Crystal structure of R3Ge1+xSe7 (R=La, Ce, Pr, Sm, Gd and Tb, x=0.43–0.49) and magnetic properties of Ce3Ge1.47Se7

A Series of Chalcogenide Borates RE6Ta2MgQB8O26 (RE = Sm, Eu, Gd; Q = S, Se) Featuring a B4O10 Cluster

“…The Gd–Se bond distances in 4 are 2.966(2) Å, close to 2.910(1) Å in Ba 2 GdInSe 5 and 3.030(1) Å in Gd 3 Ge 1.45 Se 7 . , The Ta–O and Mg–O distances are similar to those in Ba 6 TaGa 21 O 40 and Eu 9 MgS 2 B 20 O 41 , , respectively. In a comparison of the unit cell parameters and bond distances of 2 – 4 (Tables S1 and S2), it can be found that all of them decrease/increase regularly from 2 to 3 to 4 , obeying the lanthanide contraction rule.…”

Syntheses and characterization of two new selenides Ba5Al2Se8 and Ba5Ga2Se8

“…Chalcogenides are an interesting class of materials with amazing structural complexity [1][2][3][4][5][6] and important properties including thermoelectricity [7][8][9][10], magnetic property [11][12][13][14], nonlinear optical property [15,16], photovoltaicity [17], superconductivity [18], and luminescent property [19,20]. In the past years, many ternary chalcogenides in the A/M/Q system (A = alkaline-earth metal; M = Al, Ga, In; Q = S, Se, Te) have been discovered and studied, including the large family of the AM 2 Q 4 compounds [21][22][23][24][25], the A 2 M 2 Q 5 compounds [26], Ba 5 Ga 2 S 8 [27], Ba 4 Ga 2 S 7 [28], Ba 3 Ga 2 S 6 [28], and Mg 5 Al 2 Se 8 [29].…”

A Series of Lanthanide Selenidogermanates: The First Coexistence of Three Types of Selenidogermanate Units in the Same Architecture

“…Usually, the reported metal chalcogenidogermanates show ionic or neutral structures. − ,− However, compounds 1a and 1b exhibit rare chalcogenidogermanate structures with positive charge. Such unusual structural features could be due to the fact that part of the positive charge of the [Y 2 (μ-OH) 2 (tepa) 2 Cl] 3+ cations is compensated for by one [Ge 2 Se 6 ] 4– anion.…”

“…The integration of lanthanide metal ions (Ln 3+ ) instead of d (or ds) block metal or other chalcophilic main metal ions into metal chalcogenide architectures could result in novel lanthanide chalcogenides with useful semiconductor, magnetism, fluorescence, and other properties . In the case of lanthanide chalcogenidogermanates, they are typically prepared by flux methods under high-temperature and inert-atmosphere protection, − as exemplified by La 2 Ga 2 GeS 8 , Eu 2 Ga 2 GeS 7 , [Ln 4 (GeS 4 ) 3 ] (Ln = Ce and Nd), Eu 3 Ge 3 S 9 , Li 2 EuGeS 4 , Na 1.515 EuGeS 4 , and Ln 2 PbGe 2 S 8 (Ln = Ce and Pr), which contain tetrahedral [GeQ 4 ] 4– units. However, lanthanide chalcogenidogermanates modified with organic amines are less explored, mainly because they are generally unstable and their Q 2– (Q = S, Se, and Te) ions of chalcogenidometalate anions do not bond well with the Ln 3+ centers under solvothermal conditions .…”

“…In order to synthesize the analogues of lanthanide thiogermanates, our group tried solvothermal synthesis of lanthanide selenidogermanates and obtained a series of hybrid lanthanide selenidogermanates, (H 2 peha)­[Ln 2 (μ-OH) 2 (tepa) 2 Cl 2 ]­{[Ln 2 (μ-OH) 2 (tepa) 2 Cl] 2 (μ-Ge 2 Se 6 )}­[Ge 2 Se 6 ]­Cl 2 [Ln = Y ( 1a ) and Er ( 1b ); peha = pentaethylenexamine, tepa = tetraethylenepentamine], [Sm 2 (μ-OH) 2 (tepa) 2 (μ-Ge 2 Se 6 )] n ( 2 ), [Ho 2 (μ-OH) 2 (tepa) 2 (μ-Ge 2 Se 6 )] n ( 3 ), and [Ce 4 (tepa) 4 (μ-GeSe 4 )­(μ-GeSe 5 )­(μ-Ge 2 Se 6 )] n ( 4 ), in which selenidogermanate anions [GeSe 4 ] 4– , [GeSe 5 ] 4– , and [Ge 2 Se 6 ] 4– are bound to lanthanide complex cations via Ln–Se bonds. The reported metal chalcogenidogermanates usually show neutral or ionic structures, − ,− while compounds 1a and 1b contain rare cationic hybrid lanthanide selenidogermanates {[Ln 2 (μ-OH) 2 (tepa) 2 Cl] 2 (μ-Ge 2 Se 6 )} 2+ . Moreover, compounds 1 – 3 contain one type of selenidogermanate anion [Ge 2 Se 6 ] 4– , whereas compound 4 contains three types of selenidogermanate anions, [GeSe 4 ] 4– , [GeSe 5 ] 4– , and [Ge 2 Se 6 ] 4– , which provides the first example of the coexistence of three different selenidogermanate anions in the same architecture.…”