pinecone/core-2020-05-10-deduplication huggingface dataset:
Framework-isomerism:highly augmented copper(II) paddlewheel-based MOF with unusual (3,4)-net topology

The synthesis and structure of a new, highly augmented {Cu2} ‘paddlewheel’-based metal-organic framework (MOF) that is stabilized by tritopic benzoate ligands is reported. The structure adopts an uncommon, less-symmetrical (3,4)- connected net topology and represents a rare framework isomer of the extensively studied {Cu2}-based pto and tbo analogues. The concomitant formation of three isomeric forms using {Cu}2- ‘paddlewheel’ complexes and a single triangular, tri-functional ligand is unique and stems from the rotational flexibility of the benzoate moieties. Computational analyses support the structural studies and underline that this observed net topology can give rise to an exceptionally high surface area (>3500 m2/g), despite the triple-interpenetrated nature of the compound
Bipyridinium-bis(carboxylate) Radical Based Materials: X-ray, EPR and Paramagnetic Solid-State NMR Investigations

The zwitterionic 1,1′-bis(4-carboxyphenyl)-4,4′-bipyridinium (bp4pc) has been synthesized and crystals of its hydrated form bp4pc·2H2O and of its protonated reduced form H-bp4pc have been obtained. Upon heating, bp4pc·2H2O undergoes partial dehydration, leading to bp4pc·H2O at 160 °C, together with a color change from yellow (room temperature) to green (140 °C) and finally to brown (160–180 °C). Analysis of bond lengths in the solid state reveals the expected short (d = 1.425 Å) and long (d = 1.485 Å) C–C central bond lengths in the all-radical salt H-bp4pc and bp4pc·2H2O, respectively, whereas the distance of 1.475 Å in bp4pc·H2O does not allow a conclusion to be drawn regarding the presence of radicals in this compound. EPR and solid-state paramagnetic NMR experiments of H-bp4pc and the hydrated zwitterion bp4pc·2H2O at different temperatures, however, show that the color change of the latter upon heating is due to the presence of bipyridinium radicals, the concentration of which, although low, increases with increasing temperature. The nature of the electron donor involved in this thermal-induced electron transfer is not fully understood. Most plausible is the possibility that it is the carboxylate group with an intramolecular electron-transfer process; on the other hand it, cannot be excluded that the electron stems from the water molecule, which decomposes into O2, H+, and e– giving H-bp4pc entities
Substituent effects on the fluorescence properties of ortho-carbor­anes : unusual emission behaviour in C-(2′-pyridyl)-ortho-carboranes.

Seventeen compounds including the parent ortho-, meta- and para-carboranes and derivatives of ortho-carborane were investigated for luminescence in cyclohexane and dichloromethane solutions. Fifteen of these carboranes revealed very weak emissions in the 285–493 nm range. These carboranes may arguably be viewed as non-emissive in solutions at room temperatures. No emissions could be observed for 1,2-dimethyl-ortho-carborane and 2-methyl-1-phenyl-ortho-carborane. The carboranes with a 2′-pyridyl substituent at the cluster carbon atom gave unusual local and charge-transfer emissions indicating that different excited states are generated on photoexcitation. Of all the carboranes investigated, only 2-(diphenylphosphino)-1-phenyl-ortho-carborane, 1,2-diphenyl-ortho-carborane and 1-phenyl-2-(2′-pyridyl)-ortho-carborane are luminescent in the solid state with emissions at 476–612 nm and large Stokes shifts of 12000–13600 cm–1. The solid-state structures of 1,2-bis(2′-pyridyl)- and 1-phenyl-2-(2′-pyridyl)-ortho-carborane were determined by X-ray crystallography
What can electron microscopy tell us beyond crystal structures?

