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Title: Synthesis, crystal structure and electronic structure of the binary phase Rh{sub 2}Cd{sub 5}

Abstract

A new phase in the Rh-Cd binary system - Rh{sub 2}Cd{sub 5} has been identified and characterized by single crystal X-ray diffraction and Energy dispersive X-ray analysis. The stoichiometric compound Rh{sub 2}Cd{sub 5} crystallizes with a unit cell containing 14 atoms, in the orthorhombic space group Pbam (55). The crystal structure of Rh{sub 2}Cd{sub 5} can be described as a defect form of the In{sub 3}Pd{sub 5} structure with ordered vacancies, formed of two 2D atomic layers with the stacking sequence: ABAB. The A type layers consist of (3.6.3.6)-Kagomé nets of Cd atoms while the B type layers consist of (3{sup 5}) (3{sup 7})- nets of both Cd and Rh atoms. The stability of this line phase is investigated by first principle electronic structure calculations on the model of ordered Rh{sub 2}Cd{sub 5}. - Graphical abstract: (3.6.3.6)-Kagomé nets of cadmium atoms (top) and (3{sup 5}) (3{sup 7})- nets of both cadmium and rhodium atoms (bottom) in the structure of Rh{sub 2}Cd{sub 5}.

Authors:
 [1];  [2];  [1]
  1. Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)
  2. Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)
Publication Date:
OSTI Identifier:
22658197
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 246; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CADMIUM COMPOUNDS; CRYSTAL STRUCTURE; ELECTRONIC STRUCTURE; EXPERIMENTAL DATA; LAYERS; ORTHORHOMBIC LATTICES; RHODIUM COMPOUNDS; SIMULATION; SPACE GROUPS; VACANCIES; X-RAY DIFFRACTION

