Coordination Sphere Of Ions Research Articles

Photofunctional Lanthanoid Complexes, Coordination Polymers, and Nanocrystals for Future Photonic Applications

Abstract In this account, lanthanoid complexes, coordination polymers, and nanocrystals with photofunctional properties are introduced. To maintain the effective emission of Nd(III), Sm(III), Eu(III), Tb(III), and Yb(III) ions in organic media, the coordination sphere of the lanthanoid ions should consist of strong, bulky, and asymmetric ligands with low vibrational frequencies, that is, there are three criteria for luminescence: 1) suppression of vibrational relaxation, 2) prevention of nonradiative cross relaxation at diffusional collision, and 3) introduction of asymmetric coordination geometry for enhancing electric dipole transition. Lanthanoid coordination compounds with characteristic photosensitizing properties, photochromic properties, circularly polarized luminescence (CPL), metal ion sensing properties, solvent sensing properties, energy-conversion properties, thermostable properties, triboluminescent properties, and thermosensing properties are also described for the development of photofunctional materials. In the second half, the synthesis, photophysical magnetic, and magneto-optical properties of lanthanoid nanocrystals, EuO, EuS, and EuSe, are reported. In particular, the remarkable photophysical properties of nanoaggregates composed of EuS nanocrystals are presented. Photofunctional lanthanoid(III) complexes, coordination polymers, and nanocrystals are expected to open up a frontier field of materials science.

Quantum chemical study of inner-sphere complexes of trivalent lanthanide and actinide ions on the corundum (110) surface

Summary Sorption plays a major role in the safety assessment of nuclear waste disposal. In the present theoretical study we focused on understanding the interaction of trivalent lanthanides and actinides (La3+, Eu3+ and Cm3+) with the corundum (110) surface. Optimization of the structures were carried out using density functional theory with different basis sets. Additionally, Møller-Plesset perturbation theory of second order was used for single point energy calculations. We studied the structure of different inner-sphere complexes depending on the surface deprotonation and the number of water molecules in the first coordination shell. The most likely structure of the inner-sphere complex (tri- or tetradentate) was predicted. For the calculations we used a cluster model for the surface. By deprotonating the cluster a chemical environment at elevated pH values was mimicked. Our calculations predict the highest stability for a tetradentate inner-sphere surface complexes with five water molecules remaining in the first coordination sphere of the metal ions. The formation of the inner-sphere complexes is favored when a coordination takes place with at most one deprotonated surface aluminol group located beneath the inner-sphere complex. The mutual interaction between sorbing metal ions at the surface is studied as well. The minimal possible distance between two inner-sphere sorbed metal ions at the surface was determined to be 530 pm.

Structural and functional comparison of manganese-, iron-, cobalt-, nickel-, and copper-containing biomimic quercetinase models

A series of divalent transition metal (Mn, Fe, Co, Ni, and Cu) flavonolate (Fla) complexes MII(Fla)(L1), and MII(Fla)(L2)X (X=Cl or ClO4) with the ligands N-propanoate-N,N-bis(2-pyridylmethyl)amine (L1=HPBMPA) and N-methylpropanoate-N,N-bis(2-pyridylmethyl)amine (L2=MPBMPA) have been prepared and characterized by spectroscopic methods and two cases by X-ray crystal analysis. The coordination sphere of the central ions is distorted octahedral with N3 or N3O donor sets, which are good structural models for the cupin-type metal-containing flavonol 2,4-dioxygenases (FDO). The dioxygenation of the metal flavonolate complexes results in the oxidative cleavage of the heterocyclic ring to give the corresponding O-benzoylsalicylate complexes and carbon monoxide as biomimic FDO models. The bathochromic shift of the absorption band I (π–π∗) of the coordinated flavonolate is influenced by the metals, and a linear correlation was observed between the logarithm of the reaction rate constant with O2 and the degree of the bathochromic shift (Δλ), providing a mechanistic insight into the stoichiometric dioxygenation reactions.

