The binary tin-rich lanthanum stannides La2Sn5 and La3Sn7—A structural and bond theoretical study

Dürr, Ines; Schwarz, Michael; Röhr, Caroline

doi:10.1016/j.jssc.2011.06.035

Cited by 8 publications

(7 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In the late rare-earth mixed stannides/germanides RESnGe and RE 2 Sn 4 Ge [15,16] of the general series REM 2 (ZrSi 2 type) -LnM 3 (DyGe 3 type) the Ge atoms are exclusively forming the zig-zag chains, whereas Sn occupies the positions of the square nets. In accordance, band structure calculations for the pure stannides of the closely related series LaSn 2 (ZrGa 2 type) -LaSn 3 (Cu 3 Au type) [28] show, that the atoms in the zig-zag chains exhibit the higher negative charge when compared to the positions forming the Cu 3 Au sections of the structure.…”

Section: Aspects Of 'Coloring' In Mixed Tetrelidessupporting

confidence: 75%

“…The differences are always very small and towards a slight formal electron excess, indicating an incomplete charge transfer from lanthanum to the tetrelide anions. Band structure calculations on several La germanides[4] and stannides[5,28,29] substantiate the -bonding contributions between La-d and M-p states. In accordance, the La-Sn and La-Ge distances are decreased when compared to those in the isotypic electron-precise alkaline-earth tetrelides and the calculated valence electron densities show distinct bond critical points at the respective short La-M contacts.…”

mentioning

confidence: 74%

“…CaSn3, SrSn3 (Cu3Au) [41] LaGe3 (TaCo3) [42] LaSn3 (Cu3Au) [28] BaSn3 (Ni3Sn) [43,41] type: d Ge-Ge = 267-279.6 pm) and the variants of the ThSi 2 structure type (d Ge-Ge = 243-253 pm). Eight-membered rings of exclusively trigonal-planar coordinated M atoms are also observed in the mixed Al germanide Yb 17 Al 8 Ge 19 [27].…”

Section: Comparison Of the Anions With Those Of Other Binary Stannidementioning

confidence: 99%

See 2 more Smart Citations

The new complex lanthanum tetrelide La55Sn36.6Ge24.4

Dürr

Röhr

2012

Journal of Alloys and Compounds

Self Cite

View full text Add to dashboard Cite

Section: Aspects Of 'Coloring' In Mixed Tetrelidessupporting

confidence: 75%

mentioning

confidence: 74%

Section: Comparison Of the Anions With Those Of Other Binary Stannidementioning

confidence: 99%

See 1 more Smart Citation

The new complex lanthanum tetrelide La55Sn36.6Ge24.4

Dürr

Röhr

2012

Journal of Alloys and Compounds

Self Cite

View full text Add to dashboard Cite

“…Examples are the compounds of the CrB structure type8–10 or the tetrelides,11,12 and the mixed triel/tetrelides,13–15 forming the Pu 3 Pd 5 structure type. This effect of an incomplete electron transfer from the A cations to the M anions is strongly increased for the rare‐earth element lanthanum, so that the respective La (and other trivalent rare‐earth element) compounds typically do no longer obey the simple electron counting rules 16–21. Paired with M elements of moderate electronegativity, like e.g.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical Reduction of Carbon Dioxide to Formic Acid

et al. 2014

View full text Add to dashboard Cite

This Review provides an overview of electrochemical techniques that are implemented in addressing gaseous CO2 towards the synthesis of a particular fuel (i.e. formic acid). The electrochemical reaction mechanism, as well as the advancement of electrodes, catalyst materials, and reactor designs are reviewed and discussed. To date, the electrolytic cell is the dominant reaction site and, based on which, various catalysts have been proposed and researched. In addition, relevant work regarding reactor design optimization for the purpose of alleviating restrictions of the current CO2 electrochemical reduction system are summarized, including low reactant‐transfer rate, high reaction overpotential, and low product selectivity. The use of microfluidic techniques to build microscale electrochemical reactors is identified to be highly promising to largely increase the electrochemical performance. Finally, future challenges and opportunities of electrochemical reduction of CO2 are discussed.

show abstract

“…Die strukturelle Vielfalt binärer Lanthan-Stannide [1,2] reicht von sehr elektronenreichen Verbindungen wie z. B.…”

