One-pot synthesis of oxamidato-bridged hexarhenium trigonal prisms adorned with ester functionality

Abstract

Oxamidato-bridged Re(I)-based hexanuclear trigonal prisms with ester functionality have been synthesised via a multicomponent self-assembly process under solvothermal conditions. The self-assembly of Re₂(CO)₁₀, oxamide ligands (H₂L1 = N,N′-dibutyloxamide, H₂L2 = N,N′-dioctyloxamide, H₂L3 = N,N′-didodecyloxamide and H₂L4 = N,N′-dibenzyloxamide) and phenyl-1,3,5-tris(isonicotinate) (ptin) resulted in the formation of metallaprisms with the general formula [{(CO)₃Re(μ–η⁴-L)Re(CO)₃}₃(μ₃-ptin)₂] (1–4). The metallaprisms 1–4 have been characterised using spectroscopic techniques, and the molecular structure of 4 has been elucidated by single-crystal X-ray diffraction methods. Investigations on the guest binding ability of 2 with a few aromatic alcohols and L-tryptophan using UV–vis and fluorescence spectroscopic titration experiments revealed strong host–guest interactions. The luminescence enhancement studies of 2 and 3 have been carried out using organic-aqueous solvent mixtures.