Crystal structure, thermal behavior and vibrational studies of tetraethylammonium dihydrogenarsenate bis-arsenic acid [(C2H5)4N].[H2AsO4].[H3AsO4]2

An organic-inorganic hybrid compound of tetraethylammonium dihydrogenarsenate bis-arsenic acid salts of formula [(CH3CH2)4N].[H2AsO4].[H3AsO4]2(TEAs) were grown by the slow evaporation and characterized by means of single crystal X-ray diffraction, thermal analysis, FT-IR and Raman spectroscopy. This compound crystallize in the space groups Cc with unit cell parameters, a= 20.105(2) Å; b= 7.342(4) Å, c = 15.292(2) Å, γ = 115(4)°, Z = 4, R= 0.07. The structure has solved using direct methods and refined by least-squares analysis. In this case, the structure consists of infinite parallel two-dimensional planes built of mutually H2AsO4−, H3AsO4 tetrahedra connected by strong O-H···O hydrogen bonding. The thermoanalytical properties were studied using TG of TEAs method in the temperature ranges from 300 to 440 K for this hygroscopic sample. DSC measurement was carried out in the temperature range from 305 to 425 K

Synthesis, Crystal Structure and Characterization of [(CH3 CH2)4N] Mn1,5 Cl3 4H2O Cl 2(H2O)

Single crystals of [(CH3CH2)4N] Mn1,5 Cl3 4H2O Cl 2(H2O) were grown by the slow evaporation technique and characterized by means of single-crystal X-ray diffraction, FT-IR and Raman spectroscopy. The title compound belongs to the triclinic space group P with the following unit cell dimensions: a =7.5425(4) Å, b=9.8464 Å, c=13.7671(6) Å, α=89.951(3)°,β=89.753(3)°, γ=81.861(3)°, Z=4. These structures have solved using direct methods and refined by least-squares analysis. The structure was solved by the direct method and refined to final R value of 0.0567. The projection of [(CH3CH2)4N] Mn1,5 Cl3 4H2O Cl 2(H2O) in the plan (a,b) shows an arrangement in layers perpendicular to the direction b . The structure consists of infinite parallel two-dimensional planes built connected ions and water molecules by strong O-H…O and O-H…Cl hydrogen bonding

catena-Poly[bis­(dibenzyl­ammonium) [[dichloridomercurate(II)]-μ-sulfato-κ2 O:O′]]

The structure of the title compound, (C14H16N)2[HgCl2(SO4)], consists of an infinite chain propagating along the c direction, containing HgII ions tetra­coordinated by two bridging O atoms of bis-monodentate sulfate anions and two chloride ligands. In the the crystal, N—H⋯O hydrogen bonding between the cations and the anionic chains consolidates the packing. The crystal structure was determined from an inversion twin with approximately equal twin domains

Crystal structure and spectroscopic study of bis-tetrapropylammonium hexachlorodicuprate(II), [N(C3H7)4]2Cu2Cl6

Single crystals of the bis-tetrapropylammonium hexachlorodicuprate(II), [N(C3H7)4]2Cu2Cl6, were grown by slow evaporation solution technique at room temperature. The compound was characterized by Raman, IR and single crystal X-ray diffraction studies. Crystal data for C12H28Cl3CuN (M = 356.24 g/mol): triclinic, space group P-1 (no. 2), a = 9.3851(2) Å, b = 9.3844(2) Å, c = 11.8837(3) Å, α = 106.3330(11)°, β = 100.0280(12)°, γ = 113.2830(12)°, V = 872.95(3) Å3, Z = 2, T = 293(2) K, μ(MoKα) = 1.693 mm-1, Dcalc = 1.355 g/mm3, 8056 reflections measured (6.64 ≤ 2Θ ≤ 62.02), 5526 unique (Rint = 0.0303) which were used in all calculations. The final R1 was 0.0427 (>2σ(I)) and wR2 was 0.1312 (all data). The atomic arrangement can be described by alternating organic and inorganic layers parallel to the (101) plan, made up of tetrapropylammonium groups and Cu2Cl6 dimers, respectively. In crystal structure, the inorganic layers, built up by Cu2Cl6 dimers, are connected to the organic ones through hydrogen bonding C-H…Cl and Van der Waals interaction in order to build cation-anion-cation cohesion. These interactions cause to the formation of a three-dimensional supramolecular architecture

