The incorporation of luminescent lanthanide complexes into structurally organized solid matrices is of broad interest in materials science, as it enables the development of functional materials with diverse optical properties. In this work the successful preparation of a luminescent stable new hybrid material was carried out. A regular MCM-41 type mesostructured silica was used as support for immobilizing a photostable ternary tetraphenylimidodiphosphinate (tpip)-Eu3+ complex with the co-ligand 1,10-phenantroline (phen). The complex was immobilized using the pore volume impregnation method in dichloromethane. Spectroscopic and photophysical features were analyzed by powder X-ray diffraction, SEM, N2 adsorption/desorption, TGA, UV-Vis and FTIR diffuse reflectance, 29Si solid state NMR spectroscopy and photoluminescence spectroscopy allowing to gather evidence concerning enhanced (photo)stability of the complex upon immobilization.

Molybdenum-based CO-releasing molecules (CORMs) are attracting interest for biological and therapeutic applications. In this work two new complexes, [Mo(η3-C3H5)X(CO)2(Hpypz)] [X = Cl (1), Br (2); Hpypz = 3-(2-pyridyl)pyrazole] have been synthesized, characterized, and evaluated for their CO-release capacity, as well as antimicrobial and anticancer potential. The evaluation of the CO-release properties by the deoxymyoglobin‑carbonmonoxymyoglobin assay showed that the two complexes are comparably slow CO releasers in aqueous systems, showing a half-life of several hours, and sustained CO release over the course of the assay (6 h). Studies of biological activity were performed with complex 1 due to its better aqueous solubility. The antibacterial activity was investigated by determination of the minimum inhibitory and minimum bactericidal concentrations with the microdilution assay for gram-positive methicillin-resistant Staphylococcus aureus (MRSA) and gram-negative Escherichia coli strains. Complex 1 displayed appreciable concentration-dependent bactericidal activity against both strains. The cytotoxicity of complex 1 was evaluated on human melanoma cells (A375) and immortalized nontumorigenic keratinocytes (HaCaT). Complex 1 exhibited selective cytotoxicity, significantly reducing the cell viability of A375 cells in a dose-dependent manner while having a lower effect on HaCaT cells, suggesting its antitumor potential against melanoma. In contrast, the precursor complex [Mo(η3-C3H5)Cl(CO)2(CH3CN)2] showed reduced activity against A375 cells and higher toxicity toward HaCaT cells, highlighting the beneficial impact of the bidentate 3-(2-pyridyl)pyrazole ligand.

Molybdenum half-sandwich carbonyl complexes continue to attract attention as potential anticancer agents and prodrugs for therapeutic use of carbon monoxide. Building on the known bioactivity and hydrolytic stability of cyclopentadienyl-based Mo fragments, we report the synthesis, structural characterization, and solution behavior of two cationic half-sandwich complexes, [(eta 5-Cp)Mo(CO)2(en)][BF4] (3) and [(eta 5-Ind)Mo(CO)2(en)][BF4] (4) (Cp = cyclopentadienyl, Ind = indenyl, en = ethylenediamine). Complex 3 is described here for the first time, while 4 was structurally characterized by single-crystal X-ray diffraction, revealing a distorted square-pyramidal geometry with cis-CO ligands and a chelating en ligand positioned beneath the indenyl ring. Both compounds are air-stable in the solid state and exhibit enhanced solubility in polar media due to their ionic nature. UV-vis stability studies under simulated physiological conditions (PBS, pH 7.4, 37 degrees C) show gradual decomposition of both complexes, accelerated by visible-light irradiation and/or the presence of air. CO-release behavior was quantified using the myoglobin assay: the allyl precursors [(eta 5-Cp')Mo(eta 3-C3H5)(CO)2] were inert, whereas complexes 3 and 4 released CO slowly, with 4 exhibiting significantly faster thermal CO liberation (t1/2 approximate to 129 min; 0.74 equiv. CO after 6 h). Complex 3 showed minimal thermal CO release but underwent enhanced and sustained photodecarbonylation under visible-light irradiation, enabling controlled CO delivery. These results identify 3 and 4 as rare examples of Mo-based CO-releasing molecules capable of slow, tunable CO release under biologically relevant conditions, with 3 displaying light-responsive behavior and 4 functioning as a spontaneous thermal CO donor.

