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MgO-supported manganese carbonyl complexes were prepared by chemical vapor deposition of Mn(CO)5CH3 on partially dehydroxylated, high-area MgO powder. X-ray absorption spectra identify the resultant surface species, on average, as Mn(CO)4(Os)2 (where the two oxygen ligands are part of the MgO surface), and infrared spectra show that the chemisorption results from the reaction of Mn(CO)5CH3 with OH groups of the MgO surface. Electron paramagnetic resonance and X-ray absorption near edge data indicate that the manganese was in a positive oxidation state other than +2, but the value is not determined, and the IR spectra indicate the presence of a mixture of manganese carbonyls. Extended X-ray absorption fine structure spectra determine the average Mn-CO bond distance to be 1.87 Å and the average Mn-O bond distance to be 2.12 Å. The surface complex was found to be stable in O2 at room temperature.

Supported rhenium complexes were prepared from CH(3)Re(CO)(5) and dealuminated HY zeolite or NaY zeolite, each with a Si/Al atomic ratio of 30. The samples were characterized with infrared (IR) and extended X-ray absorption fine structure (EXAFS) spectroscopies. EXAFS data characterizing the sample formed by the reaction of CH(3)Re(CO)(5) with dealuminated HY zeolite show that the rhenium complexes were bonded to the zeolite frame, incorporating, on average, three carbonyl ligands per Re atom (as shown by Re-C and multiple-scattering Re-O EXAFS contributions). The IR spectra, consistent with this result, show that the supported rhenium carbonyls were bonded near aluminum sites of the zeolite, as shown by the decrease in intensity of the IR bands characterizing the acidic silanol groups resulting from the reaction of the rhenium carbonyl with the zeolite. This supported metal complex was characterized by narrow peaks in the ν(CO) region of the IR spectrum, indicating highly uniform species. In contrast, the species formed from CH(3)Re(CO)(5) on NaY zeolite lost fewer carbonyl ligands than those formed on HY zeolite and were significantly less uniform, as indicated by the greater breadth of the ν(CO) bands in the IR spectra. The results show the importance of zeolite H(+) sites for the formation of uniform supported rhenium carbonyls from CH(3)Re(CO)(5); the formation of such uniform complexes did not occur on the NaY zeolite.

Two carbonyl complexes of rhenium, [HRe(CO)(5)] and [CH(3)Re(CO)(5)], were used to probe surface sites of TiO(2) (anatase). These complexes were adsorbed from the gas phase onto anatase powder that had been treated in flowing O(2) or under vacuum to vary the density of surface OH sites. Infrared (IR) spectra demonstrate the variation in the number of sites, including Ti(+3)-OH and Ti(+4)-OH. IR and extended X-ray absorption fine structure (EXAFS) spectra show that chemisorption of the rhenium complexes led to their decarbonylation, with formation of surface-bound rhenium tricarbonyls, when [HRe(CO)(5)] was adsorbed, or rhenium tetracarbonyls, when [CH(3)Re(CO)(5)] was adsorbed. These reactions were accompanied by the formation of water and surface carbonates and removal of terminal hydroxyl groups associated with Ti(+3) and Ti(+4) ions on the anatase. Data characterizing the samples after adsorption of [HRe(CO)(5)] or [CH(3)Re(CO)(5)] determined a ranking of the reactivity of the surface OH sites, with the Ti(+3)-OH groups being the more reactive towards the rhenium complexes but the less likely to be dehydroxylated. The two rhenium pentacarbonyl probes provided complementary information, suggesting that the carbonate species originate from carbonyl ligands initially bonded to the rhenium and from hydroxyl groups of the titania surface, with the reaction leading to the formation of water and bridging hydroxyl groups on the titania. The results illustrate the value of using a family of organometallic complexes as probes of oxide surface sites.

This review of structurally simple and essentially molecular metal clusters on solid supports addresses synthesis, characterization, reactivity, and catalysis. Examples of supported clusters made in high yields are Os(3), Ir(4), Ir(6), and Rh(6), and typical supports are MgO, gamma-Al(2)O(3), and zeolites. Supported clusters are synthesized by adsorption of ligated molecular metal clusters, deposition of bare size-selected metal clusters from the gas phase, and adsorption of metal complexes followed by treatment to form clusters. Some metal clusters on supports have been imaged with atomic resolution. Reactions of supported metal clusters include ligand modifications, oxidative fragmentation, and migration leading to aggregation. Reactivities and catalytic properties of the clusters (e.g., for alkene hydrogenation and epoxidation) depend on the cluster size and the support (which acts as a ligand) and are distinct from those of supported particles that resemble bulk metals. Opportunities for deeper understanding of the chemistry of supported metal clusters hinge on improvements in characterization techniques such as X-ray absorption spectroscopy and high-resolution transmission electron microscopy.