Charge Ordering in alpha-(BEDT-TTF)2I3 by synchrotron x-ray diffraction

The spatial charge arrangement of a typical quasi-two-dimensional organic conductor alpha-(BEDT-TTF)2I3 is revealed by single crystal structure analysis using synchrotron radiation. The results show that the horizontal stripe type structure, which was suggested by mean field theory, is established. We also find the charge disproportion above the metal-insulator transition temperature and a significant change in transfer integrals caused by the phase transition. Our result elucidates the insulating phase of this material as a 2k_F charge density localization.Comment: 8 pages, 5 figures, 1 tabl

Bis(1,1-dimethyl­guanidinium) tetra­aqua­dimethyl­tin(IV) bis­(sulfate)

Single crystals of the title salt, (C3H10N3)2[Sn(CH3)2(H2O)4](SO4)2, formed concomitantly with the already known [Sn(CH3)3]2SO4·2H2O. In the title structure, the SnIV atom displays a slightly distorted octa­hedral coordination geometry defined by four O water atoms in the equatorial positions and two methyl groups in the axial positions. In the crystal, various O—H⋯O and N—H⋯O hydrogen-bonding inter­actions between the organic cation and the coordinated water mol­ecules as donors and the sulfate O atoms as acceptors result in a three-dimensional structure. The SnIV atom is located on an inversion centre, resulting in half of the complex metal cation being in the asymmetric unit

Modeling molecular crystals formed by spin-active metal complexes by atom-atom potentials

We apply the atom-atom potentials to molecular crystals of iron (II) complexes with bulky organic ligands. The crystals under study are formed by low-spin or high-spin molecules of Fe(phen)$_{2}$(NCS)$_{2}$ (phen = 1,10-phenanthroline), Fe(btz)$_{2}$(NCS)$_{2}$ (btz = 5,5$^{\prime }$,6,6$^{\prime}$-tetrahydro-4\textit{H},4$^{\prime}$\textit{H}-2,2$^{\prime }$-bi-1,3-thiazine), and Fe(bpz)$_{2}$(bipy) (bpz = dihydrobis(1-pyrazolil)borate, and bipy = 2,2$^{\prime}$-bipyridine). All molecular geometries are taken from the X-ray experimental data and assumed to be frozen. The unit cell dimensions and angles, positions of the centers of masses of molecules, and the orientations of molecules corresponding to the minimum energy at 1 atm and 1 GPa are calculated. The optimized crystal structures are in a good agreement with the experimental data. Sources of the residual discrepancies between the calculated and experimental structures are discussed. The intermolecular contributions to the enthalpy of the spin transitions are found to be comparable with its total experimental values. It demonstrates that the method of atom-atom potentials is very useful for modeling organometalic crystals undergoing the spin transitions

Stimulated grip strength measurement: Validation of a novel method for functional assessment

BackgroundReliable measurement of functional recovery is critical in translational peripheral nerve regeneration research. Behavioral functional assessments such as volitional grip strength testing (vGST) are limited by inherent behavioral variability. Isometric tetanic force testing (ITFT) is highly reliable but precludes serial measurements. Combining elements of vGST and ITFT, stimulated grip strength testing (sGST) involves percutaneous median nerve stimulation to elicit maximal tetanic contraction of digital flexors, thereby allowing for consistent measurement of maximal grip strength.MethodsWe measured side‐to‐side equivalence of force using sGST, vGST, and ITFT to determine relative reliability and repeatability. We also performed weekly force measurements following median nerve repair.ResultssGST demonstrated greater reliability and inter‐trial repeatability than vGST and similar reliability to ITFT, with the added benefit of serial measurements.ConclusionssGST is a valid method for assessing functional recovery that addresses the limitations of the currently available modalities used in translational peripheral nerve regeneration research.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151883/1/mus26646.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151883/2/mus26646_am.pd

Chirality in charge-transfer salts of BEDT-TTF of tris(oxalato)chromate(III)

Crystallisation from chiral electrolyte (R)-(−)-carvone has produced three new chiral semiconducting salts of BEDT-TTF from racemic anion tri(oxalato)chromate(III)