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Infrared reflection absorption spectroscopy (IRRAS) is a powerful surface-sensitive analytical technique to characterize the adsorbed molecules on metal surfaces down to (sub)monolayer coverage. In this paper, a new (inert) gas cell is presented that expands the scope of the commercially available Bruker PMA50 module. The cell is designed as a sample holder to measure thin films of molecules adsorbed on a metal substrate under a specific gaseous atmosphere. The dimensions of the cell are chosen in such a way that it can be transferred into a glovebox via the standard entrance port (Ø150 mm), allowing the investigation of air-sensitive molecules under an inert-gas atmosphere. The cell has two hose connections through which the gas atmosphere can be varied as desired. This also allows for studying the reactivity of the adsorbed structures toward the surrounding gas in situ and in a (potentially) time-dependent fashion. Furthermore, the metal substrate can be irradiated via an exposure window to investigate the influence of light on the adsorbed molecules and/or their reactivity. Using the polarization-modulation (PM-) IRRAS technique along with the described gas cell, an air-sensitive molybdenum(0) tricarbonyl complex adsorbed on an Au(111) surface is investigated. This complex reacts with molecular oxygen to the molybdenum(VI) trioxo analog, and this conversion is accelerated by irradiation with light of 365 and 440 nm. [ABSTRACT FROM AUTHOR] more...

Adsorption of metal‐organic complexes on metallic surfaces to produce well‐defined single site catalysts is a novel approach combining the advantages of homogeneous and heterogeneous catalysis. To avoid the "surface trans‐effect" a dome‐shaped molybdenum(0) tricarbonyl complex supported by an tolylazacalix[3](2,6)pyridine ligand is synthesized. This vacuum‐evaporable complex both activates CO and reacts with molecular oxygen (O2) to form a Mo(VI) trioxo complex which in turn is capable of catalytically mediating oxygen transfer. The molybdenum tricarbonyl‐ and trioxo complexes are investigated in the solid state, in homogeneous solution and on noble metal surfaces (Cu, Au) employing a range of spectroscopic and analytical methods. [ABSTRACT FROM AUTHOR] more...

Adsorption of metal‐organic complexes on metallic surfaces to produce well‐defined single site catalysts is a novel approach combining the advantages of homogeneous and heterogeneous catalysis. To avoid the "surface trans‐effect" a dome‐shaped molybdenum(0) tricarbonyl complex supported by an tolylazacalix[3](2,6)pyridine ligand is synthesized. This vacuum‐evaporable complex both activates CO and reacts with molecular oxygen (O2) to form a Mo(VI) trioxo complex which in turn is capable of catalytically mediating oxygen transfer. The molybdenum tricarbonyl‐ and trioxo complexes are investigated in the solid state, in homogeneous solution and on noble metal surfaces (Cu, Au) employing a range of spectroscopic and analytical methods. [ABSTRACT FROM AUTHOR] more...

Molybdenum( 0)- Tricarbonyl Complex Supported by anAzacalix- pyridine Ligand: Synthesis, Characterization, Surface Deposition and Conversion to a Molybdenum( VI)- Trioxo Complex with O2 [Extracted from the article] more...

Self‐assembled monolayers (SAMs) decorated with photoisomerizable azobenzene glycosides are useful tools for investigating the effect of ligand orientation on carbohydrate recognition. However, photoswitching of SAMs between two specific states is characterized by a limited capacity. The goal of this study is the improvement of photoswitchable azobenzene glyco‐SAMs. Different concepts, in particular self‐dilution and rigid biaryl backbones, have been investigated. The required SH‐functionalized azobenzene glycoconjugates were synthesized through a modular approach, and the respective glyco‐SAMs were fabricated on Au(111). Their photoswitching properties have been extensively investigated by applying a powerful set of methods (IRRAS, XPS, and NEXAFS). Indeed, the combination of tailor‐made biaryl‐azobenzene glycosides and suitable diluent molecules led to photoswitchable glyco‐SAMs with a significantly enhanced and unprecedented switching capacity. [ABSTRACT FROM AUTHOR] more...

The syntheses of molybdenum dinitrogen complexes supported by the tridentate PEP ligands (E = N, P) prPP(Ph)P = (Ph2PCH2CH2CHscript>2)2P(Ph), prPPHP = (Ph2PCH2CH2CH2)2PH, PN(Ph)P = (Ph2PCH2CH2)2N(Ph) and prPN(Ph)P = (Ph2PCH2CH2CH2)2N(Ph) are reported. Together with the coligand dmpm = (CH3)2PCH2P(CH3)2 dinitrogen complexes of the type [Mo(N2)(PEP)(dmpm)] are formed. The new systems are characterized by IR and NMR spectroscopy and compared with the literature-known complex [Mo(N2)(dpepp)(dmpm)] (1) (dpepp = PhP(CH2CH2PPh2)2). The consequences of the substitution of the central P-donor of dpepp by N and the replacement of its C2 by C3 linkages as well as the exchange of the EPh by an EH function are investigated with respect to the stability of the corresponding N2-complexes. Importantly, the activation of the N2 ligand drastically increases upon replacing the trans-phosphine with a trans-amine donor. [ABSTRACT FROM AUTHOR] more...

The syntheses of molybdenum dinitrogen complexes supported by the tridentate PEP ligands (E = N, P) prPP(Ph)P = (Ph2PCH2CH2CH2)2P(Ph), prPPHP = (Ph2PCH2CH2CH2)2PH, PN(Ph)P = (Ph2PCH2CH2)2N(Ph) and prPN(Ph)P = (Ph2PCH2CH2CH2)2N(Ph) are reported. Together with the coligand dmpm = (CH3)2PCH2P(CH3)2 dinitrogen complexes of the type [Mo(N2)(PEP)(dmpm)] are formed. The new systems are characterized by IR and NMR spectroscopy and compared with the literature-known complex [Mo(N2)(dpepp)(dmpm)] (1) (dpepp = PhP(CH2CH2PPh2)2). The consequences of the substitution of the central P-donor of dpepp by N and the replacement of its C2 by C3 linkages as well as the exchange of the EPh by an EH function are investigated with respect to the stability of the corresponding N2-complexes. Importantly, the activation of the N2 ligand drastically increases upon replacing the trans-phosphine with a trans-amine donor. [ABSTRACT FROM AUTHOR] more...