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Four complex metal antimony tartrates have been synthesized in single crystal form by slowly evaporating aqueous solutions of potassium antimony tartrate (tartar emetic) and metal nitrates or chlorides. Crystal structures of these compounds all contain infinite layers formed by linking antimony tartrate dimers with M–O bonds, with M = Li, La, Ce or Nd. Dehydration of the La and Ce compounds at elevated temperatures led to new layered structures via single-crystal to single-crystal transformations. [ABSTRACT FROM AUTHOR]

Seven complex metal antimony tartrates have been synthesized in single crystal form by slowly evaporating aqueous solutions of potassium antimony tartrate (tartar emetic) and divalent metal nitrates or perchlorates. Crystal structures of these compounds all contain infinite chains formed by linking antimony tartrate dimers with divalent metal ions. While infinite chains of antimony tartrate dimers bridged by single Zn2+ ions or by double Mg2+ ions were reported previously, new types of chains with alternating single and double bridging cations are observed in this work. [ABSTRACT FROM AUTHOR]

A new compound KLi[Sb2(C4H2O6)2] · 4H2O, 1, was synthesized in single crystal form by slowly evaporating an aqueous solution of potassium antimony tartrate and lithium nitrate. The structure of 1 consists of homochiral layers of antimony tartrate dimers linked by LiO4 tetrahedra. The interlayer water molecules can be reversibly driven out by heating or exchanged by small alcohol molecules under ambient conditions, occurring via single-crystal to single-crystal transformations. To accommodate different interlayer molecules, the interlayer space is changed by adjusting the relative lateral shift of neighboring layers. A similar adjustment in the layer stacking also occurs in a structural phase transition caused by order-disorder transformation of the arrangement of interlayer methanol molecules at low temperature. [ABSTRACT FROM AUTHOR]

The nanoporous frameworks VO(bdc), MIL-47, and M(OH)(bdc), MIL-53; bdc=1,4-benzenedicarboxylate, can absorb various guest species in their channels. As synthesized, the channels are filled with H 2 bdc molecules that have been reported to be disordered, except for [In(OH)bdc](H 2 bdc) 3/4 , 1 , which has a inorganic-organic hybrid Vernier structure with the H 2 bdc molecules forming an ordered sublattice. Based on X-ray data from large single crystals grown by hydrothermal techniques, similar Vernier structures have been found for MIL-47, [VO(bdc)](H 2 bdc) 5/7 , 2 , MIL-53Al, [Al(OH)(bdc)](H 2 bdc) 11/16 , 3 , and MIL-53Ga, [Ga(OH)(bdc)](H 2 bdc) 12/17 , 4 . The Vernier structures of 2–4 at room temperature were determined based on superstructure unit cells that index both host and guest sublattices: 2 , space group P2 1 , a =23.903(2), b =17.191(2), c =25.722(2) Å, β =105.914(8)°; 3 , P2 1 / n , a =105.224(4), b =12.2441(5), c =17.0143(6) Å, β =89.99(1)°; 4 , P2 1 , a =114.562(5), b =12.1503(5), c =17.4275(7) Å, β =89.99(1)°. The number of guest H 2 bdc molecules per framework metal ion is determined by the ratio of the repeat distances of the two sublattices which depends on the size of the metal ion in the octahedral chain. The octahedral chains are parallel to [201] in 2 , and to [100] in 3 and 4 . Remarkably, all atoms in 3 and 4 show significant sinusoidal modulations transverse to the chain axis. [ABSTRACT FROM AUTHOR]

Deformation of the microporous MIL-47 framework VO(bdc), bdc = 1,4-benzenedicarboxylate, upon absorption of carbon disulfide, tetrahydrothiophene, thiomorpholine and thioxane is investigated by single crystal X-ray diffraction. Intercalation of CS 2 significantly expands the channel opening by a breathing deformation mode of the framework characterized solely by a cooperative translation of the octahedral chains, in contrast to intercalation of many other molecules that usually cause contraction of the channel opening. Upon loading of CS 2 the short diagonal of the rhombic channel expanded by 0.91 Å and the maximum spherical void diameter increases to 8.0 Å from 7.6 Å of VO(bdc) with empty channels. Loading of the three cyclic organosulfur molecules all results in a strong twisting deformation of the framework featured by cooperative rotation of the octahedral chains by 21.3°–28.2°, bending of the bdc ligand and lowering of the space group symmetry from P nma to P2 1 2 1 2 1 . The maximum spherical void diameter of the framework decreases to 6.8 Å from 7.6 Å upon intercalation of tetrahydrothiophene or thiomorpholine, and to 6.0 Å upon intercalation of thioxane. Intercalation of thioxane leads to the highest degree of twisting known for the VO(bdc) framework combined with a substantial breathing contraction of the channel. The host–guest interactions are predominantly van der Waals in nature and the framework deformations are presumably driven by maximizing the van der Waals contacts. [ABSTRACT FROM AUTHOR]

