A New Manganese(II) Phosphate Templated by Ethylenediamine:  (C₂H₁₀N₂)[Mn₂(HPO₄)₃(H₂O)]. Hydrothermal Synthesis, Crystal Structure, and Spectroscopic and Magnetic Properties

Abstract

A new manganese(II) phosphate templated by ethylenediamine, (C 2 H 10 N 2 )[Mn 2 (HPO 4 ) 3 -(H 2 O)], has been prepared by hydrothermal synthesis and characterized by single-crystal diffraction data and spectroscopic and magnetic techniques. The compound crystallizes in the monoclinic space group P2 1 /n with a ) 21.961(7), b ) 9.345(1), c ) 6.639(2) Å; β ) 91.06(2)°; V ) 1362.3(6) Å 3 ; and Z ) 4. The structure consists of anionic sheets of formula [Mn 2 (HPO 4 ) 3 ] 2-, being the charge compensated by ethylendiammonium cations. The sheets are constructed by edge-sharing MnO 6 octahedra, MnO 5 trigonal bipyramids, and hydrogen phosphate tetrahedra. Within a layer, the edge-sharing octahedra and the trigonal bipyramids are linked in an alternating way, forming zigzag chains along the [001] direction. The ethylenediammonium cations and the water molecules are located in the interlayer space. The compound has been characterized by IR spectroscopy. A study of the compound by luminescence and diffuse reflectance spectroscopies is carried out. The Dq and Racah parameters have been calculated for Mn(II) ions in octahedral sites. The ESR spectra at different temperatures of the compound show isotropic signals, with a g value that remains unchanged with variation in temperature. The intensity and the line width of the ESR signals increase continuously from room temperature to 4.2 K. Magnetic measurements from room temperature to 1.8 K indicate the presence of antiferromagnetic interactions. A value of J/k ) -0.75 K for the exchange parameter has been calculated by fitting the experimental magnetic data to a triangular lattice antiferromagnet of S ) 5 / 2 spins.

The Synthesis and Characterization of a New Manganese Phosphate Templated by Piperazine

“…Until now just one organic}inorganic hybrid material based on manganese phosphate has been known to exist (9). In addition a number of organically templated three-dimensional manganese}gallium phosphates have been known (10}12).…”

An Ionic Nickel(II) Phosphate with Ethylenediamine: (C2H10N2)[Ni(H2O)6](HPO4)2. Hydrothermal Synthesis, Crystal Structure, and Spectroscopic Properties

“…An open-framework cobalt phosphate with ethylenediammonium cations containing a tetrahedrally coordinated cobalt(II) center (20) has been synthesized and studied. Recently, we have prepared a layered Mn(II) phosphate templated by ethylenediamine in which the metallic cation exhibits simultaneously trigonal bipyramid and octahedron coordination polyhedra (21). It can be concluded that the choice of organic guest molecules often has a large in#uence on the "nal structure of the material.…”

Carbon Dots in a Matrix: Energy‐Transfer‐Enhanced Room‐Temperature Red Phosphorescence

“…As shown in Figure b, two emission bands at λ =430 nm and 620 nm derived from the confined CDs and Mn 2+ centers in the matrix, respectively, can be observed in the spectrum of CDs@MnAPO‐CJ50, while a phosphorescence band at λ =620 nm is observed in delayed spectra. The phosphorescence excitation spectrum (Figure c) recorded at λ =620 nm indicates a core at λ =420 nm, which corresponds to the 4A 1 energy level of the Mn 2+ ion . When excited by a lamp at λ =365 nm, the composite exhibits pink emission as a result of the existence of fluorescence and phosphorescence (Figure a), and a bright red afterglow can be observed for 119 ms; the corresponding CIE coordinates are shown in Figure S9.…”