The metal-catalyzed epoxidation of olefins is an important reaction in organic synthesis, as epoxides are useful intermediates for the production of bulk and fine chemicals. Molybdenum complexes are known as effective catalysts for selective epoxidation with alkyl hydroperoxides as oxidants. Very early on, it was recognized that molybdenum hexacarbonyl could be used directly as a catalyst precursor, being con-verted in situ to a soluble MoVI active species. In recent years this field has expanded greatly with the study of a wide range of group 6 carbonyl complexes as precursors to catalysts and/or functional metal oxides. In this review, pioneering work on the use of group 6 hexacarbonyls, mainly Mo(CO)6, as pre-catalysts is summarized, followed by a comprehensive analysis of recent research in which heteroleptic complexes of the type [Mo(CO)x(L)n] (x = 3 or 4; n = 1 or 3) and [MXm(CO)3(L)n] (M = Mo, W; X = halide; m = 1 or 2; n = 1 or 2) were employed, where L is a N-, O-or P-donor ligand. The topics covered include precursor synthesis and structural chemistry, solvent, oxidant and ligand effects, catalytic applications for the valorization of functionalized and nonfunctionalized olefins, catalyst activation and mechanistic studies. Current understanding about the oxidation of the heteroleptic Mo0/II complexes to oxomolybde-num complexes or hybrid materials is discussed, with a review of the behavior of these compounds as (pre)catalysts for homogeneous or heterogeneous olefin epoxidation.(c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

The unique propertiesof Egyptian blue, a cuprorivaite pigment,were herein studied through a holistic computational and experimentalapproach. A reliable model of the crystal of cuprorivaite was obtainedthrough periodic density functional theory calculations, allowingfor the elucidation of its lattice dynamics, including assessmentof structural, electronic, and vibrational properties. From this model,a sound assignment of the inelastic neutron scattering spectrum wasobtained, along with estimated values of heat capacity and Debye temperature,band-gap values, and magnetic properties of the crystal. Inelasticneutron scattering and diffuse reflectance infrared Fourier transformspectroscopies provided enlightenment on the chemical surfaces ofthe pigment Egyptian blue Rwhich was missing hitherto and iscritical for potential applications of the pigment, such as thoseinvolving host-matrix interactions or requiring surface derivatization Rwhileconfirming the simulation results. On that account, it was found thatthe intensity of the dangling & nu;SiOd mode is ca. 8-13%of the total & nu;SiO modes. Moreover, and regarding the electronicproperties, the band structure confirmed that CaCuSi4O(10) is a direct band-gap semiconductor, with the valence band maximumand the conduction band minimum located at the & UGamma;-point, in boththe alpha (spin-up) and beta (spin-down) density bands. A reliable model of the crystal of cuprorivaitewas achievedvia periodic TDF calculations, which enabled the elucidation of itslattice dynamics, including the evaluation of its structural, electronic,and vibrational properties with implications for its surface chemistryanalysis assessment.

Campholenic aldehyde (CPA), an important flavor and fragrance intermediate, can be obtained by the Lewis acid-catalyzed isomerization of alpha-pinene oxide (PinOx), although achieving high yields ( > 90%) is a difficult challenge due to the high reactivity of the epoxide. In the present work, indenyl-molybdenum(II)bipyridine complexes [IndMo(bipy R )(CO) 2 ](BF 4 ) (bipy R = 2,2 ' -bipyridine (R = H ) or 4,4 ' -disubstituted2,2 ' -bipyridine) have been combined with various ionic liquid solvents to develop an efficient process for the selective conversion of PinOx to CPA under mild (35 degrees C) conditions. Excellent CPA yields (95%) were repeatedly obtained within 1 min reaction time for the easily recyclable catalytic system comprising [IndMo(4,4 ' -dinonyl-2,2 ' -bipyridine)(CO) 2 ](BF 4 ) and choline bis(trifluoromethylsulfonyl)imide.(c) 2022 Elsevier B.V. All rights reserved.

The photoactivatable CO‐releasing molecule (photoCORM) [Mo(CO) 3 (CNCH 2 COOH) 3 ] (ALF795) has been incorporated into a Zn,Al layered double hydroxide (LDH) host by a coprecipitation synthesis strategy. Powder X‐ray diffraction (PXRD) of the resultant material Zn,Al‐ALF795 showed that the ALF795 guest molecules assembled into a monolayer to give a basal spacing of 16.0 Å. FTIR and 13 C{ 1 H} CP MAS NMR spectroscopy confirmed that the molecular structure of the tricarbonyl complex was retained upon intercalation. Scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDS) and elemental analyses confirmed the phase‐purity of Zn,Al‐ALF795. The myoglobin assay was used to demonstrate that intercalated ALF795 retains the photoactive behavior of the free CORM, with a substantial fraction (42 %) of the high CO payload (2.46 mmol g –1 ) being released after exposure to UV light for 3 h under simulated physiological conditions. In addition, gas chromatography was used to track sequential light‐ and H 2 O 2 ‐triggered decarbonylation of free and intercalated ALF795. In biological buffer solution (HEPES), less than 2 % Mo leaching from Zn,Al‐ALF795 took place after 5 h, showing the strong capacity of the LDH host to retain the unaltered complex and decarbonylation fragments.