WZ thanks Professor Jun Yuan for a useful discussion during the revision of this article. The authors wish to thank EPSRC for financial support to the electron microscopy facility (No. EP/F019580/1) and a Platform grant (No. EP/K015540/1). Date of Acceptance: 08/01/2016Transmission electron microscopy is a powerful tool to directly image crystal structures. Not only that, it is often used to reveal crystal size and morphology, crystal orientation, crystal defects, surface structures, superstructures, etc. However, due to the 2D nature of TEM images, it is easy to make mistakes when we try to recover a 3D structure from them. Scanning electron microscopy is able to provide information on the particle size, morphology and surface topography. However, obtaining information on crystallinity of particles using SEM is difficult. In this microreview article, some practical cases of transmission and scanning electron microscopy investigations of inorganic crystals are reviewed. Commonly occurring uncertainties, imperfection and misunderstandings are discussed.Publisher PDFPeer reviewe
Neutral 1,3,5-Triaza-7-phosphaadamantane-Ruthenium(II) Complexes as Precursors for the Preparation of Highly Water-Soluble Derivatives

The monodentate phosphane ligand 1,3,5-triaza-7-phosphaadamantane (PTA) imparts excellent water solubility to its complexes. We aimed to prepare precursors with one or more PTA coligands for solubility and one or more labile ligands for facile replacement by a linker. For this purpose, we investigated the reactivity of the neutral isomers trans- and cis-RuCl2(PTA)4 (1 and 2) towards 2,2′-bipyridine (bpy), as a model chelating diimine linker. The new derivatives mer-[Ru(bpy)Cl(PTA)3]Cl (9) and fac-[Ru(bpy)Cl(PTA)3]Cl (10) were prepared and characterized. We also found that PTA reacts rapidly with cis,fac-RuCl2(dmso-O)(dmso-S)3 (11) and trans-RuCl2(dmso-S)4 (13) under mild conditions through the replacement\ud
of pairs of mutually trans dmso ligands with high selectivity, even when in stoichiometric defect. Thus, 11 affords cis,cis,trans-RuCl2(dmso-S)2(PTA)2 (12), whereas 13 gives 1. The two dmso ligands of 12 can be replaced selectively by chelating diimines such as bpy to afford the less symmetrical all-cis product cis,cis-Ru(bpy)Cl2(PTA)2 (16)
Multimetallic (de)hydrogenation catalysed processes

The use of different metals working together in a
synergistic way, allows synthetic transformations that are not
achievable by other means. The metal cooperation becomes
important in catalytic processes for the synthesis of sophisticated
molecules or difficult transformations. A rationale design of
multimetallic catalysed processes entails metal complexes and
reaction conditions being compatible, which in general is not
straightforward. A key feature for success found in all systems
dealing with multimetallic processes is catalyst stability. The use of
robust metal complexes increases the probability of success in the
search of tandem catalytic processes. This microreview is based on
the recent and most important findings of multimetallic catalysed
processes that involved (de)hydrogenation reactions. The field
constitutes a research area that is full of potential and can be
foreseen that relevant applications will be described in the near
future.MINECO (CTQ2015-69153-C2-2-R), Generalitat Valenciana (AICO/2015/039), 
Universitat Jaume I (P1.1B2015-09
Impact of the metal centre and functionalization on the mechanical behaviour of MIL-53 metal–organic frameworks

The French National Agency for Research ANR “MODS” (ANR-12-BS10-0005) is thanked for its financial support.An extended series of MIL-53(M)_X metal–organic frameworks (MIL = Materials of Institute Lavoisier; M = Al, Cr, Fe, Sc; X = Cl, CH3, NO2) have been systematically investiaged to explore the impact of the nature of both the metal centre and the functions grafted on to the organic linker on the mechanical behaviour of this family of highly flexible hybrid porous frameworks under the application of an external pressure of up to 3 GPa. The high-pressure X-ray diffraction measurements allowed the characterization of the pressure-induced phase transitions of the hydrated structures, the associated volume changes/pressure transitions, and their mechanical resilience through the determination of their bulk moduli.PostprintPostprintPeer reviewe
Cooperative high-temperature spin crossover accompanied by a highly anisotropic structural distortion

