Browsing by Author "Auckett, JE"
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- ItemAnisotropic thermal and guest-induced responses of an ultramicroporous framework with rigid linkers(John Wiley & Sons, Inc, 2018-02-16) Auckett, JE; Duyker, SG; Izgorodina, EI; Hawes, CS; Turner, DR; Batten, SR; Peterson, VKThe interdependent effects of temperature and guest uptake on the structure of the ultramicroporous metal–organic framework [Cu3(cdm)4] (cdm=C(CN)2(CONH2)−) were explored in detail by using in situ neutron scattering and density functional theory calculations. The tetragonal lattice displays an anisotropic thermal response related to a hinged “lattice-fence” mechanism, unusual for this topology, which is facilitated by pivoting of the rigid cdm anion about the Cu nodes. Calculated pore-size metrics clearly illustrate the potential for temperature-mediated adsorption in ultramicroporous frameworks due to thermal fluctuations of the pore diameter near the value of the target guest kinetic diameter, though in [Cu3(cdm)4] this is counteracted by a competing contraction of the pore with increasing temperature as a result of the anisotropic lattice response. © 2018 Wiley-VCH Verlag GmbH & Co.
- ItemAtomic-scale explorations of stimulus-responsive framework properties in an ultramicroporous gas sorbent(Society of Crystallographers in Australia and New Zealand, 2017-12-03) Auckett, JE; Duyker, SG; Izgorodina, EI; Hawes, CS; Turner, DR; Batten, SS; Peterson, VKFunctional microporous materials capable of efficiently separating and/or storing gases at noncryogenic temperatures are sought for a wide variety of important industrial applications, including pre- and post-combustion carbon capture, hydrogen fuel storage, and the purification of component gases from air. Understanding the atomic-scale interactions between the host material and guest species under variable operating conditions is essential for obtaining information about adsorption and separation mechanisms, which can in turn be used to design better sorbents targeted at specific applications. The ultramicroporous metal-organic framework [Cu3(cdm)4] (cdm = C(CN)2CONH2 -) was recently reported to exhibit moderately selective adsorption of CO2 over CH4, along with excellent exclusion of elemental gases such as H2 and N2 [1]. Although the very small pore diameter (3–4 Å) results in unpromisingly slow diffusion dynamics, its close similarity to the kinetic diameters of many small gas molecules [2] also raises the prospect of altering the gas sorption and selectivity characteristics of the material via minor structural modifications, such as might be introduced by changing the temperature and/or guest concentration during sorbent operation under industrially relevant conditions. Using a combination of in situ neutron scattering experiments and density functional theory-based calculations, we examine in detail the interplay between lattice shape, pore size, temperature, and CO2 concentration in [Cu3(cdm)4]. The rare and interesting fundamental property of areal negative thermal expansion (NTE) in [Cu3(cdm)4] is attributed to a new variation of a well-known NTE mechanism, and is triggered by dynamic motions of the rigid cdm ligand within the constraints of the complicated framework topology. Although the thermal response of the pore diameter is surprisingly insignificant due to competition between multiple effects, the potential for similar materials to exhibit temperature induced changes in adsorption properties is clearly demonstrated. This study illustrates the breadth and depth of information that can be obtained by combining the power of experimental and theoretical characterisation in an approach that is generally applicable to crystalline sorbent systems.
