skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Polymorphism and optical properties in [NH{sub 4}][InSe{sub 2}]

Journal Article · · Journal of Solid State Chemistry
 [1];  [2];  [1];  [1]
  1. Institute of Chemical Sciences, Heriot-Watt University, Edinburgh, Scotland EH14 4AS (United Kingdom)
  2. Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom)

The solvothermal synthesis and characterization of two indium selenides with stoichiometry [NH{sub 4}][InSe{sub 2}] is described. Yellow [NH{sub 4}][InSe{sub 2}] (1), which exhibits a layered structure, was initially prepared in an aqueous solution of trans-1,4-diaminocyclohexane, and subsequently using a concentrated ammonia solution. A red polymorph of one-dimensional character, [NH{sub 4}][InSe{sub 2}] (2), was obtained using 3,5-dimethylpyridine as solvent. [NH{sub 4}][InSe{sub 2}] (1) crystallizes in the non-centrosymmetric space group Cc (a=11.5147(6), b=11.3242(6), c=15.9969(9) Å and β=100.354(3)°). The structural motif of the layers is the In{sub 4}Se{sub 10} adamantane unit, composed of four corner-linked InSe{sub 4} tetrahedra. These units are linked by their corners, forming [InSe{sub 2}]{sup −} layers which are stacked back to back along the c-direction, and interspaced by [NH{sub 4}]{sup +}cations. The one-dimensional polymorph, (2), crystallizes in the tetragonal space group, I4/mcm (a=8.2519(16), c=6.9059 (14) Å). This structure contains infinite chains of edge-sharing InSe{sub 4} tetrahedra separated by [NH{sub 4}]{sup +} cations. - Graphical abstract: Two polymorphic forms of [NH{sub 4}][InSe{sub 2}], which are yellow and red, have been prepared and their optical properties investigated. Highlights: • Two new indium selenides prepared by a solvothermal method. • Depending on synthesis conditions, two polymorphic forms of [NH{sub 4}][InSe{sub 2}] prepared. • Layered polymorph contains In{sub 4}Se{sub 10} adamantane clusters, linked by their corners. • One-dimensional polymorph contains [InSe{sub 2}]{sup −} chains of edge-sharing tetrahedra. • Non-centrosymmetric layered polymorph shows a second harmonic generation response.

OSTI ID:
22274033
Journal Information:
Journal of Solid State Chemistry, Vol. 204; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
Country of Publication:
United States
Language:
English