On-Surface Reaction of 1,4-Dibromo-2,5-Diiodobenzene on Au(111) and Ag(100)

Abstract

The on-surface reaction processes of 1,4-dibromo-2,5-diiodobenzene (C6H2Br2I2) on Au(111) and Ag(100) were systematically investigated under ultra-high vacuum conditions by using scanning tunneling microscopy. Deiodination underwent at RT on both surfaces with the formation of organometallic intermediates connected by C–Au–C and C–Ag–C linkages. In particular, partial deiodination on Au(111) resulted in self-assembled ordered structures of organometallic trans-trimers, which were converted into longer organometallic chains after complete deiodination at 100 °C. On Ag(100), complete deiodination gave rise to disordered molecular clusters at RT and organometallic intermediates were formed via the debromination process after annealing to 150 °C. Further annealing to higher temperatures resulted in covalent C–C bonded polyphenylene chains and finally disordered graphene nanostructures via cyclodehydrogenation. Our study provides fundamental comprehension of temperature-selective on-surface dehalogenation reactions of multi-halogen-substituted precursors for constructing designer covalently bonded networks.

Pannexin1 Channel-Mediated Inflammation in Acute Ischemic Stroke

“…However, these two different types of microglia served completely different roles in physiology and function following ischemic stroke [69]. For example, activation of M1 microglia was identified to act as a pro-inflammatory role, which resulted in brain damage, while M2 microglia were regarded as an anti-inflammatory state and benefited brain repair [70,71]. Like microglia, astrocytes have been subject to debate for their potential adverse or advantageous effects during the acute phase of ischemic stroke [72].…”