Coupling ferrocene to brominated tetraazaporphyrin: exploring an alternative synthetic pathway for preparation of ferrocene-containing tetraazaporphyrins

Abstract

Abstract:A Castro-Stephens coupling reaction between metal-free 3(2),8(7)-dibromo-2(3),7(8),12(13),17(18)-tetra-tertbutyl-5,10,15,20-tetraazaporphyrin and (ferrocenylethynyl)copper resulted in the formation of copper 2(3),7(8),12(13), rin, while no products with larger number of organometallic substituents were observed. Direct coupling between ferrocenelithium and 3(2),8(7)-dibromo-2(3),7(8),12(13),17(18)-tetra-tert-butyl-5,10,15,20-tetraazaporphyrin resulted in a debromination reaction accompanied by very minor dimerization of the tetraazaporphyrin core, which was explained based on the steric properties of the parent tetraazaporphyrin. The target compounds were characterized using APCI mass spectrometry, UV-vis, and MCD spectroscopy, while the electronic structure of ferrocenylethyl-containing products was predicted by DFT approach. X-ray structures of individual positional isomers of copper 2-bromo-3,7,12,18-tetra-tertbutyl-5,10,15,20-tetraazaporphyrin and 3, 7, 12,18-tetrabromo-2,8,13,17-tetra-tert-butyl-5,10,15,20-tetraazaporphyrin were also discussed.

Initial Report on Molecular and Electronic Structure of Spherical Multiferrocenyl/tin(IV) (Hydr)oxide [(FcSn)12O14(OH)6]X2 Clusters

“…Multi-ferrocenyl-containing complexes have attracted significant interest in the past decade because of a variety of potential applications ranging from multibit information storage, redox-switchable fluorescence, optoelectronic materials, and sensors . Because of the strong recent effort in preparing multiferrocenyl systems in which redox-active ferrocene ligands interconnected via a small (benzene or simple heterocycle) − or large (porphyrinoid-type) π-system, − electron-transfer as well as metal coupling properties in these compounds are currently quite well understood. − In contrast, electronic structure and electron-transfer processes in ferrocene-functionalized organic–inorganic polyoxometallate or polychalcogenide nanoclusters have been much less explored. − Although ferrocene-decorated polyoxometallates with paramagnetic transition-metal cores , can be excellent candidates for spintronic applications, fundamental understanding of the presence or absence of the ferrocene–ferrocene coupling requires preparation of the diamagnetic polyoxometallate core. One of the most useful cores for the latter studies is tin-oxide or tin-chalcogenide clusters. −…”

Database Investigation of Halogen Bonding and Halogen···Halogen Interactions between Porphyrins: Emergence of Robust Supramolecular Motifs and Frameworks

“…Eight of these structures exhibit the β···pyrrole motif, while others exhibit Br···N halogen bonds with the M···A, β···β, and the less common β­(bromine)···A­(nitrogen) (CSD code EWUROF) and A­(bromine)···M­(nitrogen) geometries (CSD code XICTUA) (Figures S30 andS31). The shortest β···pyrrole distances in this set are found in the structures with CSD codes COGWED and FASLER (Figures S27 and S28), while the longest distances are in structures with CSD codes ZEQQUH and WAHBEP (Figure and Figures S32 and S33), where steric hindrance due to large meso -positioned pentafluorophenyl and tert -butyl substituents could play a role in determining the length of XB contacts.…”

“…The shortest Br•••N distances, at and below 3.05 Å, are observed for a set of four structures exhibiting diverse structural motifs, uncommon in the rest of the data set. These 114 and FASLER (Figures S27 and S28), 115 while the longest distances are in structures with CSD codes ZEQQUH 116 and WAHBEP 117 (Figure 26 and Figures S32 and S33), where steric hindrance due to large meso-positioned pentafluorophenyl and tert-butyl substituents could play a role in determining the length of XB contacts.…”