Small cationic tantalum clusters were prepared on the surfaces of SiO2, silica-aluminas, and gamma-Al2O3 supports by treating physisorbed pentabenzyltantalum at 523 K for 24 h in flowing H2. The rate of decomposition and the products formed in the decomposition of pentabenzyltantalum are dependent on the support composition. When the support was SiO2, the evolved products were mainly biphenyl and a small amount of toluene, indicating that the Ta-C bond in pentabenzyltantalum was activated. As the alumina content of the support increased, diphenylmethane, benzene, and ethylene were increasingly formed, and these products show that the activation of the C-C bonds linking the C atoms of methyl groups to the aromatic rings of the benzyl ligands was facilitated. Infrared spectra of the surface species and mass spectra of the effluents formed during the treatment show that the composition of the support had significant influence on the decomposition of pentabenzyltantalum, and the chemistry is inferred to be related to the electron-donor properties of the supports. Extended X-ray absorption fine structure (EXAFS) spectra recorded at the Ta LIII edge indicate the formation of clusters with a Ta-Ta first-shell coordination number of approximately 3, and images obtained by scanning transmission electron microscopy (STEM) confirm the presence of such small clusters. X-ray absorption near edge structure (XANES) data indicate that the formal oxidation state of the tantalum in the clusters decreased from approximately 3.0 to approximately 2.6 as the support was changed from SiO2 to silica-aluminas to gamma-Al2O3. The data suggest that the tantalum clusters were anchored to the supports via bridging O atoms. The EXAFS data show that the support composition had little influence on the cluster structure.

Nebulized solutions of long-acting bronchodilators provide an alternative to DPI and MDI delivery, particularly for COPD patients unable to use hand-held devices easily or correctly. The long-acting beta2-agonist, formoterol fumarate, is differentiated by its onset of significant bronchodilation within 5 min of administration. In a randomized, double-blind, double-dummy trial, COPD subjects (n=351, mean forced expiratory volume FEV1=1.3 L, 44% predicted) received nebulized formoterol fumarate (Perforomist inhalation solution; FFIS 20 microg) or DPI (Foradil Aerolizer; FA 12 microg), or placebo twice daily for 12 weeks. Efficacy was assessed with 12-h pulmonary function tests, and quality of life was assessed before and after treatment with the St. George's Respiratory Questionnaire (SGRQ). At the 12-week endpoint, FFIS significantly increased FEV1 AUC0-12h relative to placebo (p<0.0001). No evidence of tachyphylaxis was observed as indicated by maintained FEV1 AUC and reduced rescue albuterol use throughout treatment. FFIS also significantly increased peak FEV1, trough FEV1, and standardized FVC AUC0-12h compared with placebo. SGRQ assessment at Week 12 demonstrated significant and clinically meaningful improvements in total score (FFIS vs placebo, -4.9, p=0.0067), symptom, and impact scores. No significant differences in efficacy were observed between the two active treatments. Drug related AEs in the FFIS arm with a frequency > or = 1% and exceeding placebo were dry mouth, nausea, and insomnia. Nebulized FFIS provided significant improvement in respiratory status and quality of life in subjects with COPD relative to placebo and was well tolerated. The efficacy and safety profile of FFIS was comparable to FA DPI.

Samples of the anatase phase of titania were treated under vacuum to create Ti(3+) surface-defect sites and surface O(-) and O(2) (-) species (indicated by electron paramagnetic resonance (EPR) spectra), accompanied by the disappearance of bridging surface OH groups and the formation of terminal Ti(3+)-OH groups (indicated by IR spectra). EPR spectra showed that the probe molecule [Re(3)(CO)(12)H(3)] reacted preferentially with the Ti(3+) sites, forming Ti(4+) sites with OH groups as the [Re(3)(CO)(12)H(3)] was adsorbed. Extended X-ray absorption fine structure (EXAFS) spectra showed that these clusters were deprotonated upon adsorption, with the triangular metal frame remaining intact; EPR spectra demonstrated the simultaneous removal of surface O(-) and O(2) (-) species. The data determined by the three complementary techniques form the basis of a schematic representation of the surface chemistry. According to this picture, during evacuation at 773 K, defect sites are formed on hydroxylated titania as a bridging OH group is removed, forming two neighboring Ti(3+) sites, or, when a Ti(4+)-O bond is cleaved, forming a Ti(3+) site and an O(-) species, with the Ti(4+)-OH group being converted into a Ti(3+)-OH group. When the probe molecule [Re(3)(CO)(12)H(3)] is adsorbed on a titania surface with Ti(3+) defect sites, it reacts preferentially with these sites, becoming deprotonated, removing most of the oxygen radicals, and healing the defect sites.