Influence of metal ions on thermal generation of carbohydrate radicals in native and modified starch studied by EPR

AbstractInfluence of enrichment with ions from alkali (K), alkali‐earth (Mg) and d transition (Cu, Fe) metal groups of native and modified starches on the process of carbohydrate radicals generation has been studied using electron paramagnetic resonance (EPR) spectroscopy. This technique allows following the character and amount of created radicals, as well as the changes in coordination sphere of transition metal ions incorporated into starch matrix. The main difference between transition metal ions and the ions of alkali and alkali‐earth metals consisted in the character of their interactions with functional groups of starch. Transition metal ions coordinated glucose units of starch and influenced the mechanism of carbohydrate radical formation independently of the kind of starch modification. Interaction of starch, native and modified, with ions of alkali and alkali‐earth metals did not change the mechanism of radical generation, however, influenced their number. Contents of total metal ions found analytically by spectroscopic methods and by EPR allowed determination of the amount of transition metal ions engaged in interactions with starch matrix, as well as the differentiating of native and modified starch in respect of their metal ions adsorptive ability.

Comparative study of structures, thermal stabilities and dielectric properties for a ferroelectric MOF [Sr(μ-BDC)(DMF)]∞ with its solvent-free framework

A ferroelectric MOF with a formula [Sr(μ-BDC)(DMF)]∞ (1) was transformed into [Sr(μ-BDC)(CH2Cl2)x]∞ (2) using a solvent exchange approach, where DMF = N,N-dimethylformamide and BDC(2-) = benzene-1,4-dicarboxylate. The lattice solvents, CH2Cl2 molecules, in 2 were removed by heating to give the solvent-free metal-organic framework [Sr(μ-BDC)]∞ (3) and the crystal-to-crystal transformation is reversible between 1 and 3. The release of DMF molecules from 1 results in the metal-organic framework of [Sr(μ-BDC)]∞ expanding a little along the a- and b-axes. The crystal structure optimizations for 1 and 3 disclosed that the lattice expansion is associated with the alternations of the bond distances and angles in the Sr(2+) ion coordination sphere along the a- and b-axes directions. The metal-organic framework 3 collapses at temperatures of more than 600 °C; such an extremely high thermal stability is related to the closed-shell electronic structure of the Sr(2+) ion, namely, the coordinate bond between the closed-shell Sr(2+) ion and the bridged BDC(2-) ligands does not have a preferred direction, which is favored for reducing lattice strains and is responsible for the higher thermal stability. The comparative investigations for the dielectric and ferroelectric behaviors of 1 and 3 confirmed that the motion of the polar DMF molecules, but not the [Sr(μ-BDC)]∞ framework, is responsible for the ferroelectric properties of 1.

Electrochemical Behavior of Iron and Magnesium in Ionic Liquids

In this work, the electrochemical behavior of Mg and Fe in ionic liquids (IL) were studied. We performed a series of cyclic voltammetry experiments to improve the understanding of Mg behavior in an IL containing the bis(trifluoromethanesulfonylimide) ([Tf2N]) anion. The results show an irreversible deposition/dissolution of Mg at a high water concentration (ca. 1300 ppm, 50 mmol L-1) and very low reversibility (7.3%) at a moderate water concentration (ca. 65 ppm, 5 mmol L-1). The formation of a film on the electrode surface and the presence of Mg were confirmed by scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS). The process irreversibility indicates the formation of a passivating film. Because the presence of water affects the reversibility of the process, studies of Fe deposition/dissolution were conducted in two different ILs and with microelectrodes to evaluate how the water modifies the reversibility and the diffusion of ions. Water plays an important role in the reversibility of Fe deposition/dissolution being that deposition is less reversible when water is absent. The Fe diffusion is also modified because the Fe ion coordination sphere is strongly affected by the presence or absence of water; the Fe diffusion was also shown to depend on the coordination ability of the cation.

The Structure of Human DNase I Bound to Magnesium and Phosphate Ions Points to a Catalytic Mechanism Common to Members of the DNase I-like Superfamily

Recombinant human DNase I (Pulmozyme, dornase alfa) is used for the treatment of cystic fibrosis where it improves lung function and reduces the number of exacerbations. The physiological mechanism of action is thought to involve the reduction of the viscoelasticity of cystic fibrosis sputum by hydrolyzing high concentrations of DNA into low-molecular mass fragments. Here we describe the 1.95 Å resolution crystal structure of recombinant human DNase I (rhDNase I) in complex with magnesium and phosphate ions, both bound in the active site. Complementary mutagenesis data of rhDNase I coupled to a comprehensive structural analysis of the DNase I-like superfamily argue for the key catalytic role of Asn7, which is invariant among mammalian DNase I enzymes and members of this superfamily, through stabilization of the magnesium ion coordination sphere. Overall, our combined structural and mutagenesis data suggest the occurrence of a magnesium-assisted pentavalent phosphate transition state in human DNase I during catalysis, where Asp168 may play a key role as a general catalytic base.