- ItemAtomic-scale understanding of CO2 adsorption processes in metal-organic framework (MOF) materials using neutron scattering and ab-initio calculations(Australian Institute of Physics, 2016-02-04) Auckett, JE; Peterson, VK; Duyker, SGThe dependence of the industrialised world on fossil-fuel energy generation technologies and consequent increase in atmospheric CO2 concentrations has been blamed for emerging adverse climate effects, including an increase in global mean temperatures. Until renewable, carbon-free energy sources can be efficiently harnessed to meet the world’s energy needs, interim measures are sought to suppress the atmospheric release of CO2 from traditional coal and natural gas combustion processes. Microporous materials such as zeolites and metal-organic frameworks (MOFs) are therefore being investigated for the separation and capture of CO2 at various stages of the combustion cycle. MOFs represent one of the most promising classes of materials for this application, offering unrivalled tunability of structural and chemical characteristics via the substitution of metals and choice and functionalisation of ligands. In order for a MOF to be rationally tuned for improved performance, the nature of the interactions between the host framework and guest molecules must be well-understood at the atomic level. Our research targets this detailed understanding of MOFs using neutron scattering and computational methods. We are currently investigating several MOFs which display unexpected sorption properties such as “reverse sieving” – that is, selectively absorbing larger gas molecules while rejecting smaller ones – and unusual lattice expansion effects. Using in situ diffraction to locate the preferred binding sites of guest molecules in the framework, inelastic neutron scattering to probe system dynamics, and density functional theory-based molecular dynamics simulations to validate and interpret our experimental results, we are able to gain detailed information about the mechanisms of gas uptake and diffusion in these exciting new MOF materials.
- ItemCoexistence of spin glass and antiferromagnetic orders in Ba3Fe2.15W0.85O8.72(IOP Publishing, 2012-03-23) Miiller, W; Auckett, JE; Avdeev, M; Ling, CDBa 3 Fe 2.15 W 0.85 O 8.72 has been grown as large single crystals using the floating-zone method, permitting very precise characterization of the nuclear and magnetic structures by neutron and synchrotron diffraction methods. The results of our structural investigation are combined with dc and ac magnetization and heat capacity measurements to give an unusually complete and detailed picture of a complex magnetic system. The compound crystallizes in the hexagonal perovskite structure (space group P 6 3 / m m c ) and reveals antiferromagnetic order below T N = 290 K. Frequency-dependent ac susceptibility and the presence of magnetic viscosity suggest the onset of a spin glass component in this material below T f = 60 K. These findings are discussed on the basis of detailed analysis of the crystalo-chemical properties, supported by ab initio (density functional theory) calculations.(c) 2011 IOP Publishing Ltd.
- ItemCombined experimental and computational study of oxide ion conduction dynamics in Sr2Fe2O5 brownmillerite(American Chemical Society, 2013-08-13) Auckett, JE; Studer, AJ; Pellegrini, E; Ollivier, J; Johnson, MR; Schober, H; Miiller, W; Ling, CDWe report a detailed study of the dynamics of oxide ionic conduction in brownmillerite-type Sr2Fe2O5, including lattice anisotropy, based on neutron scattering studies of a large (partially twinned) single crystal in combination with ab initio molecular dynamics simulations. Single-crystal diffraction reveals supercell peaks due to long-range ordering among chains of corner-sharing FeO4 tetrahedra, which disappears on heating above 540 °C due to confined local rotations of tetrahedra. Our simulations show that these rotations are essentially isotropic, but are a precondition for the anisotropic motion that moves oxide ions into the tetrahedral layers from the octahedral layers, which we observe experimentally as a Lorentzian broadening of the quasielastic neutron scattering spectrum. This continual but incoherent movement of oxide ions in turn creates conduction pathways and activates long-range diffusion at the interface between layers, which appears to be largely isotropic in two dimensions, in contrast with previously proposed mechanisms that suggest diffusion occurs preferentially along the c axis.© 2013, American Chemical Society.
