The structures of ordered defects in thiocyanate analogues of Prussian Blue

Cliffe, Matthew J.; Keyzer, Evan N.; Bond, Andrew D.; Astle, Maxwell A.; Grey, Clare P.

doi:10.1039/d0sc01246g

Cited by 16 publications

(36 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2 . 7,25 The combination of octahedral tilting and rocksalt Msite order leaves all pseudocubic Ni 4 Bi 4 (SCN) 12 cages still equivalent by symmetry, meaning that the A-site cation ordering may not be viewed being drive by these three distortions alone. The A-site cation ordering therefore lowers the space-group symmetry further, from P2 1 /n to P1, and in addition produces a large shear strain compared to the M…”

Section: (Nh 4 ){Ni[bi(scn) 6 ]} 1 and K{ni[bi(scn) 6 ]}mentioning

confidence: 99%

“…As each cage contains four distinct orientations of the Gua + cation, and is surrounded by twelve NCSligands, this means one quarter of all NCSwill be H-bond acceptors. 25 Perovskites containing organic Asites cations are of particular interest as these organic cations can possess intrinsic electric dipoles (e.g. MeNH + 3 ) and quadrupoles (e.g Gua + ).…”

Section: Gua(scn) and Hydrogen Bondingmentioning

confidence: 99%

“…22 We focus in this paper on the family of perovskite-like materials derived from thiocyanate, A x {M[M (SCN) 6 ]}, of particular interest for their catalytic and optical function. 7,[23][24][25][26] These NCS-perovskites have complete Msite order, due to the difference between N-and S-termini of the ligand, and have large tilts due to the frontier molecular orbitals of the NCSligand. 7 The robustness of these distortions means NCS-perovskites are an ideal platform for exploring complex orderings.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Controlling Multiple Orderings in Metal Thiocyanate Molecular Perovskites Ax{Ni[Bi(SCN)6]}

Lee¹,

Ling²,

Argent³

et al. 2020

Preprint

View full text Add to dashboard Cite

We report four new A-site vacancy ordered thiocyanate double double perovskites,A1􀀀xfNi[Bi(SCN)6]1􀀀x3 }, A = K+, NH4+, CH3(NH3)+ (MeNH3+) and C(NH2)3+ (Gua+), including the first examples of thiocyanate perovskites containing organic A-site cations. We show, using a combination of X-ray and neutron diffraction, that the structure of these frameworks depends on the A-site cation, and that these frameworks possess complex vacancy-ordering patterns and cooperative octahedral tilts distinctly different from atomic perovskites. Density functional theory calculations uncover the energetic origin of these complex orders and allow us to propose a simple rule to predict favoured A-site cation orderings for a given tilt sequence. We use these insights, in combination with symmetry mode analyses, to show that these complex orders offer a new route to non-centrosymmetric perovskites which render them as excellent candidates forpiezo- and ferroelectric applications.

show abstract

Section: (Nh 4 ){Ni[bi(scn) 6 ]} 1 and K{ni[bi(scn) 6 ]}mentioning

confidence: 99%

Section: Gua(scn) and Hydrogen Bondingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Controlling Multiple Orderings in Metal Thiocyanate Molecular Perovskites Ax{Ni[Bi(SCN)6]}

Lee¹,

Ling²,

Argent³

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

“…Likewise we cannot yet say definitively whether hexacyanometallate anion incorporation is limited to the M 0 site, or whether intercalation on the A-site is also possible, such as has been observed for complex ions in the related thiocyanate PBAs. 28 In the context of optimising PBA-based battery materials a number of obvious follow-up experiments must now be carried out. First, it is important to show that vacancy filling in redoxactive PBAs is possible (our own preliminary study of Mn[Fe(CN) 6 ] 2/3 suggests it may be; see ESI †).…”

mentioning

confidence: 99%

Filling vacancies in a Prussian blue analogue using mechanochemical post-synthetic modification

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Likewise we cannot yet say definitively whether hexacyanometallate anion incorporation is limited to the M site, or whether intercalation on the A-site is also possible, such as has been observed for complex ions in the related thiocyanate PBAs. 22 In the context of optimising PBA-based battery materials a number of obvious follow-up experiments must now be carried out. First, it is important to show that vacancy filling in redox-active PBAs is possible (our own preliminary study of Mn[Fe(CN) 6 ] 2/3 suggests it is).…”

mentioning

confidence: 99%

Filling Vacancies in a Prussian Blue Analogue Using Mechanochemical Post-Synthetic Modification

Cattermull¹,

Wheeler²,

Hurlbutt³

et al. 2020

Preprint

View full text Add to dashboard Cite

Mechanochemical grinding of polycrystalline powders of the Prussian blue analogue (PBA) Mn[Co(CN) 6 ] 2/3 1/3 · xH 2 O and K 3 Co(CN) 6 consumes the latter and chemically modifies the former. A combination of inductively-coupled plasma and X-ray powder diffraction measurements suggests the hexacyanometallate vacancy fraction in this modified PBA is reduced by approximately one third under the specific conditions we explore. We infer the mechanochemically-driven incorporation of [Co(CN) 6 ] 3− ions onto the initially-vacant sites, coupled with intercalation of charge-balancing K + ions within the PBA framework cavities. Our results offer a new methodology for the synthesis of low vacancy PBAs, unlocking novel, high capacity PBA battery materials.Prussian blue analogues (PBAs) are an important and topical family of battery materials with a number of considerable advantages over longer-established charge storage systems. 1-3 On the one hand, they are chemically versatile, inexpensive, and easily made by aqueous precipitation from widely-available precursors. And, on the other hand, PBA electrochemistry is characterised by a combination of high specific capacity for Na + /K + insertion, rapid charge/discharge rates, and long cycle lives. 4 One key limitation of PBA chemistry as battery materials is the remarkably strong tendency for vacancy incorporation within the PBA structure. 5,6 Whilst hexacyanometallate vacancies help improve structural stability and increase bulk ionic conductivity, their presence reduces specific capacity. 4 Increasing energy density therefore requires synthetic routes that minimise vacancies. 7

show abstract

The structures of ordered defects in thiocyanate analogues of Prussian Blue

Abstract: We report the structures of six new divalent transition metal hexathiocyanatobismuthate Prussian Blue analogues frameworks, which contain complex ordered defect structures.

Cited by 16 publications

References 41 publications

Controlling Multiple Orderings in Metal Thiocyanate Molecular Perovskites Ax{Ni[Bi(SCN)6]}

Controlling Multiple Orderings in Metal Thiocyanate Molecular Perovskites Ax{Ni[Bi(SCN)6]}

Filling vacancies in a Prussian blue analogue using mechanochemical post-synthetic modification

Filling Vacancies in a Prussian Blue Analogue Using Mechanochemical Post-Synthetic Modification

Contact Info

Product

Resources

About