Iridium(III) products isolated in a reaction of IrCl3 with phenyl 2-pyridyl ketoxime

Abstract Synthesis and properties of two iridium(III) complexes (1 and 2) isolated from the same system upon change in organic solvent, are presented. 1 is a mononuclear compound with two bidentate oxime ligands linked by a strong intramolecular hydrogen bond and with two chlorido ligands in the central Ir3+ ion coordination sphere. 2 is a binuclear centrosymmetric anionic complex with two Ir3+ ions double-bridged by chlorido ligands and three terminal chlorido ligands further coordinated to two sodium cations to form a characteristic aggregate with acetonitrile molecules completing coordination spheres of the metal ions. Both 1 and 2 may help to develop a route to products analogous to Co(II) SMMs (Single Molecule Magnets) also as starting materials.

Metal Ions Do Not Play a Direct Role in the Formation of Carbon-Carbon Triple Bonds during Reduction of Trihaloalkyls by CrIIor VII

Carbyne radicals: Reactions of trihaloalkyl compounds with Cr(2+) or V(2+) in aqueous solutions yield alkynes and other products. Stepwise halogen abstractions from the trihaloalkyls form alkyl carbyne triradicals in solution. These radicals undergo coupling reactions, producing triply bonded alkyne molecules (see scheme). This process is not metal-assisted and does not occur in the coordination sphere of the metal ions.

Two‐Step Spin Transition in an Iron(II) Coordination Network Based on Flexible Bitopic Ligand 1‐(Tetrazol‐1‐yl)‐3‐(1,2,3‐triazol‐1‐yl)propane

AbstractFlexible bitopic ligand 1‐(tetrazol‐1‐yl)‐3‐(1,2,3‐triazol‐1‐yl)propane (ptrtz) reacts with Fe(ClO4)2·6H2O to form two‐dimensional (2D) coordination network [Fe(ptrtz)3](ClO4)2·MeCN (1) in which two chemically different spin crossover (SCO) FeII centers are observed. Although two 1,2,3‐triazole and four tetrazole rings are in the first coordination sphere of the Fe1 ions, Fe2 ions are coordinated to four 1,2,3‐triazole and two tetrazole rings. Symmetry‐related FeII ions are bridged by two disordered ptrtz molecules resulting in the formation of chains that are extended in the same direction. Alternately arranged chains containing Fe1 or Fe2 ions are cross‐linked by single ptrtz molecules to form 2D layers. At room temperature, the complex remains in a high‐spin (HS) form (χMT = 3.46 cm3 K mol–1). Spin crossover in 1 occurs in two steps separated by an inflection point at 140 K (χMT = 2.68 cm3 K mol–1, γHS ≈ 0.76). The first step is gradual and between 220 and 140 K about a quarter of all the iron(II) ions change their spin state (T1↓ = T1↑ = 165 K). Single‐crystal X‐ray diffraction studies revealed that upon lowering the temperature from 220 to 140 K, spin crossover occurs for only half of the iron(II) ions occupying Fe2 sites. It is accompanied by an alteration of the occupancy factor of ptrtz molecules bridging the Fe2 ions. Iron(II) ions occupying Fe1 sites remain in the HS form, which inhibits compression of the polymeric layer in the Fe1···Fe1 and Fe2···Fe2 linking direction. Upon further lowering the temperature, iron(II) ions occupying Fe1 sites and the rest of the iron(II) ions occupying Fe2 sites change their spin state. The second step of the spin transition is very abrupt and is accompanied by a hysteresis loop (T2↓ = 90 K, T2↑ = 96 K). The change in the spin state by iron(II) ions occupying Fe1 and Fe2 sites involves, contrary to first step, a significant shortening of the Fe1···Fe1 and Fe2···Fe2 separations.

