Synthesis of the One-dimensional Compound (Ph4P)[In(P2Se6)] in a Ph4P+-Containing Selenophosphate Flux, and Structure of [In(P2Se6)2]5- - a Discrete Molecular Fragment of the [In(P2Se6)]nn- Chain

Abstract

The reaction of one equivalent of In with a molten flux of (Ph 4 P) 2 Se 5 and P 2 Se 5 (1 : 2), at 250 °C gave the (Ph 4 P)[In(P 2 Se 6 )] (I). Stoichiometric elemental synthesis at 750 °C produced the Cs 5 In(P 2 Se 6 ) 2 (II). The thin, yellow crystals of (I), and the irregular, dark orange crystals of (II), appear to be air-and water-stable. Compound (I) crystallizes in the monoclinic space group C2/c (no. 15) and at 23 °C:Compound (II) crystallizes in the tetragonal space group P4 2 /m (no. 84) and at 23 °C: a = b = 13.886(1) A Ê , c = 7.597(2) A Ê , V = 1464.9(3) A Ê 3 , Z = 2, final R/R w = 3.9/ 5.1%. Compound (I) contains infinite [In(P 2 Se 6 )] n n± with a structure related to that of K 2 FeP 2 Se 6 . Compound (II) contains the discrete [In(P 2 Se 6 ) 2 ] 5± which can be viewed as a fragment of the [In(P 2 Se 6 )] n n± chain.

Cs3In(In4Se7)(P2Se6): A Multi‐Chromophore Chalcogenide with Excellent Nonlinear Optical Property Designed by Group Grafting

“…Bond valence sum (BVS) [15] calculations result in the values of 0.91 to 1.17 for Cs, 2.96 to 3.02 for In, 4.18 for P, and 1.80 to 2.25 for Se (Table S2), which indicates that the Cs, In, P, and Se atoms are in oxidation states of +1, +3, +4, and −2, respectively. These are also consistent with those in other selenophosphate compounds, such as Cs 5 InP 4 Se 12 , [13a] Rb 4 Sn 5 P 4 Se 20 , [14c] and Cs 5 P 5 Se 12 [14d] …”

“…But, that is challenging because the T2‐type [M 4 Q 10 ] supertetrahedron and the ethane‐like [P 2 Se 6 ] dimer have different structural topologies, and their combination will violate Pauling's fifth rule to some extent [12c] . In order to achieve this, we chose the Cs 5 In(P 2 Se 6 ) 2 [13a] that contains interesting [In(P 2 Se 6 ) 2 ] BBUs as a maternal structure, and adopted a “group grafting” strategy to successfully “grafting” T2‐type [In 4 Se 10 ] supertetrahedra on the root of [In(P 2 Se 6 ) 2 ] groups, and obtained the first NCS and polar chalcogenide‐selenophosphate Cs 3 In(In 4 Se 7 )(P 2 Se 6 ) with multi‐chromophores. Owing to the effective superposition of the functional properties of [In 4 Se 10 ] supertetrahedra and [P 2 Se 6 ] dimers, Cs 3 In(In 4 Se 7 )(P 2 Se 6 ) exhibits excellent NLO properties, including a significant SHG response (~6×AGS) and a large band gap ( E g =2.45 eV), a remarkable birefringence (Δ n =0.26 @1064 nm) and a broad IR band transmission range (0.4–19.5 μm).…”