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Surface-supported molecular overlayers have demonstrated versatility as platforms for fundamental research and a broad range of applications, from atomic-scale quantum phenomena to potential for electronic, optoelectronic and catalytic technologies. Here, we report a structural and electronic characterisation of self-assembled magnesium phthalocyanine (MgPc) mono and bilayers on the Ag(100) surface, via low-temperature scanning tunneling microscopy and spectroscopy, angle-resolved photoelectron spectroscopy (ARPES), density functional theory (DFT) and tight-binding (TB) modeling. These crystalline close-packed molecular overlayers consist of a square lattice with a basis composed of a single, flat-adsorbed MgPc molecule. Remarkably, ARPES measurements at room temperature on the monolayer reveal a momentum-resolved, two-dimensional (2D) electronic energy band, 1.27 eV below the Fermi level, with a width of ∼20 meV. This 2D band results from in-plane hybridization of highest occupied molecular orbitals of adjacent, weakly interacting MgPc's, consistent with our TB model and with DFT-derived nearest-neighbor hopping energies. This work opens the door to quantitative characterisation – as well as control and harnessing – of subtle electronic interactions between molecules in functional organic nanofilms.

Metalated phthalocyanines (Pc's) are robust and versatile molecular complexes, whose properties can be tuned by changing their functional groups and central metal atom. The electronic structure of magnesium Pc (MgPc) - structurally and electronically similar to chlorophyll - adsorbed on the Ag(100) surface is investigated by low-temperature scanning tunneling microscopy (STM) and spectroscopy (STS), non-contact atomic force microscopy (ncAFM) and density functional theory (DFT). Single, isolated MgPc's exhibit a flat, four-fold rotationally symmetric morphology, with doubly degenerate, partially populated (due to surface-to-molecule electron transfer) lowest unoccupied molecular orbitals (LUMOs). In contrast, MgPc's with neighbouring molecules in proximity undergo a lift of LUMOs degeneracy, with a near-Fermi local density of states with reduced two-fold rotational symmetry, indicative of a long-range attractive intermolecular interaction. The latter is assigned to a surface-mediated two-step electronic hybridization process. First, LUMOs interact with Ag(100) conduction electrons, forming hybrid molecule-surface orbitals with enhanced spatial extension. Then, these delocalized molecule-surface states further hybridize with those of neighbouring molecules. This work highlights how the electronic structure of molecular adsorbates - including orbital degeneracies and symmetries - can be significantly altered via surface-mediated intermolecular hybridization, over extended distances (beyond 3 nm), having important implications for prospects of molecule-based solid-state technologies., Comment: 28 pages, 4 figures; supplementary 35 pages, 19 figures

Supramolecular chemistry protocols applied on surfaces offer compelling avenues for atomic-scale control over organic-inorganic interface structures. In this approach, adsorbate-surface interactions and two-dimensional confinement can lead to morphologies and properties that differ dramatically from those achieved via conventional synthetic approaches. Here, we describe the bottom-up, on-surface synthesis of one-dimensional coordination nanostructures based on an iron (Fe)-terpyridine (tpy) interaction borrowed from functional metal-organic complexes used in photovoltaic and catalytic applications. Thermally activated diffusion of sequentially deposited ligands and metal atoms and intraligand conformational changes lead to Fe-tpy coordination and formation of these nanochains. We used low-temperature scanning tunneling microscopy and density functional theory to elucidate the atomic-scale morphology of the system, suggesting a linear tri-Fe linkage between facing, coplanar tpy groups. Scanning tunneling spectroscopy reveals the highest occupied orbitals, with dominant contributions from states located at the Fe node, and ligand states that mostly contribute to the lowest unoccupied orbitals. This electronic structure yields potential for hosting photoinduced metal-to-ligand charge transfer in the visible/near-infrared. The formation of this unusual tpy/tri-Fe/tpy coordination motif has not been observed for wet chemistry synthetic methods and is mediated by the bottom-up on-surface approach used here, offering pathways to engineer the optoelectronic properties and reactivity of metal-organic nanostructures.

Electronic devices rely on technologies allowing for the control of the flow of electron in a semiconducting material. This behaviour depends on the electronic properties of the material, at the atomic level. In particular, we focus on two different systems consisting of atomically precise low-dimensional metal-organic nanostructures on a noble metal surface, with potential for optoelectronics applications. Our experimental low temperature scanning probe microscopy and photoelectron spectroscopy measurements demonstrate the close relation between the implementation of these systems (single units or layers) and the resulting electronic properties. Our results constitute an important step for the translation of these nanosystems onto new technologies such as: catalysis, molecular electronics, light-harvesting.

Syncope is a common clinical entity, and it causes up to 3% of admission in the Emergency Department. The evaluation of syncope begins with a careful history, physical examination, and electrocardiography, with a correct identification of etiology at the presentation in up to 50% of cases. Moreover, the underlying cause of syncope remains unidentified in a elevated percentage of patients. The application of Standard Guidelines and the institution of the Observation Unit (OBI) with continuous monitoring improves patients management, chiefly in the geriatric population (> 65 years old). In older patients the clinical features of syncope are less defined, and the medical history has a limited value. The management in the OBI of this group of patient with continuous monitoring could become the best approach. The ECG monitoring can detect life-threatening arrhythmias in older patients with apparent non cardiac syncope. In the firs six months of 2005 the Emergency Department of the Ospedale San Paolo (Savona) evaluated 164 patients > 65 years old with diagnosis of syncope/pre-syncope. During monitoring we detected events of arrhythmia in 12 patients (7,3%), including ventricular tachycardia in 2, atrial fibrillation in 4, paroxysmal atrial flutter in 2, paroxysmal supraventricular tachycardia in 1, asystole in 1 and third-degree atrioventricular block in 2 patients. We briefly describe 2 of this case: in both cases the first suggestion indicates a possible non cardiac etiology, but the subsequent monitoring shows episodes of potentially fatal arrhythmia. Both an early discharge and an in non-monitorized bed admission wouldn’t have preserved the two patient by a sudden cardiac death.

The authors analyze the major trauma recorded in a couple of years in the Emergency Room of the San Paolo Hospital of Savona after the setting, in the same district, of the trauma center at the Santa Corona Hospital of Pietra Ligure. Despite the policy of centralization adopted the amount of major trauma seen at the San Paolo Hospital remained unchanged over time and the number of patients who are not rescued by medicalized ambulance is still significant. These observations underline the importance of periodically reviewing the protocols and make training on trauma also in hospitals that are not recognized as trauma center.