The dehydration behavior of the microporous copper silicate Na2(Cu2Si5O13)·3H2O conventionally denoted as CuSH-6Na was studied using single crystal X-ray data collected at temperatures -150, 25, 40, 50, 60, 70 and 120 °C. Reversible dehydration of CuSH-6Na starts at ambient temperatures under dry nitrogen flow and is complete at 70 °C. The water molecules initially present in both ordered and disordered sites were simultaneously driven out beginning at ambient temperature. The dehydration is accompanied by a negative thermal expansion of the crystal caused by a slight progressive narrowing of the channels along the direction perpendicular to the silicate layers. The fully dehydrated structure has framework copper metal sites with open coordination spheres directly exposed to the space inside the accessible channels. [ABSTRACT FROM AUTHOR]

The vanadium analog of MIL-69, V(OH)ndc·H 2 O (ndc = 2,6-naphthalenedicarboxylate) was prepared solvothermally and the structure determined by single crystal X-ray diffraction (Space Group P2 1 /c (#14), a  = 6.7936(2) Å, b  = 14.6816(4) Å, c  = 23.9156(6) Å, β = 91.734(2)°, V = 2394.3(1) Å 3 ). Anhydrous V(OH)ndc was obtained from V(OH)ndc·H 2 O by heating under nitrogen flow at 378 K in situ the crystal used to determine the structure of the as synthesized hydrated compound. The water molecules are removed on heating in a crystal to crystal transformation. Minor changes in the structure occur with no change in the V 3+ oxidation state though the space group symmetry changes from P2 1 /c to C2/c. (Space Group C2/c (#15), a  = 24.684(4) Å, b  = 7.079(2) Å, c  = 6.853(1) Å, β = 104.35(1)°, V = 1160.2(4) Å 3 ). The structure of VOndc (Space Group C2/c (#15), a  = 24.628 (2) Å, b  = 7.1434(5)Å, c  = 6.7428(4) Å, β = 104.637(3)°, V = 1147.8 Å 3 ) obtained by heating V(OH)ndc·H 2 O in air at 573 K, in contrast shows a change in oxidation state from V 3+ to V 4+ evidenced by bond valence sum calculations and by the appearance of a characteristic distorted VO 6 octahedron and an O⋯V(IV) = O chain. [ABSTRACT FROM AUTHOR]

A series of layered divalent metal formate compounds, [M(HCOO)2(HCONH2)2] (M = Mn (lMn), Ni (2Ni), Cu(3Cu), Zn(4Zn), Mg(5Mg)), have been prepared by solvothermal synthesis and their room temperature (RT) and low-temperature (LT) crystal structures, and thermal and magnetic properties determined. All the compounds contain octahedral metal ions connected by four anti-anti formato ligands to form (4,4) nets with the composition of M(HCOO)2. The oxygen atoms from two coordinating formamide ligands above and below the layer complete the M06 distorted octahedral coordination. Order--disorder phase transformations involving the formamide ligands were observed in the lMn, 2Ni, and 4Zn compounds. Like transitions in related formate structures with perovskite like topology, the transitions correspond to the ordering of the amine groups of the terminating formamide ligands which are disordered at ambient temperature. The magnetic properties of the three magnetic members of the series lMn, 2Ni, and 3Cu were investigated using microcrystalline samples, over the temperature range of 2 K--300 K under different applied fields. All compounds belong to antiferromagnetic square lattices with S = 5/2, 1, and 1/2. Exchange constants for a nearest neighbor model are presented here. Specific heat measurements indicate magnetic long-range order at lower temperatures, S = 5/2 (antiferromagnetic) and S = 1 (ferrimagnetic). [ABSTRACT FROM AUTHOR]

Highlights: [•] The new linker 1,4-phenylenebis(hydroxyacetic acid) has been synthesized. [•] The new linker combines the chirality found in metal tartrates with the rigidity of aromatic dicarboxylates. [•] The new linker reacts with the divalent metal cations Co2+, Zn2+, and Pb2+ to produce new compounds. [•] Single crystals were grown and were characterized by single crystal X-ray diffraction and infrared spectroscopy. [•] The compounds have chain structures with the chains linked through extensive hydrogen bonding. [Copyright &y& Elsevier]

Abstract: Three layered metal-oxide organic compounds, In(OH)(1,4-chdc), (1), Cr(OH)(1,4-chdc), (2), and In(OH)(1,2-chdc), (3), (H2chdc=cyclohexanedicarboxylic acid) were synthesized and characterized by thermogravimetric analysis, infrared spectroscopy, and X-ray diffraction. All three structures are formed by stacking electro- neutral layers in a simple AA sequence. The layers are built by cross-linking –OH–M–OH–M– chains with the chdc anions. Unlike the flat 1,4-benzenedicarboxylate ligand which was previously shown to connect similar metal-oxide chains into porous 3D frameworks, the bent chdc ligands link the chains to form open layers with narrow intra-layer channels. From a mixture of cis- and trans- conformations of 1,4-chdc, only the e,a-cis conformation is incorporated in 1 and 2. [Copyright &y& Elsevier]

