Complexes of transition metal carbonyl clusters with tin(II) phthalocyanine in neutral and radical anion states: methods of synthesis, structures and properties

Coordination of tin(II) phthalocyanine to transition metal carbonyl clusters in neutral {Sn(II){Pc(2-)}}(0) or radical anion {Sn(II){Pc(•3-)}}(-) states is reported. Direct interaction of Co4(CO)12 with {Sn(II){Pc(2-)}}(0) yields crystalline complex {Co4(CO)11·Sn(II){Pc(2-))} (1)....

The “Silent CO”: a new technique for calculating transition metal carbonyl force fields

The notion of a "silent CO group" (effectively an infinitely heavy CO group) is introduced to enable energy-factored force fields to be estimated accurately for molecules where there are fewer...

Charge-Flow Profiles along Curvilinear Paths: A Flexible Scheme for the Analysis of Charge Displacement upon Intermolecular Interactions

The Charge-Displacement (CD) analysis has proven to be a powerful tool for a quantitative characterization of the electron-density flow occurring upon chemical bonding along a suitably chosen interaction axis. In several classes of interesting intermolecular interactions, however, an interaction axis cannot be straightforwardly defined, and the CD analysis loses consistency and usefulness. In this article, we propose a general, flexible reformulation of the CD analysis capable of providing a quantitative view of the charge displacement along custom curvilinear paths. The new scheme naturally reduces to ordinary CD analysis if the path is chosen to be a straight line. An implementation based on a discrete sampling of the electron densities and a Voronoi space partitioning is described and shown in action on two test cases of a metal-carbonyl and a pyridine-ammonia complex.

The influence of gas purification and addition of macro amounts of metal-carbonyl complexes on the formation of single-atom metal-carbonyl-complexes

Using the Fast On-line Reaction Apparatus (FORA), the influence of various gas-purification columns onto the formation of metal carbonyl complexes (MCCs) under single-atom chemistry conditions was investigated. MCCs were synthesized from single atoms of Mo, Tc, Ru and Rh being produced by the spontaneous fission of 252Cf and recoiling into a CO-gas containing carrier gas atmosphere. The in-situ synthesized MCCs were volatile enough to be transported by the carrier gas to a charcoal trap where they were adsorbed and their subsequent decay was registered by γ-spectrometry. It was found that the type and combination of purification columns used to clean the applied CO-gas strongly influences the obtained formation and transport yields for all MCCs. With the exception of Rh-carbonyl, intense gas-purification strategies resulted in reduced formation and transport yields for MCCs in comparison with less efficient or even completely missing purification setups. It was postulated that the observed reduction in yield might depend on the content of Fe(CO)5 and Ni(CO)4, as well as potentially other MCCs, in the CO-gas, being formed by the interaction between CO and the steel-surfaces of FORA as well as from impurities in the used charcoal traps. Subsequently, it was shown that macro amounts of Fe(CO)5, Ni(CO)4, Mo(CO)6 and Re2(CO)10 added to the used process gas indeed increase significantly the overall yields for MCCs produced by 252Cf fission products. Ni(CO)4 appeared the most potent to increase the yield. Therefore, it was used in more detailed investigations. Using isothermal chromatography, it was shown that Ni(CO)4 does not affect the speciation of carbonyl species produced by the 252Cf fission product 104Mo. For 107Tc, 110Ru and 111Rh a speciation change cannot be excluded. For 111Rh a speciation change cannot be excluded. An inter-carbonyl transfer mechanism is suggested boosting the formation of MCCs. The current discovery might allow for new opportunities in various research fields, which are currently restricted by the low overall yields for MCCs produced under single-atom chemistry conditions. Examples are the chemical investigation of transactinides or the generation of radioactive ion beams from refractory metals at accelerators.

Exploring Electron-Sink Behaviors of Molecular Assemblies

Metal carbonyl clusters, such as the [Ni32C6(CO)36]6- anion, have been documented to display electron-sink phenomena. However, such large clusters suffer from inefficient yields due to their demanding and unreliable synthesis routes. To approach this obstacle, we investigated the electrochemical properties of Fe2(μ-PPh2)2(CO)6, an organometallic complex known to experience a reversible two-electron transfer process. In this work, we report a modular synthetic strategy for expanding the electron-sink capacity of molecular assemblies by installing Fe2(μ-PPh2)2(CO)6 redox mediators to arylisocyanide ligands. Specifically, the coordination of three Fe2(μ-PPh2)2(CO)6 subunits to a trifunctional arylisocyanide ligand produces an electron-sink ensemble that can accommodate six electrons, exceeding the precedent benchmark [Ni32C6(CO)36]6- anion. The redox mediators store electrons within quantized unoccupied frontier orbitals and act as individual quantum capacitors. Ultimately, we propose to modify the electrode surfaces with these redox mediators to examine the relationship between the electrode’s mesoscopic structure and its macroscopic capacitance.

Geometrically encoded SERS nanobarcodes for the logical detection of nasopharyngeal carcinoma-related progression biomarkers

The limited availability of nasopharyngeal carcinoma-related progression biomarker array kits that offer physicians comprehensive information is disadvantageous for monitoring cancer progression. To develop a biomarker array kit, systematic identification and differentiation of a large number of distinct molecular surface-enhanced Raman scattering (SERS) reporters with high spectral temporal resolution is a major challenge. To address this unmet need, we use the chemistry of metal carbonyls to construct a series of unique SERS reporters with the potential to provide logical and highly multiplex information during testing. In this study, we report that geometric control over metal carbonyls on nanotags can produce 14 distinct barcodes that can be decoded unambiguously using commercial Raman spectroscopy. These metal carbonyl nanobarcodes are tested on human blood samples and show strong sensitivity (0.07 ng/mL limit of detection, average CV of 6.1% and >92% degree of recovery) and multiplexing capabilities for MMPs.