Core Viewpoint - The discovery of metal-centered planar [15]annulenes represents a significant advancement in organic metal chemistry, suggesting potential applications in material science due to their high stability and ease of functionalization [2][4]. Group 1: Research Findings - The research team reported the preparation of three types of metal-centered planar [15]annulenes, with the highest symmetry fragment exhibiting D5h symmetry, where the metal center is shared by five identical five-membered rings [3]. - Density functional theory calculations indicate that the d-orbitals of the metal conjugate with these five-membered rings, imparting aromaticity to them [3]. - The overall framework shows structural and spectral similarities to metal-expanded porphyrins with multiple nitrogen donors, establishing a connection between annulene chemistry and classical coordination chemistry based on heteroatoms [4]. Group 2: Implications - The study suggests that metal-centered planar annulenes could serve as promising building blocks in material science, highlighting their potential for future applications [4].