Mononuclear manganese(II) complexes of phenyl 2-pyridyl ketoxime – models for studies of Q-band EPR properties

Abstract Structure and properties of a series of mononuclear manganese(II) complexes with phenyl 2-pyridyl ketoxime (ppkoH) as ligand are presented. [Mn(ClC6H4COO)2 (ppkoH)2] · 0.5 CH3OH and [Mn(ClC6H4COO)2(ppkoH)2](1 and 2) are isolated from the same reaction system and differ by disordered solvent content and conformation of the complex molecules. [MnCl2(ppkoH)2] · 0.02 C2H5OH(3) was obtained in order to modify the central Mn2+ ion coordination sphere with respect to 1/2. Strong intramolecular hydrogen bonds of the O–H···O and O–H···Cl type are present in 1/2 and 3, respectively. Moreover, weak C–H···O (1–3), C–H···Cl (3), π···π (1–2) and Cl···π (2) contacts can be found. The complexes display well-resolved Q-band EPR spectra and may serve as model compounds for further studies.

Cleavage of a CC bond during a solvothermal process leading to a mononuclear rhenium(III) product

A new system is reported, where solvothermal conditions lead to a cleavage of a CC bond in 2,2′-bipyridine-3,3′,6,6′-tetracarboxylic acid, that might be catalyzed by the starting rhenium salt, ammonium hexachloridorhenate(IV). The resulting product (1) is a rhenium(III) complex, including the applied ligand and its decomposition product in the Re3 + ion coordination sphere. 1 is characterized by X-ray diffraction, magnetic and spectroscopic, as well as TGA property measurements.

Editorial

Wolfgang Beck was born, together with his twin brother Reinhard, in Munich on May 5, 1932. As a student in Gymnasium his interests included soccer, skiing, tennis, music and, of course, chemistry. Now, at eighty, Prof. Beck is in very good shape, both physically and mentally. He plays an excellent weekly game of tennis, plays his electronic organ and pays regular visits to concerts and the theater. After finishing Gymnasium in 1952, he began studying chemistry at the Technische Hochschule München (now the Technische Universität München) under such academic luminaries as Hieber, Goldschmidt, Schiebe and Patat. After becoming a Diplomchemiker in 1957, he joined Walter Hieber's group and earned his Ph.D. in 1959. His thesis was entitled “On the structure of some metal carbonyl and nitrosyl compounds” and dealt with nitrosylhalides of iron and cobalt, and X-bridged dimers of the type [}Fe(ν- X)(CO)3}2] (X1S, Se, SR, SeR). Prof. Beck became a specialist in IR spectroscopy as an analytic tool for transition- metal complexes of pseudohalides (fulminate, azide) and started his independent research for his Habilitation on fulminate metal complexes (1963). Some highlights of his early research were the determination of the structure of fulminic acid H-CNO by IR, the improvement of the stability of anionic azide complexes by using large cations and the cycloaddition reactions of azide ligands in metal complexes (under very mild conditions). His successes were crowned in 1968 when he became Full Professor of Inorganic and Analytical Chemistry at the Ludwig-Maximilians-Universität München. There he initiated and developed several promising areas of research which are still highly relevant today: – Metal complexes of dyes (such as indigo) and stable radicals – Reactions of metal carbonyls with thiiranes and aziridines – Metal complexes of biologically important ligands (amino acids, peptides, sugars, steroids, nucleobases) and the anti-tumor activity of platinum complexes: pioneering work in the field of bioorganiometallic chemistry – Metal-mediated formation of peptides – Strong organometallic Lewis acids: metal complexes with weakly coordinating anions – Directed synthesis of hydrocarbon-bridged metal complexes Prof. Beck has guided around one-hundred-and-fifty coworkers and the results of their work have been published in more than six-hundred-and-fifty papers and several reviews. His success and high regard in the world of science have been honored with guest professorships such as one at the University of Wisconsin in 1977, offers of professorships at the universities at Marburg (1967) and Hamburg (1977) and by many awards such as the Karl-Winnacker Stipendium (1966), the Chemistry Award by the Academy of Science, Göttingen (1967), the Liebig Denkmünze of the German Chemical Society (1994), the Lavoisier Medal for Bioinorganic Chemistry (2002) and last, but not least, an honorary doctorate from the Technische Universität München (2011). He has been a member of the editorial boards of several scientific journals and a referee of the Deutsche Forschungsgemeinschaft (DFG, 1981-1992). In addition to his research activities, Wolfgang Beck was engaged in academic administration as Director of the Institute of Inorganic Chemistry, Dean of the Department of Chemistry and Pharmacy, and was a member of the LMU Senate. Wolfgang Beck has always enjoyed giving seminars and lectures, a pleasure shared by his students. Especially popular was his introductory experimental lecture in chemistry for first-year students, a lecture sometimes accompanied by Beck's beer... Although we regret his decision to retire in 2000, Wolfgang Beck continues to be active. He can be found in his office almost every day and publishes from ten to fifteen papers annually, a number that can be favorably compared to those of his non-retired colleagues. His last review, on the formation of peptides within the coordination sphere of metal ions appeared in the Z. Anorg. Allg. Chem. 2011, 637, 1647-1672. Now, in 2012, Wolfgang Beck claims that he is running out of material to work on. Nevertheless, he is sometimes seen in one of the labs trying to produce single crystals of compounds that were not fully characterized in the past. Thus, together with his colleagues Professors Evers and Klapötke, he was recently able to solve the structure of the historically interesting “Knallquecksilber”, a result which was met with public interest. Beck's latest project is writing the history of chemistry at the Ludwig-Maximilians-Universität from 1930 to 2000. For that, and for his constant personal engagement, the whole “chemistry family” wishes him good fortune and a long and healthy life. Prof. Dr. Ingo-Peter Lorenz LMU Munich, Germany

