Synthesis, structure and magnetism of a novel Cu4IITi5IV heterometallic cluster

A nonanuclear (Cu4Ti5IV)-Ti-II heterometallic cluster, [Ti5Cu4O6(ba)(16)] (1, Hba = benzoic acid) was synthesized in one-pot reaction under the solvothermal condition. The metallic skeleton 1 contains a Ti-5 core constructed from two vertex-shared Ti-3 triangles and four separated Cu atoms outside which are connected together by mu(3)-O2- ions. Total 16 ba- ligands adopt mu(2)-eta(1): eta(1) coordination mode to protect the overall heterometallic core. Due to the unique d-d transitions of Cu-II ion, the reflectance spectrum of 1 displays broad and strong absorption towards visible light extending to the near-infrared region. Moreover, 1 shows almost purely paramagnetic behavior with the presence of weak antiferromagnetic interactions at low temperatures. (C) 2019 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.