Engineering Heteronuclear Arrays from Ir^III‐Metalloligand and Co^II Showing Coexistence of Slow Magnetization Relaxation and Photoluminescence

Abstract

Comprehensive Summary Three heteronuclear IrIII‐CoII arrays, [Co(H2O)6]2[Ir(ppyCOO)(ppyCOOH)(bpy)]2[Ir(ppyCOO)2(bpy)]2(NO3)2⋅10.5H2O (2), [Co(H2O)6]{Co(H2O)4[Ir(ppyCOO)2(bpy)]2}[Ir(ppyCOO)2(bpy)]2⋅15H2O (3) and {Co(H2O)2[Ir(ppyCOO)2(bpy)]2}⋅2CH3OH⋅3H2O (4), have been synthesized by combining paramagnetic CoII ion with luminescent IrIII‐metalloligand, [Ir(ppyCOOH)2(bpy)][Ir(ppyCOO)2(bpy)]⋅5H2O (1), where ppyCOOH = 3‐(pyridin‐2‐yl)benzoic acid and bpy = 2,2'‐bipyridyl. Owing to the variable charged states of compound 1 at different pH, compounds 2 and 3 are discrete ionic complexes containing hydrated Co2+ cations and deprotonated [Ir(ppyCOO)2(bpy)]– anions as well as coexisting neutral [Ir(ppyCOO)(ppyCOOH)(bpy)] (for 2) or Co(H2O)4[Ir(ppyCOO)2(bpy)]2 trinuclear molecule (for 3). Whereas compound 4 consists of self‐assembled two‐dimensional coordination polymer with Co‐metalloligand dative bonds. The hexa‐coordinated CoII cores in all complexes display octahedral geometries with varying degrees of distortion. In a bias dc field, the ac susceptibilities for 2—4 reveal slow magnetic relaxation. Moreover, the solid‐state phosphorescence is observed for compounds 2 and 3 due to weak supramolecular interaction between CoII ion and Ir‐moiety but is severely quenched for 4, where the Co center is strongly connected to the metalloligand. To the best of our knowledge, this is the first report of Ir‐Co systems showing both slow magnetization relaxation and photoluminescence.

Effect of Pd(ii) uptake on high-temperature phase transitions in a hybrid organic–inorganic perovskite semiconductor

“…[11][12][13][14][15][16][17][18][19][20][21][22] Among them, perovskite-type hybrids with the general chemical formula ABX 3 (A = organic cation, B = divalent metal and X = anion) have drawn increasing attention due to their excellent physical properties and practical applications in structural phase transitions, electricity, magnetism, luminescence and solar cells. [23][24][25][26][27][28][29] According to previous studies, hybrid organic-inorganic ABX 3 perovskites can be crystallized in two structural forms, one adopts the same structure as the inorganic ABX 3 perovskite CaTiO 3 , including a three-dimensional BX 3 framework with corner-sharing octahe-dra, where B = Pb(II), Sn(II), X = halide and A = methylammonium, 30,31 formamidinium, 32 methylhydrazinium 33,34 and aziridinium. 35,36 Another shows the same structure as the inorganic ABX 3 perovskite BaNiO 3 , containing a one-dimensional BX 3 framework with face-sharing BX 6 octahedra, such as [C 3 H 4 NS]CdBr 3 and [C 4 H 8 N]CdCl 3 .…”

Slow magnetic relaxation and spin crossover behavior in two mixed-valence Co(ii)/Co(iii) complexes

“…31–33 Searching for well-defined correlations between different structural factors and the magnetic anisotropy in transition metal complexes remains a great challenge and much more work is required to extend our knowledge for the rational design of new magnetic materials. 33–40…”