)3(O NO2)](NO3)). The sulfate complex completes the array [LM(OH2)4]2+, L = bpy, phen, M = Zn, Cd, while the nitrate is the first nitrate example for [LM(OH2)3(O X)](+) (O X = O NO2, O SO3). In all examples of the sulfate and nitrate forms here and previously defined, the metal atoms are six-coordinate, with any anionic donors lying in axial coordination sites (i.e. M–O (quasi-) normal to the LM plane). The structures of [LHg(SCN)2] (L = phen, tpy) (tpy = 2,2′:6′,2′-terpyridine), [(tpy)(CdBr2], and [Zn(tpy)2](NO3)2·2H2O are also recorded. Single crystal X-ray structure determinations have been executed for several mononuclear Zn halide, sulphate, and nitrate complexes with 2,2′-bipyridyl and 1,10-phenanthroline ligands. [ABSTRACT FROM AUTHOR]

Addition of various oxygen-donor ligands (L, all dipolar, aprotic solvents), to a solution of hydrated scandium picrate in weakly coordinating solvents (S), has yielded several crystalline adducts of the form Sc(pic)3(L) m (· n S) in which all ligands L are coordinated, subsequently characterised by a series of single crystal X-ray studies. For L = dmso, m = 3 and the picrate anions are all bound as phenoxide-O donor units, while for nmp, dma, tmp, and hmpa, m = 2 and one of the bound picrates becomes bidentate through phenoxide- and nitro-O donation. For L = ompa, m = 2 and two picrate ligands are bound through phenoxide-O while one is displaced from the primary coordination sphere. All complexes contain six-coordinate ScIII, confirming that this coordination number is a consequence of ligand bulk. Six-coordination of ScIII is observed throughout in crystalline adducts of scandium picrate with dmso, dma, nmp, tmp, hmpa, and ompa, although with variations in the adduct stoichiometry and the coordination mode of picrate. [ABSTRACT FROM AUTHOR]

X-Ray structure determinations on 41 complexes of lanthanide(iii) halides, principally bromides, with 2,2′-bipyridine, 1,10-phenanthroline, and 2,2′:6′,2″-terpyridine provide a considerable extension to the earlier work of Allan White on such materials and a substantial extension of general work on polypyridine complexes of lanthanide halides. Complexes of 1 : 1, 1 : 2, and 2 : 4 metal-to-ligand composition have been characterised across a broad selection of the lanthanide elements, many of these species showing a higher overall ratio of ligand to lanthanide due to the incorporation of uncoordinated ligand within the crystal lattice. Although stacking of the aromatic entities is apparent in these adducts, in most instances H-bonding of unbound N to coordinated water appears to be the principal interaction involved in their formation. Allan White's almost heroic dedication to systematic structural studies of all areas of coordination chemistry is exemplified in his numerous studies concerning the lanthanide elements. The present work is a meticulous investigation of lanthanide halide complexes with polypyridines considerably extending knowledge in this particular area. [ABSTRACT FROM AUTHOR]

Single crystal X-ray structural characterisations are reported for adducts of the form [(L- O)Eu(O , O ′-dpm)3] obtained by the crystallisation of tris(dipivaloylmethanato)europium(iii) (dpm = [HC(C(tBu).CO)2]−) from an array of dipolar aprotic oxygen-donor solvents L (L = N -methylpyrrolidinone (nmp), trimethylphosphate, (MeO)3PO, (tmp), hexamethylphosphoramide (hmpa), dimethylacetamide (dma), dimethyl sulfoxide (dmso), and the bidentate octamethylpyrophosphoramide (ompa). In all adducts, the resulting arrays contain seven-coordinate metal atoms, which adopt two different isomeric forms of the mono-capped trigonal prismatic stereochemistry, the L = dma and dmso adducts corresponding to one type, nmp and tmp the other. The adduct formed with ompa behaves as a pair of discrete metal environments bridged by the O -ompa- O ′ ligand, thus; [(dpm- O , O ′)3Eu(O -ompa- O ′)Eu(O , O ′-dpm)3], and is found in two forms, one in which both Eu environments is of the tmp type, the other of the dmso/dma type. In the hmpa adduct, the asymmetric unit of the structure is a disordered composite of both types. In none of the adducts is there any further solvation beyond coordination of a single L. Structural studies of crystalline adducts of [Eu(dipivaloylmethanato)3] with dmso, dma, tmp, hmpa, and ompa have shown all to contain seven-coordinate EuIII. This low coordination number appears to be a consequence of partial coordination sphere interpenetration in the solid state. [ABSTRACT FROM AUTHOR]