- ItemComplex magnetism of quasi-1D maricite-type NaFePO4(AOCNS 2015, 2015-07-23) Avdeev, M; Piltz, RO; Ling, CD; Auckett, JE; Barpanda, P; Cadogan, JMWe recently reported the magnetic structure of maricite-type NaFePO4 determined using neutron powder diffraction data collected at 3 K1. The crystal structure of this compound is derived from the olivine (Mg2SiO4) type by an ordered distribution of Na and Fe over the two inequivalent Mg sites in the olivine cell. This leads to a magnetically quasi-1D arrangement in which edge-sharing (FeO6) chains are connected to each other only via phosphate groups with a shortest interchain Fe-Fe distance of ~5 Å vs. intrachain distance of ~3.4 Å. Here we report the results of further studies using magnetometry, heat capacity, Mossbauer, and variable field and temperature powder and single crystal neutron diffraction measurements, which reveal not only an intermediate incommensurate magnetic phase existing in zero field within a very narrow interval of ~2 K, but also a metamagnetic transition around 5 T (at 2 K). We will also present and discuss the evolution of the magnetic structure of NaFePO4 as a function of temperature and magnetic field in connection with the crystal structure and compared to that of other maricite type compositions such as AgMnVO42.
- ItemContinuous negative-to-positive tuning of thermal expansion achieved by controlled gas sorption in porous coordination frameworks(Springer Nature, 2018-11-19) Auckett, JE; Barkhordarian, AA; Ogilvie, SH; Duyker, SG; Chevreau, H; Peterson, VK; Kepert, CJControl of the thermomechanical properties of functional materials is of great fundamental and technological significance, with the achievement of zero or negative thermal expansion behavior being a key goal for various applications. A dynamic, reversible mode of control is demonstrated for the first time in two Prussian blue derivative frameworks whose coefficients of thermal expansion are tuned continuously from negative to positive values by varying the concentration of adsorbed CO2. A simple empirical model that captures site-specific guest contributions to the framework expansion is derived, and displays excellent agreement with the observed lattice behaviour. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License.
- ItemExperimental and theoretical approaches to understanding selective gas adsorption in metal-organic frameworks(Australian Institute of Nuclear Science and Engineering, 2016-11-29) Auckett, JE; Duyker, SG; Peterson, VKPorous solids such as metal-organic frameworks (MOFs) are considered promising candidates for many industrial gas-separation applications, especially due to their structural and chemical versatility with respect to traditional solid sorbents such as zeolites [1]. Rational tuning of such materials for improved performance requires that the interactions between the host framework and guest molecules be well-understood at the atomic level. Our research targets this detailed understanding of framework-guest systems using in situ and operando neutron scattering experiments, in which structure and dynamics are probed as a function of guest loading and temperature, along with comprehensive atomistic density functional theory-based (DFT) calculations from which various physical and dynamical properties can be extracted. We are currently investigating several MOFs which display interesting sorption behaviours, such as shape-dependent binding, “reverse sieving” (i.e. selectively absorbing larger gas molecules while rejecting smaller ones) [2], and guest-responsive negative thermal expansion (NTE). This talk describes the suite of conventional and unconventional tools we have used to explore the structural and dynamic properties of these frameworks, yielding highly detailed information about their behaviour. Many of these methods can also be applied to a wide variety of systems involving host guest interactions.
- ItemFloating-zone growth of brownmillerite Sr2Fe2O5 and the observation of a chain-ordered superstructure by single-crystal neutron diffraction(Elsevier Science BV, 2012-10-04) Auckett, JE; Studer, AJ; Sharma, N; Ling, CDWe report the first growth of a large (cm-scale) single crystal of the brownmillerite-type oxide ionic conductor Sr2Fe2O5, by the floating-zone method. Although the crystal is twinned on a microscopic scale with respect to the unit cell of the disordered oxygen-deficient perovskite from which it forms, this twinning is not complete or equivalent in all directions, and so it presents the possibility of direction-dependent measurements of conductivity and other properties. Single crystal neutron diffraction revealed a supercell with a doubled a axis, compared to the conventional lcmm model containing disordered left- and right-handed tetrahedral chains. It corresponds to the beta = 0, gamma = 1/2 case of the 12/m(0 beta gamma)0s chain-ordering modulation proposed by D'Hondt et al. on the basis of electron microscopy and electron diffraction evidence. Its observation by neutron diffraction for the first time proves that the tetrahedral chains are long-range ordered at room temperature, and in a more complex manner than the Ibm2 model, which has previously been assumed to describe local chain order. © 2012, Elsevier Ltd.
