Stepwise Assembly of Coordination-Based Metal−Organic Networks

Abstract

Metal-organic networks (MONs) were created by a stepwise solution deposition approach from vinylpyridine-based building blocks and PdCl(2). The combined experimental and computational study demonstrates the formation of saturated, structurally organized systems on solid supports. The rigid nature and geometry of the components are well-suited to form honeycomb and parallelogram structures, as predicted by a computational study. Detailed structural information of the new MONs was obtained by optical (UV/vis) spectroscopy, ellipsometry, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and synchrotron X-ray reflectivity (XRR). Notably, the XPS elemental composition indicates the formation of a palladium coordination-based network.

A Viable Route for Lithium Ion Detection

“…[19] Spectral fitting [19h] of the XPS N 1s band of PyAzoC4-IM (Figure 1) reveals two chemically different types of N atoms, the signals of which are centered at 399.7 and 401.2 eV and account for the two nitrogen atoms of the azo group and the quaternary pyridine nitrogen atom, respectively. [20] The 2:1 intensity ratio between these two peaks exactly matches that expected on the basis of the molecular structure of calixarene PyAzoC4. Figure 1.…”

“…[19,20] The samples were excited with Al-K α radiation. Structures owing to K α2 satellite radiation were subtracted from the spectra prior to data processing.…”

“…XPS peak intensities were obtained after Shirley background removal. [19,20] Procedures to account for steady-state charging effects have been described elsewhere. [19,20] The experimental uncertainties in the binding energies lie within Ϯ0.4 eV.…”

“…[19,20] Procedures to account for steady-state charging effects have been described elsewhere. [19,20] The experimental uncertainties in the binding energies lie within Ϯ0.4 eV. Spectral fitting of the N 1s spectrum was performed, after background subtraction, by fitting the experimental profile with two symmetrical Gaussian envelopes.…”

Coordination-Based Molecular Assemblies as Electrochromic Materials: Ultra-High Switching Stability and Coloration Efficiencies

“…MA1−4 were obtained by alternating the deposition of PdCl 2 and iron polypyridyl complexes 1−4 ( Figure 1) from solution on a pyridine-terminated monolayer. 17 This monolayer is covalently bound to the surfaces of indium−tin oxide (ITO), quartz, and silicon substrates through a chlorobenzyl-functionalized coupling layer (Scheme S1, Figure S2). Pyridine-based ligands are excellent moieties for η 1 -coordination with d 8 palladium salts 18 and involve trans-(N Py -N Py ) with a four-coordinate square planar geometry.…”