Citation Formats

Koley, Biplab, Chatterjee, S., and Jana, Partha P., E-mail: ppj@chem.iitkgp.ernet.in. Synthesis, crystal structure and electronic structure of the binary phase Rh{sub 2}Cd{sub 5}. United States: N. p., 2017. Web. doi:10.1016/J.JSSC.2016.11.029.
Koley, Biplab, Chatterjee, S., & Jana, Partha P., E-mail: ppj@chem.iitkgp.ernet.in. Synthesis, crystal structure and electronic structure of the binary phase Rh{sub 2}Cd{sub 5}. United States. doi:10.1016/J.JSSC.2016.11.029.
Koley, Biplab, Chatterjee, S., and Jana, Partha P., E-mail: ppj@chem.iitkgp.ernet.in. Wed . "Synthesis, crystal structure and electronic structure of the binary phase Rh{sub 2}Cd{sub 5}". United States. doi:10.1016/J.JSSC.2016.11.029.
@article{osti_22658197,
title = {Synthesis, crystal structure and electronic structure of the binary phase Rh{sub 2}Cd{sub 5}},
author = {Koley, Biplab and Chatterjee, S. and Jana, Partha P., E-mail: ppj@chem.iitkgp.ernet.in},
abstractNote = {A new phase in the Rh-Cd binary system - Rh{sub 2}Cd{sub 5} has been identified and characterized by single crystal X-ray diffraction and Energy dispersive X-ray analysis. The stoichiometric compound Rh{sub 2}Cd{sub 5} crystallizes with a unit cell containing 14 atoms, in the orthorhombic space group Pbam (55). The crystal structure of Rh{sub 2}Cd{sub 5} can be described as a defect form of the In{sub 3}Pd{sub 5} structure with ordered vacancies, formed of two 2D atomic layers with the stacking sequence: ABAB. The A type layers consist of (3.6.3.6)-Kagomé nets of Cd atoms while the B type layers consist of (3{sup 5}) (3{sup 7})- nets of both Cd and Rh atoms. The stability of this line phase is investigated by first principle electronic structure calculations on the model of ordered Rh{sub 2}Cd{sub 5}. - Graphical abstract: (3.6.3.6)-Kagomé nets of cadmium atoms (top) and (3{sup 5}) (3{sup 7})- nets of both cadmium and rhodium atoms (bottom) in the structure of Rh{sub 2}Cd{sub 5}.},
doi = {10.1016/J.JSSC.2016.11.029},
journal = {Journal of Solid State Chemistry},
number = ,
volume = 246,
place = {United States},
year = {Wed Feb 15 00:00:00 EST 2017},
month = {Wed Feb 15 00:00:00 EST 2017}
}
  • The anion [Ru{sub 2}Rh{sub 2}(CO){sub 12}]{sup 2{minus}} (1) has been obtained by reaction of Ru{sub 3}(CO){sub 12} with [Rh(CO){sub 4}]{sup {minus}} as [N(PPh{sub 3}){sub 2}]{sup +} or (PPH{sub 4}){sup +} salts; this species reacts with acids or AuPPH{sub 3}Cl to give respectively [Ru{sub 2}Rh{sub 2}(CO){sub 12}H]{sup {minus}} (2) and [Ru{sub 2}Rh{sub 2}(CO){sub 12} (AuPPh{sub 3})]{sup {minus}} (3). The phosphonium salts (PPh{sub 4}){sub 2}[Ru{sub 2}Rh{sub 2}(CO){sub 12}]{center_dot}THF (I), (PPh{sub 4})[Ru{sub 2}Rh{sub 2}(CO){sub 12}H] (II), and (PPh{sub 4})[Ru{sub 2}Rh{sub 2}(CO){sub 12}(AuPPh{sub 3})](III) were characterized by single crystal X-ray diffraction. Anions 1 and 2 have a tetrahedral Ru{sub 2}Rh{sub 2} metal frame, whilemore » in 3 there is a trigonal-bipyramidal frame with one ruthenium atom and the gold atom in apical positions; in 2 the H atom bridges the Ru-Ru edge. {sup 1}H and {sup 31}P NMR spectra of, respectively, 2 and 3 are consistent with the crystal structures. {sup 13}C NMR spectra of both 1 and 2 show evidence of fluxional behavior at 295 K which cannot be frozen at 178 K, where the signals collapse; compound 3 at room temperature shows a partially fluxional solution structure which becomes static at ca. 250 K.« less
  • The reaction of the paramagnetic Rh/sub 2//sup 5+/ complex Rh/sub 2/(form)/sub 3/(NO/sub 3/)/sub 2/ (form = N,N'-di-p-tolylformamidinate) with an excess of the neutral ligands PPh/sub 3/, pyridine, and dimethylamine leads, via reductive elimination of one nitrate group, to the formation of the asymmetric Rh/sub 2//sup 4+/ complexes Rh/sub 2/(form)/sub 3/(NO/sub 3/)L L = PPh/sub 3/ (1), pyridine (2), N(CH/sub 3/)/sub 2/H (3). The two rhodium atoms in complexes 1-3 display different coordinations and reduced average formal oxidation states. The complexes have been characterized by IR, /sup 31/P NMR, and /sup 103/Rh NMR spectroscopic methods, which point out the nonequivalence ofmore » the two rhodium atoms. Complexes 1 and 2 have also been characterized by single-crystal X-ray