Thermal and Mechanochemical Syntheses of Luminescent Mononuclear Copper(I) Complexes

4 years ago

Thermal and Mechanochemical Syntheses of Luminescent Mononuclear Copper(I) Complexes

Masaki Yoshida, Masako Kato, Tatsuya Hasegawa, Panyi Liang, Atsushi Kobayashi

Mononuclear CuI iodide complexes, [CuI(PPh3)2L] {PPh3 = triphenylphosphine; L = 4-aminoisoquinoline (4-aiq) (2), 5-aminoisoquinoline (5-aiq) (3), and 5-nitroisoquinoline (niq) (4)}, were prepared by three different methods: normally used reactions in the solution state, mechanochemical synthesis, and newly developed solvent-free thermal synthesis. Although no solvent was required for the mechanochemical synthesis of the parent complex [CuI(PPh3)2(iq)] (1; iq = isoquinoline), a minimal amount of assisting solvent (PhCN) was required for the mechanochemical syntheses of the three functionalized isoquinoline complexes. The amino-functionalized isoquinoline complexes were successfully synthesized by heating the ground mixture of three types of starting materials at ca. 100 °C, where the PPh3 ligand melted to promote complex formation by acting as the ligand and the solvent. The emission properties strongly depend on the L ligand: Complexes 2 and 3 showed vibronic emission spectra originating from the 3ππ* excited state localized on the L ligand, whereas complex 4 did not show any emission in the visible region.Three mononuclear CuI iodide complexes with triphenylphosphine and isoquinoline derivatives were synthesized by conventional solution reactions, mechanochemical syntheses, and thermal syntheses. Complexes with amino-functionalized isoquinoline exhibited yellow or orange phosphorescence from the 3ππ* excited state, although those with nitro-functionalized isoquinoline did not show emission.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/ejic.201700734