Introduction: Ipratropium bromide (IB) is an established and effective first-line maintenance treatment for patients with chronic obstructive pulmonary disease (COPD). A new IB metered-dose inhaler (MDI) using hydrofluoroalkane 134a propellant (IB HFA) has been developed as an alternative to the MDI containing chlorofluorocarbon (IB CFC)., Objective: To compare the long-term safety and efficacy of IB HFA and IB CFC in patients with COPD., Study Design: This was a randomised, open-label, parallel-group, 1-year, multi-centre trial. Primary endpoints included adverse events (AEs) and vital signs. Secondary endpoints included therapeutic response (>15% increase in forced expiratory volume in 1 second [FEV(1)] peak change from baseline), FEV(1) area under the response-time curve (AUC)., Patients and Interventions: Patients (n = 456) with moderate-to-severe COPD, who received either IB HFA (n = 305) or IB CFC (n = 151 ), both 42µg four times daily., Results: There were no significant differences in the incidences of individual AEs between groups over the short and long term; respiratory disorders were the most common. The incidence of anticholinergic AEs possibly related to treatment was low (1.3% IB HFA, 0.7% IB CFC). Serious AEs occurred in 19.0% and 20.5%, and discontinuations due to AEs in 7.2% and 7.3%, of patients receiving IB HFA and IB CFC, respectively. Therapeutic bronchodilatory responses were achieved in 76-81% and 72-84% of patients, and AUC ranged from 0.117-0.148L and 0.117-0.174L, in patients receiving IB HFA and IB CFC, respectively., Conclusions: IB HFA had similar efficacy and tolerability to IB CFC over 1 year, supporting a seamless transition from the CFC MDI to the HFA MDI in both short- and long-term treatment.

Background: Formoterol is a beta2-adrenergic agent which, when inhaled, produces rapid and long-lasting bronchodilatation., Objective: The aim of this study was to compare the efficacy, safety, and tolerability of formoterol powder for inhalation delivered via the Aerolizer device with placebo and with albuterol delivered via metered-dose inhaler in patients with mild to moderate persistent asthma., Methods: In a multicenter, double-blind, parallel-group study, 541 patients were randomized at 26 trial sites to receive either formoterol, 12 microg twice daily; formoterol, 24 microg twice daily; albuterol, 180 microg four times daily; or a placebo for 12 weeks. The effects of each treatment on lung function, asthma symptoms, and frequency of rescue albuterol use were evaluated. Adverse effects and clinical laboratory parameters were also evaluated., Results: The bronchodilatory effects of formoterol were rapid in onset and persisted for 12 hours. Both formoterol doses were more effective than placebo and albuterol for objective measures of lung function. Morning and evening peak expiratory flow rates were more improved with formoterol, and formoterol provided significantly greater improvements in asthma symptom scores compared with both albuterol and placebo. Overall, patients taking formoterol used significantly less rescue medication than did those taking albuterol or placebo. Nocturnal awakenings occurred less often with formoterol than with placebo or albuterol. The therapeutic effects of formoterol were maintained over the entire 12 weeks of treatment. Adverse events were similar for all treatment groups, and clinical laboratory data were unremarkable., Conclusions: Rapid-onset, long-acting formoterol, administered via the Aerolizer inhaler, is an effective and safe treatment for patients with mild to moderate persistent asthma.

Background: Although inhaled glucocorticoids are recommended for all stages of persistent asthma, compliance with long-term therapy is often poor, leading to significant morbidity and mortality. A simplified, once-daily dosing regimen may foster improved compliance., Objective: To compare the efficacy and safety of once-daily (AM) administration of mometasone furoate dry powder inhaler (MF DPI) 200 microg and 400 microg with placebo in patients with asthma previously maintained only on short-acting inhaled beta-adrenergic receptor agonists., Methods: This was a 12-week, double-blind, placebo-controlled, parallel group study. The mean change from baseline to endpoint (last treatment visit) for FEV1 was the primary efficacy variable., Results: At endpoint, both doses of MF DPI were significantly more effective than placebo (P < or = .05) in improving FEV1. Based on morning peak expiratory flow rate, once-daily MF DPI 400 microg was more effective than placebo (P < or = .001) at endpoint. Both active treatments also demonstrated improvement at endpoint in asthma symptom scores, physician-evaluated response to therapy and use of rescue medication. Although both MF DPI dosages were efficacious, MF DPI 400 microg provided additional improvement in some measures of pulmonary function (eg, morning PEFR) when these agents were administered once daily in the morning. Both doses of MF DPI were well tolerated and treatment-related adverse events occurred at a similar incidence among the three treatment groups., Conclusions: The results of this study indicate that once-daily (AM) MF DPI provides a convenient and effective treatment option for patients with mild or moderate persistent asthma.