analysis. Complex 1 belongs to the monoclinic space group system P2/sub 1//n, with a = 21.529 (3) /angstrom/; b = 23.990 (3) /angstrom/, c = 11.944 (1) /angstrom/, /beta/ = 102.13 (4)/degree/, Z = 4, and R = 0.057 for 2046 reflections with I > 3/sigma/(I). The crystal structure reveals that one of the three formamidinate groups spanning the dimetal center (Rh-Rh = 2.498 (2) /angstrom/) is bonded in an unusual way, namely, /sigma/,/sigma/-N,N' with a localized double bond. Complex 2 forms monoclinic crystals in space group P2/sub 1//c with a = 10.238 (1) /angstrom/, b = 16.567 (2) /angstrom/, /beta/ = 955.6 (3)/degree/, Z = 4, and R = 0.041 for 3392 reflections with I > 3/sigma/(I). In complexes 2 and 3 of all the bridging ligands are bonded in the usual fashion, namely, /sigma/,/sigma/-N,N' with delocalized double bonds. 18 refs., 3 figs., 6 tabs..« less
  • A synthetic route is presented for the synthesis of the mixed-ligand complex Rh/sub 2/(Form)/sub 2/(O/sub 2/CCF/sub 3/)/sub 2/(H/sub 2/O)/sub 2/ )Form = (p-MeC/sub 6/H/sub 4/NC(H)NC/sub 6/H/sub 4/Me-p)/sup -/) containing the Rh/sub 24//sup +/ core/sup 6/ and the mixed-valence complex Rh/sub 2/(Form)/sub 3/(NO/sub 3/)/sub 2/ containing the Rh/sub 2//sup 5 +/ core. This method is based on the chemical oxidation with the appropriate silver salt of the Rh(I) formamidinate complex (Rh(C/sub 8/H/sub 12/)(Form))/sub 2/. In this paper the synthesis, the spectroscopic properties, and the X-ray crystal structure of the complex Rh/sub 2/(Form)/sub 3/(NO/sub 3/)/sub 2/ are described. 12 references, 1 figure,more » 3 tables.« less
  • The new compounds Ce{sub 2/3-x}Rh{sub 2}O{sub 4} (x{approx}0.11-0.14) and CeRh{sub 2}O{sub 5} have been prepared. Their structures were determined from single crystal X-ray diffraction data. Electrical and magnetic properties were also evaluated. Based on the structural analysis and physical properties, oxidation states for CeRh{sub 2}O{sub 5} can be assigned as Ce{sup 4+}Rh{sup 3+}{sub 2}O{sub 5}. A small variation in x was detected for Ce{sub 2/3-x}Rh{sub 2}O{sub 4} indicating a formula ranging from Ce{sup 3.64+}{sub 0.55}Rh{sup 3+}{sub 2}O{sub 4} to Ce{sup 3.81+}{sub 0.525}Rh{sup 3+}{sub 2}O{sub 4}. - Graphical abstract: The new compounds Ce{sub 2/3-x}Rh{sub 2}O{sub 4} (x{approx}0.11-0.14) and CeRh{sub 2}O{sub 5}more » have been prepared and their structures were determined from single crystal X-ray diffraction data. Electrical and magnetic properties were also evaluated. Highlights: > The new compounds CeRh{sub 2}O{sub 5} and Ce{sub 2/3-x}Rh{sub 2}O{sub 4} (x{approx}0.11-0.14) have been prepared. > Their structures were determined from single crystal X-ray diffraction data. > Valence picture is Ce{sup 4+}Rh{sup 3+}{sub 2}O{sub 5} and Ce{sup 3.64+}{sub 0.55}Rh{sup 3+}{sub 2}O{sub 4} to Ce{sup 3.81+}{sub 0.525}Rh{sup 3+}{sub 2}O{sub 4}.« less
  • The compound Ba{sub 2}Cu{sub 2}ThS{sub 5} has been synthesized by the reaction of BaS, S, Cu, and Th at 1173 K. It crystallizes in the monoclinic space group C{sub 2h}{sup 3}−C2/m with two formula units in a cell of dimensions a=13.5616(8) Å, b=4.1159(2) Å, c=9.3548(6) Å, β=115.89(1)° (100 K). The structure comprises Ba{sup 2+} cations and {sup 2}{sub ∞}[Cu{sub 2}ThS{sub 5}{sup 4−}] layers. The two dimensional layers are formed by the connection of ThS{sub 6} octahedra and CuS{sub 4} tetrahedra along [001] with a sequence…. oct tet tet oct tet tet…. Optical measurements performed on Ba{sub 2}Cu{sub 2}ThS{sub 5} indicatemore » an indirect band gap of 1.86 eV. DFT calculations performed with the HSE06 functional yield band gaps of 1.7 eV for Ba{sub 2}Cu{sub 2}ThS{sub 5} and 1.5 eV for the isostructural compound Ba{sub 2}Cu{sub 2}US{sub 5}. - Graphical abstract: View of the Ba{sub 2}Cu{sub 2}ThS{sub 5} structure and its indirect band gap. DFT calculation gives 1.7 eV. Highlights: ► The new solid-state compound Ba{sub 2}Cu{sub 2}ThS{sub 5} has been synthesized from BaS, S, Cu, and Th at 1173 K. ► Single-crystal optical measurements indicate of indirect band gap of 1.86 eV for Ba{sub 2}Cu{sub 2}ThS{sub 5}. ► DFT with the HSE06 functional predict band gaps of 1.7 and 1.5 eV for Ba{sub 2}Cu{sub 2}ThS{sub 5} and Ba{sub 2}Cu{sub 2}US{sub 5}.« less