important problem is related to the high acute and chronic toxicity of the lead compounds, which can cause occupational health risks and hinder massive industrial production of raw materials and photovoltaic modules. [3] The need for recycling of the lead-containing photovoltaic panels at the end of their life cycle represents another issue, which has been experienced already in the case of CdTe technology. [4] Thus, the facile photo degradation of complex iodoplumbates and their anticipated negative impact on the environment provide impetus for the development of alternative lead-free light absorbers based on metal halides. [5] Complex tin (II) and germanium (II) halides with the perovskite crystal lattice were thoroughly investigated in effort to develop a new generation of light harvesting materials for solar cells. However, ASnX 3 and AGeX 3 systems (A represents organic cation and X = I, Br) delivered inferior photovoltaic efficiencies, while demonstrating even lower intrinsic stability than the iodoplumbates due to easy disproportionation of M (II) into M (0) and M (IV). [6] Therefore, the most recent efforts have been focused on the exploration of halide complexes of the posttransition group 15 elements such as Bi and Sb. Along with the pioneering reports on BiI 3[7] and A 3 Bi 2 I 9 (A = MA or Cs), [8] a number of other bismuth halides were considered such as BiSI, BiOI, AgBi 2 I 7 , and Cs 2 AgBiX 6 (X = Br, Cl). [9] The range of antimony (III) halides investigated in photovoltaic cells is limited to A 3 Sb 2 I 9 (A = MA, Rb, Cs). [10] Unfortunately, all binary and complex Bi(III) and Sb(III) halides so far tested delivered rather modest photovoltaic performances ranging from 0.1% to 1.2%. Low external quantum efficiencies (EQEs <20-30%) strongly suggest inefficient generation of charge carriers in the photo active layer and/or their hindered transport to the respective electrodes.Here, we report the first perovskite-like antimony (V) complex halide with the pseudo-3D crystal structure, which demonstrates EQE of ≈80% and decent power conversion efficiencies close to 4% in planar junction solar cells.While the photovoltaic properties of Sb(III) iodides have been intensively investigated within the last couple of years, halide complexes of Sb(V) remain unexplored. Yet, bromoantimonates (V) or so-called mixed valence complexes containing both Sb(III) and Sb(V) species were first reported more than 70 years ago. [11] These compounds represent intensively colored

We present herein the synthesis, crystal structure, and electric and magnetic properties of the spin‐crossover salt [Mn(5‐Cl‐sal‐N‐1,5,8,12)]TCNQ1.5⋅2 CH3CN (I), where 5‐Cl‐sal‐N‐1,5,8,12=N,N′‐bis(3‐(2‐oxy‐5‐chlorobenzylideneamino)propyl)‐ethylenediamine, containing distinct conductive and magnetic blocks along with acetonitrile solvent molecules. The MnIII complex with a Schiff‐base ligand, [Mn(5‐Cl‐sal‐N‐1,5,8,12)]+, acts as the magnetic unit, and the π‐electron acceptor 7,7,8,8‐tetracyanoquinodimethane (TCNQ−) is the conducting unit. The title compound (I) exhibits semiconducting behavior with room temperature conductivity σRT≈1×10−4 ohm−1 cm−1 and activation energy Δ ≈0.20 eV. In the temperature range 73–123 K, it experiences a hysteretic phase transition accompanied by a crossover between the low‐spin S=1 and high‐spin S=2 states of MnIII and changes in bond lengths within the MnN4O2 octahedra. The pronounced shrinkage of the basal Mn−N bonds in I at the spin crossover suggests that the dx2-y2 orbital is occupied/deoccupied in this transition. Interestingly, the bromo isomorphic counterpart [Mn(5‐Br‐sal‐N‐1,5,8,12)]TCNQ1.5⋅2 CH3CN (II) of the title compound evidences no spin‐crossover phenomena and remains in the high‐spin state in the temperature range 2–300 K. Comparison of the chloro and bromo compounds allows the thermal and spin‐crossover contributions to the overall variation in bond lengths to be distinguished. The difference in magnetic behavior of these two salts has been ascribed to intermolecular supramolecular effects on the spin transition. Discrete hydrogen bonding exists between cations and cations and anions in both compounds. However, the hydrogen bonding in the crystals of II is much stronger than in I. The relatively close packing arrangement of the [Mn(5‐Br‐sal‐N‐1,5,8,12)]+ cations probably precludes their spin transformation.

In this article we report the synthesis and structure of the new Co(II) complex EtN[Co(hfac)] (I) (hfac = hexafluoroacetylacetonate) exhibiting single-ion magnet (SIM) behavior. The performed analysis of the magnetic characteristics based on the complementary experimental techniques such as static and dynamic magnetic measurements, electron paramagnetic resonance spectroscopy in conjunction with the theoretical modeling (parametric Hamiltonian and ab initio calculations) demonstrates that the SIM properties of I arise from the nonuniaxial magnetic anisotropy with strong positive axial and significant rhombic contributions.

This study presents the novel hexacoordinated Co(ii) mononuclear complex with SIM behavior.