Photolariats: synthesis, metal ion complexation and photochromism

Photolariat development, as an extension to the family of synthetic photochromic crown ether receptors, or photocrowns, is reported. Incorporated additional chelating groups, namely two anisoles or thioanisoles, contribute in completing the metal ion coordination sphere with different affinities and selectivities for a range of ions. Single-crystal X-ray diffraction analysis suggests that the thermally stable trans-form of the receptor is unsuitable for ion binding, consistent with spectrophotometric and NMR titration results, which is largely improved in the cis-form as the basis for the photocontrolled ion coordination/ejection. In terms of the azobenzene-containing receptor photochemistry, a photostationary state highly enriched in the cis-form (94:6, cis-/trans-) is reached, with slow thermal return (1.1–1.4 × 10− 5 s− 1) in the dark, which can undergo multiple cycles without discernable photodegradation.

Metal-ion rescue revisited: Biochemical detection of site-bound metal ions important for RNA folding

Within the three-dimensional architectures of RNA molecules, divalent metal ions populate specific locations, shedding their water molecules to form chelates. These interactions help the RNA adopt and maintain specific conformations and frequently make essential contributions to function. Defining the locations of these site-bound metal ions remains challenging despite the growing database of RNA structures. Metal-ion rescue experiments have provided a powerful approach to identify and distinguish catalytic metal ions within RNA active sites, but the ability of such experiments to identify metal ions that contribute to tertiary structure acquisition and structural stability is less developed and has been challenged. Herein, we use the well-defined P4-P6 RNA domain of the Tetrahymena group I intron to reevaluate prior evidence against the discriminatory power of metal-ion rescue experiments and to advance thermodynamic descriptions necessary for interpreting these experiments. The approach successfully identifies ligands within the RNA that occupy the inner coordination sphere of divalent metal ions and distinguishes them from ligands that occupy the outer coordination sphere. Our results underscore the importance of obtaining complete folding isotherms and establishing and evaluating thermodynamic models in order to draw conclusions from metal-ion rescue experiments. These results establish metal-ion rescue as a rigorous tool for identifying and dissecting energetically important metal-ion interactions in RNAs that are noncatalytic but critical for RNA tertiary structure.

Gold–silver-nanoclusters having cholic acid imprinted nanoshell

Molecular imprinted polymers (MIPs) as a recognition element for sensors are increasingly of interest and MIP-nanoparticles have started to appear in the literature. In this study, we have proposed a novel thiol ligand-capping method with polymerizable methacryloylamido-cysteine (MAC) attached to gold–silver-nanoclusters reminiscent of a self-assembled monolayer and have reconstructed surface shell by synthetic host polymers based on molecular imprinting method for cholic acid recognition. In this method, methacryloylamidohistidine–Pt(II) [MAH–Pt(II)] has used as a new metal-chelating monomer via metal coordination–chelation interactions and cholic acid. Nanoshell sensors with templates give a cavity that is selective for cholic acid. The cholic acid can simultaneously chelate to Pt(II) metal ion and fit into the shape-selective cavity. Thus, the interaction between Pt(II) ion and free coordination spheres has an effect on the binding ability of the gold–silver-nanoclusters nanosensor. The binding affinity of the cholic acid imprinted nanoparticles have investigated by using the Langmuir and Scatchard methods and determined affinity constant (Kaffinity) has found to be 2.73×104molL−1 and 2.13×108molL−1, respectively. At the last step of this procedure, cholic acid level in blood serum and urine which belong to a healthy people were determined by the prepared gold–silver-nanoclusters.