Spin transitions are a spectacular example of molecular switching that can provoke extreme electronic and structural reorganizations in coordination compounds. A new 3D cyanoheterometallic framework, [Fe(pz)(Au(CN)2)2], has been synthesized in which a highly cooperative spin crossover has been observed at 367 and 349 K in heating and cooling modes, respectively. Mössbauer spectroscopy revealed a complete transition between the diamagnetic and paramagnetic states of the iron centres. The low-spin-to-high-spin transition induced a drastic structural distortion involving a large one-directional expansion (ca. 10.6%) and contraction (ca. 9.6%) of the lattice. Negative thermal expansion along the c axis was detected below and above the transition temperature
The Ethylhexanoate route to metal oxide nanocrystals : synthesis of CoO nanooctahedra from Co¹¹2-Ethylhexanoate

CoO nanocrystals were prepared by solvothermal processing of Co 2-ethylhexanoate in oleylamine at 250 °C. The obtained products, identified as CoO by X-ray diffraction, had an octahedral shape, as seen by transmission electron microscopy, reflecting the cubic symmetry of the CoO crystallographic phase. The materials were converted into the CO₃0₄ phase after heat treatment at 400 °C. The nanocrystal evolution was investigated by FTIR spectroscopy. It was concluded that weak oleylamine bonding to the nanocrystal surface during the synthesis step favored the exchange with 2-ethylhexanoato ligands, and that the interplay between the two ligands favored the kinetic control of the growth, resulting in the finally observed octahedral morphology. The CO₃0₄ phase obtained from the heat treatment at 400 °C was used to process chemoresistive sensors, which were able to detect ethanol under dry and humid conditions (0 and 50 % r.h. HO at 25 °C) at low temperatures (100 °C)
Aroylphosphanes: base-free synthesis and their coordination\ud
chemistry with platinum-group metals

A series of aroylphosphanes have been prepared in good yield by base-free condensation of the respective aroyl chloride and HPPh2. Alongside the cyclophane m-{-C(O)- C6H4(C(O)PMe)}2 (1), the IR spectroscopic signatures of\ud
C6H4R{C(O)PPh2} (R = 3-Me 2, 3-CH2Cl 3, 4-CO2Me 4, 4-CN 5) and the bis(aroylphosphanes) C6H4{2,6-C(O)PPh2}2 (6) and C6H3N{2,6-C(O)PPh2}2 (7) are consistent with a manifestation of “phosphomide” character; however, weight of evidence suggests negligible contribution from this canonical form. Comparison is drawn to the structurally characterised O=P(C6H5Me-2)3 (8) in which the lone pair is sequestered. The coordination of 2–5 to rhodium(I), palladium(II) and platinum(II) is described, affording rare examples of aroylphosphane complexes of the platinum-group metals
Single-Ion Magnets Based on Mononuclear Cobalt(II) Complexes with Sulfadiazine

The already reported monomeric complex Co(SDZ)2bpy (1) and the new ternary complex Co(SDZ)2(6MQ)2 (2) (SDZ = sulfadiazine, bpy = 2,2′‐bipyridine, and 6MQ = 6‐methoxyquinoline) have been synthesized in order to study their magnetic properties. X‐ray diffraction studies indicate that in both compounds the SDZ acts as a bidentate ligand coordinating through the sulfonamide and the pyrimidine N atoms giving rise to a CoN6 coordination sphere. The complexes have been characterized based on elemental analyses, FTIR, UV/Vis spectroscopy, and thermogravimetric analysis (TGA, only for 2). Compounds 1 and 2 have been characterized magnetically, and they show slow relaxation of the magnetization below 9 and 6 K, respectively.Fil: Villa Perez, Cristian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Oyarzabal, Itziar. Universidad del País Vasco; EspañaFil: Echeverría, Gustavo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Valencia Uribe, Gloria Cristina. Universidad Nacional de Colombia; ColombiaFil: Seco, José M.. Universidad del País Vasco; EspañaFil: Soria, Delia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentin
Tin(IV) chalcogenide complexes:single source precursors for SnS, SnSe and SnTe nanoparticle synthesis