Section: Introductionunclassified

Neue Lanthan-Stannide/Germanide: La₃Sn_4.4Ge_0.6, La₃Sn_3.1Ge_0.9 und La₉Sn_6.7Ge_3.3 / New Lanthanum Stannide/Germanides: La₃Sn_4.4Ge_0.6, La₃Sn_3.1Ge_0.9 and La₉Sn_6.7Ge_3.3

Dürr

Röhr

2011

Zeitschrift Für Naturforschung B

Self Cite

View full text Add to dashboard Cite

Three new ternary mixed lanthanum stannide/germanides have been synthesized and characterized in the course of a systematic study of the phase formation at the 3 : 5, 3 : 4 and 1 : 1 pseudo-binary sections of the ternary system La -Ge -Sn, i. e. a study of the 'coloring' in mixed tetrelides. The structures of the title compounds have been determined using single-crystal X-ray data, and the electronic structure was analyzed by means of simple electron counting rules and FP-LAPW band structure methods. Even a very minor substitution of Sn by Ge in the 3 : 5 stannide La 3 Sn 5 already changes the structure from the Pu 3 Pd 5 type of the binary stannide towards the Tl 4 PbTe 3 type (La 3 Sn 4.4 Ge 0.6 : tetragonal, space group I4/mcm, a = 861.35(10), c = 1211.48(13) pm, Z = 4, R1 = 0.0420). According to the anionic building blocks present, isolated [Ge/Sn] 4− anions and heavily puckered 4.8 2 nets of three-bonded tin atoms (i. e. [Sn 4 ] 4− Zintl ions), a small formal electron excess (+9/ − 8) occurs, which is also apparent from the position of the minimum in the calculated tDOS. In contrast, starting from the known binary stannide La 3 Sn 4 (orthorhombic, space group Cmcm, Er 3 Ge 4 structure type) a substitution of tin by germanium is possible without a change of the structure type up to the border composition La 3 Sn 3.1 Ge 0.9 (a = 448.61(5), b = 1170.68 (14), c = 1556.0(2) pm, Z = 4, R1 = 0.0380). Germanium preferentially occupies the sites of the [Ge/Sn] 3 trimers, whereas the site of the square-planar coordinated Sn(3), which is stabilized by hypervalent bonding, is not populated by germanium. Taking the respective partial bonding into account, the Zintl electron count is also nearly exact (+9/ − 8). The new complex mixed tetrelide La 9 Sn 6.7 Ge 3.3 (tetragonal, space group P4 2 /ncm, a = 1602.04(3), c = 1724.42 (5) [M 6 ]. In this compound, the electron count following the Zintl concept also reveals only a very small formal excess of electrons (+54/ − 52).

show abstract

The binary tin-rich lanthanum stannides La2Sn5 and La3Sn7—A structural and bond theoretical study

Cited by 8 publications

References 42 publications

The new complex lanthanum tetrelide La55Sn36.6Ge24.4

The new complex lanthanum tetrelide La55Sn36.6Ge24.4

Electrochemical Reduction of Carbon Dioxide to Formic Acid

Neue Lanthan-Stannide/Germanide: La₃Sn_4.4Ge_0.6, La₃Sn_3.1Ge_0.9 und La₉Sn_6.7Ge_3.3 / New Lanthanum Stannide/Germanides: La₃Sn_4.4Ge_0.6, La₃Sn_3.1Ge_0.9 and La₉Sn_6.7Ge_3.3

Contact Info

Product

Resources

About

The binary tin-rich lanthanum stannides La2Sn5 and La3Sn7—A structural and bond theoretical study

Cited by 8 publications

References 42 publications

The new complex lanthanum tetrelide La55Sn36.6Ge24.4

The new complex lanthanum tetrelide La55Sn36.6Ge24.4

Electrochemical Reduction of Carbon Dioxide to Formic Acid

Neue Lanthan-Stannide/Germanide: La3Sn4.4Ge0.6, La3Sn3.1Ge0.9 und La9Sn6.7Ge3.3 / New Lanthanum Stannide/Germanides: La3Sn4.4Ge0.6, La3Sn3.1Ge0.9 and La9Sn6.7Ge3.3

Contact Info

Product

Resources

About

Neue Lanthan-Stannide/Germanide: La₃Sn_4.4Ge_0.6, La₃Sn_3.1Ge_0.9 und La₉Sn_6.7Ge_3.3 / New Lanthanum Stannide/Germanides: La₃Sn_4.4Ge_0.6, La₃Sn_3.1Ge_0.9 and La₉Sn_6.7Ge_3.3