Two new niobium phosphates were synthesized and their crystal structures determined from single-crystal X-ray data. [NbOF(PO4)](N2C5H7) (1) (monoclinic, space group P21/c, a=11.442(1), b=9.1983(7), c=9.1696(8) A˚, β=109.94(1)°) has a layered structure and is the first example of a negatively charged NbOF(PO4) layer analogous to the MO(H2O)PO4 (M=V, Nb) layers. The layer charge is compensated by interlayer 4-aminopyridnium cations that adopt an unusual arrangement as a consequence of H-bonding and π–π interactions. The interlayer aminopyridnium cations can be exchanged with alkylammonium ions which form bilayers inclined at ∼65° to the NbOF(PO4) layer. [(Nb0.9V1.1)O2(PO4)2(H2PO4)] (N2C2H10) (2) (orthorhombic, space group Pbca, a=15.821(2),b=9.0295(9),c=18.301(2) A˚) has a disordered three-dimensional structure based on NbO(PO4) layers cross-linked by phosphate tetrahedra, and has a similar structure to the known vanadium analog [V2O2(PO4)2(H2PO4)] (N2C2H10). [Copyright &y& Elsevier]

Abstract: Neutron powder diffraction was used to characterize the layered perovskite PrBaCo2O5+δ(PBCO) under in-situ conditions from 573 to 852°C and at pO2 =10−1–10−4 atm. The data were fit to a tetragonal model in space group P4/mmm. The oxygen vacancies were found to be localized within the Pr layer, with total oxygen stoichiometry between 5.57(1) and 5.17(2). This was verified by coulometric titration. The location of these vacancies and the anisotropic displacement of the surrounding oxygen anion sites indicate that ion transport occurs via a hopping mechanism between O sites in the Pr layer and the nearest neighbor sites in the Co layer. While the direct hopping distance between these sites was found to be greater for PBCO than previously reported for NdBaCo2O5+δ, the larger radius of Pr3+ stabilizes a higher concentration of mobile anions within the Ln layer. [Copyright &y& Elsevier]

Four new divalent tin benzenedicarboxylates (bdc) have been synthesized by hydrothermal techniques, and their structures have been determined from single crystal X-ray data. A chiral complex layer is formed by SnII and 1,2-bdc. In Sn(1,2-bdc)-II (2), such layers are stacked in a AA pattern, leading to a chiral and polar structure with the space group symmetry C2, while in Sn(1,2-bdc)-I (1) the same layer is alternately stacked with the mirror-image layer, leading to a structure with the space group C2/c. The one-sided coordination of SnII combined with the 120° angle of the carboxylate groups in 1,3-bdc results in the tubular structure of Sn(1,3-bdc) (3). The tubes are connected by very weak intertube Sn−O bonds. The compound Sn3O(1,4-bdc)2 (4) has a 3D framework structure based on Sn3O triangular secondary building units that are cross-linked by the 1,4-bdc ligands. Strong π−π interactions occur between the neighboring phenyl rings. Four divalent tin benzenedicarboxylates (bdc) have been synthesized. A chiral complex layer is formed by SnII and 1,2-bdc. The layers are stacked in an AA pattern, leading to a chiral, polar structure, or are alternately stacked with the mirror-image layer in a centric structure. The compound Sn(1,3-bdc) has a tubular structure whereas Sn3O(1,4-bdc)2 has a framework structure based on Sn3O triangular secondary building units. [ABSTRACT FROM AUTHOR]

A series of alkali-metal tin benzenedicarboxylates A2Sn2(bdc)3(H2O)x, A = Li, Na, K, Rb, Cs, in single crystal forms have been synthesized by using a hydrothermal technique. The compounds all have cubic crystal structures based on a very open anionic [Sn2(bdc)3]2− framework which is 8-fold interpenetrated noncentrosymmetrically (space group I23) in Li2Sn2(bdc)3(H2O)2, 1, K2Sn2(bdc)3, 3, Rb2Sn2(bdc)3, 4, and Cs2Sn2(bdc)3, 5, but centrosymmetrically (space group Pn3̅) in Na2Sn2(bdc)3(H2O), 2. The ion size and coordination requirements of the alkali ions play an important role in the interpenetration of the anionic framework and the symmetry of the structures. The alkali-metal tin benzenedicarboxylates A2Sn2(bdc)3(H2O)x, A = Li, Na, K, Rb, Cs, have been synthesized. The compounds have cubic crystal structures based on an open anionic [Sn2(bdc)3]2− framework, 8-fold interpenetrated noncentrosymmetrically (S.G. I23) when A = Li, K, Rb, Cs, but centrosymmetrically (S.G. Pn3̅) in Na2Sn2(bdc)3(H2O). The ion size and coordination requirements of the alkali ions determine the symmetry of the structures. [ABSTRACT FROM AUTHOR]