- ItemInsights into selective gas sorbent functionality gained by using time-resolved neutron diffraction(John Wiley & Sons, Inc, 2018-05-05) Auckett, JE; Duyker, SG; Turner, DR; Batten, SR; Peterson, VKAn understanding of the atomic-scale interactions between gas sorbent materials and their molecular guests is essential for the identification of the origins of desirable function and the rational optimization of performance. However, characterizations performed on equilibrated sorbent–guest systems may not accurately represent their behavior under dynamic operating conditions. The emergence of fast (minute-scale) neutron powder diffraction coupled with direct, real-time quantification of gas uptake opens up new possibilities for obtaining knowledge about concentration-dependent effects of guest loading upon function-critical features of sorbent materials, including atomic structure, diffusion pathways, and thermal expansion of the sorbent framework. This article presents a detailed investigation of the ultramicroporous metal–organic framework [Cu3(cdm)4] as a case study to demonstrate the variety of insights into sorbent performance that can be obtained from real-time characterizations using neutron diffraction. © 2018 Wiley-VCH Verlag GmbH & Co
- ItemLattice response of the porous coordination framework Zn(hba) to guest adsorption(Cambridge University Press, 2017-09-05) Auckett, JE; Dharma, AD; Cagnes, MP; Darwish, TA; Abrahams, BF; Barbarao, R; Hudson, TA; Robson, R; White, KF; Peterson, VKAnalysis of in situ neutron powder diffraction data collected for the porous framework material Zn(hba) during gas adsorption reveals a two-stage response of the host lattice to increasing CO2 guest concentration, suggesting progressive occupation of multiple CO2 adsorption sites with different binding strengths. The response of the lattice to moderate CH4 guest concentrations is virtually indistinguishable from the response to CO2, demonstrating that the influence of host–guest interactions on the Zn(hba) framework is defined more strongly by the concentration than by the identity of the guests. © International Centre for Diffraction Data 2017
- ItemLow-T magnetic anomaly in Ca2Fe2O5 studied by single-crystal neutron diffraction(International Union of Crystallography, 2014-08-12) Auckett, JE; McIntyre, GJ; Avdeev, M; De Bruyn, H; Ling, CDCa2Fe2O5, which belongs to the Brownmillerite family of promising solid-oxide fuel cell membrane materials, is an antiferromagnet (AFM) below TN = 720 K. A small ferromagnetic (FM) canting perpendicular to the AFM easy axis has previously been established by physical properties measurements, but never observed crystallographically. More intriguingly, it has been known for some time to display an anomalous elevation in magnetic susceptibility for 60 K < T < 140 K. [1] Based on measurements performed with small oriented single crystals, Zhou et al. [2] proposed that this anomaly was due to a reorientation of the spins from the crystallographic a axis to the c axis below 40 K, with a region of minimal magnetocrystalline anisotropy in the anomalous temperature interval. In order to test this, we grew a very large (~1 cm3) single crystal by the floating-zone method and collected neutron Laue diffraction data, against which we refined both the atomic and magnetic structures of Ca2Fe2O5 between 10 K and 300 K. We designed and built an ad hoc sample mount to apply a small (~35 Oe) magnetic field to the sample, ensuring perfect consistency with the magnetic susceptibility data, which were collected in a comparably small field. Our refinements against both zero-field and in-field diffraction data reproduce the G-type AFM structure of Ca2Fe2O5 excellently at room temperature, including the FM canting which we have refined to statistical significance for the first time. We can also show that in the intermediate temperature interval (T = 1 00 K), the spins are slightly less well-ordered due to competing sublattice interactions. However, careful examination of the data reveals that the material is still best described by the room-temperature magnetic structure at all measured temperatures – i.e., the spin-reorientation hypothesis is incorrect. © International Union of Crystallography
