Germanates Built from Ge₁₀(O, OH)₂₇₋₂₈ and Ge₇(O, OH, F)₁₉ Secondary Building Units: From Systematic Study of Reported Compounds to Rational Design of Novel Structures

Abstract

Design of novel porous compounds is one of the fastest-growing fields of materials chemistry due to the broad range of applications including catalysis, adsorption, and separation. Open-framework germanates have shown large structure diversity and can form structures with extra-large pores. A systematic study of the structural features of the reported germanates is a key for the design of novel porous germanates. In this work, the topological study and classification of all known germanates that are built from Ge10(O, OH)27−28 (Ge10) or Ge7(O, OH, F)19 (Ge7) secondary building units, has been undertaken. We have demonstrated that the combination of topological technique and data mining provides new insights into structural chemistry of a group of compounds. We proposed an efficient and general strategy for prediction of novel structures in germanates and other chemical systems.

|(C6N4H21)2|[Ge7O14F6]: A New Germanate Compound Constructed from Alternately Stacked Pseudo Triple‐Sheet Layers

“…From then on, more and more germanium‐containing open‐framework compounds have been synthesized. Compared with silicon that is usually tetrahedrally coordinated, germanium could be four‐, five‐, or six‐coordinate 3. The flexibility of Ge–O–Ge bond angles and diverse coordination states of germanium lead to the generation of many open‐framework germanate structures 4…”

SU-75: a disordered Ge10 germanate with pcu topology

“…More recently, we have reported two open-framework nickel germanates SUT-1 and SUT-2, in which the Ge 10 clusters form wavy 4 4 net layers connected by [Ni(en) 2 ] 2+ (en = ethylenediamine) complexes. 12 Although a topological study has been conducted on the structures of Ge 10 germanates, 13 direct comparison between structures is impeded by inconsistent choices of the composite building unit. For example, in Na 4 Ge 9 O 20 , 7 IM-14 14 and LNM-1 15 with the Ge-pharmacosiderite structure, different clusters were selected as the building unit, making the comparison between these structures difficult.…”

Photophysical properties of open-framework germanates templated by nickel complexes

“…2 The atomic structure of open-framework germanates may include heteroatoms on framework sites, for example boron, 3 silicon, 4 aluminum, 5 gallium, 5,6 antimony, 7 zirconium, 8 and niobium. 9 Recently, two openframework germanates, SUT-1 and SUT-2, built from Ge 10 O 27 building units 10 with Ni atoms introduced into an intricate porous structure of germanium oxide by establishing Ni-O bonds between molecular complexes of bis(ethylenediamine)nickel(II) nitrate [Ni(en) 2 ] (en = ethylenediamine) and the framework atoms, were reported. 11 Usually, nickel complexes are found inside the framework pores of a compound where they primarily act as filling agents (templates) responsible for framework interruptions and pore formation.…”