6313-33-3Relevant articles and documents
Syntheses, Crystal Structures, and Optical Properties of the Hexagonal Perovskites Variants ABX3 (B = Ni, A = Gu, FA, MA, X = Cl, Br; B = Mn, A = MA, X = Br)
Daub, Michael,Ketterer, Ines,Hillebrecht, Harald
, p. 280 - 287 (2018/02/09)
Herein we report on our systematic investigations on the solution processed synthesis and characterization of transition metal halides (guanidinium, formamidinium, and methylammonium nickel bromides and chlorides as well as methylammonium manganese bromide) with the composition ABX3 (A = organic cation; B = Mn, Ni; X = Cl, Br). The investigations were carried out with respect to possible applications of 3d transition metal compounds for the perovskite solar cell. All the compounds represent different variants of the hexagonal perovskite structure (2H). Crystal structures and symmetry relations are discussed. Additionally, (CH3NH3)2MnI4, which consists of tetrahedral coordinated Mn2+, and the water containing compounds (CH3NH3)MnBr3·2H2O, which forms chains of edge sharing octahedra, as well as (CH3NH3)NiCl3·2H2O, which consists of dimers of octahedra, are presented. Investigations on the crystal structures are supported by vibrational and optical spectroscopy.
Reentrant Structural and Optical Properties and Large Positive Thermal Expansion in Perovskite Formamidinium Lead Iodide
Fabini, Douglas H.,Stoumpos, Constantinos C.,Laurita, Geneva,Kaltzoglou, Andreas,Kontos, Athanassios G.,Falaras, Polycarpos,Kanatzidis, Mercouri G.,Seshadri, Ram
, p. 15392 - 15396 (2016/12/06)
The structure of the hybrid perovskite HC(NH2)2PbI3(formamidinium lead iodide) reflects competing interactions associated with molecular motion, hydrogen bonding tendencies, thermally activated soft octahedral rotations, and the propensity for the Pb2+lone pair to express its stereochemistry. High-resolution synchrotron X-ray powder diffraction reveals a continuous transition from the cubic α-phase (Pm3m, #221) to a tetragonal β-phase (P4/mbm, #127) at around 285 K, followed by a first-order transition to a tetragonal γ-phase (retaining P4/mbm, #127) at 140 K. An unusual reentrant pseudosymmetry in the β-to-γ phase transition is seen that is also reflected in the photoluminescence. Around room temperature, the coefficient of volumetric thermal expansion is among the largest for any extended crystalline solid.
Novel transition metal complexes with diaminocarbene ligands and their use in reactions catalyzed by transition metals
-
, (2008/06/13)
The invention relates to novel transition metal complexes containing at least one diaminocarbene ligand, to processes for preparing these transition metal complexes and to their use as catalysts in organic reactions.