The complex [MoO(O-2)(2)(pyrazole)(2)] (1) is an effective catalyst for the oxidation of organic sulfides (methyl-phenylsulfide and diphenylsulfide). Reactions can be run in water as the only medium, at low temperature (25 degrees C), with low catalyst loadings (0.2 mol%) and excellent H2O2 efficiency with no significant non-productive decomposition of the oxidant. Under conditions that favor sulfone formation, the overall process, including isolation of the precipitated product (by filtration or centrifugation) and recycling of the aqueous phase con-taining the catalyst, can be performed in the absence of organic or ionic liquid solvents. Catalytic results with the recycled aqueous phase were the same as those obtained in the first cycle. With water as the sole solvent, 1 is a superior catalyst to the 3,5-dimethylpyrazole complexes [MoO(O-2)(2)(dmpz)(2)] (2) and [Hdmpz](4)[Mo8O25.8(O-2)(0.2)(dmpz)(2)]center dot 4H(2)O (3). Crystal structures for 1 and 3 are presented.

The Mo-IV complex [(eta(5)-indenyl)(eta(5)-cyclopentadienyl)Mo(MeCN)(2)](BF4)(2) (1) has been used to promote two acid-catalyzed epoxide ring-opening reactions under ambient conditions. The alcoholysis of styrene oxide in neat ethanol gave 2-ethoxy-2-phenylethanol in quantitative yield within 10 min. The use of an ionic liquid (IL) as a cosolvent benefitted catalyst solubility and recycling while not impairing catalytic performance. Complex 1 in 1,2-dichloroethane was effective for the isomerization of alpha-pinene oxide to campholenic aldehyde (CPA), leading to 87% yield at 1 h of reaction. The same yield could be achieved within 1 min by using the IL [Choline][NTf2] as a solvent. CPA yields at 1 min reached near-quantitative values (98%) upon recycling of the catalyst/IL mixture, demonstrating an unparalleled combination of activity, selectivity and recyclability for this commercially important reaction. Considering the catalytic features of the 1/IL system, a CPA process flow diagram is proposed and compared to patented technology.

The indenyl molybdenum carbonyl complexes [IndMo(CO)(2)(L)(n)]BF4 (L = NCMe with n = 3 (1), 2,2'-bipyridine (2) or 1,4,7-trimethyltriazacyclononane (3) with n = 1) promote epoxide alcoholysis under moderate reaction conditions. Complexes 1 and 2 showed the best performance for the alcoholysis of styrene oxide with different alcohol nucleophiles (acting as both reactant and solvent), leading to the corresponding 2-alkoxy-2-phenylethanol with 100% yield at 10 min and 35 degrees C. These catalytic results are far superior to those found for previously studied molybdenum carbonyl complexes. An efficient procedure for catalyst recovery and reuse without decrease in reaction rate is described. (C) 2017 Elsevier B.V. All rights reserved.

MoO3/2,2′-bipyridine hybrids have been prepared (hydro)thermally from [MoO3(2,2′-bipy)] and compared as catalysts in styrene oxide ethanolysis and olefin epoxidation.