- ItemLow-temperature magnetic structure of Ca2Fe2O5 determined by single-crystal neutron diffraction(Australian Institute of Physics, 2014-02-06) Auckett, JE; Ling, CD; McIntyre, GJ; Avdeev, MCa2Fe2O5 is a canted antiferromagnet (TN = 720 K) which displays an anomalous elevation in its magnetic susceptibility for 60 K < T < 140 K. [1] Based on susceptibility measurements performed on oriented single crystals, Zhou et al. [2] proposed a reorientation of the antiferromagnetic (AFM) easy-axis from the crystallographic a axis to the c axis below 40 K, proceeding via a region of minimal magnetocrystalline anisotropy in the anomalous temperature interval. In order to test this proposition, we have refined the atomic and magnetic structure of Ca2Fe2O5 against high-quality neutron Laue diffraction data collected on floating-zone-grown single crystals between 10 K and 300 K. An ad hoc sample mount was designed to apply a small (~35 Oe) magnetic field to the sample, ensuring perfect compatibility with the magnetic susceptibility data, which were also collected in a small field. Our refinements against both zero-field and in-field diffraction data reproduce the G-type AFM structure of Ca2Fe2O5 excellently at room temperature, including the known ferromagnetic canting. Careful examination of the refinement results reveals that the material is in fact best described by the room-temperature magnetic structure at all measured temperatures, though in the intermediate temperature interval (measured at T = 100 K) the spins may be less well-ordered due to competing sublattice interactions.
- ItemMagnetic structure of Sr2Fe2O5 brownmillerite by single-crystal Mössbauer spectroscopy(Academic Press Inc Elsevier Science, 2013-09-01) Waerenborgh, JC; Tsipis, EV; Auckett, JE; Ling, CD; Kharton, VVIn order to determine orientation of the Fe3+ magnetic moments and electric field gradient (efg) axes in the brownmillerite-type strontium ferrite structure for both iron sublattices where the efg tensor is not axially symmetric, the Mössbauer spectra of powdered and oriented single-crystal Sr2Fe2O5 were analyzed by solving the complete Hamiltonian for hyperfine interactions in the excited and ground states of the 57Fe nuclei. The magnetic moments of both octahedrally and tetrahedrally coordinated iron cations lie on the ac-plane of the orthorhombic unit cell and are parallel to the shortest c-axis, whilst the main efg axes are parallel to the longest crystallographic axis, b. This orientation is similar to that in Ca2Fe2O5, in spite of the structural differences of strontium and calcium ferrite brownmillerites at low temperatures. © 2013, Elsevier Ltd.
- ItemNeutron Laue diffraction study of the complex low-temperature magnetic behaviour of brownmillerite-type Ca2Fe2O5(International Union of Crystallography, 2015-01-01) Auckett, JE; McIntyre, GJ; Avdeev, M; De Bruyn, H; Tan, TT; Li, S; Ling, CDThe atomic and magnetic structure of brownmillerite Ca2Fe2O5 has been refined against single-crystal neutron Laue diffraction data collected at 300, 100 and 10 K under zero-field and low-magnetic field (35 Oe = 35 × 103/4[pi] A m-1) conditions. Ca2Fe2O5 is a canted G-type antiferromagnet with Pcm'n' symmetry, the magnetic moments on Fe being directed approximately along the crystallographic c axis at room temperature. The refinement results show clearly that this magnetic structure persists down to T = 10 K, despite a previous suggestion that an anomalous magnetic susceptibility enhancement observed in Ca2Fe2O5 single crystals between 40 and 140 K might signify a reorientation of the antiferromagnetic easy axis from c to a below 40 K. Alternative explanations for this susceptibility anomaly are considered in terms of the evidence for partial or short-range loss of order in the anomalous regime, possibly due to the presence of multiple competing sublattice interactions. © International Union of Crystallography
- ItemPressure-induced intersite Bi--M (M=Ru, Ir) valence transitions in hexagonal perovskite(Wiley Online Library, 2014-02-24) Huang, Z; Auckett, JE; Blanchard, PER; Kennedy, BJ; Miller, W; Zhou, Q; Avdeev, M; Johnson, MR; Zbiri, M; Garbarino, G; Marshall, WG; Gu, QF; Ling, CDPressure-induced charge transfer from Bi to Ir/Ru is observed in the hexagonal perovskites Ba3+nBiM2+nO9+3n (n=0,1; M=Ir,Ru). These compounds show first-order, circa 1 % volume contractions at room temperature above 5 GPa, which are due to the large reduction in the effective ionic radius of Bi when the 6s shell is emptied on oxidation, compared to the relatively negligible effect of reduction on the radii of Ir or Ru. They are the first such transitions involving 4d and 5d compounds, and they double the total number of cases known. Ab initio calculations suggest that magnetic interactions through very short (ca. 2.6 Å) M[BOND]M bonds contribute to the finely balanced nature of their electronic states. © 2014 Wiley‐VCH.
