Polyselenide Chemistry of Indium and Thallium in Dimethylformamide, Acetonitrile, and Water. Syntheses, Structures, and Properties of the New Complexes [In2(Se4)4(Se5)]4−, [In2Se2(Se4)2]2−, [In3Se3(Se4)3]3−, and [Tl3Se3(Se4)3]3−

Sandeep S. Dhingra, Mercouri G. Kanatzidis*

*Corresponding author for this work

Research output: Contribution to journalArticle

48 Scopus citations

Abstract

The reaction of InCl3 with Na2Se5 in dimethylformamide (DMF) in the presence of PluPCl gave (Ph4P)4[In2(Se4)4(Se5)] (I) in 75% yield. Under the same conditions, InCl3 reacted with Na2Se5 in the presence of Pr4NBr or Et4NBr and afforded (Pr4N)4[In2(Se4)4(Se5)] (II) in 65% yield and (Et4N)4[In2(Se4)4(Se5)] (III) in 72% yield, respectively. (I) crystallizes in the triclinic space group P1̄ (No. 2) with unit cell dimensions a = 11.417(4) Å, b = 12.734(9) Å, c = 20.188(9) Å, α = 96.03(5), β = 94.69(3), γ=111.68(4), V = 2689(2) Å3, Z = 1, and R/Rw = 0.073/0.085. (II) crystallizes in the monoclinic space group P2/c (No. 13) with unit cell dimensions a = 15.997(3) Å, b = 17.376(3) Å, c = 15.168(2) Å, β = 94.56(3), V= 4202(1) Å3, Z = 2, and R/Rw = 0.069/0.080. (III) crystallizes in the triclinic space group P1̄ (No. 2) with unit cell dimensions a = 12.428(3) Å, b = 15.781(3) Å, c = 17.540(4) Å, α = 89.47(2), β = 97.90(2), γ = 94.47(2), V= 3397(1) Å3, Z = 2, and R/Rw = 0.075/0.084. Single-crystal X-ray diffraction studies show that (I), (II), and (III) contain the same anion, [In2(Se4)4(Se5)]4−. The anion consists of In3+ centers in trigonal bipyramidal coordination; each In atom is chelated by two bidentate Se42− ligands forming a [In(Se4)2] unit. Two of these [In(Se4)2] units are bridged by an Se52− chain forming a dimer. The hydrothermal reaction of InCl3 with Na2Se4 in the presence of Pr4NBr and water at 110 °C for 3 days in an evacuated sealed Pyrex tube afforded deep red crystals of (Pr4N)2[In2Se2(Se4)2] (IV), in 80% yield. Under the same conditions the reaction with [(Ph3P)2N]Cl yields [(Ph3P)2N]2[In2Se2(Se4)2] (V) in 60% yield. (IV) crystallizes in the triclinic space group P1̄ (No. 2) with unit cell dimensions a = 8.938(2) Å, b = 11.290(2) Å, c = 11.528(2) Å, α = 79.19(1), β = 105.56(1), γ = 99.84(1), V = 1093(1) Å3, Z = 1, and R/Rw = 0.045/0.049. (V) also crystallizes in the triclinic space group P1̄ (No. 2) with unit cell dimensions a = 10.931(5) Å, b = 11.302(7) Å, c = 15.189(8) Å, α = 84.98(5), β = 94.15(4), γ = 93.86(4), V= 1858(1) Å3, Z = 1, and R/Rw = 0.060/0.081. Single-crystal X-ray diffraction studies show that (IV) and (V) contain the same binuclear anion [In2Se2(Se4)2]2−. The anion contains In3+ with a tetrahedral coordination, bridged by two monoselenides to form a planar [In2Se2]2+ core with an inversion center at the middle of the In--In vector of 3.336(2) Å. The remaining two coordination sites on each In atom are occupied by the Se42− bidentate chelates. The reaction of InCl3 with Na2Se5 in 1:2 mole ratio in acetonitrile in the presence of Et4NBr afforded (Et4N)3[In3Se3(Se4)3] (VI). Similar reaction of TlCl with Na2Se5 in 1:2 mole ratio in DMFin the presence of Et4NBr gave (Et4N)3[Tl3Se3(Se4)3] (VII). Single-crystal X-ray diffraction studies show that the two compounds (VI) and (VII) are isostructural and crystallize in the monoclinic space group P21/c (No. 14). The unit cell dimensions are a = 16.747(4) Å, b = 13.701(3) Å, c = 22.227(3) Å, β = 94.16(2), V= 5086(2) Å3, Z = 4, and R/Rw = 0.045/0.051 and a = 16.813(3) Å, b = 13.774(3) Å, c = 22.186(4) Å, β = 94.13(1); V= 5126(2) Å3, Z = 4, and R/Rw = 0.072/0.087 for (VI) and (VII), respectively. The trinuclear anion [M3Se3(Se4)3]3− (M = In, Tl) in (VI) and (VII) contains M3+ with a tetrahedral coordination. Each M3+ center has a chelating Se42− ligand and is bridged to the other two M3+ centers by monoselenide, Se2−, ligands forming a six-membered [M3Se3]3+ core. Variable-temperature 77Se NMR spectra of (I)–(VII) are reported. All indiumpolyselenide complexes show the same NMR spectrum at room temperature in DMF suggesting that in solution only one In/Se species exists. UV/vis of (I)–(III) are similar, with two absorptions at ∼450 and ∼650 nm, while (IV)–(VII) have a featureless spectra. The electrochemistry of (I) and (VI) is reported. The solid-state far-IR spectra of all the compounds show strong absorptions in the 300−100 cm−1 region due to the Se-Se and M-Se stretching frequencies; tentative assignments are reported herein. Thermal gravimetric analysis data show that the compounds pyrolyze to give single-phase binary metal chalcogenides (β-In2Se3 and TlSe).

Original languageEnglish (US)
Pages (from-to)1350-1362
Number of pages13
JournalInorganic Chemistry
Volume32
Issue number8
DOIs
StatePublished - Jan 1 1993

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

Fingerprint Dive into the research topics of 'Polyselenide Chemistry of Indium and Thallium in Dimethylformamide, Acetonitrile, and Water. Syntheses, Structures, and Properties of the New Complexes [In<sub>2</sub>(Se<sub>4</sub>)<sub>4</sub>(Se<sub>5</sub>)]<sup>4−</sup>, [In<sub>2</sub>Se<sub>2</sub>(Se<sub>4</sub>)<sub>2</sub>]<sup>2−</sup>, [In<sub>3</sub>Se<sub>3</sub>(Se<sub>4</sub>)<sub>3</sub>]<sup>3−</sup>, and [Tl<sub>3</sub>Se<sub>3</sub>(Se<sub>4</sub>)<sub>3</sub>]<sup>3−</sup>'. Together they form a unique fingerprint.

  • Cite this