A family of tin(IV) bis(hexamethylsilylamide) complexes 2 – 9 have been synthesized by reaction of [Sn{N(SiMe3)2}2] ( 1 ) with the diphenyl dichalcogenanes Ph2E2 (E = S, Se, Te), the radical species TEMPO, or the group 16 elements to form the complexes [(PhE)2Sn{N(SiMe3)2}2] ( 2 – 4 ) and [(TEMPO)2Sn{N(SiMe3)2}2] ( 5 ), and [{(Me3Si)2N}2Sn(µ2-E)]2 ( 6 – 9 ) (E = S, 2 & 6 ; E = Se 3 & 7 ; E = Te, 4 & 9 , E = O2, 9 ). The isolated tin complexes were characterized by elemental analysis, NMR spectroscopy, and the molecular structures of the complexes were determined by single crystal X-ray diffraction. Thermogravimetric analysis showed complexes 2 – 4 and 6 – 8 all to have residual masses close to those expected for the formation of the corresponding “SnE” systems. Complexes 2 – 4 and 6 – 8 were also assessed for their utility in the formation of nanoparticles. The materials obtained were characterized by powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray analysis (EDX). Analysis showed formation of SnSe and SnTe from complexes 3 – 4 and 6 – 7 , respectively
Synthesis, structure and solution studies on mixed aryl/alkyl lithium zincates

Novel homo- and heteroleptic lithium zincates have been prepared by cocomplexation reactions of Zn(CH2SiMe3)2 and PhLi in low-polarity hydrocarbon solvents. X-ray crystallographic studies of products obtained by reacting the organometallic reagents in benzene or toluene yield the novel solvent-free solid-state arrangement [Li4Zn3Ph5(CH2SiMe3)5]⋡ (1). Combining Zn(CH2SiMe3)2 and PhLi in hexane in the presence of the polydentate N-donors PMDETA (N,N,N′,N′′,N′′-pentamethyldiethylenetriamine) or TMEDA (N,N,N′,N′-tetramethylethylenediamine) reveals monomeric heteroleptic [(PMDETA)LiZn(CH2SiMe3)2Ph] (2) and homoleptic [(TMEDA)LiZn(CH2SiMe3)3] (3), the result of a disproportionation process, respectively. NMR spectroscopic studies suggest that 2 and 3 retain their discrete contacted ion-pair solid-state structures in benzene solution. Variable-temperature NMR spectroscopic studies of 2 in [D8]THF reveal a complex equilibrium also including [LiZn(CH2SiMe3)3], [LiZn(CH2SiMe3)Ph2] and [LiZnPh3], an equilibrium process analogous to that of 1 in THF. This study further highlights the complexity of these reactions, which at first would appear simple
Crystallographic Insight into the Mg2+ Coordination Mode and N(SO2CF3)2– Anion Conformation in Mg[N(SO2CF3)2]2 and Its Adducts

Magnesium bis(trifluoromethylsulfonyl)amide (Mg[TFSA]2) and its adducts ([Mg(L)n][TFSA]2) with common ligands (L) such as ethanol, ethyl acetate, and water, namely [Mg(C2H5OH)4][TFSA]2, [Mg(C2H5OH)6][TFSA]2, [Mg(C2H5OOCCH3)2][TFSA]2, [Mg(H2O)2][TFSA]2, and [Mg(H2O)6][TFSA]2(H2O)2, have been prepared and characterized by single-crystal X-ray diffraction and Raman spectroscopy. In every case, Mg2+ is octahedrally coordinated by six O atoms of TFSA– and/or the ligand. The crystal structure of Mg[TFSA]2 indicates the presence of disordered cis (12 %) and trans (82 %) ligand anion conformers. [Mg(C2H5OH)4][TFSA]2 appears to be a new example of a coordination compound in which the TFSA– anions adopt a trans conformation while bonded to the metal core. The crystallographic data has allowed us to propose a scheme of stepwise σ-donor ligand coordination to the Mg2+ core in Mg[TFSA]2 and [Mg(L)n][TFSA]2 salts. This scheme is consistent with the literature data and indicates that the conformation of TFSA– anions in [Mg(L)n][TFSA]2 depends on the number of ligands coordinated to the Mg2+ core, regardless of the ligand
Triheterometallic lanthanide complexes prepared from kinetically inert lanthanide building blocks.