- ItemShort- and long-range modulated oxygen order in brownmillerite-type Sr2FeCoO5 and Ca2FeCoO5(Asia-Oceania Neutron Scattering Association, 2015-07-23) Auckett, JE; Withers, RL; Studer, AJ; Avdeev, M; Edwards, AJ; McIntyre, GJ; Ling, CDSr2FeCoO5 and Ca2FeCoO5 belong to the perovskite-derived group of oxides known as the brownmillerites (A2B2O5), which are characterised by layers of BO6 octahedra alternating with layers of chain-linked BO4 tetrahedra separated by oxygen vacancy channels. Brownmillerites have potential applications as diverse as combustion catalysts, cements, and solid oxide fuel cell cathodes. Oxide-ionic conductivity in brownmillerites is associated with the presence of oxygen vacancies adjacent to the tetrahedral chains, and is therefore influenced by the relative arrangements of oppositely twisted chains throughout the structure. Recently, a variety of modulated chain-ordering schemes have been identified in several brownmillerites that were previously thought to adopt only simple ordered or completely disordered chain arrangements. In this work, a brownmillerite chain-ordering modulation first identified in Sr2FeCoO5 by electron diffraction has been confirmed by single-crystal neutron diffraction on a large crystal grown by the floating-zone (FZ) method. Although incommensurate modulation vectors are identified on the short electron diffraction length scale, the neutron diffraction data show clearly that a commensurate arrangement dominates the crystal on average. This behaviour closely follows that of the series end-member Sr2Fe2O5, an important ionic-conductive brownmillerite, implying that Sr2FeCoO5 may display similarly favourable ionic-conductive properties. We also investigated Ca2FeCoO5, a relatively new brownmillerite characterised in 2010. The presence of well-resolved satellite reflections in single-crystal and powder neutron diffraction data support the choice of a commensurate chain-ordered arrangement to describe the structure. However, attempts to refine this structure against either data set yielded poor results. A detailed examination of neutron and x-ray precession images obtained for FZ-grown single crystals reveal the presence of certain reflections that are forbidden by the expected Pbma symmetry. Consideration of the apparent pseudo-symmetry yields evidence for a micro-intergrowth of regions with slightly different chain-ordering schemes within the dominating Pbma matrix, similar to an arrangement reported previously for Ca2MnGaO5.