Introduction: The excretion of urinary free cortisol (UFC) is a sensitive indicator of hypercortisolism. However, the low concentration of UFC compared with its total urinary metabolites and the molecular similarity between them, make a reliable UFC measurement difficult. A typical example is the increase in the measurement of UFC secondary to an increase in 6 beta-hydroxycortisol (6 beta-OHF), an unconjugated metabolite of cortisol. Since 6 beta-OHF excretion may increase up to 60 more by the administration of drugs whose metabolism is also carried out by p450 cytochrome, exists the possibility of interference with importance for the diagnosis. This problem has largely been overcome, by submitting the urine sample to a previous extraction with an organic solvent. Nevertheless, some immunoassay methods dispense the extraction step and choose to indicate reference values obtained without extraction. Aim: (1) To evaluate the influence of dichloromethane extraction in UFC levels; (2) To evaluate the interference of 6 beta-OHF in the measurement of UFC using five immunoassays; (3) To confirm the absence of 6 beta-OHF in the organic phase after extraction. Methods: The UFC concentration was determined by immunoassay, before (D) and after (E) dichloromethane extraction, in patient's urine samples and in one urine sample after addition of known amounts of 6 beta-OHF. The presence of 6 beta-OHF was evaluated by gas chromatography analysis. Results: (1) The difference between UFC results before and after extraction showed a variation between -7 and 878%; (2) The UFC levels in samples without exogenous 6 beta-OHF, showed a variation of 56-90 mu g/24 h (E) and 71-671 mu g/24 h (D). The range of UFC values after the addition of increasing amounts of 6 beta-OHF was 53-231 mu g/24 h (E) and 71-2842 mu g/24 h (D); (3) After extraction, gas chromatography analysis only showed the presence of 6 beta-OHF in the aqueous phase. Conclusion: It was demonstrated the existence of variable degrees of interference induced by the presence of 6 beta-OHF in CLU measurement by immunoassay. Each laboratory should confirm the need to submit the urine samples to a previous extraction with an organic solvent.

Metal-free cucurbit[7]uril (CB7) solid-state assemblies promote acid-catalysed alcoholysis of aliphatic and aromatic epoxides under mild conditions to give β-alkoxy alcohols, which are important intermediates for the synthesis of a vast range of compounds such as bioactive pharmaceuticals. The catalytic process is heterogeneous and the catalyst can be reused in consecutive runs without any reactivation treatment. The acid species responsible for the catalytic activity of CB7 may be entrapped hydronium ions.

The cyclopentadienyl molybdenum carbonyl complexes [(775-05H(4)R)Mo(CO)(2)(773-C3H5) and [(eta(5)-C5H5) Mo(CO)(3)(CH2R)] (R = H, COOH) have been shown to promote acid-catalysed reactions in liquid phase, under moderate conditions. The catalytic alcoholysis of styrene oxide with ethanol at 35 degrees C gave 2ethoxy-2-phenylethanol in 100% yield within 30 min for the dicarbonyl complexes and 3-6 h for the tricarbonyl complexes. Steady catalytic performances were observed in consecutive runs with the same catalytic solution, suggesting fairly good catalytic stability. In the second acid-catalysed reaction studied, the isomerization of a-pinene oxide at 55 degrees C gave campholenic aldehyde and trans-carveol in a total yield of up to 86% at 100% conversion. Chemoselectivity is shown to be solvent dependent. (C) 2015 Elsevier BY. All rights reserved.

Ferrocenium ions, [Fc](+), have been immobilised in the microporous titanosilicate ETS-10 by ion exchange of Na+/K+ ions under hydrothermal conditions. The resultant hybrid inorganic-organometallic (ETS-10/[Fc](+)) material was characterised by elemental analysis, diffuse reflectance UV-Vis spectroscopy, FT-IR spectroscopy, powder X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis. The ETS-10/[Fc](+) sample was tested as a catalyst for the isomerisation of alpha-pinene oxide (PinOx) at 35 degrees C. With alpha,alpha,alpha-trifluorotoluene (TFT) as solvent, campholenic aldehyde (CPA) was the main product formed in 38% yield at 100% conversion and 30 min reaction. Other reaction products included trans-carveol, iso-pinocamphone and trans-pinocarveol. The same PinOx conversion and CPA yield could be reached within 1 min reaction time by increasing the reaction temperature (to 55 degrees C) and the Fe:PinOx molar ratio. Other solvents (hexane, CH3CN, toluene) led to poorer results than TFT. Characterisation of the used catalyst, together with an analysis of the catalytic activity of the liquid phase obtained after contact of ETS-10/[Fc](+) with TFT, indicated that the ETS-10/[Fc](+) sample was resistant toward leaching of iron-containing active species. When the recovered solid was reused in a second batch run, catalytic activity was lower than in the first run, while selectivity to CPA was higher. (C) 2015 Elsevier B.V. All rights reserved.

A heterotetranuclear Na2Eu2 complex with uncommon photo-luminescence properties is reported. The complex exhibits good emission efficiency at ambient temperature, coupled with strong temperature dependence of the emission intensity and lifetime in the 273-333 K range, all of which are key features for non-contact luminescence-based thermometers capable of sensing and imaging temperatures in the physiological range.