Three molecular structures, each containing three different lanthanide(III) centres, have been prepared by coupling three kinetically inert lanthanide(III) complexes in an Ugi reaction. These 2 kDa molecules were purified by dialysis and characterised by NMR and luminescence techniques. The photophysical properties of these heterotrimetallic complexes were investigated and are discussed by comparison with simpler, but related, heterodimetallic compounds. It was found that an aminonaphthalene unit inhibits the sensitisation of terbium, and that the spatial arrangement of the chromophores and lanthanide(III) centres in these molecules inhibits the efficient sensitisation of europium. We conclude that the intramolecular collisions required for efficient Dexter energy transfer from the sensitiser to the lanthanide(III) centre can be prevented by steric congestion
A triarylated 1,2,3-triazol-5-ylidene ligand with a redox-active ferrocenyl substituent for rhodium(I)-catalyzed hydroformylation of 1-octene

A series of rhodium(I)–1,2,3-triazol-5-ylidene (trz) complexes are described, containing
either a novel triarylated trz ligand A′ (N1, N3-arylated, C4-ferrocenyl) {complexes 1,
[Rh(A′)Cl(cod)]; 4, [Rh(A′)Cl(CO)2]}, or N3-alkylated triazolylidenes with a C4-ferrocenyl {2,
[Rh(B′)Cl(cod)]; 5, [Rh(B′)Cl(CO)2]} or C4-phenyl substituent {3, [Rh(C′)Cl(cod)]; 6,
[Rh(C′)Cl(CO)2]}. The free mesoionic carbene (MIC) A′ is structurally characterized and its
electronic properties evaluated by employing the complex [Pd(Br)2(iPr2-bimy)(A′)] (7) in an
NMR spectroscopic analysis method. The redox activity of A′ is exploited, and the chemically
oxidized precursor Aox and complex 4ox are isolated. The mesoionic carbene complexes 1–
3, as well as in situ oxidized 1ox, are used as homogeneous catalysts for the
hydroformylation of 1-octene for the first time, and the influence of chemical oxidation of
the catalyst on the activity and chemo- and regioselectivity of the catalyst precursor 1 is
evaluated.F. D. and T. W. gratefully acknowledge financial support from the Fonds der Chemischen
Industrie (FCI). G. S. S. gratefully acknowledges financial support from the University of Cape
Town and the NRF-DST Centre of Excellence in Catalysis (C*Change). D. I. B. and D. A.
gratefully acknowledge the National Research Foundation, South Africa (NRF 87890, 97202
and 104205), and Sasol Technology R&D Pty. Ltd., South Africa for financial support.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1099-0682c2018-03-31hb2017Chemistr
α-Diimine–Palladium Complexes Incorporated in Vinylic- Addition Polynorbornenes: Synthesis and Catalytic Activity

Producción Científicaα-Diimine polymeric ligands have been synthesized using the bicyclic norbornane structure, present in vinylic-addi- tion polynorbornene ( VA-PNB). The VA-PNB–diimine ligands have been prepared by functionalization of the copolymer ob- tained by Ni-catalyzed polymerization of norbornene and nor- bornenylcarbonate. Immobilized palladium complexes of the type VA-PNB–diimine–PdX2 have been prepared, and their cata- lytic activity has been tested. The trifluoroacetato complex (X =CF3COO) can be used as a recyclable precatalyst in the Suzuki reaction. It is the source of minute amounts of homogeneous palladium active species, which carry out the catalysis with high turnover numbers. The recovered polymeric complex can be reused several times with no significant loss of activity. The polymeric analogue to Brookhart's catalyst, VA-PNB–diimine– PdMeCl, can also polymerize ethylene, although it is less active than its monomeric counterparts.MINECO-SGPI, grant CTQ2013-48406-PMINECO-SGPI, grant CTQ2016-80913-PJunta de Castilla y León,  grant VA302U1
One-step synthesis of 2,5-bis(chloromethyl)-1,4-dioxane from epichlorohydrin using ZIF-8, taking advantage of structural defects