- ItemSingle crystal neutron diffraction studies of low-temperature magnetic spin reorientation in Ca2Fe2O5(Australian Institute of Nuclear Science and Engineering, 2013-12-15) Auckett, JE; Ling, CD; McIntyre, GJCa2Fe2O5 is a canted antiferromagnet (T{sub N} = 720 K) ) which displays an anomalous elevation in its magnetic susceptibility for 60 K T < 140 K. Based on susceptibility measurements performed on oriented single crystals, Zhou et al. [2] proposed a reorientation of the antiferromagnetic (AFM) easy-axis from the crystallographic a axis to the c axis below 40 K, proceeding via a region of minimal magnetocrystalline anisotropy in the anomalous temperature interval. In order to test this proposition, we have refined the atomic and magnetic structure of Ca{sub 2}F{sub e}2O{sub 5} against high-quality neutron Laue diffraction data collected on floating-zone-grown single crystals between 10 K and 300 K. An ad hoc sample mount was designed to apply a small (-35 Oe) magnetic field to the sample, ensuring perfect compatibility with the magnetic susceptibility data, which were also collected in a small field. Our refinements against both zero-field and in-field diffraction data reproduce the G-type AFM structure of Ca{sub 2}Fe{sub 2}O{sub 5} excellently at room temperature, including the known ferromagnetic canting. Careful examination of the refinement results reveals that the material is in fact best described by the room-temperature magnetic structure model as low as T=10 K, while the intermediate interval (measured at T=100 K) is characterised by subtle changes in the magnetic structure, including a reversal of the magnitudes of the magnetic moments on the two distinct Fe{sup 3+} sites.
- ItemSingle-crystal neutron diffraction study of superstructure ordering and domain behaviour in brownmillerite-type Ca2Fe2O5(CSIRO Publishing, 2014-09-15) Auckett, JE; Studer, AJ; Ling, CDWe show that large single crystals of brownmillerite-type Ca2Fe2O5 can be grown using the floating-zone method under ambient pressure conditions, provided that the feed rods are pre-annealed to a very high density. Neutron diffraction data collected from these crystals show the emergence of a long-range ordered incommensurate phase at high temperature. The observation of this phase for the first time using neutrons proves that the incommensurate ordering of tetrahedral chains upon heating Ca2Fe2O5 is a truly long-range and bulk phenomenon. The results are used to compare and contrast the structures of Ca2Fe2O5 and Sr2Fe2O5, and are consistent with experimental observations of significantly higher oxide ionic conduction in the latter material.
- ItemSquare grid metal–chloranilate networks as robust host systems for guest sorption(John Wiley & Sons, Inc, 2019-02-02) Kingsbury, CJ; Abrahams, BF; Auckett, JE; Chevreau, H; Dharma, AD; Duyker, SG; He, QL; Hua, C; Hudson, TA; Murray, KS; Phonsri, W; Peterson, VK; Robson, R; White, KFReaction of the chloranilate dianion with Y(NO3)3 in the presence of Et4N+ in the appropriate proportions results in the formation of (Et4N)[Y(can)2], which consists of anionic square-grid coordination polymer sheets with interleaved layers of counter-cations. These counter-cations, which serve as squat pillars between [Y(can)2] sheets, lead to alignment of the square grid sheets and the subsequent generation of square channels running perpendicular to the sheets. The crystals are found to be porous and retain crystallinity following cycles of adsorption and desorption. This compound exhibits a high affinity for volatile guest molecules, which could be identified within the framework by crystallographic methods. In situ neutron powder diffraction indicates a size-shape complementarity leading to a strong interaction between host and guest for CO2 and CH4. Single-crystal X-ray diffraction experiments indicate significant interactions between the host framework and discrete I2 or Br2 molecules. A series of isostructural compounds (cat)[MIII(X-an)2] with M=Sc, Gd, Tb, Dy, Ho, Er, Yb, Lu, Bi or In, cat=Et4N, Me4N and X-an=chloranilate, bromanilate or cyanochloranilate bridging ligands have been generated. The magnetic properties of representative examples (Et4N)[Gd(can)2] and (Et4N)[Dy(can)2] are reported with normal DC susceptibility but unusual AC susceptibility data noted for (Et4N)[Gd(can)2]. © 2019 Wiley-VCH Verlag GmbH & Co