fac-[M(CO)3] (M = Mn or Re)-based capped metallacalix[3]arenes

• Published in: Journal of organometallic chemistry 2024-07, Vol.1015, p.123238, Article 123238
• Main Authors: Bayya, Shruthi, Borkar, Reema L., Mishra, Isha, Shankar, Bhaskaran, Priyatharsini, Maruthupandiyan, Sathiyendiran, Malaichamy
• Format: Article
• Language: English
• Subjects: Metallacalixarene; Rhenium; Solvothermal; Supramolecule; Tritopic
• ISSN: 0022-328X; 1872-8561
• DOI: 10.1016/j.jorganchem.2024.123238

•Self-assembly of fac-[M(CO)3] (M = Mn or Re)-based neutral heteroleptic metallocages.•5,6-di-(methoxycarbonyl)-benzimidazolyl substituted N donor-based tripodal ligand.•Metallocalix[3]arenes capped with ester functionalized flexible tritopic framework. A flexible tritopic ligand, 1,3,5-tri(5,6-di-(methoxycarbonyl)-benzimidazol-1-ylmethyl)-2,4,6-trimethylbenzene (Tebim) was designed, synthesized and characterized. Six neutral heteroleptic fac-[M(CO)3]-based capped metallacalix[3]arenes with/without six or twelve ester decorated motifs were synthesized via one-pot approach using M2(CO)10 (M = Mn or Re), rigid angular bidentate ligand (benzimidazole (H-bim) or 5,6-di-(methoxycarbonyl)-benzimidazole (H-ebim)), and tritopic ligand (1,3,5-tri(benzimidazol-1-ylmethyl)-benzene (Tbim) or Tebim). All capped metallacalix[3]arenes are characterized using FT-IR, 1H NMR spectroscopy and mass spectrometry. The 1H NMR spectra for all the complexes displayed a simple and symmetrical pattern with characteristic upfield and downfield shifts for the protons of both the coordinated ligands, which signifies that synthesized capped metallacalix[3]arenes retains the structural framework in the solution. Further, the molecular structures of 1 and 3b were confirmed by single crystal X-ray diffraction analysis.