We demonstrate herein the ZIF-8-only-mediated catalysis of the cyclodimerization of epichlorohydrin to 2,5-bis(chloromethyl)-1,4-dioxane in the absence of co-catalyst and solvent. The easy handling and economic aspects of ZIF-8, in addition to the one-step reaction to produce the cyclodimer, make this catalyst attractive even for industry. It has been clearly illustrated that the nature of the method used to synthesize ZIF-8 affected the yields of the cyclodimers. Specifically, the method employed to produce ZIF-8 directly influences the amount of crystal structural defects, which in turn impacts their performance as catalysts. To emphasize the role of defects, other physical properties, such as surface area and particle size, were controlled during the synthesis of the ZIF-8 catalysts. Remarkably, the amount of structural defects was quantified by temperature program desorption analysis
Electronic-Structure Calculations of Cation-Ordered II-III Layered Double Hydroxides: Origin of the Distortion of the Metal-Coordination Symmetry

Cation ordering brings down the crystal symmetry and introduces distortion into the coordination polyhedra around the divalent cations. In particular, edge sharing of the differently sized M(OH)6 polyhedra causes a non-uniform distension of the array of hydroxy ions. The question arises as to whether this distortion has its origin in the Jahnâ��Teller distortion of metal coordination or a 2D â��Peierlsâ��-type distortion of the array of hydroxy ions. To address this question, DFT calculations were performed on the sulfate-intercalated Cuâ��Cr, Znâ��Cr, and Znâ��Al layered double hydroxides (LDHs). An analysis of the density of states shows that the distortion of the Cu2+ coordination polyhedron is due to the Jahnâ��Teller effect, whereas the Zn2+ coordination polyhedron in Znâ��Al LDH likely suffers a â��Peierlsâ��-type distortion. In the Znâ��Cr LDH, electronic-structure calculations do not predict any distortion in the metal coordination, which is in agreement with experimental results that show only a slight departure from ideal symmetry. Â© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei
Antiferromagnetic Interactions in Copper(II) µ-Oxalato Dinuclear Complexes: The Role of the Counterion

We report the preparation, crystal structure determination, magnetic properties and DFT calculations of five oxalato‐bridged dicopper(II) complexes of formula [Cu2(bpy)2(H2O)2(C2O4)](CF3SO3)2 (1), [Cu2(bpy)2(C2O4)](PF6)2 (2), [Cu2(bpy)2(C2O4)](ClO4)2 (3), [Cu2(bpy)2Cl2(C2O4)]·H2O (4) and [Cu2(bpy)2(NO2)2(C2O4)] (5) (bpy = 2,2′‐bipyridine and C2O42– = oxalate). Compounds 1, 2, 4 and 5 crystallize in the monoclinic system and 3 crystallizes in the triclinic system. The oxalate ligands in 1–5 adopt the bis‐bidentate coordination mode and the two bpy molecules act as terminal ligands. The coordination of the counterions and the surroundings of the copper(II) ions differentiate the five compounds. The four nearest neighbours of copper(II) in 1–4 are roughly in the plane of the CuC2O4Cu framework, whereas they are in an almost perpendicular plane in 5. Using the isotropic Hamiltonian H = –J S1·S2, where S1 and S2 are the spin quantum operators for Cu1 and Cu2; J is –384 cm–1 for 1, –392 cm–1 for 2 and –387 cm–1 for 3, slightly decreasing to –328 cm–1 for 4 and falling to –14 cm–1 for 5. The influence of the anions on the magnetic properties of this family of compounds is explained by the changes in the overlap of the magnetic orbitals through the oxalate bridge. DFT calculations reproduce well the experimental values of J and provide an illustration of the magnetic orbital