Chemical and morphological origins of the improved stability in various polymer–perovskite hybrid thin films under ambient environmental conditions are investigated.

The characterization of electrical double layers is important since the interfacial electric field and electrolyte environment directly affect the reaction mechanisms and catalytic rates of electrochemical processes. In this work, we introduce a spectroscopic method based on a Stark shift ruler that enables mapping the electric field strength across the electric double layer of electrode/electrolyte interfaces. We use the tungsten-pentacarbonyl­(1,4-phenelenediisocyanide) complex attached to the gold surface as a molecular ruler. The carbonyl (CO) and isocyanide (NC) groups of the self-assembled monolayer (SAM) provide multiple vibrational reporters situated at different distances from the electrode. Measurements of Stark shifts under operando electrochemical conditions and direct comparisons to density functional theory (DFT) simulations reveal distance-dependent electric field strength from the electrode surface. This electric field profile can be described by the Gouy–Chapman–Stern model with Stern layer thickness of ∼4.5 Å, indicating substantial solvent and electrolyte penetration within the SAM. Significant electro-induction effect is observed on the W center that is ∼1.2 nm away from the surface despite rapid decay of the electric field (∼90%) within 1 nm. The applied methodology and reported findings should be particularly valuable for the characterization of a wide range of microenvironments surrounding molecular electrocatalysts at electrode interfaces and the positioning of electrocatalysts at specific distances from the electrode surface for optimal functionality.

The synthesis of electrode-attached Rh­(I) diisocyanide coordination polymers that incorporate a series of arylene diisocyanide linkers and which are grown from gold surfaces by a bottom-up, layer-by-layer procedure that allows for a high level of control for the film thickness is reported. A seed layer of the arylene diisocyanide ligand is used to template directional growth of the coordination polymer made using the well-studied square-planar rhodium tetrakis­(isocyanide) as the metal node. Materials ranging from 1 to 30 layers were prepared via layer-by-layer solution-phase deposition. Characterization of the polymer films using scanning electron microscopy and ellipsometry shows layer-by-layer control in these films with linear thickness growth per layer. Phase-modulated infrared reflection absorption spectroscopy (PM-IRRAS), diffuse reflectance UV–vis, and X-ray photoelectron spectroscopy (XPS) were used to confirm the structures of the films. Although prior reports of related coordination polymers and films based on diisocyanides showed considerable air-instability, the films reported here demonstrate significantly improved chemical stability and electrochemical stability at a moderately high applied bias. Electrochemical characterization and ex situ XPS demonstrate that these diisocyanide films are stable to stripping at potentials up to −2.2 V versus decamethylferrocene in acetonitrile, supporting their relevance for electrochemical applications.

The anionic state of basic ruthenium acetate complexes of the type [Ru3O­(OAc)6]­(CO)­(L1)­(L2) (L = 4-cyanopyridine, pyridine, and N,N-dimethylaminopyridine) feature pronounced optical transitions in the near-infrared region indicative of strongly coupled mixed-valence states. A series of these clusters was prepared and studied spectroscopically in tandem with density functional theory (DFT) computational results to construct an orbital structure–function description of how the electron density is shared between the ruthenium centers in this mixed-valent state. The mixed-valency manifests itself as a combination of the nonbonding atomic orbitals of the equivalent ruthenium centers, with increased energetic splitting between the orbitals with symmetries appropriate for more efficient electronic communication. This DFT-based model agrees with the Marcus–Hush description of mixed-valency, with the added knowledge that specific orbitals contribute to different degrees in the electronic coupling between two redox centers.

Treatment of the trichloro-tin-capped trinuclear nickel cluster, [Ni3(dppm)3(μ3-Cl)(μ3-SnCl3)], 1, with 4 eq. NaHB(Et)3 yields a μ3-SnH capped trinuclear nickel cluster, [Ni3(dppm)3(μ3-H)(μ3-SnH)], 2. Single-crystal X-ray diffraction, nuclear magnetic resonance (NMR) spectroscopy,...