Preparation of new molecularly imprinted nanosensor for cholic acid determination

Molecular imprinted polymers (MIPs) as a recognition element for sensors are increasingly of interest and MIP-nanoparticles have started to appear in the literature. In this study, we have proposed a novel thiol ligand-capping method with polymerizable methacryloylamido-cysteine (MAC) attached to gold nanoparticles, reminiscent of a self-assembled monolayer and have reconstructed surface shell by synthetic host polymers based on molecular imprinting method for recognition. In this method, methacryloylamidohistidine-Pt(II) [MAH-Pt(II)] has used as a new metal-chelating monomer via metal coordination–chelation interactions and cholic acid. Nanoshell sensors with templates give a cavity that is selective for cholic acid. The cholic acid can simultaneously chelate to Pt(II) metal ion and fit into the shape-selective cavity. Thus, the interaction between Pt(II) ion and free coordination spheres has an effect on the binding ability of the gold nanoparticles nanosensor. The binding affinity of the cholic acid imprinted nanoparticles has investigated by using the Langmuir and Scatchard methods and determined affinity constant (Kaffinity) were found as 1.48×104molL−1 and 6.59×106molL−1, respectively. At the last step of this procedure, cholic acid level in blood serum and urine which belong to healthy people was determined by the prepared Au nanosensor.

Cage-like manganesephenylsiloxane with an unusual structure

A polyhedral (manganese,sodium)phenylsiloxane of the composition (C6H5SiO1,5)20(MnO)8(NaO0,5)12·2NaOH·15C2H5OH·11 H2O (the molecular formula is C150H214Mn8Na14O72Si20) was synthesized. This compound possesses the earlier undescribed shape of the cage and a rare combination of silanolate anions Si-O− and metalloxide fragments Mn-O-Mn in one structure. The coordination sphere of Mn ions is filled with silanolate anions, the O atoms in the fragments Mn-O-Si, Mn-O-Mn, and encapsulated molecules of water. The molecules of solvate ethanol are coordinated exclusively with Na+ cations and are not involved into coordination sphere of MnII ions.

Metal Complexes of Biologically Important Ligands, CLXXVI.[1] Formation of Peptides within the Coordination Sphere of Metal Ions and of Classical and Organometallic Complexes and Some Aspects of Prebiotic Chemistry

AbstractThe formation of peptide bonds in the neighborhood of metal ions is reviewed. The metal ions can function as activating and catalytic groups; they can act as templates. Metal ions can play a role as stabilizing spectators when peptides are formed within their ligands and they are able to protect the amino or carboxylate group of amino acids during peptide synthesis. Some related chemistry of metal‐peptide conjugates is included. This survey represents an attractive combination of coordination, organic, organometallic chemistry and biochemistry and reveals some interesting aspects of prebiotic chemistry.

“Fluoride molecular scissors”: A rational construction of new Mo(VI) oxofluorido/1,2,4-triazole MOFs

Abstract New molybdenum(VI) oxofluoride-organic hybrids, [Mo2F2O5(tr2ad)] (1) and [Mo2F2O5(tr2ad2)] (2), supported by angular or linear N1,N2-(1,2,4-triazol-4-yl) bridges (tr2ad, 1,3-bis(1,2,4-triazol-4-yl)adamantane; tr2ad2, 3,3′-bis(1,2,4-triazol-4-yl)-1,1′-biadamantane), were prepared in an aqueous HF solution under hydrothermal conditions. The structure of the compounds includes dinuclear corner-sharing {Mo2F2O5} cores, in which two octahedral Mo ions are linked by one oxygen atom (Mo-O 1.90–1.92 A) and two triazolyl groups (Mo-N 2.37–2.40 A). The latter occupy the cis-positions in the {Mo2F2O5(tr)2} coordination clusters (“secondary building blocks”). Terminal fluoride and two “molybdenyl” oxygen atoms complete the coordination sphere of each molybdenum ions. In both cases the ligands show the maximal tetradentate mode connecting the adjacent inorganic units into a zigzag chain.