Rectangular-Shaped Expanded Phthalocyanines with Two Central Metal Atoms

Abstract

Expanded phthalocyanine (Pc) congeners with two Mo or W central metal ions and four isoindole ring moieties have been synthesized using normal Pc formation conditions in the presence of urea. The products have been characterized by electrochemistry; mass spectrometry (MS); IR, electron paramagnetic resonance (EPR), NMR, electronic absorption, and magnetic circular dichroism (MCD) spectroscopies; and X-ray analysis. The X-ray structures have rectangular C(2v) symmetry and provide evidence that the central Mo atoms are linked by a single bond and coordinated by two isoindole nitrogen atoms and two nitrogen atoms from the amine moieties. The electronic absorption bands extend into the 1200-1500 nm region. This can be explained using Gouterman's four-orbital theory. The experimental NMR data and theoretical calculations provide evidence for a heteroaromatic 22-π-electron conjugation system for the ring-expanded Pc system, which satisfies Hückel's (4n + 2)π aromaticity.

Superazaporphyrins: Meso‐Pentaazapentaphyrins and One of Their Low‐Symmetry Derivatives

“…Calculated stick absorption spectra are attached at the bottom of Figure 2, with obtained data summarized in Table S1 of the Supporting Information, and the MO energy levels and isosurface plots of some frontier MOs shown in Figure 3. The optimized structures of [ 1 ] 2− , [ 5′ ] 2− , and [ 6′ ] 2− are also distorted, thus agreeing well with the crystal structures of the reported SPc6c,d and 5 b , which, therefore, suggests that the influence of the uranyl cation on the structure is indeed marginal. The calculated Q bands, which are transitions mainly from the HOMO to LUMO and LUMO+1, were estimated at wavelengths close to the experimental values for the compounds.…”

Synthesis of Meso‐Substituted Subphthalocyanine–Subporphyrin Hybrids: Boron Subtribenzodiazaporphyrins

“…Of particular importance are recent synthetic efforts to prepare modified structures where the macrocyclic core (usually aromatic) itself is perturbed, yielding derivatives with fundamentally different properties and uses 2–5. Studies have focused separately on ring‐expanded6 and ‐contracted7 analogues.…”

“…[2–5] Studies have focused separately on ring-expanded[6] and -contracted[7] analogues. The manipulation of porphyrin-like structures has proved most straightforward for ring-expanded systems, with synthetic strategies building on established polypyrrole construction methods.…”

Recent advances in computational studies of organometallic sheets: Magnetism, adsorption and catalysis

“…5. [53] Recent experimental advances by Matsushita et al [54] have provided us an expanded Pc congener containing a Mo 2 dimer and four isoindole moieties. Inspired by this interesting molecular structure, one wonders whether a 2D Mo 2 Pc can be constructed and what properties would such a 2D sheet have?…”