Crystalline products of the reactions of lanthanide picrates, Ln(pic)3 (pic = 2,4,6-trinitrophenoxide), with hexamethylphosphoramide (hmpa) and octamethylpyrophosphoramide (ompa) have been characterised by single-crystal X-ray diffraction studies. With hmpa and lighter lanthanides (La, Sm, Eu), isomorphous species (monoclinic, P 21/ c , Z 4) of stoichiometry [Ln(pic)3(hmpa)3]·0.5H2O, have been defined where the molecular units in the lattice contain 9-coordinate Ln with tricapped trigonal-prismatic coordination geometry. The picrate ligands are bidentate through phenoxide-O and 2-nitro-O, with the latter occupying the capping positions, while the hmpa ligands are singly O-bound to one trigonal face. Heavier lanthanides (Gd, Lu) and Y have been found to give isomorphous (monoclinic, P 21/ n , Z 4) species of stoichiometry [Ln(pic)3(hmpa)2], with 8-coordinate Ln of an irregular geometry best considered as close to that of a bicapped trigonal-prism. The picrate ligands chelate in the same manner as in the lighter Ln complexes but with one spanning a trigonal edge, and the hmpa-O donors occuping two apices of the other trigonal face. The ligand ompa has been found to act as a bidentate chelate in all isolated species, displacing one picrate from the metal ion coordination sphere to give ionic complexes. For La, Nd, and Gd, isomorphous (monoclinic, P 21/ n , Z 4) complexes of stoichiometry [Ln(pic)2(ompa)2(OH2)](pic)·0.5H2O containing 9-coordinate, tricapped trigonal-prismatic Ln with a single aqua ligand have been defined, while for Er, Yb, Lu, and Y, both the coordinated and lattice water molecules are lost in isomorphous (monoclininc, P 21/ c , Z 8) 8-coordinate, square-antiprismatic species of stoichiometry [Ln(pic)2(ompa)2](pic). For Er, further polymorphs, one monoclinic, P 21/ c , and the other triclinic, CH19251_IE1.gif , have also been characterised. Structural studies of adducts of the lanthanide picrates with hexamethylphosphoramide (hmpa) and octamethylpyrophosphoramide (ompa) provide significant contrasts with those of analogous adducts with dimethylsulfoxide and trimethylphosphate. Adducts of hmpa show a transition from 9-coordinate (hmpa)3 to 8-coordinate (hmpa)2 species, while ompa displaces one picrate from the primary coordination sphere. [ABSTRACT FROM AUTHOR]

Adducts of dimethylsulfoxide, dmso = Me2SO, with lanthanide(iii) picrates (picrate = 2,4,6-trinitrophenoxide, pic) of stoichiometry Ln(pic)3·3dmso have been prepared and characterised by single-crystal X-ray structure determinations as discrete, neutral, mononuclear molecular species. Such complexes have been obtained across the gamut of Ln, specifically for Ln = La, Pr, Nd, Sm, Gd, Dy, Yb, Lu, and Y, presumably also accessible for other intermediate members, the series being isomorphous (monoclinic, C 2/ c , Z = 8); a second triclinic P CH19169_IE1.gif form has also been identified for Ln = La, Pr. In both forms, the metal atom coordination environments are nine-coordinate, tricapped trigonal prismatic, [Ln(dmso- O)3(pic- O,O′)3], two of the three unidentate ligands lying in one of the trigonal planes and one in the other (an isomer we have termed meridional, mer). A hydrated form of Ln(pic)3·2dmso·H2O stoichiometry has also been defined for Ln = Sm, Gd, Lu, the metal atom environment again nine-coordinate, [Ln(dmso- O)2(H2 O)(pic- O,O′)3], but now fac , with the three unidentate ligands occupying one triangular face of the tricapped trigonal prism and involved in a centrosymmetric H-bonding array with the three similar ligands of an adjacent complex; the three capping atoms are nitro-oxygen atoms, the phenoxy- O triad occupying the other face. Structural characterisation of adducts of lanthanide picrates with dimethylsulfoxide has provided evidence that the 9-coordinate, tricapped trigonal-prismatic, mer -[Ln(pic)3(dmso)3] form with chelating picrate ligands may extend through the full series. Partial aquation of the tris(dmso) complexes to [Ln(pic)3(dmso)2(OH2)] provides three examples of an otherwise similar but facial isomer. [ABSTRACT FROM AUTHOR]

Ten manganese(I) tricarbonyl diimine complexes bound to variably functionalised 5‐aryl‐tetrazolato ligands were prepared, and their photochemical properties were investigated. Upon exposure to light at 365 nm, each complex decomposed to its free diimine and tetrazolato ligands, simultaneously dissociating three CO ligands, as evidenced by changes in the IR spectra of the irradiated complexes over time. The anti‐bacterial properties of one of these complexes were tested against Escherichia coli. While the complex displayed no effect on the bacterial growth in the dark, pre‐irradiated solutions inhibited bacterial growth. Comparative studies revealed that the antibacterial properties originate from the presence of free 1,10‐phenanthroline. [ABSTRACT FROM AUTHOR]