Amination of crystal-like 1,4-phenylene-bridged periodic mesoporous organosilica (Ph-PMO) was achieved with about 35% conversion of phenylene groups. Ferrocenylimine groups were subsequently anchored onto this material by condensation of acetylferrocene with amino groups. Elemental analysis indicated that about 15% of amino groups in PMO-NH2 were derivatized, resulting in an iron loading of 0.21 mmol g(-1). Evidence for the presence of ferrocenylimine groups in the derivatized material (PMO-Fc) was obtained from C-13 cross-polarization (CP) magic-angle spinning (MAS) NMR and FT-IR spectroscopies. PMO-Fc was further characterized by Si-29 MAS NMR spectroscopy, powder X-ray diffraction (XRD), N-2 adsorption-desorption, and thermogravimetric analysis (TGA). Powder XRD and N-2 adsorption-desorption data for PMO-NH2 and PMO-Fc indicated that the mesoporous structure and molecular-scale periodicity in PMO-NH2 were largely retained upon treatment with acetylferrocene. The material PMO-Fc was examined as a catalyst for the oxidation of styrene at 55 degrees C using hydroperoxides as oxidants. The reaction products were benzaldehyde (major) and styrene oxide (minor), with the aldehyde being formed in yields of 25-27% at 24 h. Recycling experiments indicated that the material was susceptible to leaching of catalytically active species into the liquid phase due to the pronounced water sensitivity of the azomethine linkage. (C) 2013 Elsevier B.V. All rights reserved.

The complex [{(η5-Ind)Mo(CO)2(μ-Cl)}2] (1) has been tested for the industrially relevant catalytic isomerisation of α-pinene oxide (PinOx) to campholenic aldehyde (CPA) in the liquid phase. PinOx conversion and CPA selectivity are strongly influenced by the solvent employed. Complete conversion of PinOx was achieved within 1 min at 55 °C or 30 min at 35 °C using 1,2-dichloroethane as solvent, giving CPA in 68% yield. Other products included trans-carveol, iso-pinocamphone and trans-pinocarveol. The stability of 1 under the reaction conditions used was investigated by using FT-IR spectroscopy and electrospray ionisation mass spectrometry (ESI-MS) to characterise recovered solids. In the presence of air/moisture 1 undergoes oxidative decarbonylation upon dissolution to give oxomolybdenum species that are proposed to include a tetranuclear oxomolybdenum(V) complex. Conversely, ESI-MS studies of 1 dissolved in dry acetonitrile show mononuclear species of the type [IndMo(CO)2(CH3CN)n]+. The crystal structure of the ring-slipped dicarbonyl complex [(η3-Ind)Mo(CO)2Cl(CH3CN)2] (2) (obtained after dissolution of 1 in acetonitrile) is reported.

The complex CpMo(CO)(3)CH2COOH (1) (Cp = eta(5)-C5H5) has been examined as a precatalyst for the epoxidation of cis-cyclooctene and alpha-pinene using tert-butylhydroperoxide (TBHP) as oxidant. A high turnover frequency of ca. 600 mol mol(Mo)(-1) h(-1) was achieved in the epoxidation of cyclooctene, giving the epoxide as the only reaction product. With alpha-pinene as substrate, the added-value products a-pinene oxide and campholenic aldehyde were obtained. Two different approaches to facilitate catalyst recovery and reuse were explored: (1) use of an ionic liquid (IL) as solvent, and (2) intercalation of 1 in a Zn, Al layered double hydroxide (LDH) by a direct synthesis (coprecipitation) route. Characterization of the LDH by powder X-ray diffraction, thermogravimetric analysis, FT-IR and C-13 CP MAS NMR spectroscopies showed that the CpMo(CO)(3)CH2COO- anions intercalate in a bilayer arrangement, resulting in an interlayer spacing of 20.7 angstrom. In the epoxidation of cyclooctene, catalytic activity in the first batch run was very high for the catalyst/IL mixture and moderate for the LDH. Characterization of the LDH after catalysis indicated that nearly complete oxidative decarbonylation of supported complexes had occurred (by reaction with TBHP), resulting in the presence of immobilized oxomolybdenum species. However, catalytic activities for both the recovered LDH and catalyst/IL decreased in consecutive runs, due in part to progressive removal of active species during either the catalytic reaction (for the LDH) or the solvent extraction/work-up (for the catalyst/IL mixture). (C) 2013 Elsevier B.V. All rights reserved.