Introduction 30 Magnets have been discovered about four millenniums ago in ancient Greece. 31 Nowadays, in 2015, permanent magnets market is valued to 15 billion € and is 32 expected to grow according to the demands for medical and industrial devices. In 33 this market, the segment occupied by the badly named rare-earth 1-based magnets 34 continues to expand owing to superior properties (such as saturation magnetization). 35 In the 1990s, a new class of magnets emerged in the scientific community with the discovery of the single-molecule magnets (SMMs) [1]. In these magnets, the magnetic memory is stored by the magnetic moment of a single molecule constituted of 12 manganese ions. This scientific finding reduced the size of a storage unit (byte) to nanometer. At the same time, the storage capacity of hard disks based on molecules would increase drastically. The drawback is the operating temperature range, below liquid helium (À269 C). In the last three decades, the quest for better SMMs never really stopped. In 2003, Ishikawa et al. [2] discovered that a single lanthanide ion (Ln ¼ Tb III) embedded in a doubledecker complex behaved as a SMM. To date, the lanthanide series is the most productive SMMs line in Mendeleev's periodic table with a recent tremendous record of closure of the magnetic hysteresis loop at 60 K [3, 4], close to liquid nitrogen. 47 Tetrathiafulvalene (TTF) and its analogues are well known in the field of molec-48 ular materials to produce organic metals, semiconductors, and superconductors 49 [5, 6]. The functionalization of the electron donor TTF core by an acceptor moiety 50 contributed to the development of functional materials such as switches, sensors, 51 photovoltaic cells, and nonlinear optical systems [7-9]. It was then logical to adapt 52 the acceptor moiety to coordinate transition metals for (1) elaboration of 53 multifunctional materials with both paramagnetism and electrical conductivity 54 [10, 11] and (2) the synthesis of polynuclear transition metal complexes exhibiting 55 SMM properties embedded in a conducting material [12-16]. One must admit that 56 all tentative proposals were not very successful except Oshio's work [17] which 57 shows SMM behavior but without conductivity.